refactor: consolidate auth messages into client and user_agent packages

chore(server): update Cargo.lock dependencies
tests(user-agent): basic auth tests similar to server
2026-03-01 12:49:38 +01:00 · 2026-02-26 22:41:50 +01:00 · 2026-02-26 22:41:24 +01:00 · 2026-02-26 22:22:44 +01:00 · 2026-02-26 21:42:24 +01:00 · 2026-02-26 19:22:33 +01:00
30 changed files with 1648 additions and 1304 deletions
--- a/app/.dart_tool/package_config.json
+++ b/app/.dart_tool/package_config.json
@@ -1,178 +0,0 @@
 {
  "configVersion": 2,
  "packages": [
    {
      "name": "async",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/async-2.13.0",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "boolean_selector",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/boolean_selector-2.1.2",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "characters",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/characters-1.4.0",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "clock",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/clock-1.1.2",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "collection",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/collection-1.19.1",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "cupertino_icons",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/cupertino_icons-1.0.8",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "fake_async",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/fake_async-1.3.3",
      "packageUri": "lib/",
      "languageVersion": "3.3"
    },
    {
      "name": "flutter",
      "rootUri": "file:///Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable/packages/flutter",
      "packageUri": "lib/",
      "languageVersion": "3.8"
    },
    {
      "name": "flutter_lints",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/flutter_lints-6.0.0",
      "packageUri": "lib/",
      "languageVersion": "3.8"
    },
    {
      "name": "flutter_test",
      "rootUri": "file:///Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable/packages/flutter_test",
      "packageUri": "lib/",
      "languageVersion": "3.8"
    },
    {
      "name": "leak_tracker",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/leak_tracker-11.0.2",
      "packageUri": "lib/",
      "languageVersion": "3.2"
    },
    {
      "name": "leak_tracker_flutter_testing",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/leak_tracker_flutter_testing-3.0.10",
      "packageUri": "lib/",
      "languageVersion": "3.2"
    },
    {
      "name": "leak_tracker_testing",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/leak_tracker_testing-3.0.2",
      "packageUri": "lib/",
      "languageVersion": "3.2"
    },
    {
      "name": "lints",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/lints-6.1.0",
      "packageUri": "lib/",
      "languageVersion": "3.8"
    },
    {
      "name": "matcher",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/matcher-0.12.17",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "material_color_utilities",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/material_color_utilities-0.11.1",
      "packageUri": "lib/",
      "languageVersion": "2.17"
    },
    {
      "name": "meta",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/meta-1.17.0",
      "packageUri": "lib/",
      "languageVersion": "3.5"
    },
    {
      "name": "path",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/path-1.9.1",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "sky_engine",
      "rootUri": "file:///Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable/bin/cache/pkg/sky_engine",
      "packageUri": "lib/",
      "languageVersion": "3.8"
    },
    {
      "name": "source_span",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/source_span-1.10.2",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "stack_trace",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/stack_trace-1.12.1",
      "packageUri": "lib/",
      "languageVersion": "3.4"
    },
    {
      "name": "stream_channel",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/stream_channel-2.1.4",
      "packageUri": "lib/",
      "languageVersion": "3.3"
    },
    {
      "name": "string_scanner",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/string_scanner-1.4.1",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "term_glyph",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/term_glyph-1.2.2",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "test_api",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/test_api-0.7.7",
      "packageUri": "lib/",
      "languageVersion": "3.5"
    },
    {
      "name": "vector_math",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/vector_math-2.2.0",
      "packageUri": "lib/",
      "languageVersion": "3.1"
    },
    {
      "name": "vm_service",
      "rootUri": "file:///Users/kaska/.pub-cache/hosted/pub.dev/vm_service-15.0.2",
      "packageUri": "lib/",
      "languageVersion": "3.5"
    },
    {
      "name": "app",
      "rootUri": "../",
      "packageUri": "lib/",
      "languageVersion": "3.10"
    }
  ],
  "generator": "pub",
  "generatorVersion": "3.10.8",
  "flutterRoot": "file:///Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable",
  "flutterVersion": "3.38.9",
  "pubCache": "file:///Users/kaska/.pub-cache"
 }
--- a/app/.dart_tool/package_graph.json
+++ b/app/.dart_tool/package_graph.json
@@ -1,230 +0,0 @@
 {
  "roots": [
    "app"
  ],
  "packages": [
    {
      "name": "app",
      "version": "1.0.0+1",
      "dependencies": [
        "cupertino_icons",
        "flutter"
      ],
      "devDependencies": [
        "flutter_lints",
        "flutter_test"
      ]
    },
    {
      "name": "flutter_lints",
      "version": "6.0.0",
      "dependencies": [
        "lints"
      ]
    },
    {
      "name": "flutter_test",
      "version": "0.0.0",
      "dependencies": [
        "clock",
        "collection",
        "fake_async",
        "flutter",
        "leak_tracker_flutter_testing",
        "matcher",
        "meta",
        "path",
        "stack_trace",
        "stream_channel",
        "test_api",
        "vector_math"
      ]
    },
    {
      "name": "cupertino_icons",
      "version": "1.0.8",
      "dependencies": []
    },
    {
      "name": "flutter",
      "version": "0.0.0",
      "dependencies": [
        "characters",
        "collection",
        "material_color_utilities",
        "meta",
        "sky_engine",
        "vector_math"
      ]
    },
    {
      "name": "lints",
      "version": "6.1.0",
      "dependencies": []
    },
    {
      "name": "stream_channel",
      "version": "2.1.4",
      "dependencies": [
        "async"
      ]
    },
    {
      "name": "meta",
      "version": "1.17.0",
      "dependencies": []
    },
    {
      "name": "collection",
      "version": "1.19.1",
      "dependencies": []
    },
    {
      "name": "leak_tracker_flutter_testing",
      "version": "3.0.10",
      "dependencies": [
        "flutter",
        "leak_tracker",
        "leak_tracker_testing",
        "matcher",
        "meta"
      ]
    },
    {
      "name": "vector_math",
      "version": "2.2.0",
      "dependencies": []
    },
    {
      "name": "stack_trace",
      "version": "1.12.1",
      "dependencies": [
        "path"
      ]
    },
    {
      "name": "clock",
      "version": "1.1.2",
      "dependencies": []
    },
    {
      "name": "fake_async",
      "version": "1.3.3",
      "dependencies": [
        "clock",
        "collection"
      ]
    },
    {
      "name": "path",
      "version": "1.9.1",
      "dependencies": []
    },
    {
      "name": "matcher",
      "version": "0.12.17",
      "dependencies": [
        "async",
        "meta",
        "stack_trace",
        "term_glyph",
        "test_api"
      ]
    },
    {
      "name": "test_api",
      "version": "0.7.7",
      "dependencies": [
        "async",
        "boolean_selector",
        "collection",
        "meta",
        "source_span",
        "stack_trace",
        "stream_channel",
        "string_scanner",
        "term_glyph"
      ]
    },
    {
      "name": "sky_engine",
      "version": "0.0.0",
      "dependencies": []
    },
    {
      "name": "material_color_utilities",
      "version": "0.11.1",
      "dependencies": [
        "collection"
      ]
    },
    {
      "name": "characters",
      "version": "1.4.0",
      "dependencies": []
    },
    {
      "name": "async",
      "version": "2.13.0",
      "dependencies": [
        "collection",
        "meta"
      ]
    },
    {
      "name": "leak_tracker_testing",
      "version": "3.0.2",
      "dependencies": [
        "leak_tracker",
        "matcher",
        "meta"
      ]
    },
    {
      "name": "leak_tracker",
      "version": "11.0.2",
      "dependencies": [
        "clock",
        "collection",
        "meta",
        "path",
        "vm_service"
      ]
    },
    {
      "name": "term_glyph",
      "version": "1.2.2",
      "dependencies": []
    },
    {
      "name": "string_scanner",
      "version": "1.4.1",
      "dependencies": [
        "source_span"
      ]
    },
    {
      "name": "source_span",
      "version": "1.10.2",
      "dependencies": [
        "collection",
        "path",
        "term_glyph"
      ]
    },
    {
      "name": "boolean_selector",
      "version": "2.1.2",
      "dependencies": [
        "source_span",
        "string_scanner"
      ]
    },
    {
      "name": "vm_service",
      "version": "15.0.2",
      "dependencies": []
    }
  ],
  "configVersion": 1
 }
--- a/app/.dart_tool/version
+++ b/app/.dart_tool/version
@@ -1 +0,0 @@
 3.38.9
--- a/app/macos/Flutter/ephemeral/Flutter-Generated.xcconfig
+++ b/app/macos/Flutter/ephemeral/Flutter-Generated.xcconfig
@@ -1,11 +0,0 @@
 // This is a generated file; do not edit or check into version control.
