merge: @main into client-integrity-verification

Reviewed-on: #45

.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

IMPLEMENTATION.md

@@ -67,7 +67,18 @@ The `program_client.nonce` column stores the **next usable nonce** — i.e. it i
 ## Cryptography
 
 ### Authentication
-- **Signature scheme:** ed25519
+- **Client protocol:** ed25519
+
+### 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:** RSA, Ed25519, ECDSA (secp256k1)
+- **Why:** the user agent authenticates with keys backed by platform facilities, and those facilities differ by platform
+- **Apple Silicon Secure Enclave / Secure Element:** ECDSA-only in practice
+- **Windows Hello / TPM 2.0:** currently RSA-backed in our integration
+
+This is why the user-agent auth protocol carries an explicit `KeyType`, while the SDK client protocol remains fixed to ed25519.
 
 ### Encryption at Rest
 - **Scheme:** Symmetric AEAD — currently **XChaCha20-Poly1305**
@@ -148,7 +159,7 @@ The central abstraction is the `Policy` trait. Each implementation handles one s
 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`, etc.) holding type-specific configuration.
+- **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.
 
@@ -171,7 +182,6 @@ These are checked centrally in `check_shared_constraints` before policy evaluati
 - **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.
-- **Nonce management is not implemented.** The architecture lists nonce deduplication as a core responsibility, but no nonce tracking or enforcement exists yet.
 
 ---
 
@@ -179,5 +189,5 @@ These are checked centrally in `check_shared_constraints` before policy evaluati
 
 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)

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 |

server/Cargo.lock

@@ -724,6 +724,7 @@ name = "arbiter-server"
 version = "0.1.0"
 dependencies = [
  "alloy",
+ "anyhow",
  "arbiter-proto",
  "arbiter-tokens-registry",
  "argon2",
@@ -737,11 +738,11 @@ dependencies = [
  "ed25519-dalek",
  "fatality",
  "futures",
+ "hmac",
  "insta",
  "k256",
  "kameo",
  "memsafe",
- "miette",
  "pem",
  "prost-types",
  "rand 0.10.0",

server/Cargo.toml

@@ -22,7 +22,6 @@ chrono = { version = "0.4.44", features = ["serde"] }
 rand = "0.10.0"
 rustls = { version = "0.23.37", features = ["aws-lc-rs"] }
 smlang = "0.8.0"
-miette = { version = "7.6.0", features = ["fancy", "serde"] }
 thiserror = "2.0.18"
 async-trait = "0.1.89"
 futures = "0.3.32"
@@ -43,3 +42,4 @@ k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
 rsa = { version = "0.9", features = ["sha2"] }
 sha2 = "0.10"
 spki = "0.7"
+miette = { version = "7.6.0", features = ["fancy", "serde"] }

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

@@ -122,9 +122,7 @@ async fn receive_auth_confirmation(
         .await
         .map_err(|_| AuthError::UnexpectedAuthResponse)?;
 
-    let payload = response
-        .payload
-        .ok_or(AuthError::UnexpectedAuthResponse)?;
+    let payload = response.payload.ok_or(AuthError::UnexpectedAuthResponse)?;
     match payload {
         ClientResponsePayload::Auth(response) => match response.payload {
             Some(AuthResponsePayload::Result(result))

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

@@ -1,4 +1,3 @@
-
 use std::io::{self, Write};
 
 use arbiter_client::ArbiterClient;
@@ -22,8 +21,6 @@ async fn main() {
         return;
     }
 
-   
-
     let url = match ArbiterUrl::try_from(input) {
         Ok(url) => url,
         Err(err) => {
@@ -32,7 +29,7 @@ async fn main() {
         }
     };
 
-     println!("{:#?}", url);
+    println!("{:#?}", url);
 
     let metadata = ClientMetadata {
         name: "arbiter-client test_connect".to_string(),
@@ -44,4 +41,4 @@ async fn main() {
         Ok(_) => println!("Connected and authenticated successfully."),
         Err(err) => eprintln!("Failed to connect: {:#?}", err),
     }
-}
+}

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

@@ -1,11 +1,16 @@
-use arbiter_proto::{ClientMetadata, proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl};
+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}
+    StorageError,
+    auth::{AuthError, authenticate},
+    storage::{FileSigningKeyStorage, SigningKeyStorage},
+    transport::{BUFFER_LENGTH, ClientTransport},
 };
 
 #[cfg(feature = "evm")]
@@ -30,7 +35,6 @@ pub enum Error {
 
     #[error("Storage error")]
     Storage(#[from] StorageError),
-    
 }
 
 pub struct ArbiterClient {
@@ -61,10 +65,11 @@ impl ArbiterClient {
         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 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);

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

@@ -9,4 +9,4 @@ pub use client::{ArbiterClient, Error};
 pub use storage::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
 
 #[cfg(feature = "evm")]
-pub use wallets::evm::ArbiterEvmWallet;
+pub use wallets::evm::{ArbiterEvmSignTransactionError, ArbiterEvmWallet};

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

@@ -10,14 +10,48 @@ use tokio::sync::Mutex;
 
 use arbiter_proto::proto::{
     client::{
-        ClientRequest, client_request::Payload as ClientRequestPayload,
+        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::evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    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,
@@ -96,12 +130,14 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
         transport
             .send(ClientRequest {
                 request_id,
-                payload: Some(ClientRequestPayload::EvmSignTransaction(
-                    arbiter_proto::proto::evm::EvmSignTransactionRequest {
-                        wallet_address: self.address.to_vec(),
-                        rlp_transaction,
-                    },
-                )),
+                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"))?;
@@ -121,12 +157,21 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
             .payload
             .ok_or_else(|| Error::other("missing evm sign transaction response payload"))?;
 
-        let ClientResponsePayload::EvmSignTransaction(response) = payload else {
+        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"))?;
@@ -136,9 +181,9 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
                 Signature::try_from(signature.as_slice())
                     .map_err(|_| Error::other("invalid signature returned by server"))
             }
-            EvmSignTransactionResult::EvalError(eval_error) => Err(Error::other(format!(
-                "transaction rejected by policy: {eval_error:?}"
-            ))),
+            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-proto/src/url.rs

@@ -7,7 +7,6 @@ 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,

server/crates/arbiter-server/Cargo.toml

@@ -25,7 +25,6 @@ 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"] }
@@ -49,10 +48,12 @@ pem = "3.0.6"
 k256.workspace = true
 rsa.workspace = true
 sha2.workspace = true
+hmac = "0.12"
 spki.workspace = true
 alloy.workspace = true
 prost-types.workspace = true
 arbiter-tokens-registry.path = "../arbiter-tokens-registry"
+anyhow = "1.0.102"
 
 [dev-dependencies]
 insta = "1.46.3"

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

@@ -47,6 +47,7 @@ create table if not exists useragent_client (
     id integer not null primary key,
     nonce integer not null default(1), -- used for auth challenge
     public_key blob not null,
+    pubkey_integrity_tag blob,
     key_type integer not null default(1), -- 1=Ed25519, 2=ECDSA(secp256k1)
     created_at integer not null default(unixepoch ('now')),
     updated_at integer not null default(unixepoch ('now'))

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

@@ -2,7 +2,7 @@ use arbiter_proto::{BOOTSTRAP_PATH, home_path};
 use diesel::QueryDsl;
 use diesel_async::RunQueryDsl;
 use kameo::{Actor, messages};
-use miette::Diagnostic;
+
 use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
 use thiserror::Error;
 
@@ -25,18 +25,15 @@ pub async fn generate_token() -> Result<String, std::io::Error> {
     Ok(token)
 }
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum Error {
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::database))]
     Database(#[from] db::PoolError),
 
     #[error("Database query error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::database_query))]
     Query(#[from] diesel::result::Error),
 
     #[error("I/O error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::io))]
     Io(#[from] std::io::Error),
 }
 

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

@@ -287,10 +287,7 @@ where
     Ok(())
 }
 
-pub async fn authenticate<T>(
-    props: &mut ClientConnection,
-    transport: &mut T,
-) -> Result<i32, Error>
+pub async fn authenticate<T>(props: &mut ClientConnection, transport: &mut T) -> Result<i32, Error>
 where
     T: Bi<Inbound, Result<Outbound, Error>> + Send + ?Sized,
 {
@@ -319,7 +316,7 @@ where
 
     sync_client_metadata(&props.db, info.id, &metadata).await?;
     challenge_client(transport, pubkey, info.current_nonce).await?;
-    
+
     transport
         .send(Ok(Outbound::AuthSuccess))
         .await

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

@@ -20,10 +20,7 @@ pub struct ClientConnection {
 
 impl ClientConnection {
     pub fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        Self {
-            db,
-            actors,
-        }
+        Self { db, actors }
     }
 }
 

