Merge pull request 'refactor(hashing): introduce Hashable derive macro and migrate server types' (#82) from hashing-proc-macro into main

Reviewed-on: #82
Reviewed-by: Stas <business@jexter.tech>

.claude/memory/feedback_widget_decomposition.md

@@ -0,0 +1,11 @@
+---
+name: Widget decomposition and provider subscriptions
+description: Prefer splitting screens into multiple focused files/widgets; each widget subscribes to its own relevant providers
+type: feedback
+---
+
+Split screens into multiple smaller widgets across multiple files. Each widget should subscribe only to the providers it needs (`ref.watch` at lowest possible level), rather than having one large screen widget that watches everything and passes data down as parameters.
+
+**Why:** Reduces unnecessary rebuilds; improves readability; each file has one clear responsibility.
+
+**How to apply:** When building a new screen, identify which sub-widgets need their own provider subscriptions and extract them into separate files (e.g., `widgets/grant_card.dart` watches enrichment providers itself, rather than the screen doing it and passing resolved strings down).

.gitignore

@@ -1 +1,6 @@
 target/
+scripts/__pycache__/
+.DS_Store
+.cargo/config.toml
+.vscode/
+docs/

.vscode/settings.json

@@ -1,3 +0,0 @@
-{
-    "git.enabled": false
-}

.woodpecker/server-audit.yaml

@@ -8,7 +8,7 @@ when:
       include: ['.woodpecker/server-*.yaml', 'server/**']
 
 steps:
-  - name: test
+  - name: audit
     image: jdxcode/mise:latest
     directory: server
     environment:

.woodpecker/server-lint.yaml

@@ -0,0 +1,25 @@
+when:
+  - event: pull_request
+    path:
+      include: ['.woodpecker/server-*.yaml', 'server/**']
+  - event: push
+    branch: main
+    path:
+      include: ['.woodpecker/server-*.yaml', 'server/**']
+
+steps:
+  - name: lint
+    image: jdxcode/mise:latest
+    directory: server
+    environment:
+      CARGO_TERM_COLOR: always
+      CARGO_TARGET_DIR: /usr/local/cargo/target
+      CARGO_HOME: /usr/local/cargo/registry
+    volumes:
+      - cargo-target:/usr/local/cargo/target
+      - cargo-registry:/usr/local/cargo/registry
+    commands:
+      - apt-get update && apt-get install -y pkg-config
+      - mise install rust 
+      - mise install protoc
+      - mise exec rust -- cargo clippy --all -- -D warnings

.woodpecker/server-test.yaml

@@ -24,4 +24,4 @@ steps:
       - mise install rust 
       - mise install protoc
       - mise install cargo:cargo-nextest
-      - mise exec cargo:cargo-nextest -- cargo nextest run --no-fail-fast
+      - mise exec cargo:cargo-nextest -- cargo nextest run --no-fail-fast --all-features

.woodpecker/server-vet.yaml

@@ -8,7 +8,7 @@ when:
       include: ['.woodpecker/server-*.yaml', 'server/**']
 
 steps:
-  - name: test
+  - name: vet
     image: jdxcode/mise:latest
     directory: server
     environment:

.woodpecker/useragent-analyze.yaml

@@ -0,0 +1,18 @@
+when:
+  - event: pull_request
+    path:
+      include: ['.woodpecker/useragent-*.yaml', 'useragent/**']
+  - event: push
+    branch: main
+    path:
+      include: ['.woodpecker/useragent-*.yaml', 'useragent/**']
+
+steps:
+  - name: analyze
+    image: jdxcode/mise:latest
+    commands:
+      - mise install flutter 
+      - mise install protoc
+      # Reruns codegen to catch protocol drift
+      - mise codegen 
+      - cd useragent/ && flutter analyze

AGENTS.md

@@ -0,0 +1,128 @@
+# AGENTS.md
+
+This file provides guidance to Codex (Codex.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Arbiter is a **permissioned signing service** for cryptocurrency wallets. It consists of:
+- **`server/`** — Rust gRPC daemon that holds encrypted keys and enforces policies
+- **`useragent/`** — Flutter desktop app (macOS/Windows) with a Rust backend via Rinf
+- **`protobufs/`** — Protocol Buffer definitions shared between server and client
+
+The vault never exposes key material; it only produces signatures when requests satisfy configured policies.
+
+## Toolchain Setup
+
+Tools are managed via [mise](https://mise.jdx.dev/). Install all required tools:
+```sh
+mise install
+```
+
+Key versions: Rust 1.93.0 (with clippy), Flutter 3.38.9-stable, protoc 29.6, diesel_cli 2.3.6 (sqlite).
+
+## Server (Rust workspace at `server/`)
+
+### Crates
+
+| Crate | Purpose |
+|---|---|
+| `arbiter-proto` | Generated gRPC stubs + protobuf types; compiled from `protobufs/*.proto` via `tonic-prost-build` |
+| `arbiter-server` | Main daemon — actors, DB, EVM policy engine, gRPC service implementation |
+| `arbiter-useragent` | Rust client library for the user agent side of the gRPC protocol |
+| `arbiter-client` | Rust client library for SDK clients |
+
+### Common Commands
+
+```sh
+cd server
+
+# Build
+cargo build
+
+# Run the server daemon
+cargo run -p arbiter-server
+
+# Run all tests (preferred over cargo test)
+cargo nextest run
+
+# Run a single test
+cargo nextest run <test_name>
+
+# Lint
+cargo clippy
+
+# Security audit
+cargo audit
+
+# Check unused dependencies
+cargo shear
+
+# Run snapshot tests and update snapshots
+cargo insta review
+```
+
+### Architecture
+
+The server is actor-based using the **kameo** crate. All long-lived state lives in `GlobalActors`:
+
+- **`Bootstrapper`** — Manages the one-time bootstrap token written to `~/.arbiter/bootstrap_token` on first run.
+- **`KeyHolder`** — Holds the encrypted root key and manages the Sealed/Unsealed vault state machine. On unseal, decrypts the root key into a `memsafe` hardened memory cell.
+- **`FlowCoordinator`** — Coordinates cross-connection flow between user agents and SDK clients.
+- **`EvmActor`** — Handles EVM transaction policy enforcement and signing.
+
+Per-connection actors live under `actors/user_agent/` and `actors/client/`, each with `auth` (challenge-response authentication) and `session` (post-auth operations) sub-modules.
+
+**Database:** SQLite via `diesel-async` + `bb8` connection pool. Schema managed by embedded Diesel migrations in `crates/arbiter-server/migrations/`. DB file lives at `~/.arbiter/arbiter.sqlite`. Tests use a temp-file DB via `db::create_test_pool()`.
+
+**Cryptography:**
+- Authentication: ed25519 (challenge-response, nonce-tracked per peer)
+- Encryption at rest: XChaCha20-Poly1305 (versioned via `scheme` field for transparent migration on unseal)
+- Password KDF: Argon2
+- Unseal transport: X25519 ephemeral key exchange
+- TLS: self-signed certificate (aws-lc-rs backend), fingerprint distributed via `ArbiterUrl`
+
+**Protocol:** gRPC with Protocol Buffers. The `ArbiterUrl` type encodes host, port, CA cert, and bootstrap token into a single shareable string (printed to console on first run).
+
+### Proto Regeneration
+
+When `.proto` files in `protobufs/` change, rebuild to regenerate:
+```sh
+cd server && cargo build -p arbiter-proto
+```
+
+### Database Migrations
+
+```sh
+# Create a new migration
+diesel migration generate <name> --migration-dir crates/arbiter-server/migrations
+
+# Run migrations manually (server also runs them on startup)
+diesel migration run --migration-dir crates/arbiter-server/migrations
+```
+
+## User Agent (Flutter + Rinf at `useragent/`)
+
+The Flutter app uses [Rinf](https://rinf.cunarist.org) to call Rust code. The Rust logic lives in `useragent/native/hub/` as a separate crate that uses `arbiter-useragent` for the gRPC client.
+
+Communication between Dart and Rust uses typed **signals** defined in `useragent/native/hub/src/signals/`. After modifying signal structs, regenerate Dart bindings:
+
+```sh
+cd useragent && rinf gen
+```
+
+### Common Commands
+
+```sh
+cd useragent
+
+# Run the app (macOS or Windows)
+flutter run
+
+# Regenerate Rust↔Dart signal bindings
+rinf gen
+
+# Analyze Dart code
+flutter analyze
+```
+
+The Rinf Rust entry point is `useragent/native/hub/src/lib.rs`. It spawns actors defined in `useragent/native/hub/src/actors/` which handle Dart↔server communication via signals.

ARCHITECTURE.md

@@ -3,7 +3,6 @@
 Arbiter is a permissioned signing service for cryptocurrency wallets. It runs as a background service on the user's machine with an optional client application for vault management.
 
 **Core principle:** The vault NEVER exposes key material. It only produces signatures when a request satisfies the configured policies.
-
 ---
 
 ## 1. Peer Types
@@ -12,6 +11,7 @@ Arbiter distinguishes two kinds of peers:
 
 - **User Agent** — A client application used by the owner to manage the vault (create wallets, approve SDK clients, configure policies).
 - **SDK Client** — A consumer of signing capabilities, typically an automation tool. In the future, this could include a browser-based wallet.
+- **Recovery Operator** — A dormant recovery participant with narrowly scoped authority used only for custody recovery and operator replacement.
 
 ---
 
@@ -43,7 +43,149 @@ There is no bootstrap mechanism for SDK clients. They must be explicitly approve
 
 ---
 
-## 3. Server Identity
+## 3. Multi-Operator Governance
+
+When more than one User Agent is registered, the vault is treated as having multiple operators. In that mode, sensitive actions are governed by voting rather than by a single operator decision.
+
+### 3.1 Voting Rules
+
+Voting is based on the total number of registered operators:
+
+- **1 operator:** no vote is needed; the single operator decides directly.
+- **2 operators:** full consensus is required; both operators must approve.
+- **3 or more operators:** quorum is `floor(N / 2) + 1`.
+
+For a decision to count, the operator's approval or rejection must be signed by that operator's associated key. Unsigned votes, or votes that fail signature verification, are ignored.
+
+Examples:
+
+- **3 operators:** 2 approvals required
+- **4 operators:** 3 approvals required
+
+### 3.2 Actions Requiring a Vote
+
+In multi-operator mode, a successful vote is required for:
+
+- approving new SDK clients
+- granting an SDK client visibility to a wallet
+- approving a one-off transaction
+- approving creation of a persistent grant
+- approving operator replacement
+- approving server updates
+- updating Shamir secret-sharing parameters
+
+### 3.3 Special Rule for Key Rotation
+
+Key rotation always requires full quorum, regardless of the normal voting threshold.
+
+This is stricter than ordinary governance actions because rotating the root key requires every operator to participate in coordinated share refresh/update steps. The root key itself is not redistributed directly, but each operator's share material must be changed consistently.
+
+### 3.4 Root Key Custody
+
+When the vault has multiple operators, the vault root key is protected using Shamir secret sharing.
+
+The vault root key is encrypted in a way that requires reconstruction from user-held shares rather than from a single shared password.
+
+For ordinary operators, the Shamir threshold matches the ordinary governance quorum. For example:
+
+- **2 operators:** `2-of-2`
+- **3 operators:** `2-of-3`
+- **4 operators:** `3-of-4`
+
+In practice, the Shamir share set also includes Recovery Operator shares. This means the effective Shamir parameters are computed over the combined share pool while keeping the same threshold. For example:
+
+- **3 ordinary operators + 2 recovery shares:** `2-of-5`
+
+This ensures that the normal custody threshold follows the ordinary operator quorum, while still allowing dormant recovery shares to exist for break-glass recovery flows.
+
+### 3.5 Recovery Operators
+
+Recovery Operators are a separate peer type from ordinary vault operators.
+
+Their role is intentionally narrow. They can only:
+
+- participate in unsealing the vault
+- vote for operator replacement
+
+Recovery Operators do not participate in routine governance such as approving SDK clients, granting wallet visibility, approving transactions, creating grants, approving server updates, or changing Shamir parameters.
+
+### 3.6 Sleeping and Waking Recovery Operators
+
+By default, Recovery Operators are **sleeping** and do not participate in any active flow.
+
+Any ordinary operator may request that Recovery Operators **wake up**.
+
+Any ordinary operator may also cancel a pending wake-up request.
+
+This creates a dispute window before recovery powers become active. The default wake-up delay is **14 days**.
+
+Recovery Operators are therefore part of the break-glass recovery path rather than the normal operating quorum.
+
+The high-level recovery flow is:
+
+```mermaid
+sequenceDiagram
+    autonumber
+    actor Op as Ordinary Operator
+    participant Server
+    actor Other as Other Operator
+    actor Rec as Recovery Operator
+
+    Op->>Server: Request recovery wake-up
+    Server-->>Op: Wake-up pending
+    Note over Server: Default dispute window: 14 days
+
+    alt Wake-up cancelled during dispute window
+        Other->>Server: Cancel wake-up
+        Server-->>Op: Recovery cancelled
+        Server-->>Rec: Stay sleeping
+    else No cancellation for 14 days
+        Server-->>Rec: Wake up
+        Rec->>Server: Join recovery flow
+        critical Recovery authority
+            Rec->>Server: Participate in unseal
+            Rec->>Server: Vote on operator replacement
+        end
+        Server-->>Op: Recovery mode active
+    end
+```
+
+### 3.7 Committee Formation
+
+There are two ways to form a multi-operator committee:
+
+- convert an existing single-operator vault by adding new operators
+- bootstrap an unbootstrapped vault directly into multi-operator mode
+
+In both cases, committee formation is a coordinated process. Arbiter does not allow multi-operator custody to emerge implicitly from unrelated registrations.
+
+### 3.8 Bootstrapping an Unbootstrapped Vault into Multi-Operator Mode
+
+When an unbootstrapped vault is initialized as a multi-operator vault, the setup proceeds as follows:
+
+1. An operator connects to the unbootstrapped vault using a User Agent and the bootstrap token.
+2. During bootstrap setup, that operator declares:
+   - the total number of ordinary operators
+   - the total number of Recovery Operators
+3. The vault enters **multi-bootstrap mode**.
+4. While in multi-bootstrap mode:
+   - every ordinary operator must connect with a User Agent using the bootstrap token
+   - every Recovery Operator must also connect using the bootstrap token
+   - each participant is registered individually
+   - each participant's share is created and protected with that participant's credentials
+5. The vault is considered fully bootstrapped only after all declared operator and recovery-share registrations have completed successfully.
+
+This means the operator and recovery set is fixed at bootstrap completion time, based on the counts declared when multi-bootstrap mode was entered.
+
+### 3.9 Special Bootstrap Constraint for Two-Operator Vaults
+
+If a vault is declared with exactly **2 ordinary operators**, Arbiter requires at least **1 Recovery Operator** to be configured during bootstrap.
+
+This prevents the worst-case custody failure in which a `2-of-2` operator set becomes permanently unrecoverable after loss of a single operator.
+
+---
+
+## 4. Server Identity
 
 The server proves its identity using TLS with a self-signed certificate. The TLS private key is generated on first run and is long-term; no rotation mechanism exists yet due to the complexity of multi-peer coordination.
 
@@ -56,9 +198,9 @@ Peers verify the server by its **public key fingerprint**:
 
 ---
 
-## 4. Key Management
+## 5. Key Management
 
-### 4.1 Key Hierarchy
+### 5.1 Key Hierarchy
 
 There are three layers of keys:
 
@@ -73,19 +215,19 @@ This layered design enables:
 - **Password rotation** without re-encrypting every wallet key (only the root key is re-encrypted).
 - **Root key rotation** without requiring the user to change their password.
 
-### 4.2 Encryption at Rest
+### 5.2 Encryption at Rest
 
 The database stores everything in encrypted form using symmetric AEAD. The encryption scheme is versioned to support transparent migration — when the vault unseals, Arbiter automatically re-encrypts any entries that are behind the current scheme version. See [IMPLEMENTATION.md](IMPLEMENTATION.md) for the specific scheme and versioning mechanism.
 
 ---
 
-## 5. Vault Lifecycle
+## 6. Vault Lifecycle
 
-### 5.1 Sealed State
+### 6.1 Sealed State
 
 On boot, the root key is encrypted and the server cannot perform any signing operations. This state is called **Sealed**.
 
-### 5.2 Unseal Flow
+### 6.2 Unseal Flow
 
 To transition to the **Unsealed** state, a User Agent must provide the password:
 
@@ -96,7 +238,7 @@ To transition to the **Unsealed** state, a User Agent must provide the password:
    - **Success:** The root key is decrypted and placed into a hardened memory cell. The server transitions to `Unsealed`. Any entries pending encryption scheme migration are re-encrypted.
    - **Failure:** The server returns an error indicating the password is incorrect.
 
-### 5.3 Memory Protection
+### 6.3 Memory Protection
 
 Once unsealed, the root key must be protected in memory against:
 
@@ -108,9 +250,9 @@ See [IMPLEMENTATION.md](IMPLEMENTATION.md) for the current and planned memory pr
 
 ---
 
-## 6. Permission Engine
+## 7. Permission Engine
 
-### 6.1 Fundamental Rules
+### 7.1 Fundamental Rules
 
 - SDK clients have **no access by default**.
 - Access is granted **explicitly** by a User Agent.
@@ -120,11 +262,45 @@ Each blockchain requires its own policy system due to differences in static tran
 
 Arbiter is also responsible for ensuring that **transaction nonces are never reused**.
 
-### 6.2 EVM Policies
+### 7.2 EVM Policies
 
 Every EVM grant is scoped to a specific **wallet** and **chain ID**.
 
-#### 6.2.1 Transaction Sub-Grants
+#### 7.2.0 Transaction Signing Sequence
+
+The high-level interaction order is:
+
+```mermaid
+sequenceDiagram
+    autonumber
+    actor SDK as SDK Client
+    participant Server
+    participant UA as User Agent
+
+    SDK->>Server: SignTransactionRequest
+    Server->>Server: Resolve wallet and wallet visibility
+    alt Visibility approval required
+        Server->>UA: Ask for wallet visibility approval
+        UA-->>Server: Vote result
+    end
+    Server->>Server: Evaluate transaction
+    Server->>Server: Load grant and limits context
+    alt Grant approval required
+        Server->>UA: Ask for execution / grant approval
+        UA-->>Server: Vote result
+        opt Create persistent grant
+            Server->>Server: Create and store grant
+        end
+        Server->>Server: Retry evaluation
+    end
+    critical Final authorization path
+        Server->>Server: Check limits and record execution
+        Server-->>Server: Signature or evaluation error
+    end
+    Server-->>SDK: Signature or error
+```
+
+#### 7.2.1 Transaction Sub-Grants
 
 Arbiter maintains an ever-expanding database of known contracts and their ABIs. Based on contract knowledge, transaction requests fall into three categories:
 
@@ -148,7 +324,7 @@ Available restrictions:
 
 These transactions have no `calldata` and therefore cannot interact with contracts. They can be subject to the same volume and rate restrictions as above.
 
-#### 6.2.2 Global Limits
+#### 7.2.2 Global Limits
 
 In addition to sub-grant-specific restrictions, the following limits can be applied across all grant types:
 

CLAUDE.md

@@ -0,0 +1,128 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Arbiter is a **permissioned signing service** for cryptocurrency wallets. It consists of:
+- **`server/`** — Rust gRPC daemon that holds encrypted keys and enforces policies
+- **`useragent/`** — Flutter desktop app (macOS/Windows) with a Rust backend via Rinf
+- **`protobufs/`** — Protocol Buffer definitions shared between server and client
+
+The vault never exposes key material; it only produces signatures when requests satisfy configured policies.
+
+## Toolchain Setup
+
+Tools are managed via [mise](https://mise.jdx.dev/). Install all required tools:
+```sh
+mise install
+```
+
+Key versions: Rust 1.93.0 (with clippy), Flutter 3.38.9-stable, protoc 29.6, diesel_cli 2.3.6 (sqlite).
+
+## Server (Rust workspace at `server/`)
+
+### Crates
+
+| Crate | Purpose |
+|---|---|
+| `arbiter-proto` | Generated gRPC stubs + protobuf types; compiled from `protobufs/*.proto` via `tonic-prost-build` |
+| `arbiter-server` | Main daemon — actors, DB, EVM policy engine, gRPC service implementation |
+| `arbiter-useragent` | Rust client library for the user agent side of the gRPC protocol |
+| `arbiter-client` | Rust client library for SDK clients |
+
+### Common Commands
+
+```sh
+cd server
+
+# Build
+cargo build
+
+# Run the server daemon
+cargo run -p arbiter-server
+
+# Run all tests (preferred over cargo test)
+cargo nextest run
+
+# Run a single test
+cargo nextest run <test_name>
+
+# Lint
+cargo clippy
+
+# Security audit
+cargo audit
+
+# Check unused dependencies
+cargo shear
+
+# Run snapshot tests and update snapshots
+cargo insta review
+```
+
+### Architecture
+
+The server is actor-based using the **kameo** crate. All long-lived state lives in `GlobalActors`:
+
+- **`Bootstrapper`** — Manages the one-time bootstrap token written to `~/.arbiter/bootstrap_token` on first run.
+- **`KeyHolder`** — Holds the encrypted root key and manages the Sealed/Unsealed vault state machine. On unseal, decrypts the root key into a `memsafe` hardened memory cell.
+- **`FlowCoordinator`** — Coordinates cross-connection flow between user agents and SDK clients.
+- **`EvmActor`** — Handles EVM transaction policy enforcement and signing.
+
+Per-connection actors live under `actors/user_agent/` and `actors/client/`, each with `auth` (challenge-response authentication) and `session` (post-auth operations) sub-modules.
+
+**Database:** SQLite via `diesel-async` + `bb8` connection pool. Schema managed by embedded Diesel migrations in `crates/arbiter-server/migrations/`. DB file lives at `~/.arbiter/arbiter.sqlite`. Tests use a temp-file DB via `db::create_test_pool()`.
+
+**Cryptography:**
+- Authentication: ed25519 (challenge-response, nonce-tracked per peer)
+- Encryption at rest: XChaCha20-Poly1305 (versioned via `scheme` field for transparent migration on unseal)
+- Password KDF: Argon2
+- Unseal transport: X25519 ephemeral key exchange
+- TLS: self-signed certificate (aws-lc-rs backend), fingerprint distributed via `ArbiterUrl`
+
+**Protocol:** gRPC with Protocol Buffers. The `ArbiterUrl` type encodes host, port, CA cert, and bootstrap token into a single shareable string (printed to console on first run).
+
+### Proto Regeneration
+
+When `.proto` files in `protobufs/` change, rebuild to regenerate:
+```sh
+cd server && cargo build -p arbiter-proto
+```
+
+### Database Migrations
+
+```sh
+# Create a new migration
+diesel migration generate <name> --migration-dir crates/arbiter-server/migrations
+
+# Run migrations manually (server also runs them on startup)
+diesel migration run --migration-dir crates/arbiter-server/migrations
+```
+
+## User Agent (Flutter + Rinf at `useragent/`)
+
+The Flutter app uses [Rinf](https://rinf.cunarist.org) to call Rust code. The Rust logic lives in `useragent/native/hub/` as a separate crate that uses `arbiter-useragent` for the gRPC client.
+
+Communication between Dart and Rust uses typed **signals** defined in `useragent/native/hub/src/signals/`. After modifying signal structs, regenerate Dart bindings:
+
+```sh
+cd useragent && rinf gen
+```
+
+### Common Commands
+
+```sh
+cd useragent
+
+# Run the app (macOS or Windows)
+flutter run
+
+# Regenerate Rust↔Dart signal bindings
+rinf gen
+
+# Analyze Dart code
+flutter analyze
+```
+
+The Rinf Rust entry point is `useragent/native/hub/src/lib.rs`. It spawns actors defined in `useragent/native/hub/src/actors/` which handle Dart↔server communication via signals.

IMPLEMENTATION.md

@@ -4,10 +4,77 @@ This document covers concrete technology choices and dependencies. For the archi
 
 ---
 
+## Client Connection Flow
+
+### Authentication Result Semantics
+
+Authentication no longer uses an implicit success-only response shape. Both `client` and `user-agent` return explicit auth status enums over the wire.
+
+- **Client:** `AuthResult` may return `SUCCESS`, `INVALID_KEY`, `INVALID_SIGNATURE`, `APPROVAL_DENIED`, `NO_USER_AGENTS_ONLINE`, or `INTERNAL`
+- **User-agent:** `AuthResult` may return `SUCCESS`, `INVALID_KEY`, `INVALID_SIGNATURE`, `BOOTSTRAP_REQUIRED`, `TOKEN_INVALID`, or `INTERNAL`
+
+This makes transport-level failures and actor/domain-level auth failures distinct:
+
+- **Transport/protocol failures** are surfaced as stream/status errors
+- **Authentication failures** are surfaced as successful protocol responses carrying an explicit auth status
+
+Clients are expected to handle these status codes directly and present the concrete failure reason to the user.
+
+### New Client Approval
+
+When a client whose public key is not yet in the database connects, all connected user agents are asked to approve the connection. The first agent to respond determines the outcome; remaining requests are cancelled via a watch channel.
+
+```mermaid
+flowchart TD
+    A([Client connects]) --> B[Receive AuthChallengeRequest]
+    B --> C{pubkey in DB?}
+
+    C -- yes --> D[Read nonce\nIncrement nonce in DB]
+    D --> G
+
+    C -- no --> E[Ask all UserAgents:\nClientConnectionRequest]
+    E --> F{First response}
+    F -- denied --> Z([Reject connection])
+    F -- approved --> F2[Cancel remaining\nUserAgent requests]
+    F2 --> F3[INSERT client\nnonce = 1]
+    F3 --> G[Send AuthChallenge\nwith nonce]
+
+    G --> H[Receive AuthChallengeSolution]
+    H --> I{Signature valid?}
+    I -- no --> Z
+    I -- yes --> J([Session started])
+```
+
+### Known Issue: Concurrent Registration Race (TOCTOU)
+
+Two connections presenting the same previously-unknown public key can race through the approval flow simultaneously:
+
+1. Both check the DB → neither is registered.
+2. Both request approval from user agents → both receive approval.
+3. Both `INSERT` the client record → the second insert silently overwrites the first, resetting the nonce.
+
+This means the first connection's nonce is invalidated by the second, causing its challenge verification to fail. A fix requires either serialising new-client registration (e.g. an in-memory lock keyed on pubkey) or replacing the separate check + insert with an `INSERT OR IGNORE` / upsert guarded by a unique constraint on `public_key`.
+
+### Nonce Semantics
+
+The `program_client.nonce` column stores the **next usable nonce** — i.e. it is always one ahead of the nonce last issued in a challenge.
+
+- **New client:** inserted with `nonce = 1`; the first challenge is issued with `nonce = 0`.
+- **Existing client:** the current DB value is read and used as the challenge nonce, then immediately incremented within the same exclusive transaction, preventing replay.
+
+---
+
 ## Cryptography
 
 ### Authentication
-- **Signature scheme:** ed25519
+- **Client protocol:** ML-DSA
+
+### User-Agent Authentication
+
+User-agent authentication supports multiple signature schemes because platform-provided "hardware-bound" keys do not expose a uniform algorithm across operating systems and hardware.
+
+- **Supported schemes:** ML-DSA
+- **Why:** Secure Enclave (MacOS) support them natively, on other platforms we could emulate while they roll-out
 
 ### Encryption at Rest
 - **Scheme:** Symmetric AEAD — currently **XChaCha20-Poly1305**
@@ -22,14 +89,147 @@ This document covers concrete technology choices and dependencies. For the archi
 ## Communication
 
 - **Protocol:** gRPC with Protocol Buffers
+- **Request/response matching:** multiplexed over a single bidirectional stream using per-connection request IDs
 - **Server identity distribution:** `ServerInfo` protobuf struct containing the TLS public key fingerprint
 - **Future consideration:** grpc-web lacks bidirectional stream support, so a browser-based wallet may require protojson over WebSocket
 
+### Request Multiplexing
+
+Both `client` and `user-agent` connections support multiple in-flight requests over one gRPC bidi stream.
+
+- Every request carries a monotonically increasing request ID
+- Every normal response echoes the request ID it corresponds to
+- Out-of-band server messages omit the response ID entirely
+- The server rejects already-seen request IDs at the transport adapter boundary before business logic sees the message
+
+This keeps request correlation entirely in transport/client connection code while leaving actor and domain handlers unaware of request IDs.
+
+---
+
+## EVM Policy Engine
+
+### Overview
+
+The EVM engine classifies incoming transactions, enforces grant constraints, and records executions. It is the sole path through which a wallet key is used for signing.
+
+The central abstraction is the `Policy` trait. Each implementation handles one semantic transaction category and owns its own database tables for grant storage and transaction logging.
+
+### Transaction Evaluation Flow
+
+`Engine::evaluate_transaction` runs the following steps in order:
+
+1. **Classify** — Each registered policy's `analyze(context)` inspects the transaction fields (`chain`, `to`, `value`, `calldata`). The first one returning `Some(meaning)` wins. If none match, the transaction is rejected as `UnsupportedTransactionType`.
+2. **Find grant** — `Policy::try_find_grant` queries for a non-revoked grant covering this wallet, client, chain, and target address.
+3. **Check shared constraints** — `check_shared_constraints` runs in the engine before any policy-specific logic. It enforces the validity window, gas fee caps, and transaction count rate limit (see below).
+4. **Evaluate** — `Policy::evaluate` checks the decoded meaning against the grant's policy-specific constraints and returns any violations.
+5. **Record** — If `RunKind::Execution` and there are no violations, the engine writes to `evm_transaction_log` and calls `Policy::record_transaction` for any policy-specific logging (e.g., token transfer volume).
+
+The detailed branch structure is shown below:
+
+```mermaid
+flowchart TD
+    A[SDK Client sends sign transaction request] --> B[Server resolves wallet]
+    B --> C{Wallet exists?}
+
+    C -- No --> Z1[Return wallet not found error]
+    C -- Yes --> D[Check SDK client wallet visibility]
+
+    D --> E{Wallet visible to SDK client?}
+    E -- No --> F[Start wallet visibility voting flow]
+    F --> G{Vote approved?}
+    G -- No --> Z2[Return wallet access denied error]
+    G -- Yes --> H[Persist wallet visibility]
+    E -- Yes --> I[Classify transaction meaning]
+    H --> I
+
+    I --> J{Meaning supported?}
+    J -- No --> Z3[Return unsupported transaction error]
+    J -- Yes --> K[Find matching grant]
+
+    K --> L{Grant exists?}
+    L -- Yes --> M[Check grant limits]
+    L -- No --> N[Start execution or grant voting flow]
+
+    N --> O{User-agent decision}
+    O -- Reject --> Z4[Return no matching grant error]
+    O -- Allow once --> M
+    O -- Create grant --> P[Create grant with user-selected limits]
+    P --> Q[Persist grant]
+    Q --> M
+
+    M --> R{Limits exceeded?}
+    R -- Yes --> Z5[Return evaluation error]
+    R -- No --> S[Record transaction in logs]
+    S --> T[Produce signature]
+    T --> U[Return signature to SDK client]
+
+    note1[Limit checks include volume, count, and gas constraints.]
+    note2[Grant lookup depends on classified meaning, such as ether transfer or token transfer.]
+
+    K -. uses .-> note2
+    M -. checks .-> note1
+```
+
+### Policy Trait
+
+| Method | Purpose |
+|---|---|
+| `analyze` | Pure — classifies a transaction into a typed `Meaning`, or `None` if this policy doesn't apply |
+| `evaluate` | Checks the `Meaning` against a `Grant`; returns a list of `EvalViolation`s |
+| `create_grant` | Inserts policy-specific rows; returns the specific grant ID |
+| `try_find_grant` | Finds a matching non-revoked grant for the given `EvalContext` |
+| `find_all_grants` | Returns all non-revoked grants (used for listing) |
+| `record_transaction` | Persists policy-specific data after execution |
+
+`analyze` and `evaluate` are intentionally separate: classification is pure and cheap, while evaluation may involve DB queries (e.g., fetching past transfer volume).
+
+### Registered Policies
+
+**EtherTransfer** — plain ETH transfers (empty calldata)
+
+- Grant requires: allowlist of recipient addresses + one volumetric rate limit (max ETH over a time window)
+- Violations: recipient not in allowlist, cumulative ETH volume exceeded
+
+**TokenTransfer** — ERC-20 `transfer(address,uint256)` calls
+
+- Recognised by ABI-decoding the `transfer(address,uint256)` selector against a static registry of known token contracts (`arbiter_tokens_registry`)
+- Grant requires: token contract address, optional recipient restriction, zero or more volumetric rate limits
+- Violations: recipient mismatch, any volumetric limit exceeded
+
+### Grant Model
+
+Every grant has two layers:
+
+- **Shared (`evm_basic_grant`)** — wallet, chain, validity period, gas fee caps, transaction count rate limit. One row per grant regardless of type.
+- **Specific** — policy-owned tables (`evm_ether_transfer_grant`, `evm_token_transfer_grant`) holding type-specific configuration.
+
+`find_all_grants` uses a `#[diesel::auto_type]` base join between the specific and shared tables, then batch-loads related rows (targets, volume limits) in two additional queries to avoid N+1.
+
+The engine exposes `list_all_grants` which collects across all policy types into `Vec<Grant<SpecificGrant>>` via a blanket `From<Grant<S>> for Grant<SpecificGrant>` conversion.
+
+### Shared Constraints (enforced by the engine)
+
+These are checked centrally in `check_shared_constraints` before policy evaluation:
+
+| Constraint | Fields | Behaviour |
+|---|---|---|
+| Validity window | `valid_from`, `valid_until` | Emits `InvalidTime` if current time is outside the range |
+| Gas fee cap | `max_gas_fee_per_gas`, `max_priority_fee_per_gas` | Emits `GasLimitExceeded` if either cap is breached |
+| Tx count rate limit | `rate_limit` (`count` + `window`) | Counts rows in `evm_transaction_log` within the window; emits `RateLimitExceeded` if at or above the limit |
+
+---
+
+### Known Limitations
+
+- **Only EIP-1559 transactions are supported.** Legacy and EIP-2930 types are rejected outright.
+- **No opaque-calldata (unknown contract) grant type.** The architecture describes a category for unrecognised contracts, but no policy implements it yet. Any transaction that is not a plain ETH transfer or a known ERC-20 transfer is unconditionally rejected.
+- **Token registry is static.** Tokens are recognised only if they appear in the hard-coded `arbiter_tokens_registry` crate. There is no mechanism to register additional contracts at runtime.
+
 ---
 
 ## Memory Protection
 
 The unsealed root key must be held in a hardened memory cell resistant to dumps, page swaps, and hibernation.
 