 FLUTTER_ROOT=/Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable
 FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/app
 COCOAPODS_PARALLEL_CODE_SIGN=true
 FLUTTER_BUILD_DIR=build
 FLUTTER_BUILD_NAME=1.0.0
 FLUTTER_BUILD_NUMBER=1
 DART_OBFUSCATION=false
 TRACK_WIDGET_CREATION=true
 TREE_SHAKE_ICONS=false
 PACKAGE_CONFIG=.dart_tool/package_config.json
--- a/app/macos/Flutter/ephemeral/flutter_export_environment.sh
+++ b/app/macos/Flutter/ephemeral/flutter_export_environment.sh
@@ -1,12 +0,0 @@
 #!/bin/sh
 # This is a generated file; do not edit or check into version control.
 export "FLUTTER_ROOT=/Users/kaska/.local/share/mise/installs/flutter/3.38.9-stable"
 export "FLUTTER_APPLICATION_PATH=/Users/kaska/Documents/Projects/Major/arbiter/app"
 export "COCOAPODS_PARALLEL_CODE_SIGN=true"
 export "FLUTTER_BUILD_DIR=build"
 export "FLUTTER_BUILD_NAME=1.0.0"
 export "FLUTTER_BUILD_NUMBER=1"
 export "DART_OBFUSCATION=false"
 export "TRACK_WIDGET_CREATION=true"
 export "TREE_SHAKE_ICONS=false"
 export "PACKAGE_CONFIG=.dart_tool/package_config.json"
--- a/protobufs/arbiter.proto
+++ b/protobufs/arbiter.proto
@@ -2,7 +2,6 @@ syntax = "proto3";
 package arbiter;
 import "auth.proto";
 import "client.proto";
 import "user_agent.proto";
@@ -12,6 +11,6 @@ message ServerInfo {
 }
 service ArbiterService {
-  rpc Client(stream ClientRequest) returns (stream ClientResponse);
+  rpc Client(stream arbiter.client.ClientRequest) returns (stream arbiter.client.ClientResponse);
-  rpc UserAgent(stream UserAgentRequest) returns (stream UserAgentResponse);
+  rpc UserAgent(stream arbiter.user_agent.UserAgentRequest) returns (stream arbiter.user_agent.UserAgentResponse);
 }
--- a/protobufs/auth.proto
+++ b/protobufs/auth.proto
@@ -1,35 +0,0 @@
 syntax = "proto3";
 package arbiter.auth;
 import "google/protobuf/timestamp.proto";
 message AuthChallengeRequest {
  bytes pubkey = 1;
  optional string bootstrap_token = 2;
 }
 message AuthChallenge {
  bytes pubkey = 1;
  int32 nonce = 2;
 }
 message AuthChallengeSolution {
  bytes signature = 1;
 }
 message AuthOk {}
 message ClientMessage {
  oneof payload {
    AuthChallengeRequest auth_challenge_request = 1;
    AuthChallengeSolution auth_challenge_solution = 2;
  }
 }
 message ServerMessage {
  oneof payload {
    AuthChallenge auth_challenge = 1;
    AuthOk auth_ok = 2;
  }
 }
--- a/protobufs/client.proto
+++ b/protobufs/client.proto
@@ -1,17 +1,32 @@
 syntax = "proto3";
-package arbiter;
+package arbiter.client;
-import "auth.proto";
+message AuthChallengeRequest {
  bytes pubkey = 1;
 }
 message AuthChallenge {
  bytes pubkey = 1;
  int32 nonce = 2;
 }
 message AuthChallengeSolution {
  bytes signature = 1;
 }
 message AuthOk {}
 message ClientRequest {
  oneof payload {
-    arbiter.auth.ClientMessage auth_message = 1;
+    AuthChallengeRequest auth_challenge_request = 1;
    AuthChallengeSolution auth_challenge_solution = 2;
  }
 }
 message ClientResponse {
  oneof payload {
-    arbiter.auth.ServerMessage auth_message = 1;
+    AuthChallenge auth_challenge = 1;
    AuthOk auth_ok = 2;
  }
 }
--- a/protobufs/user_agent.proto
+++ b/protobufs/user_agent.proto
@@ -1,10 +1,25 @@
 syntax = "proto3";
-package arbiter;
+package arbiter.user_agent;
 import "auth.proto";
 import "google/protobuf/empty.proto";
 message AuthChallengeRequest {
  bytes pubkey = 1;
  optional string bootstrap_token = 2;
 }
 message AuthChallenge {
  bytes pubkey = 1;
  int32 nonce = 2;
 }
 message AuthChallengeSolution {
  bytes signature = 1;
 }
 message AuthOk {}
 message UnsealStart {
  bytes client_pubkey = 1;
 }
@@ -35,17 +50,19 @@ enum VaultState {
 message UserAgentRequest {
  oneof payload {
-    arbiter.auth.ClientMessage auth_message = 1;
+    AuthChallengeRequest auth_challenge_request = 1;
-    UnsealStart unseal_start = 2;
+    AuthChallengeSolution auth_challenge_solution = 2;
-    UnsealEncryptedKey unseal_encrypted_key = 3;
+    UnsealStart unseal_start = 3;
-    google.protobuf.Empty query_vault_state = 4;
+    UnsealEncryptedKey unseal_encrypted_key = 4;
    google.protobuf.Empty query_vault_state = 5;
  }
 }
 message UserAgentResponse {
  oneof payload {
-    arbiter.auth.ServerMessage auth_message = 1;
+    AuthChallenge auth_challenge = 1;
-    UnsealStartResponse unseal_start_response = 2;
+    AuthOk auth_ok = 2;
-    UnsealResult unseal_result = 3;
+    UnsealStartResponse unseal_start_response = 3;
-    VaultState vault_state = 4;
+    UnsealResult unseal_result = 4;
    VaultState vault_state = 5;
  }
 }
--- a/server/Cargo.lock
+++ b/server/Cargo.lock
@@ -47,9 +47,9 @@ dependencies = [
 [[package]]
 name = "anyhow"
-version = "1.0.101"
+version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f0e0fee31ef5ed1ba1316088939cea399010ed7731dba877ed44aeb407a75ea"
+checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 [[package]]
 name = "arbiter-client"
@@ -121,9 +121,13 @@ version = "0.1.0"
 dependencies = [
 "arbiter-proto",
 "ed25519-dalek",
 "http",
 "kameo",
 "rustls-webpki",
 "smlang",
 "thiserror",
 "tokio",
 "tokio-stream",
 "tonic",
 "tracing",
 "x25519-dalek",
@@ -166,7 +170,7 @@ checksum = "3109e49b1e4909e9db6515a30c633684d68cdeaa252f215214cb4fa1a5bfee2c"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "synstructure",
 ]
@@ -178,7 +182,7 @@ checksum = "7b18050c2cd6fe86c3a76584ef5e0baf286d038cda203eb6223df2cc413565f7"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -189,7 +193,7 @@ checksum = "9035ad2d096bed7955a320ee7e2230574d28fd3c3a0f186cbea1ff3c7eed5dbb"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -206,9 +210,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 [[package]]
 name = "aws-lc-rs"
-version = "1.15.4"
+version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b7b6141e96a8c160799cc2d5adecd5cbbe5054cb8c7c4af53da0f83bb7ad256"
+checksum = "d9a7b350e3bb1767102698302bc37256cbd48422809984b98d292c40e2579aa9"
 dependencies = [
 "aws-lc-sys",
 "untrusted 0.7.1",
@@ -344,18 +348,18 @@ dependencies = [
 [[package]]
 name = "block-buffer"
-version = "0.11.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96eb4cdd6cf1b31d671e9efe75c5d1ec614776856cefbe109ca373554a6d514f"
+checksum = "cdd35008169921d80bc60d3d0ab416eecb028c4cd653352907921d95084790be"
 dependencies = [
 "hybrid-array",
 ]
 [[package]]
 name = "bumpalo"
-version = "3.19.1"
+version = "3.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5dd9dc738b7a8311c7ade152424974d8115f2cdad61e8dab8dac9f2362298510"
+checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
 [[package]]
 name = "bytes"
@@ -418,9 +422,9 @@ dependencies = [
 [[package]]
 name = "chrono"
-version = "0.4.43"
+version = "0.4.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fac4744fb15ae8337dc853fee7fb3f4e48c0fbaa23d0afe49c447b4fab126118"
+checksum = "c673075a2e0e5f4a1dde27ce9dee1ea4558c7ffe648f576438a20ca1d2acc4b0"
 dependencies = [