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

@@ -6,11 +6,10 @@ use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
 use crate::{
     actors::{
         GlobalActors,
-        client::ClientConnection, flow_coordinator::RegisterClient,
-       
+        client::ClientConnection,
         evm::{ClientSignTransaction, SignTransactionError},
+        flow_coordinator::RegisterClient,
         keyholder::KeyHolderState,
-       
     },
     db,
     evm::VetError,
@@ -95,7 +94,10 @@ impl Actor for ClientSession {
 impl ClientSession {
     pub fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
         let props = ClientConnection::new(db, actors);
-        Self { props, client_id: 0 }
+        Self {
+            props,
+            client_id: 0,
+        }
     }
 }
 

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

@@ -25,45 +25,36 @@ use crate::{
 
 pub use crate::evm::safe_signer;
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum SignTransactionError {
     #[error("Wallet not found")]
-    #[diagnostic(code(arbiter::evm::sign::wallet_not_found))]
     WalletNotFound,
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::database))]
     Database(#[from] DatabaseError),
 
     #[error("Keyholder error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::keyholder))]
     Keyholder(#[from] crate::actors::keyholder::Error),
 
     #[error("Keyholder mailbox error")]
-    #[diagnostic(code(arbiter::evm::sign::keyholder_send))]
     KeyholderSend,
 
     #[error("Signing error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::signing))]
     Signing(#[from] alloy::signers::Error),
 
     #[error("Policy error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::vet))]
     Vet(#[from] evm::VetError),
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Keyholder error: {0}")]
-    #[diagnostic(code(arbiter::evm::keyholder))]
     Keyholder(#[from] crate::actors::keyholder::Error),
 
     #[error("Keyholder mailbox error")]
-    #[diagnostic(code(arbiter::evm::keyholder_send))]
     KeyholderSend,
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::evm::database))]
     Database(#[from] DatabaseError),
 }
 

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

@@ -15,7 +15,7 @@ use crate::actors::{
 pub struct Args {
     pub client: ClientProfile,
     pub user_agents: Vec<ActorRef<UserAgentSession>>,
-    pub reply: ReplySender<Result<bool, ApprovalError>>
+    pub reply: ReplySender<Result<bool, ApprovalError>>,
 }
 
 pub struct ClientApprovalController {
@@ -39,7 +39,11 @@ impl Actor for ClientApprovalController {
     type Error = ();
 
     async fn on_start(
-        Args { client, mut user_agents, reply }: Self::Args,
+        Args {
+            client,
+            mut user_agents,
+            reply,
+        }: Self::Args,
         actor_ref: ActorRef<Self>,
     ) -> Result<Self, Self::Error> {
         let this = Self {

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

@@ -8,7 +8,14 @@ use kameo::{Actor, Reply, messages};
 use strum::{EnumDiscriminants, IntoDiscriminant};
 use tracing::{error, info};
 
-use crate::safe_cell::SafeCell;
+use crate::{
+    crypto::{
+        KeyCell, derive_key,
+        encryption::v1::{self, Nonce},
+        integrity::v1::compute_integrity_tag,
+    },
+    safe_cell::SafeCell,
+};
 use crate::{
     db::{
         self,
@@ -17,9 +24,6 @@ use crate::{
     },
     safe_cell::SafeCellHandle as _,
 };
-use encryption::v1::{self, KeyCell, Nonce};
-
-pub mod encryption;
 
 #[derive(Default, EnumDiscriminants)]
 #[strum_discriminants(derive(Reply), vis(pub), name(KeyHolderState))]
@@ -35,36 +39,28 @@ enum State {
     },
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Keyholder is already bootstrapped")]
-    #[diagnostic(code(arbiter::keyholder::already_bootstrapped))]
     AlreadyBootstrapped,
     #[error("Keyholder is not bootstrapped")]
-    #[diagnostic(code(arbiter::keyholder::not_bootstrapped))]
     NotBootstrapped,
     #[error("Invalid key provided")]
-    #[diagnostic(code(arbiter::keyholder::invalid_key))]
     InvalidKey,
 
     #[error("Requested aead entry not found")]
-    #[diagnostic(code(arbiter::keyholder::aead_not_found))]
     NotFound,
 
     #[error("Encryption error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::encryption_error))]
     Encryption(#[from] chacha20poly1305::aead::Error),
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::database_error))]
     DatabaseConnection(#[from] db::PoolError),
 
     #[error("Database transaction error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::database_transaction_error))]
     DatabaseTransaction(#[from] diesel::result::Error),
 
     #[error("Broken database")]
-    #[diagnostic(code(arbiter::keyholder::broken_database))]
     BrokenDatabase,
 }
 
@@ -114,14 +110,13 @@ impl KeyHolder {
                         .first(conn)
                         .await?;
 
-                    let mut nonce =
-                        v1::Nonce::try_from(current_nonce.as_slice()).map_err(|_| {
-                            error!(
-                                "Broken database: invalid nonce for root key history id={}",
-                                root_key_id
-                            );
-                            Error::BrokenDatabase
-                        })?;
+                    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)
@@ -144,12 +139,12 @@ impl KeyHolder {
             return Err(Error::AlreadyBootstrapped);
         }
         let salt = v1::generate_salt();
-        let mut seal_key = v1::derive_seal_key(seal_key_raw, &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 = v1::Nonce::default();
-        let data_encryption_nonce = v1::Nonce::default();
+        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();
@@ -224,7 +219,7 @@ impl KeyHolder {
             error!("Broken database: invalid salt for root key");
             Error::BrokenDatabase
         })?;
-        let mut seal_key = v1::derive_seal_key(seal_key_raw, &salt);
+        let mut seal_key = derive_key(seal_key_raw, &salt);
 
         let mut root_key = SafeCell::new(current_key.ciphertext.clone());
 
@@ -244,7 +239,7 @@ impl KeyHolder {
 
         self.state = State::Unsealed {
             root_key_history_id: current_key.id,
-            root_key: v1::KeyCell::try_from(root_key).map_err(|err| {
+            root_key: KeyCell::try_from(root_key).map_err(|err| {
                 error!(?err, "Broken database: invalid encryption key size");
                 Error::BrokenDatabase
             })?,
@@ -255,7 +250,22 @@ impl KeyHolder {
         Ok(())
     }
 
-    // Decrypts the `aead_encrypted` entry with the given ID and returns the plaintext
+    // Signs a generic integrity payload using the vault-derived integrity key
+    #[message]
+    pub fn sign_integrity_tag(
+        &mut self,
+        purpose_tag: Vec<u8>,
+        data_parts: Vec<Vec<u8>>,
+    ) -> Result<Vec<u8>, Error> {
+        let State::Unsealed { root_key, .. } = &mut self.state else {
+            return Err(Error::NotBootstrapped);
+        };
+
+        let tag =
+            compute_integrity_tag(root_key, &purpose_tag, data_parts.iter().map(Vec::as_slice));
+        Ok(tag.to_vec())
+    }
+
     #[message]
     pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, Error> {
         let State::Unsealed { root_key, .. } = &mut self.state else {
@@ -291,6 +301,7 @@ impl KeyHolder {
         let State::Unsealed {
             root_key,
             root_key_history_id,
+            ..
         } = &mut self.state
         else {
             return Err(Error::NotBootstrapped);

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

@@ -1,5 +1,4 @@
 use kameo::actor::{ActorRef, Spawn};
-use miette::Diagnostic;
 use thiserror::Error;
 
 use crate::{
@@ -17,14 +16,12 @@ pub mod flow_coordinator;
 pub mod keyholder;
 pub mod user_agent;
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum SpawnError {
     #[error("Failed to spawn Bootstrapper actor")]
-    #[diagnostic(code(SpawnError::Bootstrapper))]
     Bootstrapper(#[from] bootstrap::Error),
 
     #[error("Failed to spawn KeyHolder actor")]
-    #[diagnostic(code(SpawnError::KeyHolder))]
     KeyHolder(#[from] keyholder::Error),
 }
 

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

@@ -1,17 +1,27 @@
 use arbiter_proto::transport::Bi;
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
 use diesel_async::RunQueryDsl;
+use kameo::error::SendError;
 use tracing::error;
 
 use super::Error;
 use crate::{
     actors::{
         bootstrap::ConsumeToken,
+        keyholder::{self, SignIntegrityTag},
         user_agent::{AuthPublicKey, UserAgentConnection, auth::Outbound},
     },
+    crypto::integrity::v1::USERAGENT_INTEGRITY_TAG,
     db::schema,
 };
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AttestationStatus {
+    Attested,
+    NotAttested,
+    Unavailable,
+}
+
 pub struct ChallengeRequest {
     pub pubkey: AuthPublicKey,
 }
@@ -40,7 +50,11 @@ smlang::statemachine!(
     }
 );
 