-- **Current:** Using the `memsafe` crate as an interim solution
-- **Planned:** Custom implementation based on `mlock` (Unix) and `VirtualProtect` (Windows)
+- **Current:** A dedicated memory-protection abstraction is in place, with `memsafe` used behind that abstraction today
+- **Planned:** Additional backends can be introduced behind the same abstraction, including a custom implementation based on `mlock` (Unix) and `VirtualProtect` (Windows)

LICENSE

@@ -0,0 +1,190 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
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+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
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+   END OF TERMS AND CONDITIONS
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+   Copyright 2026 MarketTakers
+
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+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
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+   See the License for the specific language governing permissions and
+   limitations under the License.

README.md

@@ -0,0 +1,13 @@
+# Arbiter
+> Policy-first multi-client wallet daemon, allowing permissioned transactions across blockchains
+
+## Security warning
+Arbiter can't meaningfully protect against host compromise. Potential attack flow:
+- Attacker steals TLS keys from database
+- Pretends to be server; just accepts user agent challenge solutions
+- Pretend to be in sealed state and performing DH with client
+- Steals user password and derives seal key
+
+While this attack is highly targetive, it's still possible. 
+
+> This software is experimental. Do not use with funds you cannot afford to lose.

app/.dart_tool/extension_discovery/vs_code.json

@@ -0,0 +1 @@
+{"version":2,"entries":[{"package":"app","rootUri":"../","packageUri":"lib/"}]}

app/.dart_tool/package_config.json

@@ -31,6 +31,12 @@
       "packageUri": "lib/",
       "languageVersion": "3.4"
     },
+    {
+      "name": "cupertino_icons",
+      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/cupertino_icons-1.0.8",
+      "packageUri": "lib/",
+      "languageVersion": "3.1"
+    },
     {
       "name": "fake_async",
       "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/fake_async-1.3.3",
@@ -158,7 +164,7 @@
       "languageVersion": "3.5"
     },
     {
-      "name": "arbiter",
+      "name": "app",
       "rootUri": "../",
       "packageUri": "lib/",
       "languageVersion": "3.10"

app/.dart_tool/package_graph.json

@@ -1,12 +1,13 @@
 {
   "roots": [
-    "arbiter"
+    "app"
   ],
   "packages": [
     {
-      "name": "arbiter",
-      "version": "0.1.0",
+      "name": "app",
+      "version": "1.0.0+1",
       "dependencies": [
+        "cupertino_icons",
         "flutter"
       ],
       "devDependencies": [
@@ -39,6 +40,11 @@
         "vector_math"
       ]
     },
+    {
+      "name": "cupertino_icons",
+      "version": "1.0.8",
+      "dependencies": []
+    },
     {
       "name": "flutter",
       "version": "0.0.0",

app/lib/main.dart

@@ -1,122 +0,0 @@
-import 'package:flutter/material.dart';
-
-void main() {
-  runApp(const MyApp());
-}
-
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
-
-  // This widget is the root of your application.
-  @override
-  Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Flutter Demo',
-      theme: ThemeData(
-        // This is the theme of your application.
-        //
-        // TRY THIS: Try running your application with "flutter run". You'll see
-        // the application has a purple toolbar. Then, without quitting the app,
-        // try changing the seedColor in the colorScheme below to Colors.green
-        // and then invoke "hot reload" (save your changes or press the "hot
-        // reload" button in a Flutter-supported IDE, or press "r" if you used
-        // the command line to start the app).
-        //
-        // Notice that the counter didn't reset back to zero; the application
-        // state is not lost during the reload. To reset the state, use hot
-        // restart instead.
-        //
-        // This works for code too, not just values: Most code changes can be
-        // tested with just a hot reload.
-        colorScheme: .fromSeed(seedColor: Colors.deepPurple),
-      ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
-  final String title;
-
-  @override
-  State<MyHomePage> createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
-    return Scaffold(
-      appBar: AppBar(
-        // TRY THIS: Try changing the color here to a specific color (to
-        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
-        // change color while the other colors stay the same.
-        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
-        title: Text(widget.title),
-      ),
-      body: Center(
-        // Center is a layout widget. It takes a single child and positions it
-        // in the middle of the parent.
-        child: Column(
-          // Column is also a layout widget. It takes a list of children and
-          // arranges them vertically. By default, it sizes itself to fit its
-          // children horizontally, and tries to be as tall as its parent.
-          //
-          // Column has various properties to control how it sizes itself and
-          // how it positions its children. Here we use mainAxisAlignment to
-          // center the children vertically; the main axis here is the vertical
-          // axis because Columns are vertical (the cross axis would be
-          // horizontal).
-          //
-          // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
-          // action in the IDE, or press "p" in the console), to see the
-          // wireframe for each widget.
-          mainAxisAlignment: .center,
-          children: [
-            const Text('You have pushed the button this many times:'),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headlineMedium,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
-      ),
-    );
-  }
-}

app/macos/Flutter/Flutter-Debug.xcconfig

@@ -1 +0,0 @@
-#include "ephemeral/Flutter-Generated.xcconfig"

app/macos/Flutter/Flutter-Release.xcconfig

@@ -1 +0,0 @@
-#include "ephemeral/Flutter-Generated.xcconfig"

app/macos/Flutter/GeneratedPluginRegistrant.swift

@@ -1,10 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-import FlutterMacOS
-import Foundation
-
-
-func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
-}

app/macos/Flutter/ephemeral/Flutter-Generated.xcconfig

@@ -1,10 +1,10 @@
 // This is a generated file; do not edit or check into version control.
 FLUTTER_ROOT=/Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable
-FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/useragent
+FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/app
 COCOAPODS_PARALLEL_CODE_SIGN=true
 FLUTTER_BUILD_DIR=build
-FLUTTER_BUILD_NAME=0.1.0
-FLUTTER_BUILD_NUMBER=0.1.0
+FLUTTER_BUILD_NAME=1.0.0
+FLUTTER_BUILD_NUMBER=1
 DART_OBFUSCATION=false
 TRACK_WIDGET_CREATION=true
 TREE_SHAKE_ICONS=false

app/macos/Flutter/ephemeral/flutter_export_environment.sh

@@ -1,11 +1,11 @@
 #!/bin/sh
 # This is a generated file; do not edit or check into version control.
 export "FLUTTER_ROOT=/Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable"
-export "FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/useragent"
+export "FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/app"
 export "COCOAPODS_PARALLEL_CODE_SIGN=true"
 export "FLUTTER_BUILD_DIR=build"
-export "FLUTTER_BUILD_NAME=0.1.0"
-export "FLUTTER_BUILD_NUMBER=0.1.0"
+export "FLUTTER_BUILD_NAME=1.0.0"
+export "FLUTTER_BUILD_NUMBER=1"
 export "DART_OBFUSCATION=false"
 export "TRACK_WIDGET_CREATION=true"
 export "TREE_SHAKE_ICONS=false"

app/pubspec.lock

@@ -1,213 +0,0 @@
-# Generated by pub
-# See https://dart.dev/tools/pub/glossary#lockfile
-packages:
-  async:
-    dependency: transitive
-    description:
-      name: async
-      sha256: "758e6d74e971c3e5aceb4110bfd6698efc7f501675bcfe0c775459a8140750eb"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.13.0"
-  boolean_selector:
-    dependency: transitive
-    description:
-      name: boolean_selector
-      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.1.2"
-  characters:
-    dependency: transitive
-    description:
-      name: characters
-      sha256: f71061c654a3380576a52b451dd5532377954cf9dbd272a78fc8479606670803
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.4.0"
-  clock:
-    dependency: transitive
-    description:
-      name: clock
-      sha256: fddb70d9b5277016c77a80201021d40a2247104d9f4aa7bab7157b7e3f05b84b
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.1.2"
-  collection:
-    dependency: transitive
-    description:
-      name: collection
-      sha256: "2f5709ae4d3d59dd8f7cd309b4e023046b57d8a6c82130785d2b0e5868084e76"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.19.1"
-  cupertino_icons:
-    dependency: "direct main"
-    description:
-      name: cupertino_icons
-      sha256: ba631d1c7f7bef6b729a622b7b752645a2d076dba9976925b8f25725a30e1ee6
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.0.8"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      sha256: "5368f224a74523e8d2e7399ea1638b37aecfca824a3cc4dfdf77bf1fa905ac44"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.3.3"
-  flutter:
-    dependency: "direct main"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  flutter_lints:
-    dependency: "direct dev"
-    description:
-      name: flutter_lints
-      sha256: "3105dc8492f6183fb076ccf1f351ac3d60564bff92e20bfc4af9cc1651f4e7e1"
-      url: "https://pub.dev"
-    source: hosted
-    version: "6.0.0"
-  flutter_test:
-    dependency: "direct dev"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  leak_tracker:
-    dependency: transitive
-    description:
-      name: leak_tracker
-      sha256: "33e2e26bdd85a0112ec15400c8cbffea70d0f9c3407491f672a2fad47915e2de"
-      url: "https://pub.dev"
-    source: hosted
-    version: "11.0.2"
-  leak_tracker_flutter_testing:
-    dependency: transitive
-    description:
-      name: leak_tracker_flutter_testing
-      sha256: "1dbc140bb5a23c75ea9c4811222756104fbcd1a27173f0c34ca01e16bea473c1"
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.0.10"
-  leak_tracker_testing:
-    dependency: transitive
-    description:
-      name: leak_tracker_testing
-      sha256: "8d5a2d49f4a66b49744b23b018848400d23e54caf9463f4eb20df3eb8acb2eb1"
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.0.2"
-  lints:
-    dependency: transitive
-    description:
-      name: lints
-      sha256: "12f842a479589fea194fe5c5a3095abc7be0c1f2ddfa9a0e76aed1dbd26a87df"
-      url: "https://pub.dev"
-    source: hosted
-    version: "6.1.0"
-  matcher:
-    dependency: transitive
-    description:
-      name: matcher
-      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.12.17"
-  material_color_utilities:
-    dependency: transitive
-    description:
-      name: material_color_utilities
-      sha256: f7142bb1154231d7ea5f96bc7bde4bda2a0945d2806bb11670e30b850d56bdec
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.11.1"
-  meta:
-    dependency: transitive
-    description:
-      name: meta
-      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.17.0"
-  path:
-    dependency: transitive
-    description:
-      name: path
-      sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.9.1"
-  sky_engine:
-    dependency: transitive
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  source_span:
-    dependency: transitive
-    description:
-      name: source_span
-      sha256: "56a02f1f4cd1a2d96303c0144c93bd6d909eea6bee6bf5a0e0b685edbd4c47ab"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.10.2"
-  stack_trace:
-    dependency: transitive
-    description:
-      name: stack_trace
-      sha256: "8b27215b45d22309b5cddda1aa2b19bdfec9df0e765f2de506401c071d38d1b1"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.12.1"
-  stream_channel:
-    dependency: transitive
-    description:
-      name: stream_channel
-      sha256: "969e04c80b8bcdf826f8f16579c7b14d780458bd97f56d107d3950fdbeef059d"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.1.4"
-  string_scanner:
-    dependency: transitive
-    description:
-      name: string_scanner
-      sha256: "921cd31725b72fe181906c6a94d987c78e3b98c2e205b397ea399d4054872b43"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.4.1"
-  term_glyph:
-    dependency: transitive
-    description:
-      name: term_glyph
-      sha256: "7f554798625ea768a7518313e58f83891c7f5024f88e46e7182a4558850a4b8e"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.2.2"
-  test_api:
-    dependency: transitive
-    description:
-      name: test_api
-      sha256: ab2726c1a94d3176a45960b6234466ec367179b87dd74f1611adb1f3b5fb9d55
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.7.7"
-  vector_math:
-    dependency: transitive
-    description:
-      name: vector_math
-      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.2.0"
-  vm_service:
-    dependency: transitive
-    description:
-      name: vm_service
-      sha256: "45caa6c5917fa127b5dbcfbd1fa60b14e583afdc08bfc96dda38886ca252eb60"
-      url: "https://pub.dev"
-    source: hosted
-    version: "15.0.2"
-sdks:
-  dart: ">=3.10.8 <4.0.0"
-  flutter: ">=3.18.0-18.0.pre.54"

app/pubspec.yaml

@@ -1,89 +0,0 @@
-name: app
-description: "A new Flutter project."
-# The following line prevents the package from being accidentally published to
-# pub.dev using `flutter pub publish`. This is preferred for private packages.
-publish_to: 'none' # Remove this line if you wish to publish to pub.dev
-
-# The following defines the version and build number for your application.
-# A version number is three numbers separated by dots, like 1.2.43
-# followed by an optional build number separated by a +.
-# Both the version and the builder number may be overridden in flutter
-# build by specifying --build-name and --build-number, respectively.
-# In Android, build-name is used as versionName while build-number used as versionCode.
-# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
-# In iOS, build-name is used as CFBundleShortVersionString while build-number is used as CFBundleVersion.
-# Read more about iOS versioning at
-# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
-# In Windows, build-name is used as the major, minor, and patch parts
-# of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0+1
-
-environment:
-  sdk: ^3.10.8
-
-# Dependencies specify other packages that your package needs in order to work.
-# To automatically upgrade your package dependencies to the latest versions
-# consider running `flutter pub upgrade --major-versions`. Alternatively,
-# dependencies can be manually updated by changing the version numbers below to
-# the latest version available on pub.dev. To see which dependencies have newer
-# versions available, run `flutter pub outdated`.
-dependencies:
-  flutter:
-    sdk: flutter
-
-  # The following adds the Cupertino Icons font to your application.
-  # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^1.0.8
-
-dev_dependencies:
-  flutter_test:
-    sdk: flutter
-
-  # The "flutter_lints" package below contains a set of recommended lints to
-  # encourage good coding practices. The lint set provided by the package is
-  # activated in the `analysis_options.yaml` file located at the root of your
-  # package. See that file for information about deactivating specific lint
-  # rules and activating additional ones.
-  flutter_lints: ^6.0.0
-
-# For information on the generic Dart part of this file, see the
-# following page: https://dart.dev/tools/pub/pubspec
-
-# The following section is specific to Flutter packages.
-flutter:
-
-  # The following line ensures that the Material Icons font is
-  # included with your application, so that you can use the icons in
-  # the material Icons class.
-  uses-material-design: true
-
-  # To add assets to your application, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
-
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/to/resolution-aware-images
-
-  # For details regarding adding assets from package dependencies, see
-  # https://flutter.dev/to/asset-from-package
-
-  # To add custom fonts to your application, add a fonts section here,
-  # in this "flutter" section. Each entry in this list should have a
-  # "family" key with the font family name, and a "fonts" key with a
-  # list giving the asset and other descriptors for the font. For
-  # example:
-  # fonts:
-  #   - family: Schyler
-  #     fonts:
-  #       - asset: fonts/Schyler-Regular.ttf
-  #       - asset: fonts/Schyler-Italic.ttf
-  #         style: italic
-  #   - family: Trajan Pro
-  #     fonts:
-  #       - asset: fonts/TrajanPro.ttf
-  #       - asset: fonts/TrajanPro_Bold.ttf
-  #         weight: 700
-  #
-  # For details regarding fonts from package dependencies,
-  # see https://flutter.dev/to/font-from-package

app/windows/flutter/generated_plugin_registrant.cc

@@ -1,11 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-// clang-format off
-
-#include "generated_plugin_registrant.h"
-
-
-void RegisterPlugins(flutter::PluginRegistry* registry) {
-}

docs/superpowers/plans/2026-03-28-grant-grid-view.md

@@ -0,0 +1,821 @@
+# Grant Grid View Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add an "EVM Grants" dashboard tab that displays all grants as enriched cards (type, chain, wallet address, client name) with per-card revoke support.
+
+**Architecture:** A new `walletAccessListProvider` fetches wallet accesses with their DB row IDs. The screen (`grants.dart`) watches only `evmGrantsProvider` for top-level state. Each `GrantCard` widget (its own file) watches enrichment providers (`walletAccessListProvider`, `evmProvider`, `sdkClientsProvider`) and the revoke mutation directly — keeping rebuilds scoped to the card. The screen is registered as a dashboard tab in `AdaptiveScaffold`.
+
+**Tech Stack:** Flutter, Riverpod (`riverpod_annotation` + `build_runner` codegen), `sizer` (adaptive sizing), `auto_route`, Protocol Buffers (Dart), `Palette` design tokens.
+
+---
+
+## File Map
+
+| File | Action | Responsibility |
+|---|---|---|
+| `useragent/lib/theme/palette.dart` | Modify | Add `Palette.token` (indigo accent for token-transfer cards) |
+| `useragent/lib/features/connection/evm/wallet_access.dart` | Modify | Add `listAllWalletAccesses()` function |
+| `useragent/lib/providers/sdk_clients/wallet_access_list.dart` | Create | `WalletAccessListProvider` — fetches full wallet access list with IDs |
+| `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart` | Create | `GrantCard` widget — watches enrichment providers + revoke mutation; one card per grant |
+| `useragent/lib/screens/dashboard/evm/grants/grants.dart` | Create | `EvmGrantsScreen` — watches `evmGrantsProvider`; handles loading/error/empty/data states; renders `GrantCard` list |
+| `useragent/lib/router.dart` | Modify | Register `EvmGrantsRoute` in dashboard children |
+| `useragent/lib/screens/dashboard.dart` | Modify | Add Grants entry to `routes` list and `NavigationDestination` list |
+
+---
+
+## Task 1: Add `Palette.token`
+
+**Files:**
+- Modify: `useragent/lib/theme/palette.dart`
+
+- [ ] **Step 1: Add the color**
+
+Replace the contents of `useragent/lib/theme/palette.dart` with:
+
+```dart
+import 'package:flutter/material.dart';
+
+class Palette {
+  static const ink = Color(0xFF15263C);
+  static const coral = Color(0xFFE26254);
+  static const cream = Color(0xFFFFFAF4);
+  static const line = Color(0x1A15263C);
+  static const token = Color(0xFF5C6BC0);
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/theme/palette.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(theme): add Palette.token for token-transfer grant cards"
+jj new
+```
+
+---
+
+## Task 2: Add `listAllWalletAccesses` feature function
+
+**Files:**
+- Modify: `useragent/lib/features/connection/evm/wallet_access.dart`
+
+`readClientWalletAccess` (existing) filters the list to one client's wallet IDs and returns `Set<int>`. This new function returns the complete unfiltered list with row IDs so the grant cards can resolve wallet_access_id → wallet + client.
+
+- [ ] **Step 1: Append function**
+
+Add at the bottom of `useragent/lib/features/connection/evm/wallet_access.dart`:
+
+```dart
+Future<List<SdkClientWalletAccess>> listAllWalletAccesses(
+  Connection connection,
+) async {
+  final response = await connection.ask(
+    UserAgentRequest(listWalletAccess: Empty()),
+  );
+  if (!response.hasListWalletAccessResponse()) {
+    throw Exception(
+      'Expected list wallet access response, got ${response.whichPayload()}',
+    );
+  }
+  return response.listWalletAccessResponse.accesses.toList(growable: false);
+}
+```
+
+Each returned `SdkClientWalletAccess` has:
+- `.id` — the `evm_wallet_access` row ID (same value as `wallet_access_id` in a `GrantEntry`)
+- `.access.walletId` — the EVM wallet DB ID
+- `.access.sdkClientId` — the SDK client DB ID
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/features/connection/evm/wallet_access.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(evm): add listAllWalletAccesses feature function"
+jj new
+```
+
+---
+
+## Task 3: Create `WalletAccessListProvider`
+
+**Files:**
+- Create: `useragent/lib/providers/sdk_clients/wallet_access_list.dart`
+- Generated: `useragent/lib/providers/sdk_clients/wallet_access_list.g.dart`
+
+Mirrors the structure of `EvmGrants` in `providers/evm/evm_grants.dart` — class-based `@riverpod` with a `refresh()` method.
+
+- [ ] **Step 1: Write the provider**
+
+Create `useragent/lib/providers/sdk_clients/wallet_access_list.dart`:
+
+```dart
+import 'package:arbiter/features/connection/evm/wallet_access.dart';
+import 'package:arbiter/proto/user_agent.pb.dart';
+import 'package:arbiter/providers/connection/connection_manager.dart';
+import 'package:mtcore/markettakers.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'wallet_access_list.g.dart';
+
+@riverpod
+class WalletAccessList extends _$WalletAccessList {
+  @override
+  Future<List<SdkClientWalletAccess>?> build() async {
+    final connection = await ref.watch(connectionManagerProvider.future);
+    if (connection == null) {
+      return null;
+    }
+
+    try {
+      return await listAllWalletAccesses(connection);
+    } catch (e, st) {
+      talker.handle(e, st);
+      rethrow;
+    }
+  }
+
+  Future<void> refresh() async {
+    final connection = await ref.read(connectionManagerProvider.future);
+    if (connection == null) {
+      state = const AsyncData(null);
+      return;
+    }
+
+    state = const AsyncLoading();
+    state = await AsyncValue.guard(() => listAllWalletAccesses(connection));
+  }
+}
+```
+
+- [ ] **Step 2: Run code generation**
+
+```sh
+cd useragent && dart run build_runner build --delete-conflicting-outputs
+```
+
+Expected: `useragent/lib/providers/sdk_clients/wallet_access_list.g.dart` created. No errors.
+
+- [ ] **Step 3: Verify**
+
+```sh
+cd useragent && flutter analyze lib/providers/sdk_clients/
+```
+
+Expected: no issues.
+
+- [ ] **Step 4: Commit**
+
+```sh
+jj describe -m "feat(providers): add WalletAccessListProvider"
+jj new
+```
+
+---
+
+## Task 4: Create `GrantCard` widget
+
+**Files:**
+- Create: `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart`
+
+This widget owns all per-card logic: enrichment lookups, revoke action, and rebuild scope. The screen only passes it a `GrantEntry` — the card fetches everything else itself.
+
+**Key types:**
+- `GrantEntry` (from `proto/evm.pb.dart`): `.id`, `.shared.walletAccessId`, `.shared.chainId`, `.specific.whichGrant()`
+- `SpecificGrant_Grant.etherTransfer` / `.tokenTransfer` — enum values for the oneof
+- `SdkClientWalletAccess` (from `proto/user_agent.pb.dart`): `.id`, `.access.walletId`, `.access.sdkClientId`
+- `WalletEntry` (from `proto/evm.pb.dart`): `.id`, `.address` (List<int>)
+- `SdkClientEntry` (from `proto/user_agent.pb.dart`): `.id`, `.info.name`
+- `revokeEvmGrantMutation` — `Mutation<void>` (global; all revoke buttons disable together while any revoke is in flight)
+- `executeRevokeEvmGrant(ref, grantId: int)` — `Future<void>`
+
+- [ ] **Step 1: Write the widget**
+
+Create `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart`:
+
+```dart
+import 'package:arbiter/proto/evm.pb.dart';
+import 'package:arbiter/proto/user_agent.pb.dart';
+import 'package:arbiter/providers/evm/evm.dart';
+import 'package:arbiter/providers/evm/evm_grants.dart';
+import 'package:arbiter/providers/sdk_clients/list.dart';
+import 'package:arbiter/providers/sdk_clients/wallet_access_list.dart';
+import 'package:arbiter/theme/palette.dart';
+import 'package:flutter/material.dart';
+import 'package:hooks_riverpod/experimental/mutation.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
+
+String _shortAddress(List<int> bytes) {
+  final hex = bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
+  return '0x${hex.substring(0, 6)}...${hex.substring(hex.length - 4)}';
+}
+
+String _formatError(Object error) {
+  final message = error.toString();
+  if (message.startsWith('Exception: ')) {
+    return message.substring('Exception: '.length);
+  }
+  return message;
+}
+
+class GrantCard extends ConsumerWidget {
+  const GrantCard({super.key, required this.grant});
+
+  final GrantEntry grant;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Enrichment lookups — each watch scopes rebuilds to this card only
+    final walletAccesses =
+        ref.watch(walletAccessListProvider).asData?.value ?? const [];
+    final wallets = ref.watch(evmProvider).asData?.value ?? const [];
+    final clients = ref.watch(sdkClientsProvider).asData?.value ?? const [];
+    final revoking = ref.watch(revokeEvmGrantMutation) is MutationPending;
+
+    final isEther =
+        grant.specific.whichGrant() == SpecificGrant_Grant.etherTransfer;
+    final accent = isEther ? Palette.coral : Palette.token;
+    final typeLabel = isEther ? 'Ether' : 'Token';
+    final theme = Theme.of(context);
+    final muted = Palette.ink.withValues(alpha: 0.62);
+
+    // Resolve wallet_access_id → wallet address + client name
+    final accessById = <int, SdkClientWalletAccess>{
+      for (final a in walletAccesses) a.id: a,
+    };
+    final walletById = <int, WalletEntry>{
+      for (final w in wallets) w.id: w,
+    };
+    final clientNameById = <int, String>{
+      for (final c in clients) c.id: c.info.name,
+    };
+
+    final accessId = grant.shared.walletAccessId;
+    final access = accessById[accessId];
+    final wallet = access != null ? walletById[access.access.walletId] : null;
+
+    final walletLabel = wallet != null
+        ? _shortAddress(wallet.address)
+        : 'Access #$accessId';
+
+    final clientLabel = () {
+      if (access == null) return '';
+      final name = clientNameById[access.access.sdkClientId] ?? '';
+      return name.isEmpty ? 'Client #${access.access.sdkClientId}' : name;
+    }();
+
+    void showError(String message) {
+      if (!context.mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text(message), behavior: SnackBarBehavior.floating),
+      );
+    }
+
+    Future<void> revoke() async {
+      try {
+        await executeRevokeEvmGrant(ref, grantId: grant.id);
+      } catch (e) {
+        showError(_formatError(e));
+      }
+    }
+
+    return Container(
+      decoration: BoxDecoration(
+        borderRadius: BorderRadius.circular(24),
+        color: Palette.cream.withValues(alpha: 0.92),
+        border: Border.all(color: Palette.line),
+      ),
+      child: IntrinsicHeight(
+        child: Row(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            // Accent strip
+            Container(
+              width: 0.8.w,
+              decoration: BoxDecoration(
+                color: accent,
+                borderRadius: const BorderRadius.horizontal(
+                  left: Radius.circular(24),
+                ),
+              ),
+            ),
+            // Card body
+            Expanded(
+              child: Padding(
+                padding: EdgeInsets.symmetric(
+                  horizontal: 1.6.w,
+                  vertical: 1.4.h,
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    // Row 1: type badge · chain · spacer · revoke button
+                    Row(
+                      children: [
+                        Container(
+                          padding: EdgeInsets.symmetric(
+                            horizontal: 1.w,
+                            vertical: 0.4.h,
+                          ),
+                          decoration: BoxDecoration(
+                            color: accent.withValues(alpha: 0.15),
+                            borderRadius: BorderRadius.circular(8),
+                          ),
+                          child: Text(
+                            typeLabel,
+                            style: theme.textTheme.labelSmall?.copyWith(
+                              color: accent,
+                              fontWeight: FontWeight.w800,
+                            ),
+                          ),
+                        ),
+                        SizedBox(width: 1.w),
+                        Container(
+                          padding: EdgeInsets.symmetric(
+                            horizontal: 1.w,
+                            vertical: 0.4.h,
+                          ),
+                          decoration: BoxDecoration(
+                            color: Palette.ink.withValues(alpha: 0.06),
+                            borderRadius: BorderRadius.circular(8),
+                          ),
+                          child: Text(
+                            'Chain ${grant.shared.chainId}',
+                            style: theme.textTheme.labelSmall?.copyWith(
+                              color: muted,
+                              fontWeight: FontWeight.w700,
+                            ),
+                          ),
+                        ),
+                        const Spacer(),
+                        if (revoking)
+                          SizedBox(
+                            width: 1.8.h,
+                            height: 1.8.h,
+                            child: CircularProgressIndicator(
+                              strokeWidth: 2,
+                              color: Palette.coral,
+                            ),
+                          )
+                        else
+                          OutlinedButton.icon(
+                            onPressed: revoke,
+                            style: OutlinedButton.styleFrom(
+                              foregroundColor: Palette.coral,
+                              side: BorderSide(
+                                color: Palette.coral.withValues(alpha: 0.4),
+                              ),
+                              padding: EdgeInsets.symmetric(
+                                horizontal: 1.w,
+                                vertical: 0.6.h,
+                              ),
+                              shape: RoundedRectangleBorder(
+                                borderRadius: BorderRadius.circular(10),
+                              ),
+                            ),
+                            icon: const Icon(Icons.block_rounded, size: 16),
+                            label: const Text('Revoke'),
+                          ),
+                      ],
+                    ),
+                    SizedBox(height: 0.8.h),
+                    // Row 2: wallet address · client name
+                    Row(
+                      children: [
+                        Text(
+                          walletLabel,
+                          style: theme.textTheme.bodySmall?.copyWith(
+                            color: Palette.ink,
+                            fontFamily: 'monospace',
+                          ),
+                        ),
+                        Padding(
+                          padding: EdgeInsets.symmetric(horizontal: 0.8.w),
+                          child: Text(
+                            '·',
+                            style: theme.textTheme.bodySmall
+                                ?.copyWith(color: muted),
+                          ),
+                        ),
+                        Expanded(
+                          child: Text(
+                            clientLabel,
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis,
+                            style: theme.textTheme.bodySmall
+                                ?.copyWith(color: muted),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/screens/dashboard/evm/grants/widgets/grant_card.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(grants): add GrantCard widget with self-contained enrichment"
+jj new
+```
+
+---
+
+## Task 5: Create `EvmGrantsScreen`
+
+**Files:**
+- Create: `useragent/lib/screens/dashboard/evm/grants/grants.dart`
+
+The screen watches only `evmGrantsProvider` for top-level state (loading / error / no connection / empty / data). When there is data it renders a list of `GrantCard` widgets — each card manages its own enrichment subscriptions.
+
+- [ ] **Step 1: Write the screen**
+
+Create `useragent/lib/screens/dashboard/evm/grants/grants.dart`:
+
+```dart
+import 'package:arbiter/proto/evm.pb.dart';
+import 'package:arbiter/providers/evm/evm_grants.dart';
+import 'package:arbiter/providers/sdk_clients/wallet_access_list.dart';
+import 'package:arbiter/router.gr.dart';
+import 'package:arbiter/screens/dashboard/evm/grants/widgets/grant_card.dart';
+import 'package:arbiter/theme/palette.dart';
+import 'package:arbiter/widgets/page_header.dart';
+import 'package:auto_route/auto_route.dart';
+import 'package:flutter/material.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
+
+String _formatError(Object error) {
+  final message = error.toString();
+  if (message.startsWith('Exception: ')) {
+    return message.substring('Exception: '.length);
+  }
+  return message;
+}
+
+// ─── State panel ──────────────────────────────────────────────────────────────
+
+class _StatePanel extends StatelessWidget {
+  const _StatePanel({
+    required this.icon,
+    required this.title,
+    required this.body,
+    this.actionLabel,
+    this.onAction,
+    this.busy = false,
+  });
+
+  final IconData icon;
+  final String title;
+  final String body;
+  final String? actionLabel;
+  final Future<void> Function()? onAction;
+  final bool busy;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Container(
+      decoration: BoxDecoration(
+        borderRadius: BorderRadius.circular(24),
+        color: Palette.cream.withValues(alpha: 0.92),
+        border: Border.all(color: Palette.line),
+      ),
+      child: Padding(
+        padding: EdgeInsets.all(2.8.h),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            if (busy)
+              SizedBox(
+                width: 2.8.h,
+                height: 2.8.h,
+                child: const CircularProgressIndicator(strokeWidth: 2.5),
+              )
+            else
+              Icon(icon, size: 34, color: Palette.coral),
+            SizedBox(height: 1.8.h),
+            Text(
+              title,
+              style: theme.textTheme.headlineSmall?.copyWith(
+                color: Palette.ink,
+                fontWeight: FontWeight.w800,
+              ),
+            ),
+            SizedBox(height: 1.h),
+            Text(
+              body,
+              style: theme.textTheme.bodyLarge?.copyWith(
+                color: Palette.ink.withValues(alpha: 0.72),
+                height: 1.5,
+              ),
+            ),
+            if (actionLabel != null && onAction != null) ...[
+              SizedBox(height: 2.h),
+              OutlinedButton.icon(
+                onPressed: () => onAction!(),
+                icon: const Icon(Icons.refresh),
+                label: Text(actionLabel!),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+// ─── Grant list ───────────────────────────────────────────────────────────────
+
+class _GrantList extends StatelessWidget {
+  const _GrantList({required this.grants});
+
+  final List<GrantEntry> grants;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        for (var i = 0; i < grants.length; i++)
+          Padding(
+            padding: EdgeInsets.only(
+              bottom: i == grants.length - 1 ? 0 : 1.8.h,
+            ),
+            child: GrantCard(grant: grants[i]),
+          ),
+      ],
+    );
+  }
+}
+
+// ─── Screen ───────────────────────────────────────────────────────────────────
+
+@RoutePage()
+class EvmGrantsScreen extends ConsumerWidget {
+  const EvmGrantsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Screen watches only the grant list for top-level state decisions
+    final grantsAsync = ref.watch(evmGrantsProvider);
+
+    Future<void> refresh() async {
+      await Future.wait([
+        ref.read(evmGrantsProvider.notifier).refresh(),
+        ref.read(walletAccessListProvider.notifier).refresh(),
+      ]);
+    }
+
+    void showMessage(String message) {
+      if (!context.mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text(message), behavior: SnackBarBehavior.floating),
+      );
+    }
+
+    Future<void> safeRefresh() async {
+      try {
+        await refresh();
+      } catch (e) {
+        showMessage(_formatError(e));
+      }
+    }
+
+    final grantsState = grantsAsync.asData?.value;
+    final grants = grantsState?.grants;
+
+    final content = switch (grantsAsync) {
+      AsyncLoading() when grantsState == null => const _StatePanel(
+        icon: Icons.hourglass_top,
+        title: 'Loading grants',
+        body: 'Pulling grant registry from Arbiter.',
+        busy: true,
+      ),
+      AsyncError(:final error) => _StatePanel(
+        icon: Icons.sync_problem,
+        title: 'Grant registry unavailable',
+        body: _formatError(error),
+        actionLabel: 'Retry',
+        onAction: safeRefresh,
+      ),
+      AsyncData(:final value) when value == null => _StatePanel(
+        icon: Icons.portable_wifi_off,
+        title: 'No active server connection',
+        body: 'Reconnect to Arbiter to list EVM grants.',
+        actionLabel: 'Refresh',
+        onAction: safeRefresh,
+      ),
+      _ when grants != null && grants.isEmpty => _StatePanel(
+        icon: Icons.policy_outlined,
+        title: 'No grants yet',
+        body: 'Create a grant to allow SDK clients to sign transactions.',
+        actionLabel: 'Create grant',
+        onAction: () => context.router.push(const CreateEvmGrantRoute()),
+      ),
+      _ => _GrantList(grants: grants ?? const []),
+    };
+
+    return Scaffold(
+      body: SafeArea(
+        child: RefreshIndicator.adaptive(
+          color: Palette.ink,
+          backgroundColor: Colors.white,
+          onRefresh: safeRefresh,
+          child: ListView(
+            physics: const BouncingScrollPhysics(
+              parent: AlwaysScrollableScrollPhysics(),
+            ),
+            padding: EdgeInsets.fromLTRB(2.4.w, 2.4.h, 2.4.w, 3.2.h),
+            children: [
+              PageHeader(
+                title: 'EVM Grants',
+                isBusy: grantsAsync.isLoading,
+                actions: [
+                  FilledButton.icon(
+                    onPressed: () =>
+                        context.router.push(const CreateEvmGrantRoute()),
+                    icon: const Icon(Icons.add_rounded),
+                    label: const Text('Create grant'),
+                  ),
+                  SizedBox(width: 1.w),
+                  OutlinedButton.icon(
+                    onPressed: safeRefresh,
+                    style: OutlinedButton.styleFrom(
+                      foregroundColor: Palette.ink,
+                      side: BorderSide(color: Palette.line),
+                      padding: EdgeInsets.symmetric(
+                        horizontal: 1.4.w,
+                        vertical: 1.2.h,
+                      ),
+                      shape: RoundedRectangleBorder(
+                        borderRadius: BorderRadius.circular(14),
+                      ),
+                    ),
+                    icon: const Icon(Icons.refresh, size: 18),
+                    label: const Text('Refresh'),
+                  ),
+                ],
+              ),
+              SizedBox(height: 1.8.h),
+              content,
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/screens/dashboard/evm/grants/
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(grants): add EvmGrantsScreen"
+jj new
+```
+
+---
+
+## Task 6: Wire router and dashboard tab
+
+**Files:**
+- Modify: `useragent/lib/router.dart`
+- Modify: `useragent/lib/screens/dashboard.dart`
+- Regenerated: `useragent/lib/router.gr.dart`
+
+- [ ] **Step 1: Add route to `router.dart`**
+
+Replace the contents of `useragent/lib/router.dart` with:
+
+```dart
+import 'package:auto_route/auto_route.dart';
+
+import 'router.gr.dart';
+
+@AutoRouterConfig(generateForDir: ['lib/screens'])
+class Router extends RootStackRouter {
+  @override
+  List<AutoRoute> get routes => [
+    AutoRoute(page: Bootstrap.page, path: '/bootstrap', initial: true),
+    AutoRoute(page: ServerInfoSetupRoute.page, path: '/server-info'),
+    AutoRoute(page: ServerConnectionRoute.page, path: '/server-connection'),
+    AutoRoute(page: VaultSetupRoute.page, path: '/vault'),
+    AutoRoute(page: ClientDetailsRoute.page, path: '/clients/:clientId'),
+    AutoRoute(page: CreateEvmGrantRoute.page, path: '/evm-grants/create'),
+
+    AutoRoute(
+      page: DashboardRouter.page,
+      path: '/dashboard',
+      children: [
+        AutoRoute(page: EvmRoute.page, path: 'evm'),
+        AutoRoute(page: ClientsRoute.page, path: 'clients'),
+        AutoRoute(page: EvmGrantsRoute.page, path: 'grants'),
+        AutoRoute(page: AboutRoute.page, path: 'about'),
+      ],
+    ),
+  ];
+}
+```
+
+- [ ] **Step 2: Update `dashboard.dart`**
+
+In `useragent/lib/screens/dashboard.dart`, replace the `routes` constant:
+
+```dart
+final routes = [
+  const EvmRoute(),
+  const ClientsRoute(),
+  const EvmGrantsRoute(),
+  const AboutRoute(),
+];
+```
+
+And replace the `destinations` list inside `AdaptiveScaffold`:
+
+```dart
+destinations: const [
+  NavigationDestination(
+    icon: Icon(Icons.account_balance_wallet_outlined),
+    selectedIcon: Icon(Icons.account_balance_wallet),
+    label: 'Wallets',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.devices_other_outlined),
+    selectedIcon: Icon(Icons.devices_other),
+    label: 'Clients',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.policy_outlined),
+    selectedIcon: Icon(Icons.policy),
+    label: 'Grants',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.info_outline),
+    selectedIcon: Icon(Icons.info),
+    label: 'About',
+  ),
+],
+```
+
+- [ ] **Step 3: Regenerate router**
+
+```sh
+cd useragent && dart run build_runner build --delete-conflicting-outputs
+```
+
+Expected: `lib/router.gr.dart` updated, `EvmGrantsRoute` now available, no errors.
+
+- [ ] **Step 4: Full project verify**
+
+```sh
+cd useragent && flutter analyze
+```
+
+Expected: no issues.
+
+- [ ] **Step 5: Commit**
+
+```sh
+jj describe -m "feat(nav): add Grants dashboard tab"
+jj new
+```