 "iana-time-zone",
 "js-sys",
@@ -514,9 +518,9 @@ dependencies = [
 [[package]]
 name = "crypto-common"
-version = "0.2.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "211f05e03c7d03754740fd9e585de910a095d6b99f8bcfffdef8319fa02a8331"
+checksum = "77727bb15fa921304124b128af125e7e3b968275d1b108b379190264f4423710"
 dependencies = [
 "hybrid-array",
 ]
@@ -545,7 +549,7 @@ dependencies = [
 "cfg-if",
 "cpufeatures 0.2.17",
 "curve25519-dalek-derive",
- "digest 0.11.0",
+ "digest 0.11.1",
 "fiat-crypto 0.3.0",
 "rustc_version",
 "subtle",
@@ -560,7 +564,7 @@ checksum = "f46882e17999c6cc590af592290432be3bce0428cb0d5f8b6715e4dc7b383eb3"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -584,7 +588,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "strsim",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -595,7 +599,7 @@ checksum = "d38308df82d1080de0afee5d069fa14b0326a88c14f15c5ccda35b4a6c414c81"
 dependencies = [
 "darling_core",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -634,9 +638,9 @@ dependencies = [
 [[package]]
 name = "deranged"
-version = "0.5.6"
+version = "0.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc3dc5ad92c2e2d1c193bbbbdf2ea477cb81331de4f3103f267ca18368b988c4"
+checksum = "7cd812cc2bc1d69d4764bd80df88b4317eaef9e773c75226407d9bc0876b211c"
 dependencies = [
 "powerfmt",
 ]
@@ -682,7 +686,7 @@ dependencies = [
 "dsl_auto_type",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -702,7 +706,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fe2444076b48641147115697648dc743c2c00b61adade0f01ce67133c7babe8c"
 dependencies = [
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -718,12 +722,12 @@ dependencies = [
 [[package]]
 name = "digest"
-version = "0.11.0"
+version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8bf3682cdec91817be507e4aa104314898b95b84d74f3d43882210101a545b6"
+checksum = "285743a676ccb6b3e116bc14cc69319b957867930ae9c4822f8e0f54509d7243"
 dependencies = [
- "block-buffer 0.11.0",
+ "block-buffer 0.12.0",
- "crypto-common 0.2.0",
+ "crypto-common 0.2.1",
 ]
 [[package]]
@@ -734,7 +738,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -754,7 +758,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -949,7 +953,7 @@ checksum = "e835b70203e41293343137df5c0664546da5745f82ec9b84d40be8336958447b"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1409,9 +1413,9 @@ dependencies = [
 [[package]]
 name = "js-sys"
-version = "0.3.85"
+version = "0.3.90"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c942ebf8e95485ca0d52d97da7c5a2c387d0e7f0ba4c35e93bfcaee045955b3"
+checksum = "14dc6f6450b3f6d4ed5b16327f38fed626d375a886159ca555bd7822c0c3a5a6"
 dependencies = [
 "once_cell",
 "wasm-bindgen",
@@ -1441,7 +1445,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1474,9 +1478,9 @@ dependencies = [
 [[package]]
 name = "linux-raw-sys"
-version = "0.11.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df1d3c3b53da64cf5760482273a98e575c651a67eec7f77df96b5b642de8f039"
+checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
 [[package]]
 name = "litemap"
@@ -1558,7 +1562,7 @@ checksum = "db5b29714e950dbb20d5e6f74f9dcec4edbcc1067bb7f8ed198c097b8c1a818b"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1706,9 +1710,9 @@ checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
 [[package]]
 name = "owo-colors"
-version = "4.2.3"
+version = "4.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c6901729fa79e91a0913333229e9ca5dc725089d1c363b2f4b4760709dc4a52"
+checksum = "d211803b9b6b570f68772237e415a029d5a50c65d382910b879fb19d3271f94d"
 [[package]]
 name = "parking_lot"
@@ -1788,7 +1792,7 @@ checksum = "6e918e4ff8c4549eb882f14b3a4bc8c8bc93de829416eacf579f1207a8fbf861"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1848,7 +1852,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "479ca8adacdd7ce8f1fb39ce9ecccbfe93a3f1344b3d0d97f20bc0196208f62b"
 dependencies = [
 "proc-macro2",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1920,7 +1924,7 @@ dependencies = [
 "pulldown-cmark",
 "pulldown-cmark-to-cmark",
 "regex",
- "syn 2.0.115",
+ "syn 2.0.117",
 "tempfile",
 ]
@@ -1934,7 +1938,7 @@ dependencies = [
 "itertools",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -1948,9 +1952,9 @@ dependencies = [
 [[package]]
 name = "pulldown-cmark"
-version = "0.13.0"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e8bbe1a966bd2f362681a44f6edce3c2310ac21e4d5067a6e7ec396297a6ea0"
+checksum = "83c41efbf8f90ac44de7f3a868f0867851d261b56291732d0cbf7cceaaeb55a6"
 dependencies = [
 "bitflags",
 "memchr",
@@ -2056,9 +2060,9 @@ dependencies = [
 [[package]]
 name = "regex-syntax"
-version = "0.8.9"
+version = "0.8.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a96887878f22d7bad8a3b6dc5b7440e0ada9a245242924394987b21cf2210a4c"
+checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
 [[package]]
 name = "relative-path"
@@ -2075,7 +2079,7 @@ dependencies = [
 "proc-macro-error",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2127,7 +2131,7 @@ dependencies = [
 "regex",
 "relative-path",
 "rustc_version",
- "syn 2.0.115",
+ "syn 2.0.117",
 "unicode-ident",
 ]
@@ -2157,9 +2161,9 @@ dependencies = [
 [[package]]
 name = "rustix"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "146c9e247ccc180c1f61615433868c99f3de3ae256a30a43b49f67c2d9171f34"
+checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
 "bitflags",
 "errno",
@@ -2170,9 +2174,9 @@ dependencies = [
 [[package]]
 name = "rustls"
-version = "0.23.36"
+version = "0.23.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c665f33d38cea657d9614f766881e4d510e0eda4239891eea56b4cadcf01801b"
+checksum = "758025cb5fccfd3bc2fd74708fd4682be41d99e5dff73c377c0646c6012c73a4"
 dependencies = [
 "aws-lc-rs",
 "log",
@@ -2267,7 +2271,7 @@ checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2300,7 +2304,7 @@ checksum = "7c5f3b1e2dc8aad28310d8410bd4d7e180eca65fca176c52ab00d364475d0024"
 dependencies = [
 "cfg-if",
 "cpufeatures 0.2.17",
- "digest 0.11.0",
+ "digest 0.11.1",
 ]
 [[package]]
@@ -2437,7 +2441,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2480,9 +2484,9 @@ dependencies = [
 [[package]]
 name = "syn"
-version = "2.0.115"
+version = "2.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e614ed320ac28113fa64972c4262d5dbc89deacdfd00c34a3e4cea073243c12"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -2503,14 +2507,14 @@ checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
 name = "tempfile"
-version = "3.25.0"
+version = "3.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0136791f7c95b1f6dd99f9cc786b91bb81c3800b639b3478e561ddb7be95e5f1"
+checksum = "82a72c767771b47409d2345987fda8628641887d5466101319899796367354a0"
 dependencies = [
 "fastrand",
 "getrandom 0.4.1",