-async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Result<i32, Error> {
+async fn create_nonce(
+    db: &crate::db::DatabasePool,
+    pubkey_bytes: &[u8],
+    key_type: crate::db::models::KeyType,
+) -> Result<i32, Error> {
     let mut db_conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::internal("Database unavailable")
@@ -50,12 +64,14 @@ async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Resu
             Box::pin(async move {
                 let current_nonce = schema::useragent_client::table
                     .filter(schema::useragent_client::public_key.eq(pubkey_bytes.to_vec()))
+                    .filter(schema::useragent_client::key_type.eq(key_type))
                     .select(schema::useragent_client::nonce)
                     .first::<i32>(conn)
                     .await?;
 
                 update(schema::useragent_client::table)
                     .filter(schema::useragent_client::public_key.eq(pubkey_bytes.to_vec()))
+                    .filter(schema::useragent_client::key_type.eq(key_type))
                     .set(schema::useragent_client::nonce.eq(current_nonce + 1))
                     .execute(conn)
                     .await?;
@@ -75,7 +91,11 @@ async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Resu
         })
 }
 
-async fn register_key(db: &crate::db::DatabasePool, pubkey: &AuthPublicKey) -> Result<(), Error> {
+async fn register_key(
+    db: &crate::db::DatabasePool,
+    pubkey: &AuthPublicKey,
+    integrity_tag: Option<Vec<u8>>,
+) -> Result<(), Error> {
     let pubkey_bytes = pubkey.to_stored_bytes();
     let key_type = pubkey.key_type();
     let mut conn = db.get().await.map_err(|e| {
@@ -88,6 +108,7 @@ async fn register_key(db: &crate::db::DatabasePool, pubkey: &AuthPublicKey) -> R
             schema::useragent_client::public_key.eq(pubkey_bytes),
             schema::useragent_client::nonce.eq(1),
             schema::useragent_client::key_type.eq(key_type),
+            schema::useragent_client::pubkey_integrity_tag.eq(integrity_tag),
         ))
         .execute(&mut conn)
         .await
@@ -120,8 +141,15 @@ where
         &mut self,
         ChallengeRequest { pubkey }: ChallengeRequest,
     ) -> Result<ChallengeContext, Self::Error> {
+        match self.verify_pubkey_attestation_status(&pubkey).await? {
+            AttestationStatus::Attested | AttestationStatus::Unavailable => {}
+            AttestationStatus::NotAttested => {
+                return Err(Error::InvalidChallengeSolution);
+            }
+        }
+
         let stored_bytes = pubkey.to_stored_bytes();
-        let nonce = create_nonce(&self.conn.db, &stored_bytes).await?;
+        let nonce = create_nonce(&self.conn.db, &stored_bytes, pubkey.key_type()).await?;
 
         self.transport
             .send(Ok(Outbound::AuthChallenge { nonce }))
@@ -161,7 +189,15 @@ where
             return Err(Error::InvalidBootstrapToken);
         }
 
-        register_key(&self.conn.db, &pubkey).await?;
+        let integrity_tag = self
+            .try_sign_pubkey_integrity_tag(&pubkey)
+            .await
+            .map_err(|err| {
+                error!(?err, "Failed to sign user-agent pubkey integrity tag");
+                Error::internal("Failed to sign user-agent pubkey integrity tag")
+            })?;
+
+        register_key(&self.conn.db, &pubkey, integrity_tag).await?;
 
         self.transport
             .send(Ok(Outbound::AuthSuccess))
@@ -210,16 +246,111 @@ where
             }
         };
 
-        if !valid {
-            error!("Invalid challenge solution signature");
-            return Err(Error::InvalidChallengeSolution);
+        match valid {
+            true => {
+                self.transport
+                    .send(Ok(Outbound::AuthSuccess))
+                    .await
+                    .map_err(|_| Error::Transport)?;
+                Ok(key.clone())
+            }
+            false => {
+                self.transport
+                    .send(Err(Error::InvalidChallengeSolution))
+                    .await
+                    .map_err(|_| Error::Transport)?;
+                Err(Error::InvalidChallengeSolution)
+            }
+        }
+    }
+}
+
+impl<T> AuthContext<'_, T>
+where
+    T: Bi<super::Inbound, Result<super::Outbound, Error>> + Send,
+{
+    async fn try_sign_pubkey_integrity_tag(
+        &self,
+        pubkey: &AuthPublicKey,
+    ) -> Result<Option<Vec<u8>>, Error> {
+        let signed = self
+            .conn
+            .actors
+            .key_holder
+            .ask(SignIntegrityTag {
+                purpose_tag: USERAGENT_INTEGRITY_TAG.to_vec(),
+                data_parts: vec![
+                    (pubkey.key_type() as i32).to_be_bytes().to_vec(),
+                    pubkey.to_stored_bytes(),
+                ],
+            })
+            .await;
+
+        match signed {
+            Ok(tag) => Ok(Some(tag)),
+            Err(SendError::HandlerError(keyholder::Error::NotBootstrapped)) => Ok(None),
+            Err(SendError::HandlerError(err)) => {
+                error!(
+                    ?err,
+                    "Keyholder failed to sign user-agent pubkey integrity tag"
+                );
+                Err(Error::internal(
+                    "Keyholder failed to sign user-agent pubkey integrity tag",
+                ))
+            }
+            Err(err) => {
+                error!(
+                    ?err,
+                    "Failed to contact keyholder for user-agent pubkey integrity tag"
+                );
+                Err(Error::internal(
+                    "Failed to contact keyholder for user-agent pubkey integrity tag",
+                ))
+            }
+        }
+    }
+
+    async fn verify_pubkey_attestation_status(
+        &self,
+        pubkey: &AuthPublicKey,
+    ) -> Result<AttestationStatus, Error> {
+        let stored_tag: Option<Option<Vec<u8>>> = {
+            let mut conn = self.conn.db.get().await.map_err(|e| {
+                error!(error = ?e, "Database pool error");
+                Error::internal("Database unavailable")
+            })?;
+
+            schema::useragent_client::table
+                .filter(schema::useragent_client::public_key.eq(pubkey.to_stored_bytes()))
+                .filter(schema::useragent_client::key_type.eq(pubkey.key_type()))
+                .select(schema::useragent_client::pubkey_integrity_tag)
+                .first::<Option<Vec<u8>>>(&mut conn)
+                .await
+                .optional()
+                .map_err(|e| {
+                    error!(error = ?e, "Database error");
+                    Error::internal("Database operation failed")
+                })?
+        };
+
+        let Some(stored_tag) = stored_tag else {
+            return Err(Error::UnregisteredPublicKey);
+        };
+
+        let Some(expected_tag) = self.try_sign_pubkey_integrity_tag(pubkey).await? else {
+            return Ok(AttestationStatus::Unavailable);
+        };
+
+        match stored_tag {
+            Some(stored_tag) if stored_tag == expected_tag => Ok(AttestationStatus::Attested),
+            Some(_) => {
+                error!("User-agent pubkey integrity tag mismatch");
+                Ok(AttestationStatus::NotAttested)
+            }
+            None => {
+                error!("Missing pubkey integrity tag for registered key while vault is unsealed");
+                Ok(AttestationStatus::NotAttested)
+            }
         }
-
-        self.transport
-            .send(Ok(Outbound::AuthSuccess))
-            .await
-            .map_err(|_| Error::Transport)?;
-
-        Ok(key.clone())
     }
 }

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

@@ -5,8 +5,8 @@ use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
 use diesel_async::{AsyncConnection, RunQueryDsl};
 use kameo::error::SendError;
-use kameo::prelude::Context;
 use kameo::messages;
+use kameo::prelude::Context;
 use tracing::{error, info};
 use x25519_dalek::{EphemeralSecret, PublicKey};
 

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

@@ -1,6 +1,5 @@
 use std::sync::Arc;
 
-use miette::Diagnostic;
 use thiserror::Error;
 
 use crate::{
@@ -11,30 +10,24 @@ use crate::{
 
 pub mod tls;
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum InitError {
     #[error("Database setup failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_setup))]
     DatabaseSetup(#[from] db::DatabaseSetupError),
 
     #[error("Connection acquire failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_pool))]
     DatabasePool(#[from] db::PoolError),
 
     #[error("Database query error: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_query))]
     DatabaseQuery(#[from] diesel::result::Error),
 
     #[error("TLS initialization failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::tls_init))]
     Tls(#[from] tls::InitError),
 
     #[error("Actor spawn failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::actor_spawn))]
     ActorSpawn(#[from] crate::actors::SpawnError),
 
     #[error("I/O Error: {0}")]
-    #[diagnostic(code(arbiter_server::init::io))]
     Io(#[from] std::io::Error),
 }
 

server/crates/arbiter-server/src/context/tls.rs

@@ -1,8 +1,8 @@
-use std::{net::IpAddr, string::FromUtf8Error};
+use std::{net::Ipv4Addr, string::FromUtf8Error};
 