docs/superpowers/specs/2026-03-28-grant-grid-view-design.md

@@ -0,0 +1,170 @@
+# Grant Grid View — Design Spec
+
+**Date:** 2026-03-28
+
+## Overview
+
+Add a "Grants" dashboard tab to the Flutter user-agent app that displays all EVM grants as a card-based grid. Each card shows a compact summary (type, chain, wallet address, client name) with a revoke action. The tab integrates into the existing `AdaptiveScaffold` navigation alongside Wallets, Clients, and About.
+
+## Scope
+
+- New `walletAccessListProvider` for fetching wallet access entries with their DB row IDs
+- New `EvmGrantsScreen` as a dashboard tab
+- Grant card widget with enriched display (type, chain, wallet, client)
+- Revoke action wired to existing `executeRevokeEvmGrant` mutation
+- Dashboard tab bar and router updated
+- New token-transfer accent color added to `Palette`
+
+**Out of scope:** Fixing grant creation (separate task).
+
+---
+
+## Data Layer
+
+### `walletAccessListProvider`
+
+**File:** `useragent/lib/providers/sdk_clients/wallet_access_list.dart`
+
+- `@riverpod` class, watches `connectionManagerProvider.future`
+- Returns `List<SdkClientWalletAccess>?` (null when not connected)
+- Each entry: `.id` (wallet_access_id), `.access.walletId`, `.access.sdkClientId`
+- Exposes a `refresh()` method following the same pattern as `EvmGrants.refresh()`
+
+### Enrichment at render time (Approach A)
+
+The `EvmGrantsScreen` watches four providers:
+1. `evmGrantsProvider` — the grant list
+2. `walletAccessListProvider` — to resolve wallet_access_id → (wallet_id, sdk_client_id)
+3. `evmProvider` — to resolve wallet_id → wallet address
+4. `sdkClientsProvider` — to resolve sdk_client_id → client name
+
+All lookups are in-memory Maps built inside the build method; no extra model class needed.
+
+Fallbacks:
+- Wallet address not found → `"Access #N"` where N is the wallet_access_id
+- Client name not found → `"Client #N"` where N is the sdk_client_id
+
+---
+
+## Route Structure
+
+```
+/dashboard
+  /evm          ← existing (Wallets tab)
+  /clients      ← existing (Clients tab)
+  /grants       ← NEW (Grants tab)
+  /about        ← existing
+
+/evm-grants/create  ← existing push route (unchanged)
+```
+
+### Changes to `router.dart`
+
+Add inside dashboard children:
+```dart
+AutoRoute(page: EvmGrantsRoute.page, path: 'grants'),
+```
+
+### Changes to `dashboard.dart`
+
+Add to `routes` list:
+```dart
+const EvmGrantsRoute()
+```
+
+Add `NavigationDestination`:
+```dart
+NavigationDestination(
+  icon: Icon(Icons.policy_outlined),
+  selectedIcon: Icon(Icons.policy),
+  label: 'Grants',
+),
+```
+
+---
+
+## Screen: `EvmGrantsScreen`
+
+**File:** `useragent/lib/screens/dashboard/evm/grants/grants.dart`
+
+```
+Scaffold
+└─ SafeArea
+   └─ RefreshIndicator.adaptive (refreshes evmGrantsProvider + walletAccessListProvider)
+      └─ ListView (BouncingScrollPhysics + AlwaysScrollableScrollPhysics)
+         ├─ PageHeader
+         │    title: 'EVM Grants'
+         │    isBusy: evmGrantsProvider.isLoading
+         │    actions: [CreateGrantButton, RefreshButton]
+         ├─ SizedBox(height: 1.8.h)
+         └─ <content>
+```
+
+### State handling
+
+Matches the pattern from `EvmScreen` and `ClientsScreen`:
+
+| State | Display |
+|---|---|
+| Loading (no data yet) | `_StatePanel` with spinner, "Loading grants" |
+| Error | `_StatePanel` with coral icon, error message, Retry button |
+| No connection | `_StatePanel`, "No active server connection" |
+| Empty list | `_StatePanel`, "No grants yet", with Create Grant shortcut |
+| Data | Column of `_GrantCard` widgets |
+
+### Header actions
+
+**CreateGrantButton:** `FilledButton.icon` with `Icons.add_rounded`, pushes `CreateEvmGrantRoute()` via `context.router.push(...)`.
+
+**RefreshButton:** `OutlinedButton.icon` with `Icons.refresh`, calls `ref.read(evmGrantsProvider.notifier).refresh()`.
+
+---
+
+## Grant Card: `_GrantCard`
+
+**Layout:**
+
+```
+Container (rounded 24, Palette.cream bg, Palette.line border)
+└─ IntrinsicHeight > Row
+   ├─ Accent strip (0.8.w wide, full height, rounded left)
+   └─ Padding > Column
+        ├─ Row 1: TypeBadge + ChainChip + Spacer + RevokeButton
+        └─ Row 2: WalletText + "·" + ClientText
+```
+
+**Accent color by grant type:**
+- Ether transfer → `Palette.coral`
+- Token transfer → `Palette.token` (new entry in `Palette` — indigo, e.g. `Color(0xFF5C6BC0)`)
+
+**TypeBadge:** Small pill container with accent color background at 15% opacity, accent-colored text. Label: `'Ether'` or `'Token'`.
+
+**ChainChip:** Small container: `'Chain ${grant.shared.chainId}'`, muted ink color.
+
+**WalletText:** Short hex address (`0xabc...def`) from wallet lookup, `bodySmall`, monospace font family.
+
+**ClientText:** Client name from `sdkClientsProvider` lookup, or fallback string. `bodySmall`, muted ink.
+
+**RevokeButton:**
+- `OutlinedButton` with `Icons.block_rounded` icon, label `'Revoke'`
+- `foregroundColor: Palette.coral`, `side: BorderSide(color: Palette.coral.withValues(alpha: 0.4))`
+- Disabled (replaced with `CircularProgressIndicator`) while `revokeEvmGrantMutation` is pending — note: this is a single global mutation, so all revoke buttons disable while any revoke is in flight
+- On press: calls `executeRevokeEvmGrant(ref, grantId: grant.id)`; shows `SnackBar` on error
+
+---
+
+## Adaptive Sizing
+
+All sizing uses `sizer` units (`1.h`, `1.w`, etc.). No hardcoded pixel values.
+
+---
+
+## Files to Create / Modify
+
+| File | Action |
+|---|---|
+| `lib/theme/palette.dart` | Modify — add `Palette.token` color |
+| `lib/providers/sdk_clients/wallet_access_list.dart` | Create |
+| `lib/screens/dashboard/evm/grants/grants.dart` | Create |
+| `lib/router.dart` | Modify — add grants route to dashboard children |
+| `lib/screens/dashboard.dart` | Modify — add tab to routes list and NavigationDestinations |

mise.lock

@@ -1,35 +1,69 @@
+# @generated - this file is auto-generated by `mise lock` https://mise.jdx.dev/dev-tools/mise-lock.html
+
+[[tools.ast-grep]]
+version = "0.42.0"
+backend = "aqua:ast-grep/ast-grep"
+
+[tools.ast-grep."platforms.linux-arm64"]
+checksum = "sha256:5c830eae8456569e2f7212434ed9c238f58dca412d76045418ed6d394a755836"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-aarch64-unknown-linux-gnu.zip"
+
+[tools.ast-grep."platforms.linux-arm64-musl"]
+checksum = "sha256:5c830eae8456569e2f7212434ed9c238f58dca412d76045418ed6d394a755836"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-aarch64-unknown-linux-gnu.zip"
+
+[tools.ast-grep."platforms.linux-x64"]
+checksum = "sha256:e825a05603f0bcc4cd9076c4cc8c9abd6d008b7cd07d9aa3cc323ba4b8606651"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-x86_64-unknown-linux-gnu.zip"
+
+[tools.ast-grep."platforms.linux-x64-musl"]
+checksum = "sha256:e825a05603f0bcc4cd9076c4cc8c9abd6d008b7cd07d9aa3cc323ba4b8606651"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-x86_64-unknown-linux-gnu.zip"
+
+[tools.ast-grep."platforms.macos-arm64"]
+checksum = "sha256:fc300d5293b1c770a5aece03a8a193b92e71e87cec726c28096990691a582620"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-aarch64-apple-darwin.zip"
+
+[tools.ast-grep."platforms.macos-x64"]
+checksum = "sha256:979ffe611327056f4730a1ae71b0209b3b830f58b22c6ed194cda34f55400db2"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-x86_64-apple-darwin.zip"
+
+[tools.ast-grep."platforms.windows-x64"]
+checksum = "sha256:55836fa1b2c65dc7d61615a4d9368622a0d2371a76d28b9a165e5a3ab6ae32a4"
+url = "https://github.com/ast-grep/ast-grep/releases/download/0.42.0/app-x86_64-pc-windows-msvc.zip"
+
 [[tools."cargo:cargo-audit"]]
 version = "0.22.1"
 backend = "cargo:cargo-audit"
 
-[[tools."cargo:cargo-features"]]
-version = "1.0.0"
-backend = "cargo:cargo-features"
+[[tools."cargo:cargo-edit"]]
+version = "0.13.9"
+backend = "cargo:cargo-edit"
 
 [[tools."cargo:cargo-features-manager"]]
 version = "0.11.1"
 backend = "cargo:cargo-features-manager"
 
+[[tools."cargo:cargo-insta"]]
+version = "1.46.3"
+backend = "cargo:cargo-insta"
+
+[[tools."cargo:cargo-mutants"]]
+version = "27.0.0"
+backend = "cargo:cargo-mutants"
+
 [[tools."cargo:cargo-nextest"]]
 version = "0.9.126"
 backend = "cargo:cargo-nextest"
 
 [[tools."cargo:cargo-shear"]]
-version = "1.9.1"
+version = "1.11.2"
 backend = "cargo:cargo-shear"
 
 [[tools."cargo:cargo-vet"]]
 version = "0.10.2"
 backend = "cargo:cargo-vet"
 
-[[tools."cargo:diesel-cli"]]
-version = "2.3.6"
-backend = "cargo:diesel-cli"
-
-[tools."cargo:diesel-cli".options]
-default-features = "false"
-features = "sqlite,sqlite-bundled"
-
 [[tools."cargo:diesel_cli"]]
 version = "2.3.6"
 backend = "cargo:diesel_cli"
@@ -45,11 +79,73 @@ backend = "asdf:flutter"
 [[tools.protoc]]
 version = "29.6"
 backend = "aqua:protocolbuffers/protobuf/protoc"
-"platforms.linux-arm64" = { checksum = "sha256:2594ff4fcae8cb57310d394d0961b236190ad9c5efbfdf1f597ea471d424fe79", url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-aarch_64.zip"}
-"platforms.linux-x64" = { checksum = "sha256:48785a926e73ffa3f68e2f22b14e7b849620c7a1d36809ac9249a5495e280323", url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-x86_64.zip"}
-"platforms.macos-arm64" = { checksum = "sha256:b9576b5fa1a1ef3fe13a8c91d9d8204b46545759bea5ae155cd6ba2ea4cdaeed", url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-osx-aarch_64.zip"}
-"platforms.macos-x64" = { checksum = "sha256:312f04713946921cc0187ef34df80241ddca1bab6f564c636885fd2cc90d3f88", url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-osx-x86_64.zip"}
-"platforms.windows-x64" = { checksum = "sha256:1ebd7c87baffb9f1c47169b640872bf5fb1e4408079c691af527be9561d8f6f7", url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-win64.zip"}
+
+[tools.protoc."platforms.linux-arm64"]
+checksum = "sha256:2594ff4fcae8cb57310d394d0961b236190ad9c5efbfdf1f597ea471d424fe79"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-aarch_64.zip"
+
+[tools.protoc."platforms.linux-arm64-musl"]
+checksum = "sha256:2594ff4fcae8cb57310d394d0961b236190ad9c5efbfdf1f597ea471d424fe79"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-aarch_64.zip"
+
+[tools.protoc."platforms.linux-x64"]
+checksum = "sha256:48785a926e73ffa3f68e2f22b14e7b849620c7a1d36809ac9249a5495e280323"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-x86_64.zip"
+
+[tools.protoc."platforms.linux-x64-musl"]
+checksum = "sha256:48785a926e73ffa3f68e2f22b14e7b849620c7a1d36809ac9249a5495e280323"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-linux-x86_64.zip"
+
+[tools.protoc."platforms.macos-arm64"]
+checksum = "sha256:b9576b5fa1a1ef3fe13a8c91d9d8204b46545759bea5ae155cd6ba2ea4cdaeed"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-osx-aarch_64.zip"
+
+[tools.protoc."platforms.macos-x64"]
+checksum = "sha256:312f04713946921cc0187ef34df80241ddca1bab6f564c636885fd2cc90d3f88"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-osx-x86_64.zip"
+
+[tools.protoc."platforms.windows-x64"]
+checksum = "sha256:1ebd7c87baffb9f1c47169b640872bf5fb1e4408079c691af527be9561d8f6f7"
+url = "https://github.com/protocolbuffers/protobuf/releases/download/v29.6/protoc-29.6-win64.zip"
+
+[[tools.python]]
+version = "3.14.3"
+backend = "core:python"
+
+[tools.python."platforms.linux-arm64"]
+checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.linux-arm64-musl"]
+checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.linux-x64"]
+checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.linux-x64-musl"]
+checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.macos-arm64"]
+checksum = "sha256:c43aecde4a663aebff99b9b83da0efec506479f1c3f98331442f33d2c43501f9"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.macos-x64"]
+checksum = "sha256:9ab41dbc2f100a2a45d1833b9c11165f51051c558b5213eda9a9731d5948a0c0"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"
+
+[tools.python."platforms.windows-x64"]
+checksum = "sha256:bbe19034b35b0267176a7442575ae7dc6343480fd4d35598cb7700173d431e09"
+url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-pc-windows-msvc-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [[tools.rust]]
 version = "1.93.0"

mise.toml

@@ -2,10 +2,22 @@
 "cargo:diesel_cli" = { version = "2.3.6", features = "sqlite,sqlite-bundled", default-features = false }
 "cargo:cargo-audit" = "0.22.1"
 "cargo:cargo-vet" = "0.10.2"
-
 flutter = "3.38.9-stable"
 protoc = "29.6"
-rust = "1.93.0"
+"rust" = {version = "1.93.0", components = "clippy"}
 "cargo:cargo-features-manager" = "0.11.1"
 "cargo:cargo-nextest" = "0.9.126"
 "cargo:cargo-shear" = "latest"
+"cargo:cargo-insta" = "1.46.3"
+python = "3.14.3"
+ast-grep = "0.42.0"
+"cargo:cargo-edit" = "0.13.9"
+"cargo:cargo-mutants" = "27.0.0"
+
+[tasks.codegen]
+sources = ['protobufs/*.proto', 'protobufs/**/*.proto']
+outputs = ['useragent/lib/proto/**']
+run = '''
+dart pub global activate protoc_plugin && \
+protoc --dart_out=grpc:useragent/lib/proto --proto_path=protobufs/ $(find protobufs -name '*.proto' | sort)
+'''

protobufs/arbiter.proto

@@ -2,30 +2,8 @@ syntax = "proto3";
 
 package arbiter;
 
-import "auth.proto";
-
-message ClientRequest {
-  oneof payload {
-    arbiter.auth.ClientMessage auth_message = 1;
-  }
-}
-
-message ClientResponse {
-  oneof payload {
-    arbiter.auth.ServerMessage auth_message = 1;
-  }
-}
-
-message UserAgentRequest {
-  oneof payload {
-    arbiter.auth.ClientMessage auth_message = 1;
-  }
-}
-message UserAgentResponse {
-  oneof payload {
-    arbiter.auth.ServerMessage auth_message = 1;
-  }
-}
+import "client.proto";
+import "user_agent.proto";
 
 message ServerInfo {
   string version = 1;
@@ -33,6 +11,6 @@ message ServerInfo {
 }
 
 service ArbiterService {
-  rpc Client(stream ClientRequest) returns (stream ClientResponse);
-  rpc UserAgent(stream UserAgentRequest) returns (stream UserAgentResponse);
+  rpc Client(stream arbiter.client.ClientRequest) returns (stream arbiter.client.ClientResponse);
+  rpc UserAgent(stream arbiter.user_agent.UserAgentRequest) returns (stream arbiter.user_agent.UserAgentResponse);
 }

protobufs/auth.proto

@@ -1,35 +0,0 @@
-syntax = "proto3";
-
-package arbiter.auth;
-
-import "google/protobuf/timestamp.proto";
-
-message AuthChallengeRequest {
-  bytes pubkey = 1;
-  optional string bootstrap_token = 2;
-}
-
-message AuthChallenge {
-  bytes pubkey = 1;
-  int32 nonce = 2;
-}
-
-message AuthChallengeSolution {
-  bytes signature = 1;
-}
-
-message AuthOk {}
-
-message ClientMessage {
-  oneof payload {
-    AuthChallengeRequest auth_challenge_request = 1;
-    AuthChallengeSolution auth_challenge_solution = 2;
-  }
-}
-
-message ServerMessage {
-  oneof payload {
-    AuthChallenge auth_challenge = 1;
-    AuthOk auth_ok = 2;
-  }
-}

protobufs/client.proto

@@ -0,0 +1,25 @@
+syntax = "proto3";
+
+package arbiter.client;
+
+import "client/auth.proto";
+import "client/evm.proto";
+import "client/vault.proto";
+
+message ClientRequest {
+  int32 request_id = 4;
+  oneof payload {
+    auth.Request auth = 1;
+    vault.Request vault = 2;
+    evm.Request evm = 3;
+  }
+}
+
+message ClientResponse {
+  optional int32 request_id = 7;
+  oneof payload {
+    auth.Response auth = 1;
+    vault.Response vault = 2;
+    evm.Response evm = 3;
+  }
+}

protobufs/client/auth.proto

@@ -0,0 +1,43 @@
+syntax = "proto3";
+
+package arbiter.client.auth;
+
+import "shared/client.proto";
+
+message AuthChallengeRequest {
+  bytes pubkey = 1;
+  arbiter.shared.ClientInfo client_info = 2;
+}
+
+message AuthChallenge {
+  bytes pubkey = 1;
+  int32 nonce = 2;
+}
+
+message AuthChallengeSolution {
+  bytes signature = 1;
+}
+
+enum AuthResult {
+  AUTH_RESULT_UNSPECIFIED = 0;
+  AUTH_RESULT_SUCCESS = 1;
+  AUTH_RESULT_INVALID_KEY = 2;
+  AUTH_RESULT_INVALID_SIGNATURE = 3;
+  AUTH_RESULT_APPROVAL_DENIED = 4;
+  AUTH_RESULT_NO_USER_AGENTS_ONLINE = 5;
+  AUTH_RESULT_INTERNAL = 6;
+}
+
+message Request {
+  oneof payload {
+    AuthChallengeRequest challenge_request = 1;
+    AuthChallengeSolution challenge_solution = 2;
+  }
+}
+
+message Response {
+  oneof payload {
+    AuthChallenge challenge = 1;
+    AuthResult result = 2;
+  }
+}

protobufs/client/evm.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package arbiter.client.evm;
+
+import "evm.proto";
+
+message Request {
+  oneof payload {
+    arbiter.evm.EvmSignTransactionRequest sign_transaction = 1;
+    arbiter.evm.EvmAnalyzeTransactionRequest analyze_transaction = 2;
+  }
+}
+
+message Response {
+  oneof payload {
+    arbiter.evm.EvmSignTransactionResponse sign_transaction = 1;
+    arbiter.evm.EvmAnalyzeTransactionResponse analyze_transaction = 2;
+  }
+}

protobufs/client/vault.proto

@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+package arbiter.client.vault;
+
+import "google/protobuf/empty.proto";
+import "shared/vault.proto";
+
+message Request {
+  oneof payload {
+    google.protobuf.Empty query_state = 1;
+  }
+}
+
+message Response {
+  oneof payload {
+    arbiter.shared.VaultState state = 1;
+  }
+}