@@ -2547,7 +2551,7 @@ checksum = "be35209fd0781c5401458ab66e4f98accf63553e8fae7425503e92fdd319783b"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2577,7 +2581,7 @@ checksum = "ebc4ee7f67670e9b64d05fa4253e753e016c6c95ff35b89b7941d6b856dec1d5"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2656,7 +2660,7 @@ checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2730,18 +2734,18 @@ dependencies = [
 [[package]]
 name = "toml_parser"
-version = "1.0.8+spec-1.1.0"
+version = "1.0.9+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0742ff5ff03ea7e67c8ae6c93cac239e0d9784833362da3f9a9c1da8dfefcbdc"
+checksum = "702d4415e08923e7e1ef96cd5727c0dfed80b4d2fa25db9647fe5eb6f7c5a4c4"
 dependencies = [
 "winnow",
 ]
 [[package]]
 name = "tonic"
-version = "0.14.4"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f32a6f80051a4111560201420c7885d0082ba9efe2ab61875c587bb6b18b9a0"
+checksum = "fec7c61a0695dc1887c1b53952990f3ad2e3a31453e1f49f10e75424943a93ec"
 dependencies = [
 "async-trait",
 "axum",
@@ -2771,21 +2775,21 @@ dependencies = [
 [[package]]
 name = "tonic-build"
-version = "0.14.4"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce6d8958ed3be404120ca43ffa0fb1e1fc7be214e96c8d33bd43a131b6eebc9e"
+checksum = "1882ac3bf5ef12877d7ed57aad87e75154c11931c2ba7e6cde5e22d63522c734"
 dependencies = [
 "prettyplease",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
 name = "tonic-prost"
-version = "0.14.4"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f86539c0089bfd09b1f8c0ab0239d80392af74c21bc9e0f15e1b4aca4c1647f"
+checksum = "a55376a0bbaa4975a3f10d009ad763d8f4108f067c7c2e74f3001fb49778d309"
 dependencies = [
 "bytes",
 "prost",
@@ -2794,16 +2798,16 @@ dependencies = [
 [[package]]
 name = "tonic-prost-build"
-version = "0.14.4"
+version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65873ace111e90344b8973e94a1fc817c924473affff24629281f90daed1cd2e"
+checksum = "f3144df636917574672e93d0f56d7edec49f90305749c668df5101751bb8f95a"
 dependencies = [
 "prettyplease",
 "proc-macro2",
 "prost-build",
 "prost-types",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "tempfile",
 "tonic-build",
 ]
@@ -2858,7 +2862,7 @@ checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -2920,9 +2924,9 @@ checksum = "dbc4bc3a9f746d862c45cb89d705aa10f187bb96c76001afab07a0d35ce60142"
 [[package]]
 name = "unicode-ident"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "537dd038a89878be9b64dd4bd1b260315c1bb94f4d784956b81e27a088d9a09e"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 [[package]]
 name = "unicode-linebreak"
@@ -3051,9 +3055,9 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.108"
+version = "0.2.113"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64024a30ec1e37399cf85a7ffefebdb72205ca1c972291c51512360d90bd8566"
+checksum = "60722a937f594b7fde9adb894d7c092fc1bb6612897c46368d18e7a20208eff2"
 dependencies = [
 "cfg-if",
 "once_cell",
@@ -3064,9 +3068,9 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.108"
+version = "0.2.113"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "008b239d9c740232e71bd39e8ef6429d27097518b6b30bdf9086833bd5b6d608"
+checksum = "0fac8c6395094b6b91c4af293f4c79371c163f9a6f56184d2c9a85f5a95f3950"
 dependencies = [
 "quote",
 "wasm-bindgen-macro-support",
@@ -3074,22 +3078,22 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.108"
+version = "0.2.113"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5256bae2d58f54820e6490f9839c49780dff84c65aeab9e772f15d5f0e913a55"
+checksum = "ab3fabce6159dc20728033842636887e4877688ae94382766e00b180abac9d60"
 dependencies = [
 "bumpalo",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "wasm-bindgen-shared",
 ]
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.108"
+version = "0.2.113"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f01b580c9ac74c8d8f0c0e4afb04eeef2acf145458e52c03845ee9cd23e3d12"
+checksum = "de0e091bdb824da87dc01d967388880d017a0a9bc4f3bdc0d86ee9f9336e3bb5"
 dependencies = [
 "unicode-ident",
 ]
@@ -3171,7 +3175,7 @@ checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -3182,7 +3186,7 @@ checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -3413,7 +3417,7 @@ dependencies = [
 "heck",
 "indexmap",
 "prettyplease",
- "syn 2.0.115",
+ "syn 2.0.117",
 "wasm-metadata",
 "wit-bindgen-core",
 "wit-component",
@@ -3429,7 +3433,7 @@ dependencies = [
 "prettyplease",
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "wit-bindgen-core",
 "wit-bindgen-rust",
 ]
@@ -3535,7 +3539,7 @@ checksum = "b659052874eb698efe5b9e8cf382204678a0086ebf46982b79d6ca3182927e5d"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "synstructure",
 ]
@@ -3556,7 +3560,7 @@ checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 "synstructure",
 ]
@@ -3577,7 +3581,7 @@ checksum = "85a5b4158499876c763cb03bc4e49185d3cccbabb15b33c627f7884f43db852e"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
@@ -3610,7 +3614,7 @@ checksum = "eadce39539ca5cb3985590102671f2567e659fca9666581ad3411d59207951f3"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn 2.0.115",
+ "syn 2.0.117",
 ]
 [[package]]
--- a/server/crates/arbiter-proto/Cargo.toml
+++ b/server/crates/arbiter-proto/Cargo.toml
@@ -19,7 +19,6 @@ rustls-pki-types.workspace = true
 base64 = "0.22.1"
 tracing.workspace = true
 [build-dependencies]
 tonic-prost-build = "0.14.3"
--- a/server/crates/arbiter-proto/build.rs
+++ b/server/crates/arbiter-proto/build.rs
@@ -11,7 +11,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
        .compile_protos(
            &[
                format!("{}/arbiter.proto", PROTOBUF_DIR),
-                format!("{}/auth.proto", PROTOBUF_DIR),
+                format!("{}/user_agent.proto", PROTOBUF_DIR),
                format!("{}/client.proto", PROTOBUF_DIR),
            ],
            &[PROTOBUF_DIR.to_string()],
        )
--- a/server/crates/arbiter-proto/src/lib.rs
+++ b/server/crates/arbiter-proto/src/lib.rs
@@ -3,13 +3,15 @@ pub mod url;
 use base64::{Engine, prelude::BASE64_STANDARD};
 use crate::proto::auth::AuthChallenge;
 pub mod proto {
    tonic::include_proto!("arbiter");
-    pub mod auth {
+    pub mod user_agent {
-        tonic::include_proto!("arbiter.auth");
+        tonic::include_proto!("arbiter.user_agent");
    }
    pub mod client {
        tonic::include_proto!("arbiter.client");
    }
 }
@@ -28,7 +30,7 @@ pub fn home_path() -> Result<std::path::PathBuf, std::io::Error> {
    Ok(arbiter_home)
 }
-pub fn format_challenge(challenge: &AuthChallenge) -> Vec<u8> {
+pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
-    let concat_form = format!("{}:{}", challenge.nonce, BASE64_STANDARD.encode(&challenge.pubkey));
+    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
-    concat_form.into_bytes().to_vec()
+    concat_form.into_bytes()
 }
--- a/server/crates/arbiter-proto/src/transport.rs
+++ b/server/crates/arbiter-proto/src/transport.rs
@@ -1,371 +1,293 @@
-//! Transport abstraction layer for bridging gRPC bidirectional streaming with kameo actors.