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper as _};
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use miette::Diagnostic;
+
 use pem::Pem;
 use rcgen::{
     BasicConstraints, Certificate, CertificateParams, CertifiedIssuer, DistinguishedName, DnType,
@@ -29,30 +29,24 @@ const ENCODE_CONFIG: pem::EncodeConfig = {
     pem::EncodeConfig::new().set_line_ending(line_ending)
 };
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum InitError {
     #[error("Key generation error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_generation))]
     KeyGeneration(#[from] rcgen::Error),
 
     #[error("Key invalid format: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_invalid_format))]
     KeyInvalidFormat(#[from] FromUtf8Error),
 
     #[error("Key deserialization error: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_deserialization))]
     KeyDeserializationError(rcgen::Error),
 
     #[error("Database error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::database_error))]
     DatabaseError(#[from] diesel::result::Error),
 
     #[error("Pem deserialization error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::pem_deserialization))]
     PemDeserializationError(#[from] rustls::pki_types::pem::Error),
 
     #[error("Database pool acquire error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::database_pool_acquire))]
     DatabasePoolAcquire(#[from] db::PoolError),
 }
 
@@ -116,9 +110,7 @@ impl TlsCa {
         ];
         params
             .subject_alt_names
-            .push(SanType::IpAddress(IpAddr::from([
-                127, 0, 0, 1,
-            ])));
+            .push(SanType::IpAddress(Ipv4Addr::LOCALHOST.into()));
 
         let mut dn = DistinguishedName::new();
         dn.push(DnType::CommonName, "Arbiter Instance Leaf");

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

@@ -0,0 +1,109 @@
+use argon2::password_hash::Salt as ArgonSalt;
+
+use rand::{
+    Rng as _, SeedableRng,
+    rngs::{StdRng, SysRng},
+};
+
+pub const ROOT_KEY_TAG: &[u8] = "arbiter/seal/v1".as_bytes();
+pub const TAG: &[u8] = "arbiter/private-key/v1".as_bytes();
+
+pub const NONCE_LENGTH: usize = 24;
+
+#[derive(Default)]
+pub struct Nonce(pub [u8; NONCE_LENGTH]);
+impl Nonce {
+    pub fn increment(&mut self) {
+        for i in (0..self.0.len()).rev() {
+            if self.0[i] == 0xFF {
+                self.0[i] = 0;
+            } else {
+                self.0[i] += 1;
+                break;
+            }
+        }
+    }
+
+    pub fn to_vec(&self) -> Vec<u8> {
+        self.0.to_vec()
+    }
+}
+impl<'a> TryFrom<&'a [u8]> for Nonce {
+    type Error = ();
+
+    fn try_from(value: &'a [u8]) -> Result<Self, Self::Error> {
+        if value.len() != NONCE_LENGTH {
+            return Err(());
+        }
+        let mut nonce = [0u8; NONCE_LENGTH];
+        nonce.copy_from_slice(value);
+        Ok(Self(nonce))
+    }
+}
+
+pub type Salt = [u8; ArgonSalt::RECOMMENDED_LENGTH];
+
+pub fn generate_salt() -> Salt {
+    let mut salt = Salt::default();
+    #[allow(
+        clippy::unwrap_used,
+        reason = "Rng failure is unrecoverable and should panic"
+    )]
+    let mut rng = StdRng::try_from_rng(&mut SysRng).unwrap();
+    rng.fill_bytes(&mut salt);
+    salt
+}
+
+#[cfg(test)]
+mod tests {
+    use std::ops::Deref as _;
+
+    use super::*;
+    use crate::{
+        crypto::derive_key,
+        safe_cell::{SafeCell, SafeCellHandle as _},
+    };
+
+    #[test]
+    pub fn derive_seal_key_deterministic() {
+        static PASSWORD: &[u8] = b"password";
+        let password = SafeCell::new(PASSWORD.to_vec());
+        let password2 = SafeCell::new(PASSWORD.to_vec());
+        let salt = generate_salt();
+
+        let mut key1 = derive_key(password, &salt);
+        let mut key2 = derive_key(password2, &salt);
+
+        let key1_reader = key1.0.read();
+        let key2_reader = key2.0.read();
+
+        assert_eq!(key1_reader.deref(), key2_reader.deref());
+    }
+
+    #[test]
+    pub fn successful_derive() {
+        static PASSWORD: &[u8] = b"password";
+        let password = SafeCell::new(PASSWORD.to_vec());
+        let salt = generate_salt();
+
+        let mut key = derive_key(password, &salt);
+        let key_reader = key.0.read();
+        let key_ref = key_reader.deref();
+
+        assert_ne!(key_ref.as_slice(), &[0u8; 32][..]);
+    }
+
+    #[test]
+    // We should fuzz this
+    pub fn test_nonce_increment() {
+        let mut nonce = Nonce([0u8; NONCE_LENGTH]);
+        nonce.increment();
+
+        assert_eq!(
+            nonce.0,
+            [
+                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
+            ]
+        );
+    }
+}

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

@@ -0,0 +1 @@
+pub mod v1;

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

@@ -0,0 +1,78 @@
+use crate::{crypto::KeyCell, safe_cell::SafeCellHandle as _};
+use chacha20poly1305::Key;
+use hmac::Mac as _;
+
+pub const USERAGENT_INTEGRITY_DERIVE_TAG: &[u8] = "arbiter/useragent/integrity-key/v1".as_bytes();
+pub const USERAGENT_INTEGRITY_TAG: &[u8] = "arbiter/useragent/pubkey-entry/v1".as_bytes();
+
+/// Computes an integrity tag for a specific domain and payload shape.
+pub fn compute_integrity_tag<'a, I>(
+    integrity_key: &mut KeyCell,
+    purpose_tag: &[u8],
+    data_parts: I,
+) -> [u8; 32]
+where
+    I: IntoIterator<Item = &'a [u8]>,
+{
+    type HmacSha256 = hmac::Hmac<sha2::Sha256>;
+
+    let mut output_tag = [0u8; 32];
+    integrity_key.0.read_inline(|integrity_key_bytes: &Key| {
+        let mut mac = <HmacSha256 as hmac::Mac>::new_from_slice(integrity_key_bytes.as_ref())
+            .expect("HMAC key initialization must not fail for 32-byte key");
+        mac.update(purpose_tag);
+        for data_part in data_parts {
+            mac.update(data_part);
+        }
+        output_tag.copy_from_slice(&mac.finalize().into_bytes());
+    });
+
+    output_tag
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{
+        crypto::{derive_key, encryption::v1::generate_salt},
+        safe_cell::{SafeCell, SafeCellHandle as _},
+    };
+
+    use super::{USERAGENT_INTEGRITY_TAG, compute_integrity_tag};
+
+    #[test]
+    pub fn integrity_tag_deterministic() {
+        let salt = generate_salt();
+        let mut integrity_key = derive_key(SafeCell::new(b"password".to_vec()), &salt);
+        let key_type = 1i32.to_be_bytes();
+        let t1 = compute_integrity_tag(
+            &mut integrity_key,
+            USERAGENT_INTEGRITY_TAG,
+            [key_type.as_slice(), b"pubkey".as_ref()],
+        );
+        let t2 = compute_integrity_tag(
+            &mut integrity_key,
+            USERAGENT_INTEGRITY_TAG,
+            [key_type.as_slice(), b"pubkey".as_ref()],
+        );
+        assert_eq!(t1, t2);
+    }
+
+    #[test]
+    pub fn integrity_tag_changes_with_payload() {
+        let salt = generate_salt();
+        let mut integrity_key = derive_key(SafeCell::new(b"password".to_vec()), &salt);
+        let key_type_1 = 1i32.to_be_bytes();
+        let key_type_2 = 2i32.to_be_bytes();
+        let t1 = compute_integrity_tag(
+            &mut integrity_key,
+            USERAGENT_INTEGRITY_TAG,
+            [key_type_1.as_slice(), b"pubkey".as_ref()],
+        );
+        let t2 = compute_integrity_tag(
+            &mut integrity_key,
+            USERAGENT_INTEGRITY_TAG,
+            [key_type_2.as_slice(), b"pubkey".as_ref()],
+        );
+        assert_ne!(t1, t2);
+    }
+}

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

@@ -1,52 +1,21 @@
 use std::ops::Deref as _;
 
-use argon2::{Algorithm, Argon2, password_hash::Salt as ArgonSalt};
+use argon2::{Algorithm, Argon2};
 use chacha20poly1305::{
     AeadInPlace, Key, KeyInit as _, XChaCha20Poly1305, XNonce,
     aead::{AeadMut, Error, Payload},
 };
 use rand::{
-    Rng as _, SeedableRng,
+    Rng as _, SeedableRng as _,
     rngs::{StdRng, SysRng},
 };
 
 use crate::safe_cell::{SafeCell, SafeCellHandle as _};
 
-pub const ROOT_KEY_TAG: &[u8] = "arbiter/seal/v1".as_bytes();
-pub const TAG: &[u8] = "arbiter/private-key/v1".as_bytes();
+pub mod encryption;
+pub mod integrity;
 