protobufs/evm.proto

@@ -0,0 +1,153 @@
+syntax = "proto3";
+
+package arbiter.evm;
+
+import "google/protobuf/empty.proto";
+import "google/protobuf/timestamp.proto";
+import "shared/evm.proto";
+
+enum EvmError {
+  EVM_ERROR_UNSPECIFIED = 0;
+  EVM_ERROR_VAULT_SEALED = 1;
+  EVM_ERROR_INTERNAL = 2;
+}
+
+message WalletEntry {
+  int32 id = 1;
+  bytes address = 2; // 20-byte Ethereum address
+}
+
+message WalletList {
+  repeated WalletEntry wallets = 1;
+}
+
+message WalletCreateResponse {
+  oneof result {
+    WalletEntry wallet = 1;
+    EvmError error = 2;
+  }
+}
+
+message WalletListResponse {
+  oneof result {
+    WalletList wallets = 1;
+    EvmError error = 2;
+  }
+}
+
+// --- Grant types ---
+
+message TransactionRateLimit {
+  uint32 count = 1;
+  int64 window_secs = 2;
+}
+
+message VolumeRateLimit {
+  bytes max_volume = 1; // U256 as big-endian bytes
+  int64 window_secs = 2;
+}
+
+message SharedSettings {
+  int32 wallet_access_id = 1;
+  uint64 chain_id = 2;
+  optional google.protobuf.Timestamp valid_from = 3;
+  optional google.protobuf.Timestamp valid_until = 4;
+  optional bytes max_gas_fee_per_gas = 5; // U256 as big-endian bytes
+  optional bytes max_priority_fee_per_gas = 6; // U256 as big-endian bytes
+  optional TransactionRateLimit rate_limit = 7;
+}
+
+message EtherTransferSettings {
+  repeated bytes targets = 1; // list of 20-byte Ethereum addresses
+  VolumeRateLimit limit = 2;
+}
+
+message TokenTransferSettings {
+  bytes token_contract = 1; // 20-byte Ethereum address
+  optional bytes target = 2; // 20-byte Ethereum address; absent means any recipient allowed
+  repeated VolumeRateLimit volume_limits = 3;
+}
+
+message SpecificGrant {
+  oneof grant {
+    EtherTransferSettings ether_transfer = 1;
+    TokenTransferSettings token_transfer = 2;
+  }
+}
+
+// --- UserAgent grant management ---
+message EvmGrantCreateRequest {
+  SharedSettings shared = 1;
+  SpecificGrant specific = 2;
+}
+
+message EvmGrantCreateResponse {
+  oneof result {
+    int32 grant_id = 1;
+    EvmError error = 2;
+  }
+}
+
+message EvmGrantDeleteRequest {
+  int32 grant_id = 1;
+}
+
+message EvmGrantDeleteResponse {
+  oneof result {
+    google.protobuf.Empty ok = 1;
+    EvmError error = 2;
+  }
+}
+
+// Basic grant info returned in grant listings
+message GrantEntry {
+  int32 id = 1;
+  int32 wallet_access_id = 2;
+  SharedSettings shared = 3;
+  SpecificGrant specific = 4;
+}
+
+message EvmGrantListRequest {
+  optional int32 wallet_access_id = 1;
+}
+
+message EvmGrantListResponse {
+  oneof result {
+    EvmGrantList grants = 1;
+    EvmError error = 2;
+  }
+}
+
+message EvmGrantList {
+  repeated GrantEntry grants = 1;
+}
+
+// --- Client transaction operations ---
+
+message EvmSignTransactionRequest {
+  bytes wallet_address = 1; // 20-byte Ethereum address
+  bytes rlp_transaction = 2; // RLP-encoded EIP-1559 transaction (unsigned)
+}
+
+// oneof because signing and evaluation happen atomically — a signing failure
+// is always either an eval error or an internal error, never a partial success
+message EvmSignTransactionResponse {
+  oneof result {
+    bytes signature = 1; // 65-byte signature: r[32] || s[32] || v[1]
+    arbiter.shared.evm.TransactionEvalError eval_error = 2;
+    EvmError error = 3;
+  }
+}
+
+message EvmAnalyzeTransactionRequest {
+  bytes wallet_address = 1; // 20-byte Ethereum address
+  bytes rlp_transaction = 2; // RLP-encoded EIP-1559 transaction
+}
+
+message EvmAnalyzeTransactionResponse {
+  oneof result {
+    arbiter.shared.evm.SpecificMeaning meaning = 1;
+    arbiter.shared.evm.TransactionEvalError eval_error = 2;
+    EvmError error = 3;
+  }
+}

protobufs/shared/client.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package arbiter.shared;
+
+message ClientInfo {
+  string name = 1;
+  optional string description = 2;
+  optional string version = 3;
+}

protobufs/shared/evm.proto

@@ -0,0 +1,74 @@
+syntax = "proto3";
+
+package arbiter.shared.evm;
+
+import "google/protobuf/empty.proto";
+
+message EtherTransferMeaning {
+  bytes to = 1; // 20-byte Ethereum address
+  bytes value = 2; // U256 as big-endian bytes
+}
+
+message TokenInfo {
+  string symbol = 1;
+  bytes address = 2; // 20-byte Ethereum address
+  uint64 chain_id = 3;
+}
+
+// Mirror of token_transfers::Meaning
+message TokenTransferMeaning {
+  TokenInfo token = 1;
+  bytes to = 2; // 20-byte Ethereum address
+  bytes value = 3; // U256 as big-endian bytes
+}
+
+// Mirror of policies::SpecificMeaning
+message SpecificMeaning {
+  oneof meaning {
+    EtherTransferMeaning ether_transfer = 1;
+    TokenTransferMeaning token_transfer = 2;
+  }
+}
+
+message GasLimitExceededViolation {
+  optional bytes max_gas_fee_per_gas = 1; // U256 as big-endian bytes
+  optional bytes max_priority_fee_per_gas = 2; // U256 as big-endian bytes
+}
+
+message EvalViolation {
+  message ChainIdMismatch {
+    uint64 expected = 1;
+    uint64 actual = 2;
+  }
+  oneof kind {
+    bytes invalid_target = 1; // 20-byte Ethereum address
+    GasLimitExceededViolation gas_limit_exceeded = 2;
+    google.protobuf.Empty rate_limit_exceeded = 3;
+    google.protobuf.Empty volumetric_limit_exceeded = 4;
+    google.protobuf.Empty invalid_time = 5;
+    google.protobuf.Empty invalid_transaction_type = 6;
+
+    ChainIdMismatch chain_id_mismatch = 7;
+  }
+}
+
+// Transaction was classified but no grant covers it
+message NoMatchingGrantError {
+  SpecificMeaning meaning = 1;
+}
+
+// Transaction was classified and a grant was found, but constraints were violated
+message PolicyViolationsError {
+  SpecificMeaning meaning = 1;
+  repeated EvalViolation violations = 2;
+}
+
+// top-level error returned when transaction evaluation fails
+message TransactionEvalError {
+  oneof kind {
+    google.protobuf.Empty contract_creation_not_supported = 1;
+    google.protobuf.Empty unsupported_transaction_type = 2;
+    NoMatchingGrantError no_matching_grant = 3;
+    PolicyViolationsError policy_violations = 4;
+  }
+}

protobufs/shared/vault.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package arbiter.shared;
+
+enum VaultState {
+  VAULT_STATE_UNSPECIFIED = 0;
+  VAULT_STATE_UNBOOTSTRAPPED = 1;
+  VAULT_STATE_SEALED = 2;
+  VAULT_STATE_UNSEALED = 3;
+  VAULT_STATE_ERROR = 4;
+}

protobufs/unseal.proto

@@ -1,14 +0,0 @@
-syntax = "proto3";
-
-package arbiter.unseal;
-
-message UserAgentKeyRequest {}
-
-message ServerKeyResponse {
-  bytes pubkey = 1;
-}
-message UserAgentSealedKey {
-  bytes sealed_key = 1;
-  bytes pubkey = 2;
-  bytes nonce = 3;
-}

protobufs/user_agent.proto

@@ -0,0 +1,28 @@
+syntax = "proto3";
+
+package arbiter.user_agent;
+
+import "user_agent/auth.proto";
+import "user_agent/evm.proto";
+import "user_agent/sdk_client.proto";
+import "user_agent/vault/vault.proto";
+
+message UserAgentRequest {
+  int32 id = 16;
+  oneof payload {
+    auth.Request auth = 1;
+    vault.Request vault = 2;
+    evm.Request evm = 3;
+    sdk_client.Request sdk_client = 4;
+  }
+}
+
+message UserAgentResponse {
+  optional int32 id = 16;
+  oneof payload {
+    auth.Response auth = 1;
+    vault.Response vault = 2;
+    evm.Response evm = 3;
+    sdk_client.Response sdk_client = 4;
+  }
+}

protobufs/user_agent/auth.proto

@@ -0,0 +1,48 @@
+syntax = "proto3";
+
+package arbiter.user_agent.auth;
+
+enum KeyType {
+  KEY_TYPE_UNSPECIFIED = 0;
+  KEY_TYPE_ED25519 = 1;
+  KEY_TYPE_ECDSA_SECP256K1 = 2;
+  KEY_TYPE_RSA = 3;
+}
+
+message AuthChallengeRequest {
+  bytes pubkey = 1;
+  optional string bootstrap_token = 2;
+  KeyType key_type = 3;
+}
+
+message AuthChallenge {
+  int32 nonce = 1;
+}
+
+message AuthChallengeSolution {
+  bytes signature = 1;
+}
+
+enum AuthResult {
+  AUTH_RESULT_UNSPECIFIED = 0;
+  AUTH_RESULT_SUCCESS = 1;
+  AUTH_RESULT_INVALID_KEY = 2;
+  AUTH_RESULT_INVALID_SIGNATURE = 3;
+  AUTH_RESULT_BOOTSTRAP_REQUIRED = 4;
+  AUTH_RESULT_TOKEN_INVALID = 5;
+  AUTH_RESULT_INTERNAL = 6;
+}
+
+message Request {
+  oneof payload {
+    AuthChallengeRequest challenge_request = 1;
+    AuthChallengeSolution challenge_solution = 2;
+  }
+}
+
+message Response {
+  oneof payload {
+    AuthChallenge challenge = 1;
+    AuthResult result = 2;
+  }
+}

protobufs/user_agent/evm.proto

@@ -0,0 +1,33 @@
+syntax = "proto3";
+
+package arbiter.user_agent.evm;
+
+import "evm.proto";
+import "google/protobuf/empty.proto";
+
+message SignTransactionRequest {
+  int32 client_id = 1;
+  arbiter.evm.EvmSignTransactionRequest request = 2;
+}
+
+message Request {
+  oneof payload {
+    google.protobuf.Empty wallet_create = 1;
+    google.protobuf.Empty wallet_list = 2;
+    arbiter.evm.EvmGrantCreateRequest grant_create = 3;
+    arbiter.evm.EvmGrantDeleteRequest grant_delete = 4;
+    arbiter.evm.EvmGrantListRequest grant_list = 5;
+    SignTransactionRequest sign_transaction = 6;
+  }
+}
+
+message Response {
+  oneof payload {
+    arbiter.evm.WalletCreateResponse wallet_create = 1;
+    arbiter.evm.WalletListResponse wallet_list = 2;
+    arbiter.evm.EvmGrantCreateResponse grant_create = 3;
+    arbiter.evm.EvmGrantDeleteResponse grant_delete = 4;
+    arbiter.evm.EvmGrantListResponse grant_list = 5;
+    arbiter.evm.EvmSignTransactionResponse sign_transaction = 6;
+  }
+}

protobufs/user_agent/sdk_client.proto

@@ -0,0 +1,100 @@
+syntax = "proto3";
+
+package arbiter.user_agent.sdk_client;
+
+import "shared/client.proto";
+import "google/protobuf/empty.proto";
+
+enum Error {
+  ERROR_UNSPECIFIED = 0;
+  ERROR_ALREADY_EXISTS = 1;
+  ERROR_NOT_FOUND = 2;
+  ERROR_HAS_RELATED_DATA = 3; // hard-delete blocked by FK (client has grants or transaction logs)
+  ERROR_INTERNAL = 4;
+}
+
+message RevokeRequest {
+  int32 client_id = 1;
+}
+
+message Entry {
+  int32 id = 1;
+  bytes pubkey = 2;
+  arbiter.shared.ClientInfo info = 3;
+  int32 created_at = 4;
+}
+
+message List {
+  repeated Entry clients = 1;
+}
+
+message RevokeResponse {
+  oneof result {
+    google.protobuf.Empty ok = 1;
+    Error error = 2;
+  }
+}
+
+message ListResponse {
+  oneof result {
+    List clients = 1;
+    Error error = 2;
+  }
+}
+
+message ConnectionRequest {
+  bytes pubkey = 1;
+  arbiter.shared.ClientInfo info = 2;
+}
+
+message ConnectionResponse {
+  bool approved = 1;
+  bytes pubkey = 2;
+}
+
+message ConnectionCancel {
+  bytes pubkey = 1;
+}
+
+message WalletAccess {
+  int32 wallet_id = 1;
+  int32 sdk_client_id = 2;
+}
+
+message WalletAccessEntry {
+  int32 id = 1;
+  WalletAccess access = 2;
+}
+
+message GrantWalletAccess {
+  repeated WalletAccess accesses = 1;
+}
+
+message RevokeWalletAccess {
+  repeated int32 accesses = 1;
+}
+
+message ListWalletAccessResponse {
+  repeated WalletAccessEntry accesses = 1;
+}
+
+message Request {
+  oneof payload {
+    ConnectionResponse connection_response = 1;
+    RevokeRequest revoke = 2;
+    google.protobuf.Empty list = 3;
+    GrantWalletAccess grant_wallet_access = 4;
+    RevokeWalletAccess revoke_wallet_access = 5;
+    google.protobuf.Empty list_wallet_access = 6;
+  }
+}
+
+message Response {
+  oneof payload {
+    ConnectionRequest connection_request = 1;
+    ConnectionCancel connection_cancel = 2;
+    RevokeResponse revoke = 3;
+    ListResponse list = 4;
+    ListWalletAccessResponse list_wallet_access = 5;
+  }
+}

protobufs/user_agent/vault/bootstrap.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+package arbiter.user_agent.vault.bootstrap;
+
+message BootstrapEncryptedKey {
+  bytes nonce = 1;
+  bytes ciphertext = 2;
+  bytes associated_data = 3;
+}
+
+enum BootstrapResult {
+  BOOTSTRAP_RESULT_UNSPECIFIED = 0;
+  BOOTSTRAP_RESULT_SUCCESS = 1;
+  BOOTSTRAP_RESULT_ALREADY_BOOTSTRAPPED = 2;
+  BOOTSTRAP_RESULT_INVALID_KEY = 3;
+}
+
+message Request {
+  BootstrapEncryptedKey encrypted_key = 2;
+}
+
+message Response {
+  BootstrapResult result = 1;
+}

protobufs/user_agent/vault/unseal.proto

@@ -0,0 +1,37 @@
+syntax = "proto3";
+
+package arbiter.user_agent.vault.unseal;
+
+message UnsealStart {
+  bytes client_pubkey = 1;
+}
+
+message UnsealStartResponse {
+  bytes server_pubkey = 1;
+}
+message UnsealEncryptedKey {
+  bytes nonce = 1;
+  bytes ciphertext = 2;
+  bytes associated_data = 3;
+}
+
+enum UnsealResult {
+  UNSEAL_RESULT_UNSPECIFIED = 0;
+  UNSEAL_RESULT_SUCCESS = 1;
+  UNSEAL_RESULT_INVALID_KEY = 2;
+  UNSEAL_RESULT_UNBOOTSTRAPPED = 3;
+}
+
+message Request {
+  oneof payload {
+    UnsealStart start = 1;
+    UnsealEncryptedKey encrypted_key = 2;
+  }
+}
+
+message Response {
+  oneof payload {
+    UnsealStartResponse start = 1;
+    UnsealResult result = 2;
+  }
+}

protobufs/user_agent/vault/vault.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+package arbiter.user_agent.vault;
+
+import "google/protobuf/empty.proto";
+import "shared/vault.proto";
+import "user_agent/vault/bootstrap.proto";
+import "user_agent/vault/unseal.proto";
+
+message Request {
+  oneof payload {
+    google.protobuf.Empty query_state = 1;
+    unseal.Request unseal = 2;
+    bootstrap.Request bootstrap = 3;
+  }
+}
+
+message Response {
+  oneof payload {
+    arbiter.shared.VaultState state = 1;
+    unseal.Response unseal = 2;
+    bootstrap.Response bootstrap = 3;
+  }
+}

scripts/gen_erc20_registry.py

@@ -0,0 +1,150 @@
+#!/usr/bin/env python3
+"""
+Fetch the Uniswap default token list and emit Rust `TokenInfo` statics.
+
+Usage:
+    python3 gen_erc20_registry.py                       # fetch from IPFS
+    python3 gen_erc20_registry.py tokens.json           # local file
+    python3 gen_erc20_registry.py tokens.json out.rs    # custom output file
+"""
+
+import json
+import re
+import sys
+import unicodedata
+import urllib.request
+
+UNISWAP_URL = "https://ipfs.io/ipns/tokens.uniswap.org"
+
+SOLANA_CHAIN_ID = 501000101
+IDENTIFIER_RE = re.compile(r"[^A-Za-z0-9]+")
+
+
+def load_tokens(source=None):
+    if source:
+        with open(source) as f:
+            return json.load(f)
+    req = urllib.request.Request(
+        UNISWAP_URL,
+        headers={"Accept": "application/json", "User-Agent": "gen_tokens/1.0"},
+    )
+    with urllib.request.urlopen(req, timeout=60) as resp:
+        return json.loads(resp.read())
+
+
+def escape(s: str) -> str:
+    return s.replace("\\", "\\\\").replace('"', '\\"')
+
+
+def to_screaming_case(name: str) -> str:
+    normalized = unicodedata.normalize("NFKD", name or "")
+    ascii_name = normalized.encode("ascii", "ignore").decode("ascii")
+    snake = IDENTIFIER_RE.sub("_", ascii_name).strip("_").upper()
+    if not snake:
+        snake = "TOKEN"
+    if snake[0].isdigit():
+        snake = f"TOKEN_{snake}"
+    return snake
+
+
+def static_name_for_token(token: dict, used_names: set[str]) -> str:
+    base = to_screaming_case(token.get("name", ""))
+    if base not in used_names:
+        used_names.add(base)
+        return base
+
+    address = token["address"]
+    suffix = f"{token['chainId']}_{address[2:].upper()[-8:]}"
+    candidate = f"{base}_{suffix}"
+
+    i = 2
+    while candidate in used_names:
+        candidate = f"{base}_{suffix}_{i}"
+        i += 1
+
+    used_names.add(candidate)
+    return candidate
+
+
+def main():
+    source = sys.argv[1] if len(sys.argv) > 1 else None
+    output = sys.argv[2] if len(sys.argv) > 2 else "generated_tokens.rs"
+    data = load_tokens(source)
+    tokens = data["tokens"]
+
+    # Deduplicate by (chainId, address)
+    seen = set()
+    unique = []
+    for t in tokens:
+        key = (t["chainId"], t["address"].lower())
+        if key not in seen:
+            seen.add(key)
+            unique.append(t)
+
+    unique.sort(key=lambda t: (t["chainId"], t.get("symbol", "").upper()))
+    evm_tokens = [t for t in unique if t["chainId"] != SOLANA_CHAIN_ID]
+
+    ver = data["version"]
+    lines = []
+    w = lines.append
+
+    w(
+        f"// Auto-generated from Uniswap token list v{ver['major']}.{ver['minor']}.{ver['patch']}"
+    )
+    w(f"// {len(evm_tokens)} tokens")
+    w("// DO NOT EDIT - regenerate with gen_erc20_registry.py")
+    w("")
+
+    used_static_names = set()
+    token_statics = []
+    for t in evm_tokens:
+        static_name = static_name_for_token(t, used_static_names)
+        token_statics.append((static_name, t))
+
+    for static_name, t in token_statics:
+        addr = t["address"]
+        name = escape(t.get("name", ""))
+        symbol = escape(t.get("symbol", ""))
+        decimals = t.get("decimals", 18)
+        logo = t.get("logoURI")
+        chain = t["chainId"]
+
+        logo_val = f'Some("{escape(logo)}")' if logo else "None"
+
+        w(f"pub static {static_name}: TokenInfo = TokenInfo {{")
+        w(f'    name: "{name}",')
+        w(f'    symbol: "{symbol}",')
+        w(f"    decimals: {decimals},")
+        w(f'    contract: address!("{addr}"),')
+        w(f"    chain: {chain},")
+        w(f"    logo_uri: {logo_val},")
+        w("};")
+        w("")
+
+    w("pub static TOKENS: &[&TokenInfo] = &[")
+    for static_name, _ in token_statics:
+        w(f"    &{static_name},")
+    w("];")
+    w("")
+    w("pub fn get_token(")
+    w("    chain_id: alloy::primitives::ChainId,")
+    w("    address: alloy::primitives::Address,")
+    w(") -> Option<&'static TokenInfo> {")
+    w("    match (chain_id, address) {")
+    for static_name, t in token_statics:
+        w(
+            f'        ({t["chainId"]}, addr) if addr == address!("{t["address"]}") => Some(&{static_name}),'
+        )
+    w("        _ => None,")
+    w("    }")
+    w("}")
+    w("")
+
+    with open(output, "w") as f:
+        f.write("\n".join(lines))
+
+    print(f"Wrote {len(token_statics)} tokens to {output}")
+
+
+if __name__ == "__main__":
+    main()

server/.cargo/audit.toml

@@ -0,0 +1,13 @@
+[advisories]
+# RUSTSEC-2023-0071: Marvin Attack timing side-channel in rsa crate.
+# No fixed version is available upstream.
+# RSA support is required for Windows Hello / KeyCredentialManager
+# (https://learn.microsoft.com/en-us/uwp/api/windows.security.credentials.keycredentialmanager.requestcreateasync),
+# which only issues RSA-2048 keys.
+# Mitigations in place:
+#   - Signing uses BlindedSigningKey (PSS+SHA-256), which applies blinding to
+#     protect the private key from timing recovery during signing.
+#   - RSA decryption is never performed; we only verify public-key signatures.
+#   - The attack requires local, high-resolution timing access against the
+#     signing process, which is not exposed in our threat model.
+ignore = ["RUSTSEC-2023-0071"]

server/.cargo/mutants.toml

@@ -0,0 +1 @@
+test_tool = "nextest"

server/.gitignore

@@ -0,0 +1,2 @@
+mutants.out/
+mutants.out.old/

server/Cargo.toml

@@ -1,26 +1,50 @@
 [workspace]
 members = [
-    "crates/arbiter-client",
-    "crates/arbiter-proto",
-    "crates/arbiter-server",
-    "crates/arbiter-useragent",
+    "crates/*",
 ]
 resolver = "3"
 
+[workspace.lints.clippy]
+disallowed-methods = "deny"
+
 
 [workspace.dependencies]
-tonic = { version = "0.14.3", features = ["deflate", "gzip", "tls-connect-info", "zstd"] }
+tonic = { version = "0.14.5", features = [
+    "deflate",
+    "gzip",
+    "tls-connect-info",
+    "zstd",
+] }
 tracing = "0.1.44"
-tokio = { version = "1.49.0", features = ["full"] }
+tokio = { version = "1.50.0", features = ["full"] }
 ed25519-dalek = { version = "3.0.0-pre.6", features = ["rand_core"] }
-chrono = { version = "0.4.43", features = ["serde"] }
+chrono = { version = "0.4.44", features = ["serde"] }
 rand = "0.10.0"
-rustls = "0.23.36"
+rustls = { version = "0.23.37", features = ["aws-lc-rs", "logging", "prefer-post-quantum", "std"], default-features = false }
 smlang = "0.8.0"
-miette = { version = "7.6.0", features = ["fancy", "serde"] }
 thiserror = "2.0.18"
 async-trait = "0.1.89"
-futures = "0.3.31"
+futures = "0.3.32"
 tokio-stream = { version = "0.1.18", features = ["full"] }
 kameo = "0.19.2"
 prost-types = { version = "0.14.3", features = ["chrono"] }
+x25519-dalek = { version = "2.0.1", features = ["getrandom"] }
+rstest = "0.26.1"
+rustls-pki-types = "1.14.0"
+alloy = "1.7.3"
+rcgen = { version = "0.14.7", features = [
+    "aws_lc_rs",
+    "pem",
+    "x509-parser",
+    "zeroize",
+], default-features = false }
+k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
+rsa = { version = "0.9", features = ["sha2"] }
+sha2 = "0.10"
+spki = "0.7"
+prost = "0.14.3"
+miette = { version = "7.6.0", features = ["fancy", "serde"] }
+mutants = "0.0.4"
+ml-dsa = { version = "0.1.0-rc.8", features = ["zeroize"] }
+base64 = "0.22.1"
+hmac = "0.12.1"

server/clippy.toml

@@ -0,0 +1,9 @@
+disallowed-methods = [
+    # RSA decryption is forbidden: the rsa crate has RUSTSEC-2023-0071 (Marvin Attack).
+    # We only use RSA for Windows Hello (KeyCredentialManager) public-key verification — decryption
+    # is never required and must not be introduced.
+    { path = "rsa::RsaPrivateKey::decrypt", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). Only PSS signing/verification is permitted." },
+    { path = "rsa::RsaPrivateKey::decrypt_blinded", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). Only PSS signing/verification is permitted." },
+    { path = "rsa::traits::Decryptor::decrypt", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
+    { path = "rsa::traits::RandomizedDecryptor::decrypt_with_rng", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt_with_rng() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
+]

server/crates/arbiter-client/Cargo.toml

@@ -3,5 +3,24 @@ name = "arbiter-client"
 version = "0.1.0"
 edition = "2024"
 repository = "https://git.markettakers.org/MarketTakers/arbiter"
+license = "Apache-2.0"
+
+[lints]
+workspace = true
+
+[features]
+evm = ["dep:alloy"]
 
 [dependencies]
+arbiter-proto.path = "../arbiter-proto"
+arbiter-crypto.path = "../arbiter-crypto"
+alloy = { workspace = true, optional = true }
+tonic.workspace = true
+tonic.features = ["tls-aws-lc"]
+tokio.workspace = true
+tokio-stream.workspace = true
+thiserror.workspace = true
+http = "1.4.0"
+rustls-webpki = { version = "0.103.10", features = ["aws-lc-rs"] }
+async-trait.workspace = true
+rand.workspace = true

server/crates/arbiter-client/src/auth.rs

@@ -0,0 +1,152 @@
+use arbiter_crypto::authn::{CLIENT_CONTEXT, SigningKey, format_challenge};
+use arbiter_proto::{
+    ClientMetadata,
+    proto::{
+        client::{
+            ClientRequest,
+            auth::{
+                self as proto_auth, AuthChallenge, AuthChallengeRequest, AuthChallengeSolution,
+                AuthResult, request::Payload as AuthRequestPayload,
+                response::Payload as AuthResponsePayload,
+            },
+            client_request::Payload as ClientRequestPayload,
+            client_response::Payload as ClientResponsePayload,
+        },
+        shared::ClientInfo as ProtoClientInfo,
+    },
+};
+
+use crate::{
+    storage::StorageError,
+    transport::{ClientTransport, next_request_id},
+};
+
+#[derive(Debug, thiserror::Error)]
+pub enum AuthError {
+    #[error("Auth challenge was not returned by server")]
+    MissingAuthChallenge,
+
+    #[error("Client approval denied by User Agent")]
+    ApprovalDenied,
+
+    #[error("No User Agents online to approve client")]
+    NoUserAgentsOnline,
+
+    #[error("Unexpected auth response payload")]
+    UnexpectedAuthResponse,
+
+    #[error("Signing key storage error")]
+    Storage(#[from] StorageError),
+}
+
+fn map_auth_result(code: i32) -> AuthError {
+    match AuthResult::try_from(code).unwrap_or(AuthResult::Unspecified) {
+        AuthResult::ApprovalDenied => AuthError::ApprovalDenied,
+        AuthResult::NoUserAgentsOnline => AuthError::NoUserAgentsOnline,
+        AuthResult::Unspecified
+        | AuthResult::Success
+        | AuthResult::InvalidKey
+        | AuthResult::InvalidSignature
+        | AuthResult::Internal => AuthError::UnexpectedAuthResponse,
+    }
+}
+
+async fn send_auth_challenge_request(
+    transport: &mut ClientTransport,
+    metadata: ClientMetadata,
+    key: &SigningKey,
+) -> std::result::Result<(), AuthError> {
+    transport
+        .send(ClientRequest {
+            request_id: next_request_id(),
+            payload: Some(ClientRequestPayload::Auth(proto_auth::Request {
+                payload: Some(AuthRequestPayload::ChallengeRequest(AuthChallengeRequest {
+                    pubkey: key.public_key().to_bytes(),
+                    client_info: Some(ProtoClientInfo {
+                        name: metadata.name,
+                        description: metadata.description,
+                        version: metadata.version,
+                    }),
+                })),
+            })),
+        })
+        .await
+        .map_err(|_| AuthError::UnexpectedAuthResponse)
+}
+
+async fn receive_auth_challenge(
+    transport: &mut ClientTransport,
+) -> std::result::Result<AuthChallenge, AuthError> {
+    let response = transport
+        .recv()
+        .await
+        .map_err(|_| AuthError::MissingAuthChallenge)?;
+
+    let payload = response.payload.ok_or(AuthError::MissingAuthChallenge)?;
+    match payload {
+        ClientResponsePayload::Auth(response) => match response.payload {
+            Some(AuthResponsePayload::Challenge(challenge)) => Ok(challenge),
+            Some(AuthResponsePayload::Result(result)) => Err(map_auth_result(result)),
+            None => Err(AuthError::MissingAuthChallenge),
+        },
+        _ => Err(AuthError::UnexpectedAuthResponse),
+    }
+}
+
+async fn send_auth_challenge_solution(
+    transport: &mut ClientTransport,
+    key: &SigningKey,
+    challenge: AuthChallenge,
+) -> std::result::Result<(), AuthError> {
+    let challenge_payload = format_challenge(challenge.nonce, &challenge.pubkey);
+    let signature = key
+        .sign_message(&challenge_payload, CLIENT_CONTEXT)
+        .map_err(|_| AuthError::UnexpectedAuthResponse)?
+        .to_bytes();
+
+    transport
+        .send(ClientRequest {
+            request_id: next_request_id(),
+            payload: Some(ClientRequestPayload::Auth(proto_auth::Request {
+                payload: Some(AuthRequestPayload::ChallengeSolution(
+                    AuthChallengeSolution { signature },
+                )),
+            })),
+        })
+        .await
+        .map_err(|_| AuthError::UnexpectedAuthResponse)
+}
+
+async fn receive_auth_confirmation(
+    transport: &mut ClientTransport,
+) -> std::result::Result<(), AuthError> {
+    let response = transport
+        .recv()
+        .await
+        .map_err(|_| AuthError::UnexpectedAuthResponse)?;
+
+    let payload = response.payload.ok_or(AuthError::UnexpectedAuthResponse)?;
+    match payload {
+        ClientResponsePayload::Auth(response) => match response.payload {
+            Some(AuthResponsePayload::Result(result))
+                if AuthResult::try_from(result).ok() == Some(AuthResult::Success) =>
+            {
+                Ok(())
+            }
+            Some(AuthResponsePayload::Result(result)) => Err(map_auth_result(result)),
+            _ => Err(AuthError::UnexpectedAuthResponse),
+        },
+        _ => Err(AuthError::UnexpectedAuthResponse),
+    }
+}
+
+pub(crate) async fn authenticate(
+    transport: &mut ClientTransport,
+    metadata: ClientMetadata,
+    key: &SigningKey,
+) -> std::result::Result<(), AuthError> {
+    send_auth_challenge_request(transport, metadata, key).await?;
+    let challenge = receive_auth_challenge(transport).await?;
+    send_auth_challenge_solution(transport, key, challenge).await?;
+    receive_auth_confirmation(transport).await
+}

server/crates/arbiter-client/src/bin/test_connect.rs

@@ -0,0 +1,44 @@
+use std::io::{self, Write};
+
+use arbiter_client::ArbiterClient;
+use arbiter_proto::{ClientMetadata, url::ArbiterUrl};
+
+#[tokio::main]
+async fn main() {
+    println!("Testing connection to Arbiter server...");
+    print!("Enter ArbiterUrl: ");
+    let _ = io::stdout().flush();
+
+    let mut input = String::new();
+    if let Err(err) = io::stdin().read_line(&mut input) {
+        eprintln!("Failed to read input: {err}");
+        return;
+    }
+
+    let input = input.trim();
+    if input.is_empty() {
+        eprintln!("ArbiterUrl cannot be empty");
+        return;
+    }
+
+    let url = match ArbiterUrl::try_from(input) {
+        Ok(url) => url,
+        Err(err) => {
+            eprintln!("Invalid ArbiterUrl: {err}");
+            return;
+        }
+    };
+
+    println!("{:#?}", url);
+
+    let metadata = ClientMetadata {
+        name: "arbiter-client test_connect".to_string(),
+        description: Some("Manual connection smoke test".to_string()),
+        version: Some(env!("CARGO_PKG_VERSION").to_string()),
+    };
+
+    match ArbiterClient::connect(url, metadata).await {
+        Ok(_) => println!("Connected and authenticated successfully."),
+        Err(err) => eprintln!("Failed to connect: {:#?}", err),
+    }
+}

server/crates/arbiter-client/src/client.rs

@@ -0,0 +1,95 @@
+use arbiter_crypto::authn::SigningKey;
+use arbiter_proto::{
+    ClientMetadata, proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl,
+};
+use std::sync::Arc;
+use tokio::sync::{Mutex, mpsc};
+use tokio_stream::wrappers::ReceiverStream;
+use tonic::transport::ClientTlsConfig;
+
+use crate::{
+    StorageError,
+    auth::{AuthError, authenticate},
+    storage::{FileSigningKeyStorage, SigningKeyStorage},
+    transport::{BUFFER_LENGTH, ClientTransport},
+};
+
+#[cfg(feature = "evm")]
+use crate::wallets::evm::ArbiterEvmWallet;
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("gRPC error")]
+    Grpc(#[from] tonic::Status),
+
+    #[error("Could not establish connection")]
+    Connection(#[from] tonic::transport::Error),
+
+    #[error("Invalid server URI")]
+    InvalidUri(#[from] http::uri::InvalidUri),
+
+    #[error("Invalid CA certificate")]
+    InvalidCaCert(#[from] webpki::Error),
+
+    #[error("Authentication error")]
+    Authentication(#[from] AuthError),
+
+    #[error("Storage error")]
+    Storage(#[from] StorageError),
+}
+
+pub struct ArbiterClient {
+    #[allow(dead_code)]
+    transport: Arc<Mutex<ClientTransport>>,
+}
+
+impl ArbiterClient {
+    pub async fn connect(url: ArbiterUrl, metadata: ClientMetadata) -> Result<Self, Error> {
+        let storage = FileSigningKeyStorage::from_default_location()?;
+        Self::connect_with_storage(url, metadata, &storage).await
+    }
+
+    pub async fn connect_with_storage<S: SigningKeyStorage>(
+        url: ArbiterUrl,
+        metadata: ClientMetadata,
+        storage: &S,
+    ) -> Result<Self, Error> {
+        let key = storage.load_or_create()?;
+        Self::connect_with_key(url, metadata, key).await
+    }
+
+    pub async fn connect_with_key(
+        url: ArbiterUrl,
+        metadata: ClientMetadata,
+        key: SigningKey,
+    ) -> Result<Self, Error> {
+        let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)?.to_owned();
+        let tls = ClientTlsConfig::new().trust_anchor(anchor);
+
+        let channel =
+            tonic::transport::Channel::from_shared(format!("https://{}:{}", url.host, url.port))?
+                .tls_config(tls)?
+                .connect()
+                .await?;
+
+        let mut client = ArbiterServiceClient::new(channel);
+        let (tx, rx) = mpsc::channel(BUFFER_LENGTH);
+        let response_stream = client.client(ReceiverStream::new(rx)).await?.into_inner();
+
+        let mut transport = ClientTransport {
+            sender: tx,
+            receiver: response_stream,
+        };
+
+        authenticate(&mut transport, metadata, &key).await?;
+
+        Ok(Self {
+            transport: Arc::new(Mutex::new(transport)),
+        })
+    }
+
+    #[cfg(feature = "evm")]
+    pub async fn evm_wallets(&self) -> Result<Vec<ArbiterEvmWallet>, Error> {
+        todo!("fetch EVM wallet list from server")
+    }
+}

server/crates/arbiter-client/src/lib.rs

@@ -1,14 +1,12 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
+mod auth;
+mod client;
+mod storage;
+mod transport;
+pub mod wallets;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+pub use auth::AuthError;
+pub use client::{ArbiterClient, Error};
+pub use storage::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
 