+//! Transport-facing abstractions for protocol/session code.
 //!
-//! This module provides a clean separation between the gRPC transport layer and business logic
+//! This module separates three concerns:
 //! by modeling the connection as two linked kameo actors:
 //!
-//! - A **transport actor** ([`GrpcTransportActor`]) that owns the gRPC stream and channel,
+//! - protocol/session logic wants a small duplex interface ([`Bi`])
-//!   forwarding inbound messages to the business actor and outbound messages to the client.
+//! - transport adapters push concrete stream items to an underlying IO layer
-//! - A **business logic actor** that receives inbound messages from the transport actor and
+//! - transport boundaries translate between protocol-facing and transport-facing
-//!   sends outbound messages back through the transport actor.
+//!   item types via direction-specific converters
 //!
-//! The [`wire()`] function sets up bidirectional linking between the two actors, ensuring
+//! [`Bi`] is intentionally minimal and transport-agnostic:
-//! that if either actor dies, the other is notified and can shut down gracefully.
+//! - [`Bi::recv`] yields inbound protocol messages
 //! - [`Bi::send`] accepts outbound protocol/domain items
 //!
-//! # Terminology
+//! # Generic Ordering Rule
 //!
-//! - **InboundMessage**: a message received by the transport actor from the channel/socket
+//! This module uses a single convention consistently: when a type or trait is
-//!   and forwarded to the business actor.
+//! parameterized by protocol message directions, the generic parameters are
-//! - **OutboundMessage**: a message produced by the business actor and sent to the transport
+//! declared as `Inbound` first, then `Outbound`.
 //!   actor to be forwarded to the channel/socket.
 //!
-//! # Architecture
+//! For [`Bi`], that means `Bi<Inbound, Outbound>`:
 //! - `recv() -> Option<Inbound>`
 //! - `send(Outbound)`
 //!
 //! For adapter types that are parameterized by direction-specific converters,
 //! inbound-related converter parameters are declared before outbound-related
 //! converter parameters.
 //!
 //! [`RecvConverter`] and [`SendConverter`] are infallible conversion traits used
 //! by adapters to map between protocol-facing and transport-facing item types.
 //! The traits themselves are not result-aware; adapters decide how transport
 //! errors are handled before (or instead of) conversion.
 //!
 //! [`grpc::GrpcAdapter`] combines:
 //! - a tonic inbound stream
 //! - a Tokio sender for outbound transport items
 //! - a [`RecvConverter`] for the receive path
 //! - a [`SendConverter`] for the send path
 //!
 //! [`DummyTransport`] is a no-op implementation useful for tests and local actor
 //! execution where no real network stream exists.
 //!
 //! # Component Interaction
 //!
 //! ```text
-//! gRPC Stream ──InboundMessage──▶ GrpcTransportActor ──tell(InboundMessage)──▶ BusinessActor
+//! inbound (network -> protocol)
-//!                                 ▲                                    │
+//! ============================
-//!                                 └─tell(Result<OutboundMessage, _>)────┘
+//!
-//!                                 │
+//! tonic::Streaming<RecvTransport>
-//!                          mpsc::Sender ──▶ Client
+//!     -> grpc::GrpcAdapter::recv()
 //!          |
 //!          +--> on `Ok(item)`: RecvConverter::convert(RecvTransport) -> Inbound
 //!          +--> on `Err(status)`: log error and close stream (`None`)
 //!     -> Bi::recv()
 //!     -> protocol/session actor
 //!
 //! outbound (protocol -> network)
 //! ==============================
 //!
 //! protocol/session actor
 //!     -> Bi::send(Outbound)
 //!     -> grpc::GrpcAdapter::send()
 //!          |
 //!          +--> SendConverter::convert(Outbound) -> SendTransport
 //!     -> Tokio mpsc::Sender<SendTransport>
 //!     -> tonic response stream
 //! ```
 //!
-//! # Example
+//! # Design Notes
 //!
-//! ```rust,ignore
+//! - `send()` returns [`Error`] only for transport delivery failures (for
-//! let (tx, rx) = mpsc::channel(1000);
+//!   example, when the outbound channel is closed).
-//! let context = server_context.clone();
+//! - [`grpc::GrpcAdapter`] logs tonic receive errors and treats them as stream
-//!
+//!   closure (`None`).
-//! wire(
+//! - When protocol-facing and transport-facing types are identical, use
-//!     |transport_ref| MyBusinessActor::new(context, transport_ref),
+//!   [`IdentityRecvConverter`] / [`IdentitySendConverter`].
 //!     |business_recipient, business_id| GrpcTransportActor {
 //!         sender: tx,
 //!         receiver: grpc_stream,
 //!         business_logic_actor: business_recipient,
 //!         business_logic_actor_id: business_id,
 //!     },
 //! ).await;
 //!
 //! Ok(Response::new(ReceiverStream::new(rx)))
 //! ```
-use futures::{Stream, StreamExt};
+use std::marker::PhantomData;
 use kameo::{
    Actor,
    actor::{ActorRef, PreparedActor, Recipient, Spawn, WeakActorRef},
    mailbox::Signal,
    prelude::Message,
 };
 use tokio::{
    select,
    sync::mpsc::{self, error::SendError},
 };
 use tonic::{Status, Streaming};
 use tracing::{debug, error};
-/// A bidirectional stream abstraction for sans-io testing.
+/// Errors returned by transport adapters implementing [`Bi`].
 pub enum Error {
    /// The outbound side of the transport is no longer accepting messages.
    ChannelClosed,
 }
 /// Minimal bidirectional transport abstraction used by protocol code.
 ///
-/// Combines a [`Stream`] of incoming messages with the ability to [`send`](Bi::send)
+/// `Bi<Inbound, Outbound>` models a duplex channel with:
-/// outgoing responses. This trait allows business logic to be tested without a real
+/// - inbound items of type `Inbound` read via [`Bi::recv`]
-/// gRPC connection by swapping in an in-memory implementation.