-pub const NONCE_LENGTH: usize = 24;
-
-#[derive(Default)]
-pub struct Nonce([u8; NONCE_LENGTH]);
-impl Nonce {
-    pub fn increment(&mut self) {
-        for i in (0..self.0.len()).rev() {
-            if self.0[i] == 0xFF {
-                self.0[i] = 0;
-            } else {
-                self.0[i] += 1;
-                break;
-            }
-        }
-    }
-
-    pub fn to_vec(&self) -> Vec<u8> {
-        self.0.to_vec()
-    }
-}
-impl<'a> TryFrom<&'a [u8]> for Nonce {
-    type Error = ();
-
-    fn try_from(value: &'a [u8]) -> Result<Self, Self::Error> {
-        if value.len() != NONCE_LENGTH {
-            return Err(());
-        }
-        let mut nonce = [0u8; NONCE_LENGTH];
-        nonce.copy_from_slice(value);
-        Ok(Self(nonce))
-    }
-}
+use encryption::v1::{Nonce, Salt};
 
 pub struct KeyCell(pub SafeCell<Key>);
 impl From<SafeCell<Key>> for KeyCell {
@@ -133,22 +102,9 @@ impl KeyCell {
     }
 }
 
-pub type Salt = [u8; ArgonSalt::RECOMMENDED_LENGTH];
-
-pub fn generate_salt() -> Salt {
-    let mut salt = Salt::default();
-    #[allow(
-        clippy::unwrap_used,
-        reason = "Rng failure is unrecoverable and should panic"
-    )]
-    let mut rng = StdRng::try_from_rng(&mut SysRng).unwrap();
-    rng.fill_bytes(&mut salt);
-    salt
-}
-
 /// User password might be of different length, have not enough entropy, etc...
 /// Derive a fixed-length key from the password using Argon2id, which is designed for password hashing and key derivation.
-pub fn derive_seal_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
+pub fn derive_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
     #[allow(clippy::unwrap_used)]
     let params = argon2::Params::new(262_144, 3, 4, None).unwrap();
     let hasher = Argon2::new(Algorithm::Argon2id, argon2::Version::V0x13, params);
@@ -171,37 +127,11 @@ pub fn derive_seal_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use crate::safe_cell::SafeCell;
-
-    #[test]
-    pub fn derive_seal_key_deterministic() {
-        static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
-        let password2 = SafeCell::new(PASSWORD.to_vec());
-        let salt = generate_salt();
-
-        let mut key1 = derive_seal_key(password, &salt);
-        let mut key2 = derive_seal_key(password2, &salt);
-
-        let key1_reader = key1.0.read();
-        let key2_reader = key2.0.read();
-
-        assert_eq!(key1_reader.deref(), key2_reader.deref());
-    }
-
-    #[test]
-    pub fn successful_derive() {
-        static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
-        let salt = generate_salt();
-
-        let mut key = derive_seal_key(password, &salt);
-        let key_reader = key.0.read();
-        let key_ref = key_reader.deref();
-
-        assert_ne!(key_ref.as_slice(), &[0u8; 32][..]);
-    }
+    use super::{
+        derive_key,
+        encryption::v1::{Nonce, generate_salt},
+    };
+    use crate::safe_cell::{SafeCell, SafeCellHandle as _};
 
     #[test]
     pub fn encrypt_decrypt() {
@@ -209,7 +139,7 @@ mod tests {
         let password = SafeCell::new(PASSWORD.to_vec());
         let salt = generate_salt();
 
-        let mut key = derive_seal_key(password, &salt);
+        let mut key = derive_key(password, &salt);
         let nonce = Nonce(*b"unique nonce 123 1231233"); // 24 bytes for XChaCha20Poly1305
         let associated_data = b"associated data";
         let mut buffer = b"secret data".to_vec();
@@ -226,18 +156,4 @@ mod tests {
         let buffer = buffer.read();
         assert_eq!(*buffer, b"secret data");
     }
-
-    #[test]
-    // We should fuzz this
-    pub fn test_nonce_increment() {
-        let mut nonce = Nonce([0u8; NONCE_LENGTH]);
-        nonce.increment();
-
-        assert_eq!(
-            nonce.0,
-            [
-                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
-            ]
-        );
-    }
 }

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

@@ -5,7 +5,7 @@ use diesel_async::{
     sync_connection_wrapper::SyncConnectionWrapper,
 };
 use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
-use miette::Diagnostic;
+
 use thiserror::Error;
 use tracing::info;
 
@@ -21,26 +21,21 @@ static DB_FILE: &str = "arbiter.sqlite";
 
 const MIGRATIONS: EmbeddedMigrations = embed_migrations!("migrations");
 
-#[derive(Error, Diagnostic, Debug)]
+#[derive(Error, Debug)]
 pub enum DatabaseSetupError {
     #[error("Failed to determine home directory")]
-    #[diagnostic(code(arbiter::db::home_dir))]
     HomeDir(std::io::Error),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::connection))]
     Connection(diesel::ConnectionError),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::concurrency))]
     ConcurrencySetup(diesel::result::Error),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::migration))]
     Migration(Box<dyn std::error::Error + Send + Sync>),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::pool))]
     Pool(#[from] PoolInitError),
 }
 

server/crates/arbiter-server/src/db/models.rs

@@ -242,6 +242,7 @@ pub struct UseragentClient {
     pub id: i32,
     pub nonce: i32,
     pub public_key: Vec<u8>,
+    pub pubkey_integrity_tag: Option<Vec<u8>>,
     pub created_at: SqliteTimestamp,
     pub updated_at: SqliteTimestamp,
     pub key_type: KeyType,

server/crates/arbiter-server/src/db/schema.rs

@@ -178,6 +178,7 @@ diesel::table! {
         id -> Integer,
         nonce -> Integer,
         public_key -> Binary,
+        pubkey_integrity_tag -> Nullable<Binary>,
         key_type -> Integer,
         created_at -> Integer,
         updated_at -> Integer,

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

@@ -28,39 +28,32 @@ pub mod policies;
 mod utils;
 
 /// Errors that can only occur once the transaction meaning is known (during policy evaluation)
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum PolicyError {
     #[error("Database error")]
     Database(#[from] crate::db::DatabaseError),
     #[error("Transaction violates policy: {0:?}")]
-    #[diagnostic(code(arbiter_server::evm::policy_error::violation))]
     Violations(Vec<EvalViolation>),
     #[error("No matching grant found")]
-    #[diagnostic(code(arbiter_server::evm::policy_error::no_matching_grant))]
     NoMatchingGrant,
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum VetError {
     #[error("Contract creation transactions are not supported")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::contract_creation_unsupported))]
     ContractCreationNotSupported,
     #[error("Engine can't classify this transaction")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::unsupported))]
     UnsupportedTransactionType,
     #[error("Policy evaluation failed: {1}")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::evaluated))]
     Evaluated(SpecificMeaning, #[source] PolicyError),
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum AnalyzeError {
     #[error("Engine doesn't support granting permissions for contract creation")]
-    #[diagnostic(code(arbiter_server::evm::analyze_error::contract_creation_not_supported))]
     ContractCreationNotSupported,
 
     #[error("Unsupported transaction type")]
-    #[diagnostic(code(arbiter_server::evm::analyze_error::unsupported_transaction_type))]
     UnsupportedTransactionType,
 }
 

server/crates/arbiter-server/src/evm/policies.rs

@@ -6,7 +6,7 @@ use diesel::{
     ExpressionMethods as _, QueryDsl, SelectableHelper, result::QueryResult, sqlite::Sqlite,
 };
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use miette::Diagnostic;
+
 use thiserror::Error;
 
 use crate::{
@@ -33,33 +33,27 @@ pub struct EvalContext {
     pub max_priority_fee_per_gas: u128,
 }
 
-#[derive(Debug, Error, Diagnostic)]
+#[derive(Debug, Error)]
 pub enum EvalViolation {
     #[error("This grant doesn't allow transactions to the target address {target}")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_target))]
     InvalidTarget { target: Address },
 
     #[error("Gas limit exceeded for this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::gas_limit_exceeded))]
     GasLimitExceeded {
         max_gas_fee_per_gas: Option<U256>,
         max_priority_fee_per_gas: Option<U256>,
     },
 
     #[error("Rate limit exceeded for this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::rate_limit_exceeded))]
     RateLimitExceeded,
 
     #[error("Transaction exceeds volumetric limits of the grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::volumetric_limit_exceeded))]
     VolumetricLimitExceeded,
 
     #[error("Transaction is outside of the grant's validity period")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_time))]
     InvalidTime,
 
     #[error("Transaction type is not allowed by this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_transaction_type))]
     InvalidTransactionType,
 }
 