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+#[cfg(feature = "evm")]
+pub use wallets::evm::{ArbiterEvmSignTransactionError, ArbiterEvmWallet};

server/crates/arbiter-client/src/storage.rs

@@ -0,0 +1,133 @@
+use arbiter_crypto::authn::SigningKey;
+use arbiter_proto::home_path;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, thiserror::Error)]
+pub enum StorageError {
+    #[error("I/O error")]
+    Io(#[from] std::io::Error),
+
+    #[error("Invalid signing key length in storage: expected {expected} bytes, got {actual} bytes")]
+    InvalidKeyLength { expected: usize, actual: usize },
+}
+
+pub trait SigningKeyStorage {
+    fn load_or_create(&self) -> std::result::Result<SigningKey, StorageError>;
+}
+
+#[derive(Debug, Clone)]
+pub struct FileSigningKeyStorage {
+    path: PathBuf,
+}
+
+impl FileSigningKeyStorage {
+    pub const DEFAULT_FILE_NAME: &str = "sdk_client_ml_dsa.key";
+
+    pub fn new(path: impl Into<PathBuf>) -> Self {
+        Self { path: path.into() }
+    }
+
+    pub fn from_default_location() -> std::result::Result<Self, StorageError> {
+        Ok(Self::new(home_path()?.join(Self::DEFAULT_FILE_NAME)))
+    }
+
+    fn read_key(path: &Path) -> std::result::Result<SigningKey, StorageError> {
+        let bytes = std::fs::read(path)?;
+        let raw: [u8; 32] =
+            bytes
+                .try_into()
+                .map_err(|v: Vec<u8>| StorageError::InvalidKeyLength {
+                    expected: 32,
+                    actual: v.len(),
+                })?;
+        Ok(SigningKey::from_seed(raw))
+    }
+}
+
+impl SigningKeyStorage for FileSigningKeyStorage {
+    fn load_or_create(&self) -> std::result::Result<SigningKey, StorageError> {
+        if let Some(parent) = self.path.parent() {
+            std::fs::create_dir_all(parent)?;
+        }
+
+        if self.path.exists() {
+            return Self::read_key(&self.path);
+        }
+
+        let key = SigningKey::generate();
+        let raw_key = key.to_seed();
+
+        // Use create_new to prevent accidental overwrite if another process creates the key first.
+        match std::fs::OpenOptions::new()
+            .create_new(true)
+            .write(true)
+            .open(&self.path)
+        {
+            Ok(mut file) => {
+                use std::io::Write as _;
+                file.write_all(&raw_key)?;
+                Ok(key)
+            }
+            Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
+                Self::read_key(&self.path)
+            }
+            Err(err) => Err(StorageError::Io(err)),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
+
+    fn unique_temp_key_path() -> std::path::PathBuf {
+        let nanos = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .expect("clock should be after unix epoch")
+            .as_nanos();
+        std::env::temp_dir().join(format!(
+            "arbiter-client-key-{}-{}.bin",
+            std::process::id(),
+            nanos
+        ))
+    }
+
+    #[test]
+    fn file_storage_creates_and_reuses_key() {
+        let path = unique_temp_key_path();
+        let storage = FileSigningKeyStorage::new(path.clone());
+
+        let key_a = storage
+            .load_or_create()
+            .expect("first load_or_create should create key");
+        let key_b = storage
+            .load_or_create()
+            .expect("second load_or_create should read same key");
+
+        assert_eq!(key_a.to_seed(), key_b.to_seed());
+        assert!(path.exists());
+
+        std::fs::remove_file(path).expect("temp key file should be removable");
+    }
+
+    #[test]
+    fn file_storage_rejects_invalid_key_length() {
+        let path = unique_temp_key_path();
+        std::fs::write(&path, [42u8; 31]).expect("should write invalid key file");
+        let storage = FileSigningKeyStorage::new(path.clone());
+
+        let err = storage
+            .load_or_create()
+            .expect_err("storage should reject non-32-byte key file");
+
+        match err {
+            StorageError::InvalidKeyLength { expected, actual } => {
+                assert_eq!(expected, 32);
+                assert_eq!(actual, 31);
+            }
+            other => panic!("unexpected error: {other:?}"),
+        }
+
+        std::fs::remove_file(path).expect("temp key file should be removable");
+    }
+}

server/crates/arbiter-client/src/transport.rs

@@ -0,0 +1,44 @@
+use arbiter_proto::proto::client::{ClientRequest, ClientResponse};
+use std::sync::atomic::{AtomicI32, Ordering};
+use tokio::sync::mpsc;
+
+pub(crate) const BUFFER_LENGTH: usize = 16;
+static NEXT_REQUEST_ID: AtomicI32 = AtomicI32::new(1);
+
+pub(crate) fn next_request_id() -> i32 {
+    NEXT_REQUEST_ID.fetch_add(1, Ordering::Relaxed)
+}
+
+#[derive(Debug, thiserror::Error)]
+pub(crate) enum ClientSignError {
+    #[error("Transport channel closed")]
+    ChannelClosed,
+
+    #[error("Connection closed by server")]
+    ConnectionClosed,
+}
+
+pub(crate) struct ClientTransport {
+    pub(crate) sender: mpsc::Sender<ClientRequest>,
+    pub(crate) receiver: tonic::Streaming<ClientResponse>,
+}
+
+impl ClientTransport {
+    pub(crate) async fn send(
+        &mut self,
+        request: ClientRequest,
+    ) -> std::result::Result<(), ClientSignError> {
+        self.sender
+            .send(request)
+            .await
+            .map_err(|_| ClientSignError::ChannelClosed)
+    }
+
+    pub(crate) async fn recv(&mut self) -> std::result::Result<ClientResponse, ClientSignError> {
+        match self.receiver.message().await {
+            Ok(Some(resp)) => Ok(resp),
+            Ok(None) => Err(ClientSignError::ConnectionClosed),
+            Err(_) => Err(ClientSignError::ConnectionClosed),
+        }
+    }
+}

server/crates/arbiter-client/src/wallets/evm.rs

@@ -0,0 +1,192 @@
+use alloy::{
+    consensus::SignableTransaction,
+    network::TxSigner,
+    primitives::{Address, B256, ChainId, Signature},
+    signers::{Error, Result, Signer},
+};
+use async_trait::async_trait;
+use std::sync::Arc;
+use tokio::sync::Mutex;
+
+use arbiter_proto::proto::{
+    client::{
+        ClientRequest,
+        client_request::Payload as ClientRequestPayload,
+        client_response::Payload as ClientResponsePayload,
+        evm::{
+            self as proto_evm, request::Payload as EvmRequestPayload,
+            response::Payload as EvmResponsePayload,
+        },
+    },
+    evm::{
+        EvmSignTransactionRequest,
+        evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    },
+    shared::evm::TransactionEvalError,
+};
+
+use crate::transport::{ClientTransport, next_request_id};
+
+/// A typed error payload returned by [`ArbiterEvmWallet`] transaction signing.
+///
+/// This is wrapped into `alloy::signers::Error::Other`, so consumers can downcast by [`TryFrom`] and
+/// interpret the concrete policy evaluation failure instead of parsing strings.
+#[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
+pub enum ArbiterEvmSignTransactionError {
+    #[error("transaction rejected by policy: {0:?}")]
+    PolicyEval(TransactionEvalError),
+}
+
+impl<'a> TryFrom<&'a Error> for &'a ArbiterEvmSignTransactionError {
+    type Error = ();
+
+    fn try_from(value: &'a Error) -> Result<Self, Self::Error> {
+        if let Error::Other(inner) = value
+            && let Some(eval_error) = inner.downcast_ref()
+        {
+            Ok(eval_error)
+        } else {
+            Err(())
+        }
+    }
+}
+
+pub struct ArbiterEvmWallet {
+    transport: Arc<Mutex<ClientTransport>>,
+    address: Address,
+    chain_id: Option<ChainId>,
+}
+
+impl ArbiterEvmWallet {
+    pub(crate) fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
+        Self {
+            transport,
+            address,
+            chain_id: None,
+        }
+    }
+
+    pub fn address(&self) -> Address {
+        self.address
+    }
+
+    pub fn with_chain_id(mut self, chain_id: ChainId) -> Self {
+        self.chain_id = Some(chain_id);
+        self
+    }
+
+    fn validate_chain_id(&self, tx: &mut dyn SignableTransaction<Signature>) -> Result<()> {
+        if let Some(chain_id) = self.chain_id
+            && !tx.set_chain_id_checked(chain_id)
+        {
+            return Err(Error::TransactionChainIdMismatch {
+                signer: chain_id,
+                tx: tx.chain_id().unwrap(),
+            });
+        }
+
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl Signer for ArbiterEvmWallet {
+    async fn sign_hash(&self, _hash: &B256) -> Result<Signature> {
+        Err(Error::other(
+            "hash-only signing is not supported for ArbiterEvmWallet; use transaction signing",
+        ))
+    }
+
+    fn address(&self) -> Address {
+        self.address
+    }
+
+    fn chain_id(&self) -> Option<ChainId> {
+        self.chain_id
+    }
+
+    fn set_chain_id(&mut self, chain_id: Option<ChainId>) {
+        self.chain_id = chain_id;
+    }
+}
+
+#[async_trait]
+impl TxSigner<Signature> for ArbiterEvmWallet {
+    fn address(&self) -> Address {
+        self.address
+    }
+
+    async fn sign_transaction(
+        &self,
+        tx: &mut dyn SignableTransaction<Signature>,
+    ) -> Result<Signature> {
+        self.validate_chain_id(tx)?;
+
+        let mut transport = self.transport.lock().await;
+        let request_id = next_request_id();
+        let rlp_transaction = tx.encoded_for_signing();
+
+        transport
+            .send(ClientRequest {
+                request_id,
+                payload: Some(ClientRequestPayload::Evm(proto_evm::Request {
+                    payload: Some(EvmRequestPayload::SignTransaction(
+                        EvmSignTransactionRequest {
+                            wallet_address: self.address.to_vec(),
+                            rlp_transaction,
+                        },
+                    )),
+                })),
+            })
+            .await
+            .map_err(|_| Error::other("failed to send evm sign transaction request"))?;
+
+        let response = transport
+            .recv()
+            .await
+            .map_err(|_| Error::other("failed to receive evm sign transaction response"))?;
+
+        if response.request_id != Some(request_id) {
+            return Err(Error::other(
+                "received mismatched response id for evm sign transaction",
+            ));
+        }
+
+        let payload = response
+            .payload
+            .ok_or_else(|| Error::other("missing evm sign transaction response payload"))?;
+
+        let ClientResponsePayload::Evm(proto_evm::Response {
+            payload: Some(payload),
+        }) = payload
+        else {
+            return Err(Error::other(
+                "unexpected response payload for evm sign transaction request",
+            ));
+        };
+
+        let EvmResponsePayload::SignTransaction(response) = payload else {
+            return Err(Error::other(
+                "unexpected evm response payload for sign transaction request",
+            ));
+        };
+
+        let result = response
+            .result
+            .ok_or_else(|| Error::other("missing evm sign transaction result"))?;
+
+        match result {
+            EvmSignTransactionResult::Signature(signature) => {
+                Signature::try_from(signature.as_slice())
+                    .map_err(|_| Error::other("invalid signature returned by server"))
+            }
+            EvmSignTransactionResult::EvalError(eval_error) => Err(Error::other(
+                ArbiterEvmSignTransactionError::PolicyEval(eval_error),
+            )),
+            EvmSignTransactionResult::Error(code) => Err(Error::other(format!(
+                "server failed to sign transaction with error code {code}"
+            ))),
+        }
+    }
+}

server/crates/arbiter-client/src/wallets/mod.rs

@@ -0,0 +1,2 @@
+#[cfg(feature = "evm")]
+pub mod evm;

server/crates/arbiter-crypto/.gitignore

@@ -0,0 +1 @@
+/target

server/crates/arbiter-crypto/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "arbiter-crypto"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+ml-dsa = {workspace = true, optional = true }
+rand = {workspace = true, optional = true}
+base64 = {workspace = true, optional = true }
+memsafe = {version = "0.4.0", optional = true}
+hmac.workspace = true
+alloy.workspace = true
+chrono.workspace = true
+
+[lints]
+workspace = true
+
+[features]
+default = ["authn", "safecell"]
+authn = ["dep:ml-dsa", "dep:rand", "dep:base64"]
+safecell = ["dep:memsafe"]

server/crates/arbiter-crypto/src/authn/mod.rs

@@ -0,0 +1,2 @@
+pub mod v1;
+pub use v1::*;

server/crates/arbiter-crypto/src/authn/v1.rs

@@ -0,0 +1,193 @@
+use base64::{Engine as _, prelude::BASE64_STANDARD};
+use hmac::digest::Digest;
+use ml_dsa::{
+    EncodedVerifyingKey, Error, KeyGen, MlDsa87, Seed, Signature as MlDsaSignature,
+    SigningKey as MlDsaSigningKey, VerifyingKey as MlDsaVerifyingKey, signature::Keypair as _,
+};
+
+pub static CLIENT_CONTEXT: &[u8] = b"arbiter_client";
+pub static USERAGENT_CONTEXT: &[u8] = b"arbiter_user_agent";
+
+pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
+    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
+    concat_form.into_bytes()
+}
+
+pub type KeyParams = MlDsa87;
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct PublicKey(Box<MlDsaVerifyingKey<KeyParams>>);
+
+impl crate::hashing::Hashable for PublicKey {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_bytes());
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Signature(Box<MlDsaSignature<KeyParams>>);
+
+#[derive(Debug)]
+pub struct SigningKey(Box<MlDsaSigningKey<KeyParams>>);
+
+impl PublicKey {
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.0.encode().0.to_vec()
+    }
+
+    pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
+        self.0.verify_with_context(
+            &format_challenge(nonce, &self.to_bytes()),
+            context,
+            &signature.0,
+        )
+    }
+}
+
+impl Signature {
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.0.encode().0.to_vec()
+    }
+}
+
+impl SigningKey {
+    pub fn generate() -> Self {
+        Self(Box::new(KeyParams::key_gen(&mut rand::rng())))
+    }
+
+    pub fn from_seed(seed: [u8; 32]) -> Self {
+        Self(Box::new(KeyParams::from_seed(&Seed::from(seed))))
+    }
+
+    pub fn to_seed(&self) -> [u8; 32] {
+        self.0.to_seed().into()
+    }
+
+    pub fn public_key(&self) -> PublicKey {
+        self.0.verifying_key().into()
+    }
+
+    pub fn sign_message(&self, message: &[u8], context: &[u8]) -> Result<Signature, Error> {
+        self.0
+            .signing_key()
+            .sign_deterministic(message, context)
+            .map(Into::into)
+    }
+
+    pub fn sign_challenge(&self, nonce: i32, context: &[u8]) -> Result<Signature, Error> {
+        self.sign_message(
+            &format_challenge(nonce, &self.public_key().to_bytes()),
+            context,
+        )
+    }
+}
+
+impl From<MlDsaVerifyingKey<KeyParams>> for PublicKey {
+    fn from(value: MlDsaVerifyingKey<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl From<MlDsaSignature<KeyParams>> for Signature {
+    fn from(value: MlDsaSignature<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl From<MlDsaSigningKey<KeyParams>> for SigningKey {
+    fn from(value: MlDsaSigningKey<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl TryFrom<Vec<u8>> for PublicKey {
+    type Error = ();
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        Self::try_from(value.as_slice())
+    }
+}
+
+impl TryFrom<&'_ [u8]> for PublicKey {
+    type Error = ();
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        let encoded = EncodedVerifyingKey::<KeyParams>::try_from(value).map_err(|_| ())?;
+        Ok(Self(Box::new(MlDsaVerifyingKey::decode(&encoded))))
+    }
+}
+
+impl TryFrom<Vec<u8>> for Signature {
+    type Error = ();
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        Self::try_from(value.as_slice())
+    }
+}
+
+impl TryFrom<&'_ [u8]> for Signature {
+    type Error = ();
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        MlDsaSignature::try_from(value)
+            .map(|sig| Self(Box::new(sig)))
+            .map_err(|_| ())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ml_dsa::{KeyGen, MlDsa87, signature::Keypair as _};
+
+    use super::{CLIENT_CONTEXT, PublicKey, Signature, SigningKey, USERAGENT_CONTEXT};
+
+    #[test]
+    fn public_key_round_trip_decodes() {
+        let key = MlDsa87::key_gen(&mut rand::rng());
+        let encoded = PublicKey::from(key.verifying_key()).to_bytes();
+
+        let decoded = PublicKey::try_from(encoded.as_slice()).expect("public key should decode");
+
+        assert_eq!(decoded, PublicKey::from(key.verifying_key()));
+    }
+
+    #[test]
+    fn signature_round_trip_decodes() {
+        let key = SigningKey::generate();
+        let signature = key
+            .sign_message(b"challenge", CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        let decoded =
+            Signature::try_from(signature.to_bytes().as_slice()).expect("signature should decode");
+
+        assert_eq!(decoded, signature);
+    }
+
+    #[test]
+    fn challenge_verification_uses_context_and_canonical_key_bytes() {
+        let key = SigningKey::generate();
+        let public_key = key.public_key();
+        let nonce = 17;
+        let signature = key
+            .sign_challenge(nonce, CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        assert!(public_key.verify(nonce, CLIENT_CONTEXT, &signature));
+        assert!(!public_key.verify(nonce, USERAGENT_CONTEXT, &signature));
+    }
+
+    #[test]
+    fn signing_key_round_trip_seed_preserves_public_key_and_signing() {
+        let original = SigningKey::generate();
+        let restored = SigningKey::from_seed(original.to_seed());
+
+        assert_eq!(restored.public_key(), original.public_key());
+
+        let signature = restored
+            .sign_challenge(9, CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        assert!(restored.public_key().verify(9, CLIENT_CONTEXT, &signature));
+    }
+}

server/crates/arbiter-crypto/src/hashing.rs

@@ -0,0 +1,111 @@
+pub use hmac::digest::Digest;
+use std::collections::HashSet;
+
+/// Deterministically hash a value by feeding its fields into the hasher in a consistent order.
+#[diagnostic::on_unimplemented(
+    note = "for local types consider adding `#[derive(arbiter_macros::Hashable)]` to your `{Self}` type",
+    note = "for types from other crates check whether the crate offers a `Hashable` implementation"
+)]
+pub trait Hashable {
+    fn hash<H: Digest>(&self, hasher: &mut H);
+}
+
+macro_rules! impl_numeric {
+    ($($t:ty),*) => {
+        $(
+            impl Hashable for $t {
+                fn hash<H: Digest>(&self, hasher: &mut H) {
+                    hasher.update(&self.to_be_bytes());
+                }
+            }
+        )*
+    };
+}
+
+impl_numeric!(u8, u16, u32, u64, i8, i16, i32, i64);
+
+impl Hashable for &[u8] {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self);
+    }
+}
+
+impl Hashable for String {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_bytes());
+    }
+}
+
+impl<T: Hashable + PartialOrd> Hashable for Vec<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable + PartialOrd> Hashable for HashSet<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Option<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        match self {
+            Some(value) => {
+                hasher.update([1]);
+                value.hash(hasher);
+            }
+            None => hasher.update([0]),
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Box<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        self.as_ref().hash(hasher);
+    }
+}
+
+impl<T: Hashable> Hashable for &T {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        (*self).hash(hasher);
+    }
+}
+
+impl Hashable for alloy::primitives::Address {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_slice());
+    }
+}
+
+impl Hashable for alloy::primitives::U256 {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_be_bytes::<32>());
+    }
+}
+
+impl Hashable for chrono::Duration {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.num_seconds().to_be_bytes());
+    }
+}
+
+impl Hashable for chrono::DateTime<chrono::Utc> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.timestamp_millis().to_be_bytes());
+    }
+}

server/crates/arbiter-crypto/src/lib.rs

@@ -0,0 +1,5 @@
+#[cfg(feature = "authn")]
+pub mod authn;
+pub mod hashing;
+#[cfg(feature = "safecell")]
+pub mod safecell;

server/crates/arbiter-crypto/src/safecell.rs

@@ -0,0 +1,116 @@
+use std::ops::{Deref, DerefMut};
+use std::{any::type_name, fmt};
+
+use memsafe::MemSafe;
+
+pub trait SafeCellHandle<T> {
+    type CellRead<'a>: Deref<Target = T>
+    where
+        Self: 'a,
+        T: 'a;
+    type CellWrite<'a>: Deref<Target = T> + DerefMut<Target = T>
+    where
+        Self: 'a,
+        T: 'a;
+
+    fn new(value: T) -> Self
+    where
+        Self: Sized;
+
+    fn read(&mut self) -> Self::CellRead<'_>;
+    fn write(&mut self) -> Self::CellWrite<'_>;
+
+    fn new_inline<F>(f: F) -> Self
+    where
+        Self: Sized,
+        T: Default,
+        F: for<'a> FnOnce(&'a mut T),
+    {
+        let mut cell = Self::new(T::default());
+        {
+            let mut handle = cell.write();
+            f(handle.deref_mut());
+        }
+        cell
+    }
+
+    #[inline(always)]
+    fn read_inline<F, R>(&mut self, f: F) -> R
+    where
+        F: FnOnce(&T) -> R,
+    {
+        f(&*self.read())
+    }
+
+    #[inline(always)]
+    fn write_inline<F, R>(&mut self, f: F) -> R
+    where
+        F: FnOnce(&mut T) -> R,
+    {
+        f(&mut *self.write())
+    }
+}
+
+pub struct MemSafeCell<T>(MemSafe<T>);
+
+impl<T> fmt::Debug for MemSafeCell<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MemSafeCell")
+            .field("inner", &format_args!("<protected {}>", type_name::<T>()))
+            .finish()
+    }
+}
+
+impl<T> SafeCellHandle<T> for MemSafeCell<T> {
+    type CellRead<'a>
+        = memsafe::MemSafeRead<'a, T>
+    where
+        Self: 'a,
+        T: 'a;
+    type CellWrite<'a>
+        = memsafe::MemSafeWrite<'a, T>
+    where
+        Self: 'a,
+        T: 'a;
+
+    fn new(value: T) -> Self {
+        match MemSafe::new(value) {
+            Ok(inner) => Self(inner),
+            Err(err) => {
+                // If protected memory cannot be allocated, process integrity is compromised.
+                abort_memory_breach("safe cell allocation", &err)
+            }
+        }
+    }
+
+    #[inline(always)]
+    fn read(&mut self) -> Self::CellRead<'_> {
+        match self.0.read() {
+            Ok(inner) => inner,
+            Err(err) => abort_memory_breach("safe cell read", &err),
+        }
+    }
+
+    #[inline(always)]
+    fn write(&mut self) -> Self::CellWrite<'_> {
+        match self.0.write() {
+            Ok(inner) => inner,
+            Err(err) => {
+                // If protected memory becomes unwritable here, treat it as a fatal memory breach.
+                abort_memory_breach("safe cell write", &err)
+            }
+        }
+    }
+}
+
+fn abort_memory_breach(action: &str, err: &memsafe::error::MemoryError) -> ! {
+    eprintln!("fatal {action}: {err}");
+    // SAFETY: Intentionally cause a segmentation fault to prevent further execution in a compromised state.
+    unsafe {
+        let unsafe_pointer = std::ptr::null_mut::<u8>();
+        std::ptr::write_volatile(unsafe_pointer, 0);
+    }
+    std::process::abort();
+}
+
+pub type SafeCell<T> = MemSafeCell<T>;

server/crates/arbiter-macros/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "arbiter-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "2.0", features = ["derive", "fold", "full", "visit-mut"] }
+
+[dev-dependencies]
+arbiter-crypto = { path = "../arbiter-crypto" }
+
+[lints]
+workspace = true

server/crates/arbiter-macros/src/hashable.rs

@@ -0,0 +1,133 @@
+use proc_macro2::{Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::parse_quote;
+use syn::spanned::Spanned;
+use syn::{DataStruct, DeriveInput, Fields, Generics, Index};
+
+use crate::utils::{HASHABLE_TRAIT_PATH, HMAC_DIGEST_PATH};
+
+pub(crate) fn derive(input: &DeriveInput) -> TokenStream {
+    match &input.data {
+        syn::Data::Struct(struct_data) => hashable_struct(input, struct_data),
+        syn::Data::Enum(_) => {
+            syn::Error::new_spanned(input, "Hashable can currently be derived only for structs")
+                .to_compile_error()
+        }
+        syn::Data::Union(_) => {
+            syn::Error::new_spanned(input, "Hashable cannot be derived for unions")
+                .to_compile_error()
+        }
+    }
+}
+
+fn hashable_struct(input: &DeriveInput, struct_data: &syn::DataStruct) -> TokenStream {
+    let ident = &input.ident;
+    let hashable_trait = HASHABLE_TRAIT_PATH.to_path();
+    let hmac_digest = HMAC_DIGEST_PATH.to_path();
+    let generics = add_hashable_bounds(input.generics.clone(), &hashable_trait);
+    let field_accesses = collect_field_accesses(struct_data);
+    let hash_calls = build_hash_calls(&field_accesses, &hashable_trait);
+
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
+    quote! {
+        #[automatically_derived]
+        impl #impl_generics #hashable_trait for #ident #ty_generics #where_clause {
+            fn hash<H: #hmac_digest>(&self, hasher: &mut H) {
+                #(#hash_calls)*
+            }
+        }
+    }
+}
+
+fn add_hashable_bounds(mut generics: Generics, hashable_trait: &syn::Path) -> Generics {
+    for type_param in generics.type_params_mut() {
+        type_param.bounds.push(parse_quote!(#hashable_trait));
+    }
+
+    generics
+}
+
+struct FieldAccess {
+    access: TokenStream,
+    span: Span,
+}
+
+fn collect_field_accesses(struct_data: &DataStruct) -> Vec<FieldAccess> {
+    match &struct_data.fields {
+        Fields::Named(fields) => {
+            // Keep deterministic alphabetical order for named fields.
+            // Do not remove this sort, because it keeps hash output stable regardless of source order.
+            let mut named_fields = fields
+                .named
+                .iter()
+                .map(|field| {
+                    let name = field
+                        .ident
+                        .as_ref()
+                        .expect("Fields::Named(fields) must have names")
+                        .clone();
+                    (name.to_string(), name)
+                })
+                .collect::<Vec<_>>();
+
+            named_fields.sort_by(|a, b| a.0.cmp(&b.0));
+
+            named_fields
+                .into_iter()
+                .map(|(_, name)| FieldAccess {
+                    access: quote! { #name },
+                    span: name.span(),
+                })
+                .collect()
+        }
+        Fields::Unnamed(fields) => fields
+            .unnamed
+            .iter()
+            .enumerate()
+            .map(|(i, field)| FieldAccess {
+                access: {
+                    let index = Index::from(i);
+                    quote! { #index }
+                },
+                span: field.ty.span(),
+            })
+            .collect(),
+        Fields::Unit => Vec::new(),
+    }
+}
+
+fn build_hash_calls(
+    field_accesses: &[FieldAccess],
+    hashable_trait: &syn::Path,
+) -> Vec<TokenStream> {
+    field_accesses
+        .iter()
+        .map(|field| {
+            let access = &field.access;
+            let call = quote! {
+                #hashable_trait::hash(&self.#access, hasher);
+            };
+
+            respan(call, field.span)
+        })
+        .collect()
+}
+
+/// Recursively set span on all tokens, including interpolated ones.
+fn respan(tokens: TokenStream, span: Span) -> TokenStream {
+    tokens
+        .into_iter()
+        .map(|tt| match tt {
+            TokenTree::Group(g) => {
+                let mut new = proc_macro2::Group::new(g.delimiter(), respan(g.stream(), span));
+                new.set_span(span);
+                TokenTree::Group(new)
+            }
+            mut other => {
+                other.set_span(span);
+                other
+            }
+        })
+        .collect()
+}

server/crates/arbiter-macros/src/lib.rs

@@ -0,0 +1,10 @@
+use syn::{DeriveInput, parse_macro_input};
+
+mod hashable;
+mod utils;
+
+#[proc_macro_derive(Hashable)]
+pub fn derive_hashable(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    hashable::derive(&input).into()
+}

server/crates/arbiter-macros/src/utils.rs

@@ -0,0 +1,19 @@
+pub struct ToPath(pub &'static str);
+
+impl ToPath {
+    pub fn to_path(&self) -> syn::Path {
+        syn::parse_str(self.0).expect("Invalid path")
+    }
+}
+
+macro_rules! ensure_path {
+    ($path:path) => {{
+        #[cfg(test)]
+        #[expect(unused_imports)]
+        use $path as _;
+        ToPath(stringify!($path))
+    }};
+}
+
+pub const HASHABLE_TRAIT_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Hashable);
+pub const HMAC_DIGEST_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Digest);

server/crates/arbiter-proto/Cargo.toml

@@ -3,18 +3,34 @@ name = "arbiter-proto"
 version = "0.1.0"
 edition = "2024"
 repository = "https://git.markettakers.org/MarketTakers/arbiter"
+license = "Apache-2.0"
 