+/// - outbound items of type `Outbound` written via [`Bi::send`]
-///
+pub trait Bi<Inbound, Outbound>: Send + Sync + 'static {
 /// # Type Parameters
 /// - `T`: `InboundMessage` received from the channel/socket (e.g., `UserAgentRequest`)
 /// - `U`: `OutboundMessage` sent to the channel/socket (e.g., `UserAgentResponse`)
 pub trait Bi<T, U>: Stream<Item = Result<T, Status>> + Send + Sync + 'static {
    type Error;
    fn send(
        &mut self,
-        item: Result<U, Status>,
+        item: Outbound,
-    ) -> impl std::future::Future<Output = Result<(), Self::Error>> + Send;
+    ) -> impl std::future::Future<Output = Result<(), Error>> + Send;
    fn recv(&mut self) -> impl std::future::Future<Output = Option<Inbound>> + Send;
 }
-/// Concrete [`Bi`] implementation backed by a tonic gRPC [`Streaming`] and an [`mpsc::Sender`].
+/// Converts transport-facing inbound items into protocol-facing inbound items.
-///
+pub trait RecvConverter: Send + Sync + 'static {
-/// This is the production implementation used in gRPC service handlers. The `request_stream`
+    type Input;
-/// receives messages from the client, and `response_sender` sends responses back.
+    type Output;
-pub struct BiStream<T, U> {
+
-    pub request_stream: Streaming<T>,
+    fn convert(&self, item: Self::Input) -> Self::Output;
    pub response_sender: mpsc::Sender<Result<U, Status>>,
 }
-impl<T, U> Stream for BiStream<T, U>
+/// Converts protocol/domain outbound items into transport-facing outbound items.
-where
+pub trait SendConverter: Send + Sync + 'static {
-    T: Send + 'static,
+    type Input;
-    U: Send + 'static,
+    type Output;
 {
    type Item = Result<T, Status>;
-    fn poll_next(
+    fn convert(&self, item: Self::Input) -> Self::Output;
-        mut self: std::pin::Pin<&mut Self>,
+}
-        cx: &mut std::task::Context<'_>,
+
-    ) -> std::task::Poll<Option<Self::Item>> {
+/// A [`RecvConverter`] that forwards values unchanged.
-        self.request_stream.poll_next_unpin(cx)
+pub struct IdentityRecvConverter<T> {
    _marker: PhantomData<T>,
 }
 impl<T> IdentityRecvConverter<T> {
    pub fn new() -> Self {
        Self {
            _marker: PhantomData,
        }
    }
 }
-impl<T, U> Bi<T, U> for BiStream<T, U>
+impl<T> Default for IdentityRecvConverter<T> {
-where
+    fn default() -> Self {
-    T: Send + 'static,
+        Self::new()
    U: Send + 'static,
 {
    type Error = SendError<Result<U, Status>>;
    async fn send(&mut self, item: Result<U, Status>) -> Result<(), Self::Error> {
        self.response_sender.send(item).await
    }
 }
-/// Marker trait for transport actors that can receive outbound messages of type `T`.
+impl<T> RecvConverter for IdentityRecvConverter<T>
-///
+where
-/// Implement this on your transport actor to indicate it can handle outbound messages
+    T: Send + Sync + 'static,
 /// produced by the business actor. Requires the actor to implement [`Message<Result<T, E>>`]
 /// so business logic can forward responses via [`tell()`](ActorRef::tell).
 ///
 /// # Example
 ///
 /// ```rust,ignore
 /// #[derive(Actor)]
 /// struct MyTransportActor { /* ... */ }
 ///
 /// impl Message<Result<MyResponse, MyError>> for MyTransportActor {
 ///     type Reply = ();
 ///     async fn handle(&mut self, msg: Result<MyResponse, MyError>, _ctx: &mut Context<Self, Self::Reply>) -> Self::Reply {
 ///         // forward outbound message to channel/socket
 ///     }
 /// }
 ///
 /// impl TransportActor<MyResponse, MyError> for MyTransportActor {}
 /// ```
 pub trait TransportActor<Outbound: Send + 'static, DomainError: Send + 'static>:
    Actor + Send + Message<Result<Outbound, DomainError>>
 {
    type Input = T;
    type Output = T;
    fn convert(&self, item: Self::Input) -> Self::Output {
        item
    }
 }
-/// A kameo actor that bridges a gRPC bidirectional stream with a business logic actor.
+/// A [`SendConverter`] that forwards values unchanged.
-///
+pub struct IdentitySendConverter<T> {
-/// This actor owns the gRPC [`Streaming`] receiver and an [`mpsc::Sender`] for responses.
+    _marker: PhantomData<T>,
 /// It multiplexes between its own mailbox (for outbound messages from the business actor)
 /// and the gRPC stream (for inbound client messages) using [`tokio::select!`].
 ///
 /// # Message Flow
 ///
 /// - **Inbound**: Messages from the gRPC stream are forwarded to `business_logic_actor`
 ///   via [`tell()`](Recipient::tell).
 /// - **Outbound**: The business actor sends `Result<Outbound, DomainError>` messages to this
 ///   actor, which forwards them through the `sender` channel to the gRPC response stream.
 ///
 /// # Lifecycle
 ///
 /// - If the business logic actor dies (detected via actor linking), this actor stops,
 ///   which closes the gRPC stream.
 /// - If the gRPC stream closes or errors, this actor stops, which (via linking) notifies
 ///   the business actor.
 /// - Error responses (`Err(DomainError)`) are forwarded to the client and then the actor stops,
 ///   closing the connection.
 ///
 /// # Type Parameters
 /// - `Outbound`: `OutboundMessage` sent to the client (e.g., `UserAgentResponse`)
 /// - `Inbound`: `InboundMessage` received from the client (e.g., `UserAgentRequest`)
 /// - `E`: The domain error type, must implement `Into<tonic::Status>` for gRPC conversion
 pub struct GrpcTransportActor<Outbound, Inbound, DomainError>
 where
    Outbound: Send + 'static,
    Inbound: Send + 'static,
    DomainError: Into<tonic::Status> + Send + 'static,
 {
    sender: mpsc::Sender<Result<Outbound, tonic::Status>>,
    receiver: tonic::Streaming<Inbound>,
    business_logic_actor: Recipient<Inbound>,
    _error: std::marker::PhantomData<DomainError>,
 }
-impl<Outbound, Inbound, DomainError> GrpcTransportActor<Outbound, Inbound, DomainError>
+impl<T> IdentitySendConverter<T> {
    pub fn new() -> Self {
        Self {
            _marker: PhantomData,
        }
    }
 }
 impl<T> Default for IdentitySendConverter<T> {
    fn default() -> Self {
        Self::new()
    }
 }
 impl<T> SendConverter for IdentitySendConverter<T>
 where
-    Outbound: Send + 'static,
+    T: Send + Sync + 'static,
    Inbound: Send + 'static,
    DomainError: Into<tonic::Status> + Send + 'static,
 {
    type Input = T;
    type Output = T;
    fn convert(&self, item: Self::Input) -> Self::Output {
        item
    }
 }
 /// gRPC-specific transport adapters and helpers.
 pub mod grpc {
    use futures::StreamExt;
    use tokio::sync::mpsc;
    use tonic::Streaming;
    use super::{Bi, Error, RecvConverter, SendConverter};
    /// [`Bi`] adapter backed by a tonic gRPC bidirectional stream.
    ///
    /// Tonic receive errors are logged and treated as stream closure (`None`).