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

@@ -140,7 +140,9 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
         let Some(payload) = auth_request.payload else {
             let _ = self
                 .bi
-                .send(Err(Status::invalid_argument("Missing client auth request payload")))
+                .send(Err(Status::invalid_argument(
+                    "Missing client auth request payload",
+                )))
                 .await;
             return None;
         };
@@ -170,9 +172,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                     metadata: client_metadata_from_proto(client_info),
                 })
             }
-            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution {
-                signature,
-            }) => {
+            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {
                 let Ok(signature) = ed25519_dalek::Signature::try_from(signature.as_slice()) else {
                     let _ = self
                         .send_auth_result(ProtoAuthResult::InvalidSignature)

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

@@ -34,7 +34,9 @@ pub(super) async fn dispatch(
     req: proto_evm::Request,
 ) -> Result<ClientResponsePayload, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing client EVM request payload"));
+        return Err(Status::invalid_argument(
+            "Missing client EVM request payload",
+        ));
     };
 
     match payload {
@@ -59,13 +61,13 @@ pub(super) async fn dispatch(
                 ))) => EvmSignTransactionResponse {
                     result: Some(vet_error.convert()),
                 },
-                Err(kameo::error::SendError::HandlerError(
-                    SignTransactionRpcError::Internal,
-                )) => EvmSignTransactionResponse {
-                    result: Some(EvmSignTransactionResult::Error(
-                        ProtoEvmError::Internal.into(),
-                    )),
-                },
+                Err(kameo::error::SendError::HandlerError(SignTransactionRpcError::Internal)) => {
+                    EvmSignTransactionResponse {
+                        result: Some(EvmSignTransactionResult::Error(
+                            ProtoEvmError::Internal.into(),
+                        )),
+                    }
+                }
                 Err(err) => {
                     warn!(error = ?err, "Failed to sign EVM transaction");
                     EvmSignTransactionResponse {
@@ -78,8 +80,8 @@ pub(super) async fn dispatch(
 
             Ok(wrap_response(EvmResponsePayload::SignTransaction(response)))
         }
-        EvmRequestPayload::AnalyzeTransaction(_) => {
-            Err(Status::unimplemented("EVM transaction analysis is not yet implemented"))
-        }
+        EvmRequestPayload::AnalyzeTransaction(_) => Err(Status::unimplemented(
+            "EVM transaction analysis is not yet implemented",
+        )),
     }
 }

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

@@ -0,0 +1 @@
+

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

@@ -0,0 +1 @@
+

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

@@ -12,11 +12,9 @@ use kameo::{actor::ActorRef, error::SendError};
 use tonic::Status;
 use tracing::warn;
 
-use crate::{
-    actors::{
-        client::session::{ClientSession, Error, HandleQueryVaultState},
-        keyholder::KeyHolderState,
-    },
+use crate::actors::{
+    client::session::{ClientSession, Error, HandleQueryVaultState},
+    keyholder::KeyHolderState,
 };
 
 pub(super) async fn dispatch(
@@ -24,7 +22,9 @@ pub(super) async fn dispatch(
     req: proto_vault::Request,
 ) -> Result<ClientResponsePayload, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing client vault request payload"));
+        return Err(Status::invalid_argument(
+            "Missing client vault request payload",
+        ));
     };
 
     match payload {

server/crates/arbiter-server/src/grpc/common/inbound.rs

@@ -28,9 +28,8 @@ impl TryConvert for RawEvmTransaction {
     type Error = tonic::Status;
 
     fn try_convert(self) -> Result<Self::Output, Self::Error> {
-        let tx = TxEip1559::decode(&mut self.0.as_slice()).map_err(|_| {
-            tonic::Status::invalid_argument("Invalid EVM transaction format")
-        })?;
+        let tx = TxEip1559::decode(&mut self.0.as_slice())
+            .map_err(|_| tonic::Status::invalid_argument("Invalid EVM transaction format"))?;
         Ok(tx)
     }
-}
+}

server/crates/arbiter-server/src/grpc/common/outbound.rs

@@ -1,9 +1,12 @@
 use alloy::primitives::U256;
 use arbiter_proto::proto::{
-    evm::{EvmError as ProtoEvmError, evm_sign_transaction_response::Result as EvmSignTransactionResult},
+    evm::{
+        EvmError as ProtoEvmError,
+        evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    },
     shared::evm::{
-        EvalViolation as ProtoEvalViolation, GasLimitExceededViolation,
-        NoMatchingGrantError, PolicyViolationsError, SpecificMeaning as ProtoSpecificMeaning,
+        EvalViolation as ProtoEvalViolation, GasLimitExceededViolation, NoMatchingGrantError,
+        PolicyViolationsError, SpecificMeaning as ProtoSpecificMeaning,
         TokenInfo as ProtoTokenInfo, TransactionEvalError as ProtoTransactionEvalError,
         eval_violation::Kind as ProtoEvalViolationKind,
         specific_meaning::Meaning as ProtoSpecificMeaningKind,

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

@@ -1,12 +1,10 @@
 use tokio::sync::mpsc;
 
 use arbiter_proto::{
-    proto::{
-        user_agent::{
-            UserAgentRequest, UserAgentResponse,
-            user_agent_request::Payload as UserAgentRequestPayload,
-            user_agent_response::Payload as UserAgentResponsePayload,
-        },
+    proto::user_agent::{
+        UserAgentRequest, UserAgentResponse,
+        user_agent_request::Payload as UserAgentRequestPayload,
+        user_agent_response::Payload as UserAgentResponsePayload,
     },
     transport::{Error as TransportError, Receiver, Sender, grpc::GrpcBi},
 };
@@ -19,6 +17,7 @@ use crate::{
     actors::user_agent::{OutOfBand, UserAgentConnection, UserAgentSession},
     grpc::request_tracker::RequestTracker,
 };
+
 mod auth;
 mod evm;
 mod inbound;

server/crates/arbiter-server/src/grpc/user_agent/auth.rs

@@ -1,12 +1,14 @@
 use arbiter_proto::{
     proto::user_agent::{
-        UserAgentRequest, UserAgentResponse, auth::{
+        UserAgentRequest, UserAgentResponse,
+        auth::{
             self as proto_auth, AuthChallenge as ProtoAuthChallenge,
             AuthChallengeRequest as ProtoAuthChallengeRequest,
             AuthChallengeSolution as ProtoAuthChallengeSolution, AuthResult as ProtoAuthResult,
             KeyType as ProtoKeyType, request::Payload as AuthRequestPayload,
             response::Payload as AuthResponsePayload,
-        }, user_agent_request::Payload as UserAgentRequestPayload,
+        },
+        user_agent_request::Payload as UserAgentRequestPayload,
         user_agent_response::Payload as UserAgentResponsePayload,
     },
     transport::{Bi, Error as TransportError, Receiver, Sender, grpc::GrpcBi},
@@ -63,7 +65,9 @@ impl Sender<Result<auth::Outbound, auth::Error>> for AuthTransportAdapter<'_> {
             Ok(Outbound::AuthChallenge { nonce }) => {
                 AuthResponsePayload::Challenge(ProtoAuthChallenge { nonce })
             }
-            Ok(Outbound::AuthSuccess) => AuthResponsePayload::Result(ProtoAuthResult::Success.into()),
+            Ok(Outbound::AuthSuccess) => {
+                AuthResponsePayload::Result(ProtoAuthResult::Success.into())
+            }
             Err(Error::UnregisteredPublicKey) => {
                 AuthResponsePayload::Result(ProtoAuthResult::InvalidKey.into())
             }
@@ -171,9 +175,9 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                     bootstrap_token,
                 })
             }
-            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution {
-                signature,
-            }) => Some(auth::Inbound::AuthChallengeSolution { signature }),
+            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {
+                Some(auth::Inbound::AuthChallengeSolution { signature })
+            }
         }
     }
 }