 [dependencies]
 tonic.workspace = true
 tokio.workspace = true
 futures.workspace = true
 hex = "0.4.3"
-tonic-prost = "0.14.3"
-prost = "0.14.3"
+tonic-prost = "0.14.5"
+prost.workspace = true
 kameo.workspace = true
+url = "2.5.8"
+miette.workspace = true
+thiserror.workspace = true
+rustls-pki-types.workspace = true
+base64.workspace = true
 prost-types.workspace = true
+tracing.workspace = true
+async-trait.workspace = true
+tokio-stream.workspace = true
 
 [build-dependencies]
-tonic-prost-build = "0.14.3"
+tonic-prost-build = "0.14.5"
+protoc-bin-vendored = "3"
 
+[dev-dependencies]
+rstest.workspace = true
+rand.workspace = true
+rcgen.workspace = true
 
+[package.metadata.cargo-shear]
+ignored = ["tonic-prost", "prost", "kameo"]

server/crates/arbiter-proto/build.rs

@@ -3,16 +3,19 @@ use tonic_prost_build::configure;
 static PROTOBUF_DIR: &str = "../../../protobufs";
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("cargo::rerun-if-changed={PROTOBUF_DIR}");
+
     configure()
         .message_attribute(".", "#[derive(::kameo::Reply)]")
         .compile_protos(
             &[
                 format!("{}/arbiter.proto", PROTOBUF_DIR),
-                format!("{}/auth.proto", PROTOBUF_DIR),
+                format!("{}/user_agent.proto", PROTOBUF_DIR),
+                format!("{}/client.proto", PROTOBUF_DIR),
+                format!("{}/evm.proto", PROTOBUF_DIR),
             ],
             &[PROTOBUF_DIR.to_string()],
         )
-        
         .unwrap();
     Ok(())
 }

server/crates/arbiter-proto/src/lib.rs

@@ -1,19 +1,77 @@
-use crate::proto::auth::AuthChallenge;
+pub mod transport;
+pub mod url;
 
 pub mod proto {
     tonic::include_proto!("arbiter");
 
-    pub mod auth {
-        tonic::include_proto!("arbiter.auth");
+    pub mod shared {
+        tonic::include_proto!("arbiter.shared");
+
+        pub mod evm {
+            tonic::include_proto!("arbiter.shared.evm");
+        }
+    }
+
+    pub mod user_agent {
+        tonic::include_proto!("arbiter.user_agent");
+
+        pub mod auth {
+            tonic::include_proto!("arbiter.user_agent.auth");
+        }
+
+        pub mod evm {
+            tonic::include_proto!("arbiter.user_agent.evm");
+        }
+
+        pub mod sdk_client {
+            tonic::include_proto!("arbiter.user_agent.sdk_client");
+        }
+
+        pub mod vault {
+            tonic::include_proto!("arbiter.user_agent.vault");
+
+            pub mod bootstrap {
+                tonic::include_proto!("arbiter.user_agent.vault.bootstrap");
+            }
+
+            pub mod unseal {
+                tonic::include_proto!("arbiter.user_agent.vault.unseal");
+            }
+        }
+    }
+
+    pub mod client {
+        tonic::include_proto!("arbiter.client");
+
+        pub mod auth {
+            tonic::include_proto!("arbiter.client.auth");
+        }
+
+        pub mod evm {
+            tonic::include_proto!("arbiter.client.evm");
+        }
+
+        pub mod vault {
+            tonic::include_proto!("arbiter.client.vault");
+        }
+    }
+
+    pub mod evm {
+        tonic::include_proto!("arbiter.evm");
     }
 }
 
-pub mod transport;
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ClientMetadata {
+    pub name: String,
+    pub description: Option<String>,
+    pub version: Option<String>,
+}
 
-pub static BOOTSTRAP_TOKEN_PATH: &'static str = "bootstrap_token";
+pub static BOOTSTRAP_PATH: &str = "bootstrap_token";
 
 pub fn home_path() -> Result<std::path::PathBuf, std::io::Error> {
-    static ARBITER_HOME: &'static str = ".arbiter";
+    static ARBITER_HOME: &str = ".arbiter";
     let home_dir = std::env::home_dir().ok_or(std::io::Error::new(
         std::io::ErrorKind::PermissionDenied,
         "can not get home directory",
@@ -24,8 +82,3 @@ pub fn home_path() -> Result<std::path::PathBuf, std::io::Error> {
 
     Ok(arbiter_home)
 }
-
-pub fn format_challenge(challenge: &AuthChallenge) -> Vec<u8> {
-    let concat_form = format!("{}:{}", challenge.nonce, hex::encode(&challenge.pubkey));
-    concat_form.into_bytes().to_vec()
-}

server/crates/arbiter-proto/src/transport.rs

@@ -1,46 +1,163 @@
-use futures::{Stream, StreamExt};
-use tokio::sync::mpsc::{self, error::SendError};
-use tonic::{Status, Streaming};
+//! Transport-facing abstractions shared by protocol/session code.
+//!
+//! This module defines a small set of transport traits that actors and other
+//! protocol code can depend on without knowing anything about the concrete
+//! transport underneath.
+//!
+//! The abstraction is split into:
+//! - [`Sender`] for outbound delivery
+//! - [`Receiver`] for inbound delivery
+//! - [`Bi`] as the combined duplex form (`Sender + Receiver`)
+//!
+//! This split lets code depend only on the half it actually needs. For
+//! example, some actor/session code only sends out-of-band messages, while
+//! auth/state-machine code may need full duplex access.
+//!
+//! [`Bi`] remains intentionally minimal and transport-agnostic:
+//! - [`Receiver::recv`] yields inbound messages
+//! - [`Sender::send`] accepts outbound messages
+//!
+//! Transport-specific adapters, including protobuf or gRPC bridges, live in the
+//! crates that own those boundaries rather than in `arbiter-proto`.
+//!
+//! [`Bi`] deliberately does not model request/response correlation. Some
+//! transports may carry multiplexed request/response traffic, some may emit
+//! out-of-band messages, and some may be one-message-at-a-time state machines.
+//! Correlation concerns such as request IDs, pending response maps, and
+//! out-of-band routing belong in the adapter or connection layer built on top
+//! of [`Bi`], not in this abstraction itself.
+//!
+//! # Generic Ordering Rule
+//!
+//! This module consistently uses `Inbound` first and `Outbound` second in
+//! generic parameter lists.
+//!
+//! For [`Receiver`], [`Sender`], and [`Bi`], this means:
+//! - `Receiver<Inbound>`
+//! - `Sender<Outbound>`
+//! - `Bi<Inbound, Outbound>`
+//!
+//! Concretely, for [`Bi`]:
+//! - `recv() -> Option<Inbound>`
+//! - `send(Outbound)`
+//!
+//! [`expect_message`] is a small helper for linear protocol steps: it reads one
+//! inbound message from a transport and extracts a typed value from it, failing
+//! if the channel closes or the message shape is not what the caller expected.
+//!
+//! [`DummyTransport`] is a no-op implementation useful for tests and local
+//! actor execution where no real stream exists.
+//!
+//! # Design Notes
+//!
+//! - [`Bi::send`] returns [`Error`] only for transport delivery failures, such
+//!   as a closed outbound channel.
+//! - [`Bi::recv`] returns `None` when the underlying transport closes.
+//! - Message translation is intentionally out of scope for this module.
 
+use std::marker::PhantomData;
 
-// Abstraction for stream for sans-io capabilities
-pub trait Bi<T, U>: Stream<Item = Result<T, Status>> + Send + Sync + 'static {
-    type Error;
-    fn send(
-        &mut self,
-        item: Result<U, Status>,
-    ) -> impl std::future::Future<Output = Result<(), Self::Error>> + Send;
+use async_trait::async_trait;
+
+/// Errors returned by transport adapters implementing [`Bi`].
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("Transport channel is closed")]
+    ChannelClosed,
+    #[error("Unexpected message received")]
+    UnexpectedMessage,
 }
 
-// Bi-directional stream abstraction for handling gRPC streaming requests and responses
-pub struct BiStream<T, U> {
-    pub request_stream: Streaming<T>,
-    pub response_sender: mpsc::Sender<Result<U, Status>>,
-}
-
-impl<T, U> Stream for BiStream<T, U>
+/// Receives one message from `transport` and extracts a value from it using
+/// `extractor`. Returns [`Error::ChannelClosed`] if the transport closes and
+/// [`Error::UnexpectedMessage`] if `extractor` returns `None`.
+pub async fn expect_message<T, Inbound, Outbound, Target, F>(
+    transport: &mut T,
+    extractor: F,
+) -> Result<Target, Error>
 where
-    T: Send + 'static,
-    U: Send + 'static,
+    T: Bi<Inbound, Outbound> + ?Sized,
+    F: FnOnce(Inbound) -> Option<Target>,
 {
-    type Item = Result<T, Status>;
+    let msg = transport.recv().await.ok_or(Error::ChannelClosed)?;
+    extractor(msg).ok_or(Error::UnexpectedMessage)
+}
 
-    fn poll_next(
-        mut self: std::pin::Pin<&mut Self>,
-        cx: &mut std::task::Context<'_>,
-    ) -> std::task::Poll<Option<Self::Item>> {
-        self.request_stream.poll_next_unpin(cx)
+#[async_trait]
+pub trait Sender<Outbound>: Send + Sync {
+    async fn send(&mut self, item: Outbound) -> Result<(), Error>;
+}
+
+#[async_trait]
+pub trait Receiver<Inbound>: Send + Sync {
+    async fn recv(&mut self) -> Option<Inbound>;
+}
+
+/// Minimal bidirectional transport abstraction used by protocol code.
+///
+/// `Bi<Inbound, Outbound>` is the combined duplex form of [`Sender`] and
+/// [`Receiver`].
+///
+/// It models a channel with:
+/// - inbound items of type `Inbound` read via [`Bi::recv`]
+/// - outbound items of type `Outbound` written via [`Bi::send`]
+///
+/// It does not imply request/response sequencing, one-at-a-time exchange, or
+/// any built-in correlation mechanism between inbound and outbound items.
+pub trait Bi<Inbound, Outbound>: Sender<Outbound> + Receiver<Inbound> + Send + Sync {}
+
+pub trait SplittableBi<Inbound, Outbound>: Bi<Inbound, Outbound> {
+    type Sender: Sender<Outbound>;
+    type Receiver: Receiver<Inbound>;
+
+    fn split(self) -> (Self::Sender, Self::Receiver);
+    fn from_parts(sender: Self::Sender, receiver: Self::Receiver) -> Self;
+}
+
+/// No-op [`Bi`] transport for tests and manual actor usage.
+///
+/// `send` drops all items and succeeds. [`Bi::recv`] never resolves and therefore
+/// does not busy-wait or spuriously close the stream.
+pub struct DummyTransport<Inbound, Outbound> {
+    _marker: PhantomData<(Inbound, Outbound)>,
+}
+
+impl<Inbound, Outbound> Default for DummyTransport<Inbound, Outbound> {
+    fn default() -> Self {
+        Self {
+            _marker: PhantomData,
+        }
     }
 }
 
-impl<T, U> Bi<T, U> for BiStream<T, U>
+#[async_trait]
+impl<Inbound, Outbound> Sender<Outbound> for DummyTransport<Inbound, Outbound>
 where
-    T: Send + 'static,
-    U: Send + 'static,
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
 {
-    type Error = SendError<Result<U, Status>>;
-
-    async fn send(&mut self, item: Result<U, Status>) -> Result<(), Self::Error> {
-        self.response_sender.send(item).await
+    async fn send(&mut self, _item: Outbound) -> Result<(), Error> {
+        Ok(())
     }
 }
+
+#[async_trait]
+impl<Inbound, Outbound> Receiver<Inbound> for DummyTransport<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+    async fn recv(&mut self) -> Option<Inbound> {
+        std::future::pending::<()>().await;
+        None
+    }
+}
+
+impl<Inbound, Outbound> Bi<Inbound, Outbound> for DummyTransport<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+}
+
+pub mod grpc;

server/crates/arbiter-proto/src/transport/grpc.rs

@@ -0,0 +1,106 @@
+use async_trait::async_trait;
+use futures::StreamExt;
+use tokio::sync::mpsc;
+use tokio_stream::wrappers::ReceiverStream;
+
+use super::{Bi, Receiver, Sender};
+
+pub struct GrpcSender<Outbound> {
+    tx: mpsc::Sender<Result<Outbound, tonic::Status>>,
+}
+
+#[async_trait]
+impl<Outbound> Sender<Result<Outbound, tonic::Status>> for GrpcSender<Outbound>
+where
+    Outbound: Send + Sync + 'static,
+{
+    async fn send(&mut self, item: Result<Outbound, tonic::Status>) -> Result<(), super::Error> {
+        self.tx
+            .send(item)
+            .await
+            .map_err(|_| super::Error::ChannelClosed)
+    }
+}
+
+pub struct GrpcReceiver<Inbound> {
+    rx: tonic::Streaming<Inbound>,
+}
+#[async_trait]
+impl<Inbound> Receiver<Result<Inbound, tonic::Status>> for GrpcReceiver<Inbound>
+where
+    Inbound: Send + Sync + 'static,
+{
+    async fn recv(&mut self) -> Option<Result<Inbound, tonic::Status>> {
+        self.rx.next().await
+    }
+}
+
+pub struct GrpcBi<Inbound, Outbound> {
+    sender: GrpcSender<Outbound>,
+    receiver: GrpcReceiver<Inbound>,
+}
+
+impl<Inbound, Outbound> GrpcBi<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+    pub fn from_bi_stream(
+        receiver: tonic::Streaming<Inbound>,
+    ) -> (Self, ReceiverStream<Result<Outbound, tonic::Status>>) {
+        let (tx, rx) = mpsc::channel(10);
+        let sender = GrpcSender { tx };
+        let receiver = GrpcReceiver { rx: receiver };
+        let bi = GrpcBi { sender, receiver };
+        (bi, ReceiverStream::new(rx))
+    }
+}
+
+#[async_trait]
+impl<Inbound, Outbound> Sender<Result<Outbound, tonic::Status>> for GrpcBi<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+    async fn send(&mut self, item: Result<Outbound, tonic::Status>) -> Result<(), super::Error> {
+        self.sender.send(item).await
+    }
+}
+
+#[async_trait]
+impl<Inbound, Outbound> Receiver<Result<Inbound, tonic::Status>> for GrpcBi<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+    async fn recv(&mut self) -> Option<Result<Inbound, tonic::Status>> {
+        self.receiver.recv().await
+    }
+}
+
+impl<Inbound, Outbound> Bi<Result<Inbound, tonic::Status>, Result<Outbound, tonic::Status>>
+    for GrpcBi<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+}
+
+impl<Inbound, Outbound>
+    super::SplittableBi<Result<Inbound, tonic::Status>, Result<Outbound, tonic::Status>>
+    for GrpcBi<Inbound, Outbound>
+where
+    Inbound: Send + Sync + 'static,
+    Outbound: Send + Sync + 'static,
+{
+    type Sender = GrpcSender<Outbound>;
+    type Receiver = GrpcReceiver<Inbound>;
+
+    fn split(self) -> (Self::Sender, Self::Receiver) {
+        (self.sender, self.receiver)
+    }
+
+    fn from_parts(sender: Self::Sender, receiver: Self::Receiver) -> Self {
+        GrpcBi { sender, receiver }
+    }
+}

server/crates/arbiter-proto/src/url.rs

@@ -0,0 +1,129 @@
+use std::fmt::Display;
+
+use base64::{Engine as _, prelude::BASE64_URL_SAFE};
+use rustls_pki_types::CertificateDer;
+
+const ARBITER_URL_SCHEME: &str = "arbiter";
+const CERT_QUERY_KEY: &str = "cert";
+const BOOTSTRAP_TOKEN_QUERY_KEY: &str = "bootstrap_token";
+
+#[derive(Debug, Clone)]
+pub struct ArbiterUrl {
+    pub host: String,
+    pub port: u16,
+    pub ca_cert: CertificateDer<'static>,
+    pub bootstrap_token: Option<String>,
+}
+
+impl Display for ArbiterUrl {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut base = format!(
+            "{ARBITER_URL_SCHEME}://{}:{}?{CERT_QUERY_KEY}={}",
+            self.host,
+            self.port,
+            BASE64_URL_SAFE.encode(&self.ca_cert)
+        );
+        if let Some(token) = &self.bootstrap_token {
+            base.push_str(&format!("&{BOOTSTRAP_TOKEN_QUERY_KEY}={}", token));
+        }
+        f.write_str(&base)
+    }
+}
+
+#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+pub enum Error {
+    #[error("Invalid URL scheme, expected '{ARBITER_URL_SCHEME}://'")]
+    #[diagnostic(
+        code(arbiter::url::invalid_scheme),
+        help("The URL must start with '{ARBITER_URL_SCHEME}://'")
+    )]
+    InvalidScheme,
+    #[error("Missing host in URL")]
+    #[diagnostic(
+        code(arbiter::url::missing_host),
+        help("The URL must include a host, e.g., '{ARBITER_URL_SCHEME}://127.0.0.1:<port>'")
+    )]
+    MissingHost,
+    #[error("Missing port in URL")]
+    #[diagnostic(
+        code(arbiter::url::missing_port),
+        help("The URL must include a port, e.g., '{ARBITER_URL_SCHEME}://127.0.0.1:1234'")
+    )]
+    MissingPort,
+    #[error("Missing 'cert' query parameter in URL")]
+    #[diagnostic(
+        code(arbiter::url::missing_cert),
+        help("The URL must include a 'cert' query parameter")
+    )]
+    MissingCert,
+    #[error("Invalid base64 in 'cert' query parameter: {0}")]
+    #[diagnostic(code(arbiter::url::invalid_cert_base64))]
+    InvalidCertBase64(#[from] base64::DecodeError),
+}
+
+impl<'a> TryFrom<&'a str> for ArbiterUrl {
+    type Error = Error;
+
+    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
+        let url = url::Url::parse(value).map_err(|_| Error::InvalidScheme)?;
+
+        if url.scheme() != ARBITER_URL_SCHEME {
+            return Err(Error::InvalidScheme);
+        }
+
+        let host = url.host_str().ok_or(Error::MissingHost)?.to_string();
+        let port = url.port().ok_or(Error::MissingPort)?;
+        let cert_str = url
+            .query_pairs()
+            .find(|(k, _)| k == CERT_QUERY_KEY)
+            .ok_or(Error::MissingCert)?
+            .1;
+
+        let cert = BASE64_URL_SAFE.decode(cert_str.as_ref())?;
+        let cert = CertificateDer::from_slice(&cert).into_owned();
+
+        let bootstrap_token = url
+            .query_pairs()
+            .find(|(k, _)| k == BOOTSTRAP_TOKEN_QUERY_KEY)
+            .map(|(_, v)| v.to_string());
+
+        Ok(ArbiterUrl {
+            host,
+            port,
+            ca_cert: cert,
+            bootstrap_token,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use rcgen::generate_simple_self_signed;
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+
+    fn test_parsing_correctness(
+        #[values("127.0.0.1", "localhost", "192.168.1.1", "some.domain.com")] host: &str,
+
+        #[values(None, Some("token123".to_string()))] bootstrap_token: Option<String>,
+    ) {
+        let cert = generate_simple_self_signed(&["Arbiter CA".into()]).unwrap();
+        let cert = cert.cert.der();
+
+        let url = ArbiterUrl {
+            host: host.to_string(),
+            port: 1234,
+            ca_cert: cert.clone().into_owned(),
+            bootstrap_token,
+        };
+        let url_str = url.to_string();
+        let parsed_url = ArbiterUrl::try_from(url_str.as_str()).unwrap();
+        assert_eq!(url.host, parsed_url.host);
+        assert_eq!(url.port, parsed_url.port);
+        assert_eq!(url.ca_cert.to_vec(), parsed_url.ca_cert.to_vec());
+        assert_eq!(url.bootstrap_token, parsed_url.bootstrap_token);
+    }
+}

server/crates/arbiter-server/Cargo.toml

@@ -3,30 +3,31 @@ name = "arbiter-server"
 version = "0.1.0"
 edition = "2024"
 repository = "https://git.markettakers.org/MarketTakers/arbiter"
+license = "Apache-2.0"
+
+[lints]
+workspace = true
 
 [dependencies]
-diesel = { version = "2.3.6", features = [
-    "sqlite",
-    "uuid",
-    "time",
-    "chrono",
-    "serde_json",
-] }
-diesel-async = { version = "0.7.4", features = [
+diesel = { version = "2.3.7", features = ["chrono", "returning_clauses_for_sqlite_3_35", "serde_json", "time", "uuid"] }
+diesel-async = { version = "0.8.0", features = [
     "bb8",
     "migrations",
     "sqlite",
     "tokio",
 ] }
-ed25519-dalek.workspace = true
 arbiter-proto.path = "../arbiter-proto"
+arbiter-crypto.path = "../arbiter-crypto"
+arbiter-macros.path = "../arbiter-macros"
 tracing.workspace = true
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tonic.workspace = true
+tonic.features = ["tls-aws-lc"]
 tokio.workspace = true
 rustls.workspace = true
 smlang.workspace = true
-miette.workspace = true
 thiserror.workspace = true
+fatality = "0.1.1"
 diesel_migrations = { version = "2.3.1", features = ["sqlite"] }
 async-trait.workspace = true
 secrecy = "0.10.3"
@@ -34,16 +35,33 @@ futures.workspace = true
 tokio-stream.workspace = true
 dashmap = "6.1.0"
 rand.workspace = true
-rcgen = { version = "0.14.7", features = [
-    "aws_lc_rs",
-    "pem",
-    "x509-parser",
-    "zeroize",
-], default-features = false }
+rcgen.workspace = true
 chrono.workspace = true
-memsafe = "0.4.0"
 zeroize = { version = "1.8.2", features = ["std", "simd"] }
 kameo.workspace = true
+chacha20poly1305 = { version = "0.10.1", features = ["std"] }
+argon2 = { version = "0.5.3", features = ["zeroize"] }
+restructed = "0.2.2"
+strum = { version = "0.28.0", features = ["derive"] }
+pem = "3.0.6"
+sha2.workspace = true
+hmac.workspace = true
+spki.workspace = true
+alloy.workspace = true
+prost-types.workspace = true
+prost.workspace = true
+arbiter-tokens-registry.path = "../arbiter-tokens-registry"
+anyhow = "1.0.102"
+serde_with = "3.18.0"
+mutants.workspace = true
+subtle = "2.6.1"
+ml-dsa.workspace = true
+ed25519-dalek.workspace = true
+x25519-dalek.workspace = true
+k256.workspace = true
 
 [dev-dependencies]
+insta = "1.46.3"
+proptest = "1.11.0"
+rstest.workspace = true
 test-log = { version = "0.2", default-features = false, features = ["trace"] }

server/crates/arbiter-server/migrations/2026-02-14-171124-0000_init/up.sql

@@ -1,31 +1,209 @@
-create table if not exists aead_encrypted (
+create table if not exists root_key_history (
     id INTEGER not null PRIMARY KEY,
-    current_nonce integer not null default(1), -- if re-encrypted, this should be incremented
+    -- root key stored as aead encrypted artifact, with only difference that it's decrypted by unseal key (derived from user password)
+    root_key_encryption_nonce blob not null default(1), -- if re-encrypted, this should be incremented. Used for encrypting root key
+    data_encryption_nonce blob not null default(1), -- nonce used for encrypting with key itself
     ciphertext blob not null,
     tag blob not null,
-    schema_version integer not null default(1) -- server would need to reencrypt, because this means that we have changed algorithm
+    schema_version integer not null default(1), -- server would need to reencrypt, because this means that we have changed algorithm
+    salt blob not null -- for key deriviation 
+) STRICT;
+
+create table if not exists aead_encrypted (
+    id INTEGER not null PRIMARY KEY,
+    current_nonce blob not null default(1), -- if re-encrypted, this should be incremented
+    ciphertext blob not null,
+    tag blob not null,
+    schema_version integer not null default(1), -- server would need to reencrypt, because this means that we have changed algorithm
+    associated_root_key_id integer not null references root_key_history (id) on delete RESTRICT,
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create unique index if not exists uniq_nonce_per_root_key on aead_encrypted (
+    current_nonce,
+    associated_root_key_id
+);
+
+create table if not exists tls_history (
+    id INTEGER not null PRIMARY KEY,
+    cert text not null,
+    cert_key text not null, -- PEM Encoded private key
+    ca_cert text not null,
+    ca_key text not null, -- PEM Encoded private key
+    created_at integer not null default(unixepoch ('now'))
 ) STRICT;
 
 -- This is a singleton
 create table if not exists arbiter_settings (
     id INTEGER not null PRIMARY KEY CHECK (id = 1), -- singleton row, id must be 1
-    root_key_id integer references aead_encrypted (id) on delete RESTRICT, -- if null, means wasn't bootstrapped yet
-    cert_key blob not null,
-    cert blob not null
+    root_key_id integer references root_key_history (id) on delete RESTRICT, -- if null, means wasn't bootstrapped yet
+    tls_id integer references tls_history (id) on delete RESTRICT
 ) STRICT;
 
+insert into arbiter_settings (id) values (1) on conflict do nothing;
+-- ensure singleton row exists
+
 create table if not exists useragent_client (
     id integer not null primary key,
-    nonce integer not null default (1), -- used for auth challenge
+    nonce integer not null default(1), -- used for auth challenge
     public_key blob not null,
+    key_type integer not null default(1),
+    created_at integer not null default(unixepoch ('now')),
+    updated_at integer not null default(unixepoch ('now'))
+) STRICT;
+create unique index if not exists uniq_useragent_client_public_key on useragent_client (public_key, key_type);
+
+create table if not exists client_metadata (
+    id integer not null primary key,
+    name text not null, -- human-readable name for the client
+    description text, -- optional description for the client
+    version text, -- client version for tracking and debugging
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+-- created to track history of changes
+create table if not exists client_metadata_history (
+    id integer not null primary key,
+    metadata_id integer not null references client_metadata (id) on delete cascade,
+    client_id integer not null references program_client (id) on delete cascade,
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create unique index if not exists uniq_metadata_binding_client on client_metadata_history (client_id);
+
+create table if not exists program_client (
+    id integer not null primary key,
+    nonce integer not null default(1), -- used for auth challenge
+    public_key blob not null,
+    metadata_id integer not null references client_metadata (id) on delete cascade,
     created_at integer not null default(unixepoch ('now')),
     updated_at integer not null default(unixepoch ('now'))
 ) STRICT;
 
-create table if not exists program_client (
+create unique index if not exists program_client_public_key_unique
+    on program_client (public_key);
+
+create unique index if not exists uniq_program_client_public_key on program_client (public_key);
+
+create table if not exists evm_wallet (
     id integer not null primary key,
-    nonce integer not null default (1), -- used for auth challenge
-    public_key blob not null,
-    created_at integer not null default(unixepoch ('now')),
-    updated_at integer not null default(unixepoch ('now'))
+    address blob not null, -- 20-byte Ethereum address
+    aead_encrypted_id integer not null references aead_encrypted (id) on delete RESTRICT,
+    created_at integer not null default(unixepoch ('now'))
 ) STRICT;
+
+create unique index if not exists uniq_evm_wallet_address on evm_wallet (address);
+
+create unique index if not exists uniq_evm_wallet_aead on evm_wallet (aead_encrypted_id);
+
+create table if not exists evm_wallet_access (
+    id integer not null primary key,
+    wallet_id integer not null references evm_wallet (id) on delete cascade,
+    client_id integer not null references program_client (id) on delete cascade,
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create unique index if not exists uniq_wallet_access on evm_wallet_access (wallet_id, client_id);
+
+create table if not exists evm_ether_transfer_limit (
+    id integer not null primary key,
+    window_secs integer not null, -- window duration in seconds
+    max_volume blob not null -- big-endian 32-byte U256
+) STRICT;
+
+-- Shared grant properties: client scope, timeframe, fee caps, and rate limit
+create table if not exists evm_basic_grant (
+    id integer not null primary key,
+    wallet_access_id integer not null references evm_wallet_access (id) on delete restrict,
+    chain_id integer not null, -- EIP-155 chain ID
+    valid_from integer, -- unix timestamp (seconds), null = no lower bound
+    valid_until integer, -- unix timestamp (seconds), null = no upper bound
+    max_gas_fee_per_gas blob, -- big-endian 32-byte U256, null = unlimited
+    max_priority_fee_per_gas blob, -- big-endian 32-byte U256, null = unlimited
+    rate_limit_count integer, -- max transactions in window, null = unlimited
+    rate_limit_window_secs integer, -- window duration in seconds, null = unlimited
+    revoked_at integer, -- unix timestamp when revoked, null = still active
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+-- Shared transaction log for all EVM grants, used for rate limit tracking and auditing
+create table if not exists evm_transaction_log (
+    id integer not null primary key,
+    wallet_access_id integer not null references evm_wallet_access (id) on delete restrict,
+    grant_id integer not null references evm_basic_grant (id) on delete restrict,
+    chain_id integer not null,
+    eth_value blob not null, -- always present on any EVM tx
+    signed_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create index if not exists idx_evm_basic_grant_access_chain on evm_basic_grant (wallet_access_id, chain_id);
+
+-- ===============================
+-- ERC20 token transfer grant
+-- ===============================
+create table if not exists evm_token_transfer_grant (
+    id integer not null primary key,
+    basic_grant_id integer not null unique references evm_basic_grant (id) on delete cascade,
+    token_contract blob not null, -- 20-byte ERC20 contract address
+    receiver blob -- 20-byte recipient address or null if every recipient allowed
+) STRICT;
+
+-- Per-window volume limits for token transfer grants
+create table if not exists evm_token_transfer_volume_limit (
+    id integer not null primary key,
+    grant_id integer not null references evm_token_transfer_grant (id) on delete cascade,
+    window_secs integer not null, -- window duration in seconds
+    max_volume blob not null -- big-endian 32-byte U256
+) STRICT;
+
+-- Log table for token transfer grant usage
+create table if not exists evm_token_transfer_log (
+    id integer not null primary key,
+    grant_id integer not null references evm_token_transfer_grant (id) on delete restrict,
+    log_id integer not null references evm_transaction_log (id) on delete restrict,
+    chain_id integer not null, -- EIP-155 chain ID
+    token_contract blob not null, -- 20-byte ERC20 contract address
+    recipient_address blob not null, -- 20-byte recipient address
+    value blob not null, -- big-endian 32-byte U256
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create index if not exists idx_token_transfer_log_grant on evm_token_transfer_log (grant_id);
+
+create index if not exists idx_token_transfer_log_log_id on evm_token_transfer_log (log_id);
+
+create index if not exists idx_token_transfer_log_chain on evm_token_transfer_log (chain_id);
+
+-- ===============================
+-- Ether transfer grant (uses base log)
+-- ===============================
+create table if not exists evm_ether_transfer_grant (
+    id integer not null primary key,
+    basic_grant_id integer not null unique references evm_basic_grant (id) on delete cascade,
+    limit_id integer not null references evm_ether_transfer_limit (id) on delete restrict
+) STRICT;
+
+-- Specific recipient addresses for an ether transfer grant
+create table if not exists evm_ether_transfer_grant_target (
+    id integer not null primary key,
+    grant_id integer not null references evm_ether_transfer_grant (id) on delete cascade,
+    address blob not null -- 20-byte recipient address
+) STRICT;
+
+create unique index if not exists uniq_ether_transfer_target on evm_ether_transfer_grant_target (grant_id, address);
+
+-- ===============================
+-- Integrity Envelopes
+-- ===============================
+create table if not exists integrity_envelope (
+    id integer not null primary key,
+    entity_kind text not null,
+    entity_id blob not null,
+    payload_version integer not null,
+    key_version integer not null,
+    mac blob not null, -- 20-byte recipient address
+    signed_at integer not null default(unixepoch ('now')),
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create unique index if not exists uniq_integrity_envelope_entity on integrity_envelope (entity_kind, entity_id);