    /// The receive converter is only invoked for successful inbound transport
    /// items.
    pub struct GrpcAdapter<InboundConverter, OutboundConverter>
    where
        InboundConverter: RecvConverter,
        OutboundConverter: SendConverter,
    {
        sender: mpsc::Sender<OutboundConverter::Output>,
        receiver: Streaming<InboundConverter::Input>,
        inbound_converter: InboundConverter,
        outbound_converter: OutboundConverter,
    }
    impl<InboundTransport, Inbound, InboundConverter, OutboundConverter>
        GrpcAdapter<InboundConverter, OutboundConverter>
    where
        InboundConverter: RecvConverter<Input = InboundTransport, Output = Inbound>,
        OutboundConverter: SendConverter,
    {
        pub fn new(
-        sender: mpsc::Sender<Result<Outbound, tonic::Status>>,
+            sender: mpsc::Sender<OutboundConverter::Output>,
-        receiver: tonic::Streaming<Inbound>,
+            receiver: Streaming<InboundTransport>,
-        business_logic_actor: Recipient<Inbound>,
+            inbound_converter: InboundConverter,
            outbound_converter: OutboundConverter,
        ) -> Self {
            Self {
                sender,
                receiver,
-            business_logic_actor,
+                inbound_converter,
-            _error: std::marker::PhantomData,
+                outbound_converter,
        }
    }
 }
 impl<Outbound, Inbound, E> Actor for GrpcTransportActor<Outbound, Inbound, E>
 where
    Outbound: Send + 'static,
    Inbound: Send + 'static,
    E: Into<tonic::Status> + Send + 'static,
 {
    type Args = Self;
    type Error = ();
    async fn on_start(args: Self::Args, _: ActorRef<Self>) -> Result<Self, Self::Error> {
        Ok(args)
    }
    fn on_link_died(
        &mut self,
        _: WeakActorRef<Self>,
        id: kameo::prelude::ActorId,
        _: kameo::prelude::ActorStopReason,
    ) -> impl Future<
        Output = Result<std::ops::ControlFlow<kameo::prelude::ActorStopReason>, Self::Error>,
    > + Send {
        async move {
            if id == self.business_logic_actor.id() {
                error!("Business logic actor died, stopping GrpcTransportActor");
                Ok(std::ops::ControlFlow::Break(
                    kameo::prelude::ActorStopReason::Normal,
                ))
            } else {
                debug!(
                    "Linked actor {} died, but it's not the business logic actor, ignoring",
                    id
                );
                Ok(std::ops::ControlFlow::Continue(()))
            }
        }
    }
-    async fn next(
+
-        &mut self,
+    impl< InboundConverter, OutboundConverter> Bi<InboundConverter::Output, OutboundConverter::Input>
-        _: WeakActorRef<Self>,
+        for GrpcAdapter<InboundConverter, OutboundConverter>
-        mailbox_rx: &mut kameo::prelude::MailboxReceiver<Self>,
+    where
-    ) -> Option<kameo::mailbox::Signal<Self>> {
+        InboundConverter: RecvConverter,
-        select! {
+        OutboundConverter: SendConverter,
-            msg = mailbox_rx.recv() => {
+        OutboundConverter::Input: Send + 'static,
-                msg
+        OutboundConverter::Output: Send + 'static,
-            }
+    {
-            recv_msg = self.receiver.next() => {
+        #[tracing::instrument(level = "trace", skip(self, item))]
-                match recv_msg {
+        async fn send(&mut self, item: OutboundConverter::Input) -> Result<(), Error> {
-                    Some(Ok(msg)) => {
+            let outbound = self.outbound_converter.convert(item);
-                        match self.business_logic_actor.tell(msg).await {
+            self.sender
-                            Ok(_) => None,
+                .send(outbound)
-                            Err(e) => {
+                .await
-                                // TODO: this would probably require better error handling - or resending if backpressure is the issue
+                .map_err(|_| Error::ChannelClosed)
                                error!("Failed to send message to business logic actor: {}", e);
                                Some(Signal::Stop)
                            }
                        }
                    }
                    Some(Err(e)) => {
                        error!("Received error from stream: {}, stopping GrpcTransportActor", e);
                        Some(Signal::Stop)
                    }
                    None => {
                        error!("Receiver channel closed, stopping GrpcTransportActor");
                        Some(Signal::Stop)
        }
        #[tracing::instrument(level = "trace", skip(self))]
        async fn recv(&mut self) -> Option<InboundConverter::Output> {
            match self.receiver.next().await {
                Some(Ok(item)) => Some(self.inbound_converter.convert(item)),
                Some(Err(error)) => {
                    tracing::error!(error = ?error, "grpc transport recv failed; closing stream");
                    None
                }
                None => None,
            }
        }
    }
 }
-impl<Outbound, Inbound, E> Message<Result<Outbound, E>> for GrpcTransportActor<Outbound, Inbound, E>
+/// No-op [`Bi`] transport for tests and manual actor usage.
 where
    Outbound: Send + 'static,
    Inbound: Send + 'static,
    E: Into<tonic::Status> + Send + 'static,
 {
    type Reply = ();
    async fn handle(
        &mut self,
        msg: Result<Outbound, E>,
        ctx: &mut kameo::prelude::Context<Self, Self::Reply>,
    ) -> Self::Reply {
        let is_err = msg.is_err();
        let grpc_msg = msg.map_err(Into::into);
        match self.sender.send(grpc_msg).await {
            Ok(_) => {
                if is_err {
                    ctx.stop();
                }
            }
            Err(e) => {
                error!("Failed to send message: {}", e);
                ctx.stop();
            }
        }
    }
 }
 impl<Outbound, Inbound, E> TransportActor<Outbound, E> for GrpcTransportActor<Outbound, Inbound, E>
 where
    Outbound: Send + 'static,
    Inbound: Send + 'static,
    E: Into<tonic::Status> + Send + 'static,
 {
 }
 /// Wires together a transport actor and a business logic actor with bidirectional linking.
 ///
-/// This function handles the chicken-and-egg problem of two actors that need references
+/// `send` drops all items and succeeds. [`Bi::recv`] never resolves and therefore
-/// to each other at construction time. It uses kameo's [`PreparedActor`] to obtain
+/// does not busy-wait or spuriously close the stream.
-/// [`ActorRef`]s before spawning, then links both actors so that if either dies,
+pub struct DummyTransport<Inbound, Outbound> {
-/// the other is notified via [`on_link_died`](Actor::on_link_died).
+    _marker: PhantomData<(Inbound, Outbound)>,
-///
+}
-/// The business actor receives a type-erased [`Recipient<Result<Outbound, DomainError>>`] instead of an
+
-/// `ActorRef<Transport>`, keeping it decoupled from the concrete transport implementation.
+impl<Inbound, Outbound> DummyTransport<Inbound, Outbound> {
-///
+    pub fn new() -> Self {
-/// # Type Parameters
+        Self {
-/// - `Transport`: The transport actor type (e.g., [`GrpcTransportActor`])
+            _marker: PhantomData,
-/// - `Inbound`: `InboundMessage` received by the business actor from the transport
+        }
-/// - `Outbound`: `OutboundMessage` sent by the business actor back to the transport
+    }
-/// - `Business`: The business logic actor
+}
-/// - `BusinessCtor`: Closure that receives a prepared business actor and transport recipient,
+
-///   spawns the business actor, and returns its [`ActorRef`]
+impl<Inbound, Outbound> Default for DummyTransport<Inbound, Outbound> {
-/// - `TransportCtor`: Closure that receives a prepared transport actor, a recipient for
+    fn default() -> Self {
-///   inbound messages, and the business actor id, then spawns the transport actor
+        Self::new()
-///
+    }
-/// # Returns
+}
-/// A tuple of `(transport_ref, business_ref)` — actor references for both spawned actors.