server/crates/arbiter-server/src/grpc/user_agent/evm.rs

@@ -3,8 +3,7 @@ use arbiter_proto::proto::{
         EvmError as ProtoEvmError, EvmGrantCreateRequest, EvmGrantCreateResponse,
         EvmGrantDeleteRequest, EvmGrantDeleteResponse, EvmGrantList, EvmGrantListResponse,
         EvmSignTransactionResponse, GrantEntry, WalletCreateResponse, WalletEntry, WalletList,
-        WalletListResponse,
-        evm_grant_create_response::Result as EvmGrantCreateResult,
+        WalletListResponse, evm_grant_create_response::Result as EvmGrantCreateResult,
         evm_grant_delete_response::Result as EvmGrantDeleteResult,
         evm_grant_list_response::Result as EvmGrantListResult,
         evm_sign_transaction_response::Result as EvmSignTransactionResult,
@@ -165,7 +164,12 @@ async fn handle_grant_delete(
     actor: &ActorRef<UserAgentSession>,
     req: EvmGrantDeleteRequest,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
-    let result = match actor.ask(HandleGrantDelete { grant_id: req.grant_id }).await {
+    let result = match actor
+        .ask(HandleGrantDelete {
+            grant_id: req.grant_id,
+        })
+        .await
+    {
         Ok(()) => EvmGrantDeleteResult::Ok(()),
         Err(err) => {
             warn!(error = ?err, "Failed to delete EVM grant");
@@ -202,18 +206,18 @@ async fn handle_sign_transaction(
                 signature.as_bytes().to_vec(),
             )),
         },
-        Err(kameo::error::SendError::HandlerError(
-            SessionSignTransactionError::Vet(vet_error),
-        )) => EvmSignTransactionResponse {
-            result: Some(vet_error.convert()),
-        },
-        Err(kameo::error::SendError::HandlerError(
-            SessionSignTransactionError::Internal,
-        )) => EvmSignTransactionResponse {
-            result: Some(EvmSignTransactionResult::Error(
-                ProtoEvmError::Internal.into(),
-            )),
-        },
+        Err(kameo::error::SendError::HandlerError(SessionSignTransactionError::Vet(vet_error))) => {
+            EvmSignTransactionResponse {
+                result: Some(vet_error.convert()),
+            }
+        }
+        Err(kameo::error::SendError::HandlerError(SessionSignTransactionError::Internal)) => {
+            EvmSignTransactionResponse {
+                result: Some(EvmSignTransactionResult::Error(
+                    ProtoEvmError::Internal.into(),
+                )),
+            }
+        }
         Err(err) => {
             warn!(error = ?err, "Failed to sign EVM transaction");
             EvmSignTransactionResponse {
@@ -224,7 +228,7 @@ async fn handle_sign_transaction(
         }
     };
 
-    Ok(Some(wrap_evm_response(EvmResponsePayload::SignTransaction(
-        response,
-    ))))
+    Ok(Some(wrap_evm_response(
+        EvmResponsePayload::SignTransaction(response),
+    )))
 }

server/crates/arbiter-server/src/grpc/user_agent/outbound.rs

@@ -5,9 +5,7 @@ use arbiter_proto::proto::{
         TransactionRateLimit as ProtoTransactionRateLimit, VolumeRateLimit as ProtoVolumeRateLimit,
         specific_grant::Grant as ProtoSpecificGrantType,
     },
-    user_agent::sdk_client::{
-        WalletAccess, WalletAccessEntry as ProtoSdkClientWalletAccess,
-    },
+    user_agent::sdk_client::{WalletAccess, WalletAccessEntry as ProtoSdkClientWalletAccess},
 };
 use chrono::{DateTime, Utc};
 use prost_types::Timestamp as ProtoTimestamp;

server/crates/arbiter-server/src/grpc/user_agent/sdk_client.rs

@@ -1,4 +1,5 @@
 use arbiter_proto::proto::{
+    shared::ClientInfo as ProtoClientMetadata,
     user_agent::{
         sdk_client::{
             self as proto_sdk_client, ConnectionCancel as ProtoSdkClientConnectionCancel,
@@ -13,7 +14,6 @@ use arbiter_proto::proto::{
         },
         user_agent_response::Payload as UserAgentResponsePayload,
     },
-    shared::ClientInfo as ProtoClientMetadata,
 };
 use kameo::actor::ActorRef;
 use tonic::Status;
@@ -62,18 +62,22 @@ pub(super) async fn dispatch(
     req: proto_sdk_client::Request,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing SDK client request payload"));
+        return Err(Status::invalid_argument(
+            "Missing SDK client request payload",
+        ));
     };
 
     match payload {
         SdkClientRequestPayload::ConnectionResponse(resp) => {
             handle_connection_response(actor, resp).await
         }
-        SdkClientRequestPayload::Revoke(_) => {
-            Err(Status::unimplemented("SdkClientRevoke is not yet implemented"))
-        }
+        SdkClientRequestPayload::Revoke(_) => Err(Status::unimplemented(
+            "SdkClientRevoke is not yet implemented",
+        )),
         SdkClientRequestPayload::List(_) => handle_list(actor).await,
-        SdkClientRequestPayload::GrantWalletAccess(req) => handle_grant_wallet_access(actor, req).await,
+        SdkClientRequestPayload::GrantWalletAccess(req) => {
+            handle_grant_wallet_access(actor, req).await
+        }
         SdkClientRequestPayload::RevokeWalletAccess(req) => {
             handle_revoke_wallet_access(actor, req).await
         }
@@ -128,11 +132,11 @@ async fn handle_list(
             ProtoSdkClientListResult::Error(ProtoSdkClientError::Internal.into())
         }
     };
-    Ok(Some(wrap_sdk_client_response(SdkClientResponsePayload::List(
-        ProtoSdkClientListResponse {
+    Ok(Some(wrap_sdk_client_response(
+        SdkClientResponsePayload::List(ProtoSdkClientListResponse {
             result: Some(result),
-        },
-    ))))
+        }),
+    )))
 }
 
 async fn handle_grant_wallet_access(

server/crates/arbiter-server/src/grpc/user_agent/vault.rs

@@ -1,3 +1,4 @@
+use arbiter_proto::proto::shared::VaultState as ProtoVaultState;
 use arbiter_proto::proto::user_agent::{
     user_agent_response::Payload as UserAgentResponsePayload,
     vault::{
@@ -11,25 +12,21 @@ use arbiter_proto::proto::user_agent::{
         unseal::{
             self as proto_unseal, UnsealEncryptedKey as ProtoUnsealEncryptedKey,
             UnsealResult as ProtoUnsealResult, UnsealStart,
-            request::Payload as UnsealRequestPayload,
-            response::Payload as UnsealResponsePayload,
+            request::Payload as UnsealRequestPayload, response::Payload as UnsealResponsePayload,
         },
     },
 };
-use arbiter_proto::proto::shared::VaultState as ProtoVaultState;
 use kameo::{actor::ActorRef, error::SendError};
 use tonic::Status;
 use tracing::warn;
 
-use crate::{
-    actors::{
-        keyholder::KeyHolderState,
-        user_agent::{
-            UserAgentSession,
-            session::connection::{
-                BootstrapError, HandleBootstrapEncryptedKey, HandleQueryVaultState,
-                HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
-            },
+use crate::actors::{
+    keyholder::KeyHolderState,
+    user_agent::{
+        UserAgentSession,
+        session::connection::{
+            BootstrapError, HandleBootstrapEncryptedKey, HandleQueryVaultState,
+            HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
         },
     },
 };
@@ -151,7 +148,9 @@ async fn handle_bootstrap_encrypted_key(
         .await
     {
         Ok(()) => ProtoBootstrapResult::Success,
-        Err(SendError::HandlerError(BootstrapError::InvalidKey)) => ProtoBootstrapResult::InvalidKey,
+        Err(SendError::HandlerError(BootstrapError::InvalidKey)) => {
+            ProtoBootstrapResult::InvalidKey
+        }
         Err(SendError::HandlerError(BootstrapError::AlreadyBootstrapped)) => {
             ProtoBootstrapResult::AlreadyBootstrapped
         }

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

@@ -3,6 +3,7 @@ use crate::context::ServerContext;
 
 pub mod actors;
 pub mod context;
+pub mod crypto;
 pub mod db;
 pub mod evm;
 pub mod grpc;

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

@@ -1,8 +1,8 @@
 use std::net::SocketAddr;
 
+use anyhow::anyhow;
 use arbiter_proto::{proto::arbiter_service_server::ArbiterServiceServer, url::ArbiterUrl};
 use arbiter_server::{Server, actors::bootstrap::GetToken, context::ServerContext, db};
-use miette::miette;
 use rustls::crypto::aws_lc_rs;
 use tonic::transport::{Identity, ServerTlsConfig};
 use tracing::info;
@@ -10,7 +10,7 @@ use tracing::info;
 const PORT: u16 = 50051;
 
 #[tokio::main]
-async fn main() -> miette::Result<()> {
+async fn main() -> anyhow::Result<()> {
     aws_lc_rs::default_provider().install_default().unwrap();
 
     tracing_subscriber::fmt()
@@ -46,11 +46,11 @@ async fn main() -> miette::Result<()> {
 
     tonic::transport::Server::builder()
         .tls_config(tls)
-        .map_err(|err| miette!("Faild to setup TLS: {err}"))?
+        .map_err(|err| anyhow!("Failed to setup TLS: {err}"))?
         .add_service(ArbiterServiceServer::new(Server::new(context)))
         .serve(addr)
         .await
-        .map_err(|e| miette::miette!("gRPC server error: {e}"))?;
+        .map_err(|e| anyhow!("gRPC server error: {e}"))?;
 
     unreachable!("gRPC server should run indefinitely");
 }

server/crates/arbiter-server/tests/keyholder/lifecycle.rs

@@ -1,5 +1,6 @@
 use arbiter_server::{
     actors::keyholder::{Error, KeyHolder},
+    crypto::encryption::v1::{Nonce, ROOT_KEY_TAG},
     db::{self, models, schema},
     safe_cell::{SafeCell, SafeCellHandle as _},
 };
@@ -25,16 +26,10 @@ async fn test_bootstrap() {
         .unwrap();
 
     assert_eq!(row.schema_version, 1);
-    assert_eq!(
-        row.tag,
-        arbiter_server::actors::keyholder::encryption::v1::ROOT_KEY_TAG
-    );
+    assert_eq!(row.tag, ROOT_KEY_TAG);
     assert!(!row.ciphertext.is_empty());
     assert!(!row.salt.is_empty());
-    assert_eq!(
-        row.data_encryption_nonce,
-        arbiter_server::actors::keyholder::encryption::v1::Nonce::default().to_vec()
-    );
+    assert_eq!(row.data_encryption_nonce, Nonce::default().to_vec());
 }
 