server/crates/arbiter-server/src/actors.rs

@@ -1,2 +0,0 @@
-pub mod user_agent;
-pub mod client;

server/crates/arbiter-server/src/actors/bootstrap.rs

@@ -0,0 +1,101 @@
+use arbiter_proto::{BOOTSTRAP_PATH, home_path};
+use diesel::QueryDsl;
+use diesel_async::RunQueryDsl;
+use kameo::{Actor, messages};
+
+use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
+use subtle::ConstantTimeEq as _;
+use thiserror::Error;
+
+use crate::db::{self, DatabasePool, schema};
+const TOKEN_LENGTH: usize = 64;
+
+pub async fn generate_token() -> Result<String, std::io::Error> {
+    let rng: StdRng = make_rng();
+
+    let token: String = rng.sample_iter(Alphanumeric).take(TOKEN_LENGTH).fold(
+        Default::default(),
+        |mut accum, char| {
+            accum += char.to_string().as_str();
+            accum
+        },
+    );
+
+    tokio::fs::write(home_path()?.join(BOOTSTRAP_PATH), token.as_str()).await?;
+
+    Ok(token)
+}
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("Database error: {0}")]
+    Database(#[from] db::PoolError),
+
+    #[error("Database query error: {0}")]
+    Query(#[from] diesel::result::Error),
+
+    #[error("I/O error: {0}")]
+    Io(#[from] std::io::Error),
+}
+
+#[derive(Actor)]
+pub struct Bootstrapper {
+    token: Option<String>,
+}
+
+impl Bootstrapper {
+    pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
+        let row_count: i64 = {
+            let mut conn = db.get().await?;
+
+            schema::useragent_client::table
+                .count()
+                .get_result(&mut conn)
+                .await?
+        };
+
+        let token = if row_count == 0 {
+            let token = generate_token().await?;
+            Some(token)
+        } else {
+            None
+        };
+
+        Ok(Self { token })
+    }
+}
+
+#[messages]
+impl Bootstrapper {
+    #[message]
+    pub fn is_correct_token(&self, token: String) -> bool {
+        match &self.token {
+            Some(expected) => {
+                let expected_bytes = expected.as_bytes();
+                let token_bytes = token.as_bytes();
+
+                let choice = expected_bytes.ct_eq(token_bytes);
+                bool::from(choice)
+            }
+            None => false,
+        }
+    }
+
+    #[message]
+    pub fn consume_token(&mut self, token: String) -> bool {
+        if self.is_correct_token(token) {
+            self.token = None;
+            true
+        } else {
+            false
+        }
+    }
+}
+
+#[messages]
+impl Bootstrapper {
+    #[message]
+    pub fn get_token(&self) -> Option<String> {
+        self.token.clone()
+    }
+}

server/crates/arbiter-server/src/actors/client.rs

@@ -1,12 +0,0 @@
-use arbiter_proto::{
-    proto::{ClientRequest, ClientResponse},
-    transport::Bi,
-};
-
-use crate::ServerContext;
-
-pub(crate) async fn handle_client(
-    _context: ServerContext,
-    _bistream: impl Bi<ClientRequest, ClientResponse>,
-) {
-}

server/crates/arbiter-server/src/actors/client/auth.rs

@@ -0,0 +1,423 @@
+use arbiter_crypto::authn::{self, CLIENT_CONTEXT};
+use arbiter_proto::{
+    ClientMetadata,
+    transport::{Bi, expect_message},
+};
+use chrono::Utc;
+use diesel::{
+    ExpressionMethods as _, OptionalExtension as _, QueryDsl as _, SelectableHelper as _,
+    dsl::insert_into, update,
+};
+use diesel_async::RunQueryDsl as _;
+use kameo::{actor::ActorRef, error::SendError};
+use tracing::error;
+
+use crate::{
+    actors::{
+        client::{ClientConnection, ClientCredentials, ClientProfile},
+        flow_coordinator::{self, RequestClientApproval},
+        keyholder::KeyHolder,
+    },
+    crypto::integrity::{self, AttestationStatus},
+    db::{
+        self,
+        models::{ProgramClientMetadata, SqliteTimestamp},
+        schema::program_client,
+    },
+};
+
+#[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
+pub enum Error {
+    #[error("Database pool unavailable")]
+    DatabasePoolUnavailable,
+    #[error("Database operation failed")]
+    DatabaseOperationFailed,
+    #[error("Integrity check failed")]
+    IntegrityCheckFailed,
+    #[error("Invalid challenge solution")]
+    InvalidChallengeSolution,
+    #[error("Client approval request failed")]
+    ApproveError(#[from] ApproveError),
+    #[error("Transport error")]
+    Transport,
+}
+
+impl From<diesel::result::Error> for Error {
+    fn from(e: diesel::result::Error) -> Self {
+        error!(?e, "Database error");
+        Self::DatabaseOperationFailed
+    }
+}
+
+#[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
+pub enum ApproveError {
+    #[error("Internal error")]
+    Internal,
+    #[error("Client connection denied by user agents")]
+    Denied,
+    #[error("Upstream error: {0}")]
+    Upstream(flow_coordinator::ApprovalError),
+}
+
+#[derive(Debug, Clone)]
+pub enum Inbound {
+    AuthChallengeRequest {
+        pubkey: authn::PublicKey,
+        metadata: ClientMetadata,
+    },
+    AuthChallengeSolution {
+        signature: authn::Signature,
+    },
+}
+
+#[derive(Debug, Clone)]
+pub enum Outbound {
+    AuthChallenge {
+        pubkey: authn::PublicKey,
+        nonce: i32,
+    },
+    AuthSuccess,
+}
+
+/// Returns the current nonce and client ID for a registered client.
+/// Returns `None` if the pubkey is not registered.
+async fn get_current_nonce_and_id(
+    db: &db::DatabasePool,
+    pubkey: &authn::PublicKey,
+) -> Result<Option<(i32, i32)>, Error> {
+    let pubkey_bytes = pubkey.to_bytes();
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+    program_client::table
+        .filter(program_client::public_key.eq(&pubkey_bytes))
+        .select((program_client::id, program_client::nonce))
+        .first::<(i32, i32)>(&mut conn)
+        .await
+        .optional()
+        .map_err(|e| {
+            error!(error = ?e, "Database error");
+            Error::DatabaseOperationFailed
+        })
+}
+
+async fn verify_integrity(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<(), Error> {
+    let mut db_conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+
+    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?.ok_or_else(|| {
+        error!("Client not found during integrity verification");
+        Error::DatabaseOperationFailed
+    })?;
+
+    let attestation = integrity::verify_entity(
+        &mut db_conn,
+        keyholder,
+        &ClientCredentials {
+            pubkey: pubkey.clone(),
+            nonce,
+        },
+        id,
+    )
+    .await
+    .map_err(|e| {
+        error!(?e, "Integrity verification failed");
+        Error::IntegrityCheckFailed
+    })?;
+
+    if attestation != AttestationStatus::Attested {
+        error!("Integrity attestation unavailable for client {id}");
+        return Err(Error::IntegrityCheckFailed);
+    }
+
+    Ok(())
+}
+
+/// Atomically increments the nonce and re-signs the integrity envelope.
+/// Returns the new nonce, which is used as the challenge nonce.
+async fn create_nonce(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<i32, Error> {
+    let pubkey_bytes = pubkey.to_bytes();
+    let pubkey = pubkey.clone();
+
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+
+    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        let pubkey = pubkey.clone();
+        Box::pin(async move {
+            let (id, new_nonce): (i32, i32) = update(program_client::table)
+                .filter(program_client::public_key.eq(&pubkey_bytes))
+                .set(program_client::nonce.eq(program_client::nonce + 1))
+                .returning((program_client::id, program_client::nonce))
+                .get_result(conn)
+                .await?;
+
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: pubkey.clone(),
+                    nonce: new_nonce,
+                },
+                id,
+            )
+            .await
+            .map_err(|e| {
+                error!(?e, "Integrity sign failed after nonce update");
+                Error::DatabaseOperationFailed
+            })?;
+
+            Ok(new_nonce)
+        })
+    })
+    .await
+}
+
+async fn approve_new_client(
+    actors: &crate::actors::GlobalActors,
+    profile: ClientProfile,
+) -> Result<(), Error> {
+    let result = actors
+        .flow_coordinator
+        .ask(RequestClientApproval { client: profile })
+        .await;
+
+    match result {
+        Ok(true) => Ok(()),
+        Ok(false) => Err(Error::ApproveError(ApproveError::Denied)),
+        Err(SendError::HandlerError(e)) => {
+            error!(error = ?e, "Approval upstream error");
+            Err(Error::ApproveError(ApproveError::Upstream(e)))
+        }
+        Err(e) => {
+            error!(error = ?e, "Approval request to flow coordinator failed");
+            Err(Error::ApproveError(ApproveError::Internal))
+        }
+    }
+}
+
+async fn insert_client(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+    metadata: &ClientMetadata,
+) -> Result<i32, Error> {
+    use crate::db::schema::{client_metadata, program_client};
+    let pubkey = pubkey.clone();
+    let metadata = metadata.clone();
+
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+
+    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        let pubkey = pubkey.clone();
+        Box::pin(async move {
+            const NONCE_START: i32 = 1;
+
+            let metadata_id = insert_into(client_metadata::table)
+                .values((
+                    client_metadata::name.eq(&metadata.name),
+                    client_metadata::description.eq(&metadata.description),
+                    client_metadata::version.eq(&metadata.version),
+                ))
+                .returning(client_metadata::id)
+                .get_result::<i32>(conn)
+                .await?;
+
+            let client_id = insert_into(program_client::table)
+                .values((
+                    program_client::public_key.eq(pubkey.to_bytes()),
+                    program_client::metadata_id.eq(metadata_id),
+                    program_client::nonce.eq(NONCE_START),
+                ))
+                .on_conflict_do_nothing()
+                .returning(program_client::id)
+                .get_result::<i32>(conn)
+                .await?;
+
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: pubkey.clone(),
+                    nonce: NONCE_START,
+                },
+                client_id,
+            )
+            .await
+            .map_err(|e| {
+                error!(error = ?e, "Failed to sign integrity tag for new client key");
+                Error::DatabaseOperationFailed
+            })?;
+
+            Ok(client_id)
+        })
+    })
+    .await
+}
+
+async fn sync_client_metadata(
+    db: &db::DatabasePool,
+    client_id: i32,
+    metadata: &ClientMetadata,
+) -> Result<(), Error> {
+    use crate::db::schema::{client_metadata, client_metadata_history};
+
+    let now = SqliteTimestamp(Utc::now());
+
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+
+    conn.exclusive_transaction(|conn| {
+        let metadata = metadata.clone();
+        Box::pin(async move {
+            let (current_metadata_id, current): (i32, ProgramClientMetadata) =
+                program_client::table
+                    .find(client_id)
+                    .inner_join(client_metadata::table)
+                    .select((
+                        program_client::metadata_id,
+                        ProgramClientMetadata::as_select(),
+                    ))
+                    .first(conn)
+                    .await?;
+
+            let unchanged = current.name == metadata.name
+                && current.description == metadata.description
+                && current.version == metadata.version;
+            if unchanged {
+                return Ok(());
+            }
+
+            insert_into(client_metadata_history::table)
+                .values((
+                    client_metadata_history::metadata_id.eq(current_metadata_id),
+                    client_metadata_history::client_id.eq(client_id),
+                ))
+                .execute(conn)
+                .await?;
+
+            let metadata_id = insert_into(client_metadata::table)
+                .values((
+                    client_metadata::name.eq(&metadata.name),
+                    client_metadata::description.eq(&metadata.description),
+                    client_metadata::version.eq(&metadata.version),
+                ))
+                .returning(client_metadata::id)
+                .get_result::<i32>(conn)
+                .await?;
+
+            update(program_client::table.find(client_id))
+                .set((
+                    program_client::metadata_id.eq(metadata_id),
+                    program_client::updated_at.eq(now),
+                ))
+                .execute(conn)
+                .await?;
+
+            Ok::<(), diesel::result::Error>(())
+        })
+    })
+    .await
+    .map_err(|e| {
+        error!(error = ?e, "Database error");
+        Error::DatabaseOperationFailed
+    })
+}
+
+async fn challenge_client<T>(
+    transport: &mut T,
+    pubkey: authn::PublicKey,
+    nonce: i32,
+) -> Result<(), Error>
+where
+    T: Bi<Inbound, Result<Outbound, Error>> + ?Sized,
+{
+    transport
+        .send(Ok(Outbound::AuthChallenge {
+            pubkey: pubkey.clone(),
+            nonce,
+        }))
+        .await
+        .map_err(|e| {
+            error!(error = ?e, "Failed to send auth challenge");
+            Error::Transport
+        })?;
+
+    let signature = expect_message(transport, |req: Inbound| match req {
+        Inbound::AuthChallengeSolution { signature } => Some(signature),
+        _ => None,
+    })
+    .await
+    .map_err(|e| {
+        error!(error = ?e, "Failed to receive challenge solution");
+        Error::Transport
+    })?;
+
+    if !pubkey.verify(nonce, CLIENT_CONTEXT, &signature) {
+        error!("Challenge solution verification failed");
+        return Err(Error::InvalidChallengeSolution);
+    }
+
+    Ok(())
+}
+
+pub async fn authenticate<T>(props: &mut ClientConnection, transport: &mut T) -> Result<i32, Error>
+where
+    T: Bi<Inbound, Result<Outbound, Error>> + Send + ?Sized,
+{
+    let Some(Inbound::AuthChallengeRequest { pubkey, metadata }) = transport.recv().await else {
+        return Err(Error::Transport);
+    };
+
+    let client_id = match get_current_nonce_and_id(&props.db, &pubkey).await? {
+        Some((id, _)) => {
+            verify_integrity(&props.db, &props.actors.key_holder, &pubkey).await?;
+            id
+        }
+        None => {
+            approve_new_client(
+                &props.actors,
+                ClientProfile {
+                    pubkey: pubkey.clone(),
+                    metadata: metadata.clone(),
+                },
+            )
+            .await?;
+            insert_client(&props.db, &props.actors.key_holder, &pubkey, &metadata).await?
+        }
+    };
+
+    sync_client_metadata(&props.db, client_id, &metadata).await?;
+    let challenge_nonce = create_nonce(&props.db, &props.actors.key_holder, &pubkey).await?;
+    challenge_client(transport, pubkey, challenge_nonce).await?;
+
+    transport
+        .send(Ok(Outbound::AuthSuccess))
+        .await
+        .map_err(|e| {
+            error!(error = ?e, "Failed to send auth success");
+            Error::Transport
+        })?;
+
+    Ok(client_id)
+}

server/crates/arbiter-server/src/actors/client/mod.rs

@@ -0,0 +1,58 @@
+use arbiter_crypto::authn;
+use arbiter_proto::{ClientMetadata, transport::Bi};
+use kameo::actor::Spawn;
+use tracing::{error, info};
+
+use crate::{
+    actors::{GlobalActors, client::session::ClientSession},
+    crypto::integrity::Integrable,
+    db,
+};
+
+#[derive(Debug, Clone)]
+pub struct ClientProfile {
+    pub pubkey: authn::PublicKey,
+    pub metadata: ClientMetadata,
+}
+
+#[derive(arbiter_macros::Hashable)]
+pub struct ClientCredentials {
+    pub pubkey: authn::PublicKey,
+    pub nonce: i32,
+}
+
+impl Integrable for ClientCredentials {
+    const KIND: &'static str = "client_credentials";
+}
+
+pub struct ClientConnection {
+    pub(crate) db: db::DatabasePool,
+    pub(crate) actors: GlobalActors,
+}
+
+impl ClientConnection {
+    pub fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
+        Self { db, actors }
+    }
+}
+
+pub mod auth;
+pub mod session;
+
+pub async fn connect_client<T>(mut props: ClientConnection, transport: &mut T)
+where
+    T: Bi<auth::Inbound, Result<auth::Outbound, auth::Error>> + Send + ?Sized,
+{
+    let fut = auth::authenticate(&mut props, transport);
+    println!("authenticate future size: {}", std::mem::size_of_val(&fut));
+    match fut.await {
+        Ok(client_id) => {
+            ClientSession::spawn(ClientSession::new(props, client_id));
+            info!("Client authenticated, session started");
+        }
+        Err(err) => {
+            let _ = transport.send(Err(err.clone())).await;
+            error!(?err, "Authentication failed, closing connection");
+        }
+    }
+}

server/crates/arbiter-server/src/actors/client/session.rs

@@ -0,0 +1,119 @@
+use kameo::{Actor, messages};
+use tracing::error;
+
+use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
+
+use crate::{
+    actors::{
+        GlobalActors,
+        client::ClientConnection,
+        evm::{ClientSignTransaction, SignTransactionError},
+        flow_coordinator::RegisterClient,
+        keyholder::KeyHolderState,
+    },
+    db,
+    evm::VetError,
+};
+
+pub struct ClientSession {
+    props: ClientConnection,
+    client_id: i32,
+}
+
+impl ClientSession {
+    pub(crate) fn new(props: ClientConnection, client_id: i32) -> Self {
+        Self { props, client_id }
+    }
+}
+
+#[messages]
+impl ClientSession {
+    #[message]
+    pub(crate) async fn handle_query_vault_state(&mut self) -> Result<KeyHolderState, Error> {
+        use crate::actors::keyholder::GetState;
+
+        let vault_state = match self.props.actors.key_holder.ask(GetState {}).await {
+            Ok(state) => state,
+            Err(err) => {
+                error!(?err, actor = "client", "keyholder.query.failed");
+                return Err(Error::Internal);
+            }
+        };
+
+        Ok(vault_state)
+    }
+
+    #[message]
+    pub(crate) async fn handle_sign_transaction(
+        &mut self,
+        wallet_address: Address,
+        transaction: TxEip1559,
+    ) -> Result<Signature, SignTransactionRpcError> {
+        match self
+            .props
+            .actors
+            .evm
+            .ask(ClientSignTransaction {
+                client_id: self.client_id,
+                wallet_address,
+                transaction,
+            })
+            .await
+        {
+            Ok(signature) => Ok(signature),
+            Err(kameo::error::SendError::HandlerError(SignTransactionError::Vet(vet_error))) => {
+                Err(SignTransactionRpcError::Vet(vet_error))
+            }
+            Err(err) => {
+                error!(?err, "Failed to sign EVM transaction in client session");
+                Err(SignTransactionRpcError::Internal)
+            }
+        }
+    }
+}
+
+impl Actor for ClientSession {
+    type Args = Self;
+
+    type Error = Error;
+
+    async fn on_start(
+        args: Self::Args,
+        this: kameo::prelude::ActorRef<Self>,
+    ) -> Result<Self, Self::Error> {
+        args.props
+            .actors
+            .flow_coordinator
+            .ask(RegisterClient { actor: this })
+            .await
+            .map_err(|_| Error::ConnectionRegistrationFailed)?;
+        Ok(args)
+    }
+}
+
+impl ClientSession {
+    pub fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
+        let props = ClientConnection::new(db, actors);
+        Self {
+            props,
+            client_id: 0,
+        }
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Connection registration failed")]
+    ConnectionRegistrationFailed,
+    #[error("Internal error")]
+    Internal,
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum SignTransactionRpcError {
+    #[error("Policy evaluation failed")]
+    Vet(#[from] VetError),
+
+    #[error("Internal error")]
+    Internal,
+}

server/crates/arbiter-server/src/actors/evm/mod.rs

@@ -0,0 +1,273 @@
+use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
+use diesel::{
+    ExpressionMethods, OptionalExtension as _, QueryDsl, SelectableHelper as _, dsl::insert_into,
+};
+use diesel_async::RunQueryDsl;
+use kameo::{Actor, actor::ActorRef, messages};
+use rand::{SeedableRng, rng, rngs::StdRng};
+
+use crate::{
+    actors::keyholder::{CreateNew, Decrypt, KeyHolder},
+    crypto::integrity,
+    db::{
+        DatabaseError, DatabasePool,
+        models::{self},
+        schema,
+    },
+    evm::{
+        self, ListError, RunKind,
+        policies::{
+            CombinedSettings, Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning,
+            ether_transfer::EtherTransfer, token_transfers::TokenTransfer,
+        },
+    },
+};
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+pub use crate::evm::safe_signer;
+
+#[derive(Debug, thiserror::Error)]
+pub enum SignTransactionError {
+    #[error("Wallet not found")]
+    WalletNotFound,
+
+    #[error("Database error: {0}")]
+    Database(#[from] DatabaseError),
+
+    #[error("Keyholder error: {0}")]
+    Keyholder(#[from] crate::actors::keyholder::Error),
+
+    #[error("Keyholder mailbox error")]
+    KeyholderSend,
+
+    #[error("Signing error: {0}")]
+    Signing(#[from] alloy::signers::Error),
+
+    #[error("Policy error: {0}")]
+    Vet(#[from] evm::VetError),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Keyholder error: {0}")]
+    Keyholder(#[from] crate::actors::keyholder::Error),
+
+    #[error("Keyholder mailbox error")]
+    KeyholderSend,
+
+    #[error("Database error: {0}")]
+    Database(#[from] DatabaseError),
+
+    #[error("Integrity violation: {0}")]
+    Integrity(#[from] integrity::Error),
+}
+
+#[derive(Actor)]
+pub struct EvmActor {
+    pub keyholder: ActorRef<KeyHolder>,
+    pub db: DatabasePool,
+    pub rng: StdRng,
+    pub engine: evm::Engine,
+}
+
+impl EvmActor {
+    pub fn new(keyholder: ActorRef<KeyHolder>, db: DatabasePool) -> Self {
+        // is it safe to seed rng from system once?
+        // todo: audit
+        let rng = StdRng::from_rng(&mut rng());
+        let engine = evm::Engine::new(db.clone(), keyholder.clone());
+        Self {
+            keyholder,
+            db,
+            rng,
+            engine,
+        }
+    }
+}
+
+#[messages]
+impl EvmActor {
+    #[message]
+    pub async fn generate(&mut self) -> Result<(i32, Address), Error> {
+        let (mut key_cell, address) = safe_signer::generate(&mut self.rng);
+
+        let plaintext = key_cell.read_inline(|reader| SafeCell::new(reader.to_vec()));
+
+        let aead_id: i32 = self
+            .keyholder
+            .ask(CreateNew { plaintext })
+            .await
+            .map_err(|_| Error::KeyholderSend)?;
+
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let wallet_id = insert_into(schema::evm_wallet::table)
+            .values(&models::NewEvmWallet {
+                address: address.as_slice().to_vec(),
+                aead_encrypted_id: aead_id,
+            })
+            .returning(schema::evm_wallet::id)
+            .get_result(&mut conn)
+            .await
+            .map_err(DatabaseError::from)?;
+
+        Ok((wallet_id, address))
+    }
+
+    #[message]
+    pub async fn list_wallets(&self) -> Result<Vec<(i32, Address)>, Error> {
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let rows: Vec<models::EvmWallet> = schema::evm_wallet::table
+            .select(models::EvmWallet::as_select())
+            .load(&mut conn)
+            .await
+            .map_err(DatabaseError::from)?;
+
+        Ok(rows
+            .into_iter()
+            .map(|w| (w.id, Address::from_slice(&w.address)))
+            .collect())
+    }
+}
+
+#[messages]
+impl EvmActor {
+    #[message]
+    pub async fn useragent_create_grant(
+        &mut self,
+        basic: SharedGrantSettings,
+        grant: SpecificGrant,
+    ) -> Result<i32, Error> {
+        match grant {
+            SpecificGrant::EtherTransfer(settings) => self
+                .engine
+                .create_grant::<EtherTransfer>(CombinedSettings {
+                    shared: basic,
+                    specific: settings,
+                })
+                .await
+                .map_err(Error::from),
+            SpecificGrant::TokenTransfer(settings) => self
+                .engine
+                .create_grant::<TokenTransfer>(CombinedSettings {
+                    shared: basic,
+                    specific: settings,
+                })
+                .await
+                .map_err(Error::from),
+        }
+    }
+
+    #[message]
+    pub async fn useragent_delete_grant(&mut self, _grant_id: i32) -> Result<(), Error> {
+        // let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        // let keyholder = self.keyholder.clone();
+
+        // diesel_async::AsyncConnection::transaction(&mut conn, |conn| {
+        //     Box::pin(async move {
+        //         diesel::update(schema::evm_basic_grant::table)
+        //             .filter(schema::evm_basic_grant::id.eq(grant_id))
+        //             .set(schema::evm_basic_grant::revoked_at.eq(SqliteTimestamp::now()))
+        //             .execute(conn)
+        //             .await?;
+
+        //         let signed = integrity::evm::load_signed_grant_by_basic_id(conn, grant_id).await?;
+
+        //         diesel::result::QueryResult::Ok(())
+        //     })
+        // })
+        // .await
+        // .map_err(DatabaseError::from)?;
+
+        // Ok(())
+        todo!()
+    }
+
+    #[message]
+    pub async fn useragent_list_grants(&mut self) -> Result<Vec<Grant<SpecificGrant>>, Error> {
+        match self.engine.list_all_grants().await {
+            Ok(grants) => Ok(grants),
+            Err(ListError::Database(db_err)) => Err(Error::Database(db_err)),
+            Err(ListError::Integrity(integrity_err)) => Err(Error::Integrity(integrity_err)),
+        }
+    }
+
+    #[message]
+    pub async fn shared_analyze_transaction(
+        &mut self,
+        client_id: i32,
+        wallet_address: Address,
+        transaction: TxEip1559,
+    ) -> Result<SpecificMeaning, SignTransactionError> {
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let wallet = schema::evm_wallet::table
+            .select(models::EvmWallet::as_select())
+            .filter(schema::evm_wallet::address.eq(wallet_address.as_slice()))
+            .first(&mut conn)
+            .await
+            .optional()
+            .map_err(DatabaseError::from)?
+            .ok_or(SignTransactionError::WalletNotFound)?;
+        let wallet_access = schema::evm_wallet_access::table
+            .select(models::EvmWalletAccess::as_select())
+            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.id))
+            .filter(schema::evm_wallet_access::client_id.eq(client_id))
+            .first(&mut conn)
+            .await
+            .optional()
+            .map_err(DatabaseError::from)?
+            .ok_or(SignTransactionError::WalletNotFound)?;
+        drop(conn);
+
+        let meaning = self
+            .engine
+            .evaluate_transaction(wallet_access, transaction.clone(), RunKind::Execution)
+            .await?;
+
+        Ok(meaning)
+    }
+
+    #[message]
+    pub async fn client_sign_transaction(
+        &mut self,
+        client_id: i32,
+        wallet_address: Address,
+        mut transaction: TxEip1559,
+    ) -> Result<Signature, SignTransactionError> {
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let wallet = schema::evm_wallet::table
+            .select(models::EvmWallet::as_select())
+            .filter(schema::evm_wallet::address.eq(wallet_address.as_slice()))
+            .first(&mut conn)
+            .await
+            .optional()
+            .map_err(DatabaseError::from)?
+            .ok_or(SignTransactionError::WalletNotFound)?;
+        let wallet_access = schema::evm_wallet_access::table
+            .select(models::EvmWalletAccess::as_select())
+            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.id))
+            .filter(schema::evm_wallet_access::client_id.eq(client_id))
+            .first(&mut conn)
+            .await
+            .optional()
+            .map_err(DatabaseError::from)?
+            .ok_or(SignTransactionError::WalletNotFound)?;
+        drop(conn);
+
+        let raw_key: SafeCell<Vec<u8>> = self
+            .keyholder
+            .ask(Decrypt {
+                aead_id: wallet.aead_encrypted_id,
+            })
+            .await
+            .map_err(|_| SignTransactionError::KeyholderSend)?;
+
+        let signer = safe_signer::SafeSigner::from_cell(raw_key)?;
+
+        self.engine
+            .evaluate_transaction(wallet_access, transaction.clone(), RunKind::Execution)
+            .await?;
+
+        use alloy::network::TxSignerSync as _;
+        Ok(signer.sign_transaction_sync(&mut transaction)?)
+    }
+}

server/crates/arbiter-server/src/actors/flow_coordinator/client_connect_approval.rs

@@ -0,0 +1,105 @@
+use std::ops::ControlFlow;
+
+use kameo::{
+    Actor, messages,
+    prelude::{ActorId, ActorRef, ActorStopReason, Context, WeakActorRef},
+    reply::ReplySender,
+};
+
+use crate::actors::{
+    client::ClientProfile,
+    flow_coordinator::ApprovalError,
+    user_agent::{UserAgentSession, session::BeginNewClientApproval},
+};
+
+pub struct Args {
+    pub client: ClientProfile,
+    pub user_agents: Vec<ActorRef<UserAgentSession>>,
+    pub reply: ReplySender<Result<bool, ApprovalError>>,
+}
+
+pub struct ClientApprovalController {
+    /// Number of UAs that have not yet responded (approval or denial) or died.
+    pending: usize,
+    /// Number of approvals received so far.
+    approved: usize,
+    reply: Option<ReplySender<Result<bool, ApprovalError>>>,
+}
+
+impl ClientApprovalController {
+    fn send_reply(&mut self, result: Result<bool, ApprovalError>) {
+        if let Some(reply) = self.reply.take() {
+            reply.send(result);
+        }
+    }
+}
+
+impl Actor for ClientApprovalController {
+    type Args = Args;
+    type Error = ();
+
+    async fn on_start(
+        Args {
+            client,
+            mut user_agents,
+            reply,
+        }: Self::Args,
+        actor_ref: ActorRef<Self>,
+    ) -> Result<Self, Self::Error> {
+        let this = Self {
+            pending: user_agents.len(),
+            approved: 0,
+            reply: Some(reply),
+        };
+
+        for user_agent in user_agents.drain(..) {
+            actor_ref.link(&user_agent).await;
+            let _ = user_agent
+                .tell(BeginNewClientApproval {
+                    client: client.clone(),
+                    controller: actor_ref.clone(),
+                })
+                .await;
+        }
+
+        Ok(this)
+    }
+
+    async fn on_link_died(
+        &mut self,
+        _: WeakActorRef<Self>,
+        _: ActorId,
+        _: ActorStopReason,
+    ) -> Result<ControlFlow<ActorStopReason>, Self::Error> {
+        // A linked UA died before responding — counts as a non-approval.
+        self.pending = self.pending.saturating_sub(1);
+        if self.pending == 0 {
+            // At least one UA didn't approve: deny.
+            self.send_reply(Ok(false));
+            return Ok(ControlFlow::Break(ActorStopReason::Normal));
+        }
+        Ok(ControlFlow::Continue(()))
+    }
+}
+
+#[messages]
+impl ClientApprovalController {
+    #[message(ctx)]
+    pub async fn client_approval_answer(&mut self, approved: bool, ctx: &mut Context<Self, ()>) {
+        if !approved {
+            // Denial wins immediately regardless of other pending responses.
+            self.send_reply(Ok(false));
+            ctx.stop();
+            return;
+        }
+
+        self.approved += 1;
+        self.pending = self.pending.saturating_sub(1);
+
+        if self.pending == 0 {
+            // Every connected UA approved.
+            self.send_reply(Ok(true));
+            ctx.stop();
+        }
+    }
+}

server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs

@@ -0,0 +1,118 @@
+use std::{collections::HashMap, ops::ControlFlow};
+
+use kameo::{
+    Actor,
+    actor::{ActorId, ActorRef, Spawn},
+    messages,
+    prelude::{ActorStopReason, Context, WeakActorRef},
+    reply::DelegatedReply,
+};
+use tracing::info;
+
+use crate::actors::{
+    client::{ClientProfile, session::ClientSession},
+    flow_coordinator::client_connect_approval::ClientApprovalController,
+    user_agent::session::UserAgentSession,
+};
+
+pub mod client_connect_approval;
+
+#[derive(Default)]
+pub struct FlowCoordinator {
+    pub user_agents: HashMap<ActorId, ActorRef<UserAgentSession>>,
+    pub clients: HashMap<ActorId, ActorRef<ClientSession>>,
+}
+
+impl Actor for FlowCoordinator {
+    type Args = Self;
+
+    type Error = ();
+
+    async fn on_start(args: Self::Args, _: ActorRef<Self>) -> Result<Self, Self::Error> {
+        Ok(args)
+    }
+
+    async fn on_link_died(
+        &mut self,
+        _: WeakActorRef<Self>,
+        id: ActorId,
+        _: ActorStopReason,
+    ) -> Result<ControlFlow<ActorStopReason>, Self::Error> {
+        if self.user_agents.remove(&id).is_some() {
+            info!(
+                ?id,
+                actor = "FlowCoordinator",
+                event = "useragent.disconnected"
+            );
+        } else if self.clients.remove(&id).is_some() {
+            info!(
+                ?id,
+                actor = "FlowCoordinator",
+                event = "client.disconnected"
+            );
+        } else {
+            info!(
+                ?id,
+                actor = "FlowCoordinator",
+                event = "unknown.actor.disconnected"
+            );
+        }
+        Ok(ControlFlow::Continue(()))
+    }
+}
+
+#[derive(Debug, thiserror::Error, Clone, PartialEq, Eq, Hash)]
+pub enum ApprovalError {
+    #[error("No user agents connected")]
+    NoUserAgentsConnected,
+}
+
+#[messages]
+impl FlowCoordinator {
+    #[message(ctx)]
+    pub async fn register_user_agent(
+        &mut self,
+        actor: ActorRef<UserAgentSession>,
+        ctx: &mut Context<Self, ()>,
+    ) {
+        info!(id = %actor.id(), actor = "FlowCoordinator", event = "useragent.connected");
+        ctx.actor_ref().link(&actor).await;
+        self.user_agents.insert(actor.id(), actor);
+    }
+
+    #[message(ctx)]
+    pub async fn register_client(
+        &mut self,
+        actor: ActorRef<ClientSession>,
+        ctx: &mut Context<Self, ()>,
+    ) {
+        info!(id = %actor.id(), actor = "FlowCoordinator", event = "client.connected");
+        ctx.actor_ref().link(&actor).await;
+        self.clients.insert(actor.id(), actor);
+    }
+
+    #[message(ctx)]
+    pub async fn request_client_approval(
+        &mut self,
+        client: ClientProfile,
+        ctx: &mut Context<Self, DelegatedReply<Result<bool, ApprovalError>>>,
+    ) -> DelegatedReply<Result<bool, ApprovalError>> {
+        let (reply, Some(reply_sender)) = ctx.reply_sender() else {
+            unreachable!("Expected `request_client_approval` to have callback channel");
+        };
+
+        let refs: Vec<_> = self.user_agents.values().cloned().collect();
+        if refs.is_empty() {
+            reply_sender.send(Err(ApprovalError::NoUserAgentsConnected));
+            return reply;
+        }
+
+        ClientApprovalController::spawn(client_connect_approval::Args {
+            client,
+            user_agents: refs,
+            reply: reply_sender,
+        });
+
+        reply
+    }
+}

server/crates/arbiter-server/src/actors/keyholder/mod.rs

@@ -0,0 +1,454 @@
+use chrono::Utc;
+use diesel::{
+    ExpressionMethods as _, OptionalExtension, QueryDsl, SelectableHelper,
+    dsl::{insert_into, update},
+};
+use diesel_async::{AsyncConnection, RunQueryDsl};
+use hmac::Mac as _;
+use kameo::{Actor, Reply, messages};
+use strum::{EnumDiscriminants, IntoDiscriminant};
+use tracing::{error, info};
+
+use crate::crypto::{
+    KeyCell, derive_key,
+    encryption::v1::{self, Nonce},
+    integrity::v1::HmacSha256,
+};
+use crate::db::{
+    self,
+    models::{self, RootKeyHistory},
+    schema::{self},
+};
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+#[derive(Default, EnumDiscriminants)]
+#[strum_discriminants(derive(Reply), vis(pub), name(KeyHolderState))]
+enum State {
+    #[default]
+    Unbootstrapped,
+    Sealed {
+        root_key_history_id: i32,
+    },
+    Unsealed {
+        root_key_history_id: i32,
+        root_key: KeyCell,
+    },
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Keyholder is already bootstrapped")]
+    AlreadyBootstrapped,
+    #[error("Keyholder is not bootstrapped")]
+    NotBootstrapped,
+    #[error("Invalid key provided")]
+    InvalidKey,
+
+    #[error("Requested aead entry not found")]
+    NotFound,
+
+    #[error("Encryption error: {0}")]
+    Encryption(#[from] chacha20poly1305::aead::Error),
+
+    #[error("Database error: {0}")]
+    DatabaseConnection(#[from] db::PoolError),
+
+    #[error("Database transaction error: {0}")]
+    DatabaseTransaction(#[from] diesel::result::Error),
+
+    #[error("Broken database")]
+    BrokenDatabase,
+}
+
+/// Manages vault root key and tracks current state of the vault (bootstrapped/unbootstrapped, sealed/unsealed).
+/// Provides API for encrypting and decrypting data using the vault root key.
+/// Abstraction over database to make sure nonces are never reused and encryption keys are never exposed in plaintext outside of this actor.
+#[derive(Actor)]
+pub struct KeyHolder {
+    db: db::DatabasePool,
+    state: State,
+}
+
+#[messages]
+impl KeyHolder {
+    pub async fn new(db: db::DatabasePool) -> Result<Self, Error> {
+        let state = {
+            let mut conn = db.get().await?;
+
+            let (root_key_history,) = schema::arbiter_settings::table
+                .left_join(schema::root_key_history::table)
+                .select((Option::<RootKeyHistory>::as_select(),))
+                .get_result::<(Option<RootKeyHistory>,)>(&mut conn)
+                .await?;
+
+            match root_key_history {
+                Some(root_key_history) => State::Sealed {
+                    root_key_history_id: root_key_history.id,
+                },
+                None => State::Unbootstrapped,
+            }
+        };
+
+        Ok(Self { db, state })
+    }
+
+    // Exclusive transaction to avoid race condtions if multiple keyholders write
+    // additional layer of protection against nonce-reuse
+    async fn get_new_nonce(pool: &db::DatabasePool, root_key_id: i32) -> Result<Nonce, Error> {
+        let mut conn = pool.get().await?;
+
+        let nonce = conn
+            .exclusive_transaction(|conn| {
+                Box::pin(async move {
+                    let current_nonce: Vec<u8> = schema::root_key_history::table
+                        .filter(schema::root_key_history::id.eq(root_key_id))
+                        .select(schema::root_key_history::data_encryption_nonce)
+                        .first(conn)
+                        .await?;
+
+                    let mut nonce = Nonce::try_from(current_nonce.as_slice()).map_err(|_| {
+                        error!(
+                            "Broken database: invalid nonce for root key history id={}",
+                            root_key_id
+                        );
+                        Error::BrokenDatabase
+                    })?;
+                    nonce.increment();
+
+                    update(schema::root_key_history::table)
+                        .filter(schema::root_key_history::id.eq(root_key_id))
+                        .set(schema::root_key_history::data_encryption_nonce.eq(nonce.to_vec()))
+                        .execute(conn)
+                        .await?;
+
+                    Result::<_, Error>::Ok(nonce)
+                })
+            })
+            .await?;
+
+        Ok(nonce)
+    }
+
+    #[message]
+    pub async fn bootstrap(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+        if !matches!(self.state, State::Unbootstrapped) {
+            return Err(Error::AlreadyBootstrapped);
+        }
+        let salt = v1::generate_salt();
+        let mut seal_key = derive_key(seal_key_raw, &salt);
+        let mut root_key = KeyCell::new_secure_random();
+
+        // Zero nonces are fine because they are one-time
+        let root_key_nonce = Nonce::default();
+        let data_encryption_nonce = Nonce::default();
+
+        let root_key_ciphertext: Vec<u8> = root_key.0.read_inline(|reader| {
+            let root_key_reader = reader.as_slice();
+            seal_key
+                .encrypt(&root_key_nonce, v1::ROOT_KEY_TAG, root_key_reader)
+                .map_err(|err| {
+                    error!(?err, "Fatal bootstrap error");
+                    Error::Encryption(err)
+                })
+        })?;
+
+        let mut conn = self.db.get().await?;
+
+        let data_encryption_nonce_bytes = data_encryption_nonce.to_vec();
+        let root_key_history_id = conn
+            .transaction(|conn| {
+                Box::pin(async move {
+                    let root_key_history_id: i32 = insert_into(schema::root_key_history::table)
+                        .values(&models::NewRootKeyHistory {
+                            ciphertext: root_key_ciphertext,
+                            tag: v1::ROOT_KEY_TAG.to_vec(),
+                            root_key_encryption_nonce: root_key_nonce.to_vec(),
+                            data_encryption_nonce: data_encryption_nonce_bytes,
+                            schema_version: 1,
+                            salt: salt.to_vec(),
+                        })
+                        .returning(schema::root_key_history::id)
+                        .get_result(conn)
+                        .await?;
+
+                    update(schema::arbiter_settings::table)
+                        .set(schema::arbiter_settings::root_key_id.eq(root_key_history_id))
+                        .execute(conn)
+                        .await?;
+
+                    Result::<_, diesel::result::Error>::Ok(root_key_history_id)
+                })
+            })
+            .await?;
+
+        self.state = State::Unsealed {
+            root_key,
+            root_key_history_id,
+        };
+
+        info!("Keyholder bootstrapped successfully");
+
+        Ok(())
+    }
+
+    #[message]
+    pub async fn try_unseal(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+        let State::Sealed {
+            root_key_history_id,
+        } = &self.state
+        else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        // We don't want to hold connection while doing expensive KDF work
+        let current_key = {
+            let mut conn = self.db.get().await?;
+            schema::root_key_history::table
+                .filter(schema::root_key_history::id.eq(*root_key_history_id))
+                .select(RootKeyHistory::as_select())
+                .first(&mut conn)
+                .await?
+        };
+
+        let salt = &current_key.salt;
+        let salt = v1::Salt::try_from(salt.as_slice()).map_err(|_| {
+            error!("Broken database: invalid salt for root key");
+            Error::BrokenDatabase
+        })?;
+        let mut seal_key = derive_key(seal_key_raw, &salt);
+
+        let mut root_key = SafeCell::new(current_key.ciphertext.clone());
+
+        let nonce = v1::Nonce::try_from(current_key.root_key_encryption_nonce.as_slice()).map_err(
+            |_| {
+                error!("Broken database: invalid nonce for root key");
+                Error::BrokenDatabase
+            },
+        )?;
+
+        seal_key
+            .decrypt_in_place(&nonce, v1::ROOT_KEY_TAG, &mut root_key)
+            .map_err(|err| {
+                error!(?err, "Failed to unseal root key: invalid seal key");
+                Error::InvalidKey
+            })?;
+
+        self.state = State::Unsealed {
+            root_key_history_id: current_key.id,
+            root_key: KeyCell::try_from(root_key).map_err(|err| {
+                error!(?err, "Broken database: invalid encryption key size");
+                Error::BrokenDatabase
+            })?,
+        };
+
+        info!("Keyholder unsealed successfully");
+
+        Ok(())
+    }
+
+    #[message]
+    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, Error> {
+        let State::Unsealed { root_key, .. } = &mut self.state else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        let row: models::AeadEncrypted = {
+            let mut conn = self.db.get().await?;
+            schema::aead_encrypted::table
+                .select(models::AeadEncrypted::as_select())
+                .filter(schema::aead_encrypted::id.eq(aead_id))
+                .first(&mut conn)
+                .await
+                .optional()?
+                .ok_or(Error::NotFound)?
+        };
+
+        let nonce = v1::Nonce::try_from(row.current_nonce.as_slice()).map_err(|_| {
+            error!(
+                "Broken database: invalid nonce for aead_encrypted id={}",
+                aead_id
+            );
+            Error::BrokenDatabase
+        })?;
+        let mut output = SafeCell::new(row.ciphertext);
+        root_key.decrypt_in_place(&nonce, v1::TAG, &mut output)?;
+        Ok(output)
+    }
+
+    // Creates new `aead_encrypted` entry in the database and returns it's ID
+    #[message]
+    pub async fn create_new(&mut self, mut plaintext: SafeCell<Vec<u8>>) -> Result<i32, Error> {
+        let State::Unsealed {
+            root_key,
+            root_key_history_id,
+            ..
+        } = &mut self.state
+        else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        // Order matters here - `get_new_nonce` acquires connection, so we need to call it before next acquire
+        // Borrow checker note: &mut borrow a few lines above is disjoint from this field
+        let nonce = Self::get_new_nonce(&self.db, *root_key_history_id).await?;
+
+        let mut ciphertext_buffer = plaintext.write();
+        let ciphertext_buffer: &mut Vec<u8> = ciphertext_buffer.as_mut();
+        root_key.encrypt_in_place(&nonce, v1::TAG, &mut *ciphertext_buffer)?;
+
+        let ciphertext = std::mem::take(ciphertext_buffer);
+
+        let mut conn = self.db.get().await?;
+        let aead_id: i32 = insert_into(schema::aead_encrypted::table)
+            .values(&models::NewAeadEncrypted {
+                ciphertext,
+                tag: v1::TAG.to_vec(),
+                current_nonce: nonce.to_vec(),
+                schema_version: 1,
+                associated_root_key_id: *root_key_history_id,
+                created_at: Utc::now().into(),
+            })
+            .returning(schema::aead_encrypted::id)
+            .get_result(&mut conn)
+            .await?;
+
+        Ok(aead_id)
+    }
+
+    #[message]
+    pub fn get_state(&self) -> KeyHolderState {
+        self.state.discriminant()
+    }
+
+    #[message]
+    pub fn sign_integrity(&mut self, mac_input: Vec<u8>) -> Result<(i32, Vec<u8>), Error> {
+        let State::Unsealed {
+            root_key,
+            root_key_history_id,
+        } = &mut self.state
+        else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        let mut hmac = root_key
+            .0
+            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                Ok(v) => v,
+                Err(_) => unreachable!("HMAC accepts keys of any size"),
+            });
+        hmac.update(&root_key_history_id.to_be_bytes());
+        hmac.update(&mac_input);
+
+        let mac = hmac.finalize().into_bytes().to_vec();
+        Ok((*root_key_history_id, mac))
+    }
+
+    #[message]
+    pub fn verify_integrity(
+        &mut self,
+        mac_input: Vec<u8>,
+        expected_mac: Vec<u8>,
+        key_version: i32,
+    ) -> Result<bool, Error> {
+        let State::Unsealed {
+            root_key,
+            root_key_history_id,
+        } = &mut self.state
+        else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        if *root_key_history_id != key_version {
+            return Ok(false);
+        }
+
+        let mut hmac = root_key
+            .0
+            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                Ok(v) => v,
+                Err(_) => unreachable!("HMAC accepts keys of any size"),
+            });
+        hmac.update(&key_version.to_be_bytes());
+        hmac.update(&mac_input);
+
+        Ok(hmac.verify_slice(&expected_mac).is_ok())
+    }
+
+    #[message]
+    pub fn seal(&mut self) -> Result<(), Error> {
+        let State::Unsealed {
+            root_key_history_id,
+            ..
+        } = &self.state
+        else {
+            return Err(Error::NotBootstrapped);
+        };
+        self.state = State::Sealed {
+            root_key_history_id: *root_key_history_id,
+        };
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel::SelectableHelper;
+
+    use diesel_async::RunQueryDsl;
+
+    use crate::db::{self};
+    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+    use super::*;
+
+    async fn bootstrapped_actor(db: &db::DatabasePool) -> KeyHolder {
+        let mut actor = KeyHolder::new(db.clone()).await.unwrap();
+        let seal_key = SafeCell::new(b"test-seal-key".to_vec());
+        actor.bootstrap(seal_key).await.unwrap();
+        actor
+    }
+
+    #[tokio::test]
+    #[test_log::test]
+    async fn nonce_monotonic_even_when_nonce_allocation_interleaves() {
+        let db = db::create_test_pool().await;
+        let mut actor = bootstrapped_actor(&db).await;
+        let root_key_history_id = match actor.state {
+            State::Unsealed {
+                root_key_history_id,
+                ..
+            } => root_key_history_id,
+            _ => panic!("expected unsealed state"),
+        };
+
+        let n1 = KeyHolder::get_new_nonce(&db, root_key_history_id)
+            .await
+            .unwrap();
+        let n2 = KeyHolder::get_new_nonce(&db, root_key_history_id)
+            .await
+            .unwrap();
+        assert!(n2.to_vec() > n1.to_vec(), "nonce must increase");
+
+        let mut conn = db.get().await.unwrap();
+        let root_row: models::RootKeyHistory = schema::root_key_history::table
+            .select(models::RootKeyHistory::as_select())
+            .first(&mut conn)
+            .await
+            .unwrap();
+        assert_eq!(root_row.data_encryption_nonce, n2.to_vec());
+
+        let id = actor
+            .create_new(SafeCell::new(b"post-interleave".to_vec()))
+            .await
+            .unwrap();
+        let row: models::AeadEncrypted = schema::aead_encrypted::table
+            .filter(schema::aead_encrypted::id.eq(id))
+            .select(models::AeadEncrypted::as_select())
+            .first(&mut conn)
+            .await
+            .unwrap();
+        assert!(
+            row.current_nonce > n2.to_vec(),
+            "next write must advance nonce"
+        );
+    }
+}

server/crates/arbiter-server/src/actors/mod.rs

@@ -0,0 +1,47 @@
+use kameo::actor::{ActorRef, Spawn};
+use thiserror::Error;
+
+use crate::{
+    actors::{
+        bootstrap::Bootstrapper, evm::EvmActor, flow_coordinator::FlowCoordinator,
+        keyholder::KeyHolder,
+    },
+    db,
+};
+
+pub mod bootstrap;
+pub mod client;
+mod evm;
+pub mod flow_coordinator;
+pub mod keyholder;
+pub mod user_agent;
+
+#[derive(Error, Debug)]
+pub enum SpawnError {
+    #[error("Failed to spawn Bootstrapper actor")]
+    Bootstrapper(#[from] bootstrap::Error),
+
+    #[error("Failed to spawn KeyHolder actor")]
+    KeyHolder(#[from] keyholder::Error),
+}
+
+/// Long-lived actors that are shared across all connections and handle global state and operations
+#[derive(Clone)]
+pub struct GlobalActors {
+    pub key_holder: ActorRef<KeyHolder>,
+    pub bootstrapper: ActorRef<Bootstrapper>,
+    pub flow_coordinator: ActorRef<FlowCoordinator>,
+    pub evm: ActorRef<EvmActor>,
+}
+
+impl GlobalActors {
+    pub async fn spawn(db: db::DatabasePool) -> Result<Self, SpawnError> {
+        let key_holder = KeyHolder::spawn(KeyHolder::new(db.clone()).await?);
+        Ok(Self {
+            bootstrapper: Bootstrapper::spawn(Bootstrapper::new(&db).await?),
+            evm: EvmActor::spawn(EvmActor::new(key_holder.clone(), db)),
+            key_holder,
+            flow_coordinator: FlowCoordinator::spawn(FlowCoordinator::default()),
+        })
+    }
+}

server/crates/arbiter-server/src/actors/user_agent.rs

@@ -1,369 +0,0 @@
-use arbiter_proto::proto::{
-    UserAgentRequest, UserAgentResponse,
-    auth::{
-        self, AuthChallenge, AuthChallengeRequest, AuthOk, ClientMessage,
-        ServerMessage as AuthServerMessage, client_message::Payload as ClientAuthPayload,
-        server_message::Payload as ServerAuthPayload,
-    },
-    user_agent_request::Payload as UserAgentRequestPayload,
-    user_agent_response::Payload as UserAgentResponsePayload,
-};
-use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, dsl::update};
-use diesel_async::{AsyncConnection, RunQueryDsl};
-use ed25519_dalek::VerifyingKey;
-use futures::StreamExt;
-use kameo::{
-    Actor,
-    actor::{ActorRef, Spawn},
-    error::SendError,
-    messages,
-    prelude::Context,
-};
-use tokio::sync::mpsc;
-use tokio::sync::mpsc::Sender;
-use tonic::Status;
-use tracing::{error, info};
-
-use crate::{
-    ServerContext,
-    context::bootstrap::{BootstrapActor, ConsumeToken},
-    db::{self, schema},
-    errors::GrpcStatusExt,
-};
-
-/// Context for state machine with validated key and sent challenge
-/// Challenge is then transformed to bytes using shared function and verified
-#[derive(Clone, Debug)]
-pub struct ChallengeContext {
-    challenge: AuthChallenge,
-    key: VerifyingKey,
-}
-
-// Request context with deserialized public key for state machine.
-// This intermediate struct is needed because the state machine branches depending on presence of bootstrap token,
-// but we want to have the deserialized key in both branches.
-#[derive(Clone, Debug)]
-pub struct AuthRequestContext {
-    pubkey: VerifyingKey,
-    bootstrap_token: Option<String>,
-}
-
-smlang::statemachine!(
-    name: UserAgent,
-    derive_states: [Debug],
-    custom_error: false,
-    transitions: {
-        *Init + AuthRequest(AuthRequestContext) / auth_request_context =  ReceivedAuthRequest(AuthRequestContext),
-        ReceivedAuthRequest(AuthRequestContext) + ReceivedBootstrapToken = Authenticated,
-
-        ReceivedAuthRequest(AuthRequestContext) + SentChallenge(ChallengeContext) / move_challenge = WaitingForChallengeSolution(ChallengeContext),
-
-        WaitingForChallengeSolution(ChallengeContext) + ReceivedGoodSolution = Authenticated,
-        WaitingForChallengeSolution(ChallengeContext) + ReceivedBadSolution = AuthError, // block further transitions, but connection should close anyway
-    }
-);
-
-pub struct DummyContext;
-impl UserAgentStateMachineContext for DummyContext {
-    #[allow(missing_docs)]
-    #[allow(clippy::unused_unit)]
-    fn move_challenge(
-        &mut self,
-        state_data: &AuthRequestContext,
-        event_data: ChallengeContext,
-    ) -> Result<ChallengeContext, ()> {
-        Ok(event_data)
-    }
-
-    #[allow(missing_docs)]
-    #[allow(clippy::unused_unit)]
-    fn auth_request_context(
-        &mut self,
-        event_data: AuthRequestContext,
-    ) -> Result<AuthRequestContext, ()> {
-        Ok(event_data)
-    }
-}
-
-#[derive(Actor)]
-pub struct UserAgentActor {
-    db: db::DatabasePool,
-    bootstapper: ActorRef<BootstrapActor>,
-    state: UserAgentStateMachine<DummyContext>,
-    tx: Sender<Result<UserAgentResponse, Status>>,
-}
-
-impl UserAgentActor {
-    pub(crate) fn new(
-        context: ServerContext,
-        tx: Sender<Result<UserAgentResponse, Status>>,
-    ) -> Self {
-        Self {
-            db: context.db.clone(),
-            bootstapper: context.bootstrapper.clone(),
-            state: UserAgentStateMachine::new(DummyContext),
-            tx,
-        }
-    }
-
-    pub(crate) fn new_manual(
-        db: db::DatabasePool,
-        bootstapper: ActorRef<BootstrapActor>,
-        tx: Sender<Result<UserAgentResponse, Status>>,
-    ) -> Self {
-        Self {
-            db,
-            bootstapper,
-            state: UserAgentStateMachine::new(DummyContext),
-            tx,
-        }
-    }
-
-    fn transition(&mut self, event: UserAgentEvents) -> Result<(), Status> {
-        self.state.process_event(event).map_err(|e| {
-            error!(?e, "State transition failed");
-            Status::internal("State machine error")
-        })?;
-        Ok(())
-    }
-
-    async fn auth_with_bootstrap_token(
-        &mut self,
-        pubkey: ed25519_dalek::VerifyingKey,
-        token: String,
-    ) -> Result<UserAgentResponse, Status> {
-        let token_ok: bool = self
-            .bootstapper
-            .ask(ConsumeToken { token })
-            .await
-            .map_err(|e| {
-                error!(?pubkey, "Failed to consume bootstrap token: {e}");
-                Status::internal("Bootstrap token consumption failed")
-            })?;
-
-        if !token_ok {
-            error!(?pubkey, "Invalid bootstrap token provided");
-            return Err(Status::invalid_argument("Invalid bootstrap token"));
-        }
-
-        {
-            let mut conn = self.db.get().await.to_status()?;
-
-            diesel::insert_into(schema::useragent_client::table)
-                .values((
-                    schema::useragent_client::public_key.eq(pubkey.as_bytes().to_vec()),
-                    schema::useragent_client::nonce.eq(1),
-                ))
-                .execute(&mut conn)
-                .await
-                .to_status()?;
-        }
-
-        self.transition(UserAgentEvents::ReceivedBootstrapToken)?;
-
-        Ok(auth_response(ServerAuthPayload::AuthOk(AuthOk {})))
-    }
-
-    async fn auth_with_challenge(&mut self, pubkey: VerifyingKey, pubkey_bytes: Vec<u8>) -> Output {
-        let nonce: Option<i32> = {
-            let mut db_conn = self.db.get().await.to_status()?;
-            db_conn
-                .transaction(|conn| {
-                    Box::pin(async move {
-                        let current_nonce = schema::useragent_client::table
-                            .filter(
-                                schema::useragent_client::public_key.eq(pubkey.as_bytes().to_vec()),
-                            )
-                            .select(schema::useragent_client::nonce)
-                            .first::<i32>(conn)
-                            .await?;
-
-                        update(schema::useragent_client::table)
-                            .filter(
-                                schema::useragent_client::public_key.eq(pubkey.as_bytes().to_vec()),
-                            )
-                            .set(schema::useragent_client::nonce.eq(current_nonce + 1))
-                            .execute(conn)
-                            .await?;
-
-                        Result::<_, diesel::result::Error>::Ok(current_nonce)
-                    })
-                })
-                .await
-                .optional()
-                .to_status()?
-        };
-
-        let Some(nonce) = nonce else {
-            error!(?pubkey, "Public key not found in database");
-            return Err(Status::unauthenticated("Public key not registered"));
-        };
-
-        let challenge = auth::AuthChallenge {
-            pubkey: pubkey_bytes,
-            nonce: nonce,
-        };
-
-        self.transition(UserAgentEvents::SentChallenge(ChallengeContext {
-            challenge: challenge.clone(),
-            key: pubkey,
-        }))?;
-
-        info!(
-            ?pubkey,
-            ?challenge,
-            "Sent authentication challenge to client"
-        );
-
-        Ok(auth_response(ServerAuthPayload::AuthChallenge(challenge)))
-    }
-
-    fn verify_challenge_solution(
-        &self,
-        solution: &auth::AuthChallengeSolution,
-    ) -> Result<(bool, &ChallengeContext), Status> {
-        let UserAgentStates::WaitingForChallengeSolution(challenge_context) = self.state.state()
-        else {
-            error!("Received challenge solution in invalid state");
-            return Err(Status::invalid_argument(
-                "Invalid state for challenge solution",
-            ));
-        };
-        let formatted_challenge = arbiter_proto::format_challenge(&challenge_context.challenge);
-
-        let signature = solution.signature.as_slice().try_into().map_err(|_| {
-            error!(?solution, "Invalid signature length");
-            Status::invalid_argument("Invalid signature length")
-        })?;
-
-        let valid = challenge_context
-            .key
-            .verify_strict(&formatted_challenge, &signature)
-            .is_ok();
-
-        Ok((valid, challenge_context))
-    }
-}
-
-type Output = Result<UserAgentResponse, Status>;
-
-fn auth_response(payload: ServerAuthPayload) -> UserAgentResponse {
-    UserAgentResponse {
-        payload: Some(UserAgentResponsePayload::AuthMessage(AuthServerMessage {
-            payload: Some(payload),
-        })),
-    }
-}
-
-#[messages]
-impl UserAgentActor {
-    #[message(ctx)]
-    pub async fn handle_auth_challenge_request(
-        &mut self,
-        req: AuthChallengeRequest,
-        ctx: &mut Context<Self, Output>,
-    ) -> Output {
-        let pubkey = req.pubkey.as_array().ok_or(Status::invalid_argument(
-            "Expected pubkey to have specific length",
-        ))?;
-        let pubkey = VerifyingKey::from_bytes(pubkey).map_err(|err| {
-            error!(?pubkey, "Failed to convert to VerifyingKey");
-            Status::invalid_argument("Failed to convert pubkey to VerifyingKey")
-        })?;
-
-        self.transition(UserAgentEvents::AuthRequest(AuthRequestContext {
-            pubkey,
-            bootstrap_token: req.bootstrap_token.clone(),
-        }))?;
-
-        match req.bootstrap_token {
-            Some(token) => self.auth_with_bootstrap_token(pubkey, token).await,
-            None => self.auth_with_challenge(pubkey, req.pubkey).await,
-        }
-    }
-
-    #[message(ctx)]
-    pub async fn handle_auth_challenge_solution(
-        &mut self,
-        solution: auth::AuthChallengeSolution,
-        ctx: &mut Context<Self, Output>,
-    ) -> Output {
-        let (valid, challenge_context) = self.verify_challenge_solution(&solution)?;
-
-        if valid {
-            info!(
-                ?challenge_context,
-                "Client provided valid solution to authentication challenge"
-            );
-            self.transition(UserAgentEvents::ReceivedGoodSolution)?;
-            Ok(auth_response(ServerAuthPayload::AuthOk(AuthOk {})))
-        } else {
-            error!("Client provided invalid solution to authentication challenge");
-            self.transition(UserAgentEvents::ReceivedBadSolution)?;
-            Err(Status::unauthenticated("Invalid challenge solution"))
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use arbiter_proto::proto::{
-        UserAgentResponse, auth::{AuthChallengeRequest, AuthOk},
-        user_agent_response::Payload as UserAgentResponsePayload,
-    };
-    use kameo::actor::Spawn;
-
-    use crate::{
-        actors::user_agent::HandleAuthChallengeRequest, context::bootstrap::BootstrapActor, db,
-    };
-
-    use super::UserAgentActor;
-
-    #[tokio::test]
-    #[test_log::test]
-    pub async fn test_bootstrap_token_auth() {
-        let db = db::create_test_pool().await;
-        // explicitly not installing any user_agent pubkeys
-        let bootstrapper = BootstrapActor::new(&db).await.unwrap(); // this will create bootstrap token
-        let token = bootstrapper.get_token().unwrap();
-
-        let bootstrapper_ref = BootstrapActor::spawn(bootstrapper);
-        let user_agent = UserAgentActor::new_manual(
-            db.clone(),
-            bootstrapper_ref,
-            tokio::sync::mpsc::channel(1).0, // dummy channel, we won't actually send responses in this test
-        );
-        let user_agent_ref = UserAgentActor::spawn(user_agent);
-
-        // simulate client sending auth request with bootstrap token
-        let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-        let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
-
-        let result = user_agent_ref
-            .ask(HandleAuthChallengeRequest {
-                req: AuthChallengeRequest {
-                    pubkey: pubkey_bytes,
-                    bootstrap_token: Some(token),
-                },
-            })
-            .await
-            .expect("Shouldn't fail to send message");
-        
-        // auth succeeded
-        assert_eq!(
-            result,
-            UserAgentResponse {
-                payload: Some(UserAgentResponsePayload::AuthMessage(
-                    arbiter_proto::proto::auth::ServerMessage {
-                        payload: Some(arbiter_proto::proto::auth::server_message::Payload::AuthOk(
-                            AuthOk {},
-                        )),
-                    },
-                )),
-            }
-        );
-    }
-}
-
-mod transport;
-pub(crate) use transport::handle_user_agent;