 #[tokio::test]

server/crates/arbiter-server/tests/keyholder/storage.rs

@@ -1,7 +1,8 @@
 use std::collections::HashSet;
 
 use arbiter_server::{
-    actors::keyholder::{Error, encryption::v1},
+    actors::keyholder::Error,
+    crypto::encryption::v1::Nonce,
     db::{self, models, schema},
     safe_cell::{SafeCell, SafeCellHandle as _},
 };
@@ -102,7 +103,7 @@ async fn test_nonce_never_reused() {
     assert_eq!(nonces.len(), unique.len(), "all nonces must be unique");
 
     for (i, row) in rows.iter().enumerate() {
-        let mut expected = v1::Nonce::default();
+        let mut expected = Nonce::default();
         for _ in 0..=i {
             expected.increment();
         }

server/crates/arbiter-server/tests/user_agent/auth.rs

@@ -3,9 +3,11 @@ use arbiter_server::{
     actors::{
         GlobalActors,
         bootstrap::GetToken,
+        keyholder::Bootstrap,
         user_agent::{AuthPublicKey, UserAgentConnection, auth},
     },
     db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use diesel::{ExpressionMethods as _, QueryDsl, insert_into};
 use diesel_async::RunQueryDsl;
@@ -83,7 +85,6 @@ pub async fn test_bootstrap_invalid_token_auth() {
         Err(auth::Error::InvalidBootstrapToken)
     ));
 
-    // Verify no key was registered
     let mut conn = db.get().await.unwrap();
     let count: i64 = schema::useragent_client::table
         .count()
@@ -102,7 +103,6 @@ pub async fn test_challenge_auth() {
     let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
     let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
 
-    // Pre-register key with key_type
     {
         let mut conn = db.get().await.unwrap();
         insert_into(schema::useragent_client::table)
@@ -122,7 +122,6 @@ pub async fn test_challenge_auth() {
         auth::authenticate(&mut props, server_transport).await
     });
 
-    // Send challenge request
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
             pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
@@ -131,7 +130,6 @@ pub async fn test_challenge_auth() {
         .await
         .unwrap();
 
-    // Read the challenge response
     let response = test_transport
         .recv()
         .await
@@ -166,6 +164,57 @@ pub async fn test_challenge_auth() {
     task.await.unwrap().unwrap();
 }
 
+#[tokio::test]
+#[test_log::test]
+pub async fn test_challenge_auth_rejects_integrity_tag_mismatch_when_unsealed() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
+
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
+
+    {
+        let mut conn = db.get().await.unwrap();
+        insert_into(schema::useragent_client::table)
+            .values((
+                schema::useragent_client::public_key.eq(pubkey_bytes.clone()),
+                schema::useragent_client::key_type.eq(1i32),
+                schema::useragent_client::pubkey_integrity_tag.eq(Some(vec![0u8; 32])),
+            ))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+    }
+
+    let (server_transport, mut test_transport) = ChannelTransport::new();
+    let db_for_task = db.clone();
+    let task = tokio::spawn(async move {
+        let mut props = UserAgentConnection::new(db_for_task, actors);
+        auth::authenticate(&mut props, server_transport).await
+    });
+
+    test_transport
+        .send(auth::Inbound::AuthChallengeRequest {
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
+            bootstrap_token: None,
+        })
+        .await
+        .unwrap();
+
+    assert!(matches!(
+        task.await.unwrap(),
+        Err(auth::Error::InvalidChallengeSolution)
+    ));
+}
+
 #[tokio::test]
 #[test_log::test]
 pub async fn test_challenge_auth_rejects_invalid_signature() {
@@ -175,7 +224,6 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
     let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
     let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
 
-    // Pre-register key with key_type
     {
         let mut conn = db.get().await.unwrap();
         insert_into(schema::useragent_client::table)
@@ -215,7 +263,6 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
         Err(err) => panic!("Expected Ok response, got Err({err:?})"),
     };
 
-    // Sign a different challenge value so signature format is valid but verification must fail.
     let wrong_challenge = arbiter_proto::format_challenge(challenge + 1, &pubkey_bytes);
     let signature = new_key.sign(&wrong_challenge);
 
@@ -226,8 +273,10 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
         .await
         .unwrap();
 
+    let expected_err = task.await.unwrap();
+    println!("Received expected error: {expected_err:#?}");
     assert!(matches!(
-        task.await.unwrap(),
+        expected_err,
         Err(auth::Error::InvalidChallengeSolution)
     ));
 }

server/crates/arbiter-server/tests/user_agent/unseal.rs

@@ -2,14 +2,17 @@ use arbiter_server::{
     actors::{
         GlobalActors,
         keyholder::{Bootstrap, Seal},
-        user_agent::{UserAgentSession, session::connection::{
-            HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
-        }},
+        user_agent::{
+            UserAgentSession,
+            session::connection::{HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError},
+        },
     },
     db,
     safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
+use diesel::{ExpressionMethods as _, QueryDsl as _, insert_into};
+use diesel_async::RunQueryDsl;
 use kameo::actor::Spawn as _;
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
@@ -149,3 +152,42 @@ pub async fn test_unseal_retry_after_invalid_key() {
         assert!(matches!(response, Ok(())));
     }
 }
+
+#[tokio::test]
+#[test_log::test]
+pub async fn test_unseal_backfills_missing_pubkey_integrity_tags() {
+    let seal_key = b"test-seal-key";
+    let (db, user_agent) = setup_sealed_user_agent(seal_key).await;
+
+    {
+        let mut conn = db.get().await.unwrap();
+        insert_into(arbiter_server::db::schema::useragent_client::table)
+            .values((
+                arbiter_server::db::schema::useragent_client::public_key
+                    .eq(vec![1u8, 2u8, 3u8, 4u8]),
+                arbiter_server::db::schema::useragent_client::key_type.eq(1i32),
+                arbiter_server::db::schema::useragent_client::pubkey_integrity_tag
+                    .eq(Option::<Vec<u8>>::None),
+            ))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+    }
+
+    let encrypted_key = client_dh_encrypt(&user_agent, seal_key).await;
+    let response = user_agent.ask(encrypted_key).await;
+    assert!(matches!(response, Ok(())));
+
+    {
+        let mut conn = db.get().await.unwrap();
+        let tags: Vec<Option<Vec<u8>>> = arbiter_server::db::schema::useragent_client::table
+            .select(arbiter_server::db::schema::useragent_client::pubkey_integrity_tag)
+            .load(&mut conn)
+            .await
+            .unwrap();
+        assert!(
+            tags.iter()
+                .all(|tag| matches!(tag, Some(v) if v.len() == 32))
+        );
+    }
+}

useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart

@@ -30,7 +30,6 @@ class GrantCard extends ConsumerWidget {
 
   @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 [];
@@ -44,7 +43,6 @@ class GrantCard extends ConsumerWidget {
     final theme = Theme.of(context);
     final muted = Palette.ink.withValues(alpha: 0.62);
 
-    // Resolve wallet_access_id → wallet address + client name
     final accessById = <int, ua_sdk.WalletAccessEntry>{
       for (final a in walletAccesses) a.id: a,
     };
@@ -94,7 +92,6 @@ class GrantCard extends ConsumerWidget {
         child: Row(
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
-            // Accent strip
             Container(
               width: 0.8.w,
               decoration: BoxDecoration(
@@ -104,7 +101,6 @@ class GrantCard extends ConsumerWidget {
                 ),
               ),
             ),
-            // Card body
             Expanded(
               child: Padding(
                 padding: EdgeInsets.symmetric(
@@ -114,7 +110,6 @@ class GrantCard extends ConsumerWidget {
                 child: Column(
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
-                    // Row 1: type badge · chain · spacer · revoke button
                     Row(
                       children: [
                         Container(
@@ -184,7 +179,6 @@ class GrantCard extends ConsumerWidget {
                       ],
                     ),
                     SizedBox(height: 0.8.h),
-                    // Row 2: wallet address · client name
                     Row(
                       children: [
                         Text(