+
-pub async fn wire<
+impl<Inbound, Outbound> Bi<Inbound, Outbound> for DummyTransport<Inbound, Outbound>
-    Transport,
+where
-    Inbound,
+    Inbound: Send + Sync + 'static,
-    Outbound,
+    Outbound: Send + Sync + 'static,
-    DomainError,
+{
-    Business,
+    async fn send(&mut self, _item: Outbound) -> Result<(), Error> {
-    BusinessCtor,
+        Ok(())
-    TransportCtor,
+    }
->(
+
-    business_ctor: BusinessCtor,
+    fn recv(&mut self) -> impl std::future::Future<Output = Option<Inbound>> + Send {
-    transport_ctor: TransportCtor,
+        async {
-) -> (ActorRef<Transport>, ActorRef<Business>)
+            std::future::pending::<()>().await;
-where
+            None
-    Transport: TransportActor<Outbound, DomainError>,
+        }
-    Inbound: Send + 'static,
+    }
    Outbound: Send + 'static,
    DomainError: Send + 'static,
    Business: Actor + Message<Inbound> + Send + 'static,
    BusinessCtor: FnOnce(PreparedActor<Business>, Recipient<Result<Outbound, DomainError>>),
    TransportCtor:
        FnOnce(PreparedActor<Transport>, Recipient<Inbound>),
 {
    let prepared_business: PreparedActor<Business> = Spawn::prepare();
    let prepared_transport: PreparedActor<Transport> = Spawn::prepare();
    let business_ref = prepared_business.actor_ref().clone();
    let transport_ref = prepared_transport.actor_ref().clone();
    transport_ref.link(&business_ref).await;
    business_ref.link(&transport_ref).await;
    let recipient = transport_ref.clone().recipient();
    business_ctor(prepared_business, recipient);
    let business_recipient = business_ref.clone().recipient();
    transport_ctor(prepared_transport, business_recipient);
    (transport_ref, business_ref)
 }
--- a/server/crates/arbiter-server/src/actors/client.rs
+++ b/server/crates/arbiter-server/src/actors/client.rs
@@ -1,12 +0,0 @@
 use arbiter_proto::{
    proto::{ClientRequest, ClientResponse},
    transport::Bi,
 };
 use crate::ServerContext;
 pub(crate) async fn handle_client(
    _context: ServerContext,
    _bistream: impl Bi<ClientRequest, ClientResponse>,
 ) {
 }
--- a/server/crates/arbiter-server/src/actors/client/mod.rs
+++ b/server/crates/arbiter-server/src/actors/client/mod.rs
@@ -0,0 +1,289 @@
 use arbiter_proto::{
    proto::client::{
        AuthChallenge, AuthChallengeRequest, AuthChallengeSolution, AuthOk, ClientRequest,
        ClientResponse,
        client_request::Payload as ClientRequestPayload,
        client_response::Payload as ClientResponsePayload,
    },
    transport::{Bi, DummyTransport},
 };
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, dsl::update};
 use diesel_async::RunQueryDsl;
 use ed25519_dalek::VerifyingKey;
 use kameo::Actor;
 use tokio::select;
 use tracing::{error, info};
 use crate::{
    ServerContext,
    actors::client::state::{
        ChallengeContext, ClientEvents, ClientStateMachine, ClientStates, DummyContext,
    },
    db::{self, schema},
 };
 mod state;
 #[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
 pub enum ClientError {
    #[error("Expected message with payload")]
    MissingRequestPayload,
    #[error("Unexpected request payload")]
    UnexpectedRequestPayload,
    #[error("Invalid state for challenge solution")]
    InvalidStateForChallengeSolution,
    #[error("Expected pubkey to have specific length")]
    InvalidAuthPubkeyLength,
    #[error("Failed to convert pubkey to VerifyingKey")]
    InvalidAuthPubkeyEncoding,
    #[error("Invalid signature length")]
    InvalidSignatureLength,
    #[error("Public key not registered")]
    PublicKeyNotRegistered,
    #[error("Invalid challenge solution")]
    InvalidChallengeSolution,
    #[error("State machine error")]
    StateTransitionFailed,
    #[error("Database pool error")]
    DatabasePoolUnavailable,
    #[error("Database error")]
    DatabaseOperationFailed,
 }
 pub struct ClientActor<Transport>
 where
    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
 {
    db: db::DatabasePool,
    state: ClientStateMachine<DummyContext>,
    transport: Transport,
 }
 impl<Transport> ClientActor<Transport>
 where
    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
 {
    pub(crate) fn new(context: ServerContext, transport: Transport) -> Self {
        Self {
            db: context.db.clone(),
            state: ClientStateMachine::new(DummyContext),
            transport,
        }
    }
    fn transition(&mut self, event: ClientEvents) -> Result<(), ClientError> {
        self.state.process_event(event).map_err(|e| {
            error!(?e, "State transition failed");
            ClientError::StateTransitionFailed
        })?;
        Ok(())
    }
    pub async fn process_transport_inbound(&mut self, req: ClientRequest) -> Output {
        let msg = req.payload.ok_or_else(|| {
            error!(actor = "client", "Received message with no payload");
            ClientError::MissingRequestPayload
        })?;
        match msg {
            ClientRequestPayload::AuthChallengeRequest(req) => {
                self.handle_auth_challenge_request(req).await
            }
            ClientRequestPayload::AuthChallengeSolution(solution) => {
                self.handle_auth_challenge_solution(solution).await
            }
        }
    }
    async fn handle_auth_challenge_request(&mut self, req: AuthChallengeRequest) -> Output {
        let pubkey = req
            .pubkey
            .as_array()
            .ok_or(ClientError::InvalidAuthPubkeyLength)?;
        let pubkey = VerifyingKey::from_bytes(pubkey).map_err(|_err| {
            error!(?pubkey, "Failed to convert to VerifyingKey");
            ClientError::InvalidAuthPubkeyEncoding
        })?;
        self.transition(ClientEvents::AuthRequest)?;
        self.auth_with_challenge(pubkey, req.pubkey).await
    }
    async fn auth_with_challenge(&mut self, pubkey: VerifyingKey, pubkey_bytes: Vec<u8>) -> Output {
        let nonce: Option<i32> = {
            let mut db_conn = self.db.get().await.map_err(|e| {
                error!(error = ?e, "Database pool error");
                ClientError::DatabasePoolUnavailable
            })?;
            db_conn
                .exclusive_transaction(|conn| {
                    Box::pin(async move {
                        let current_nonce = schema::program_client::table
                            .filter(
                                schema::program_client::public_key.eq(pubkey.as_bytes().to_vec()),
                            )
                            .select(schema::program_client::nonce)
                            .first::<i32>(conn)
                            .await?;
                        update(schema::program_client::table)
                            .filter(
                                schema::program_client::public_key.eq(pubkey.as_bytes().to_vec()),
                            )
                            .set(schema::program_client::nonce.eq(current_nonce + 1))
                            .execute(conn)
                            .await?;
                        Result::<_, diesel::result::Error>::Ok(current_nonce)
                    })
                })
                .await
                .optional()
                .map_err(|e| {
                    error!(error = ?e, "Database error");
                    ClientError::DatabaseOperationFailed
                })?
        };
        let Some(nonce) = nonce else {
            error!(?pubkey, "Public key not found in database");
            return Err(ClientError::PublicKeyNotRegistered);
        };
        let challenge = AuthChallenge {
            pubkey: pubkey_bytes,
            nonce,
        };
        self.transition(ClientEvents::SentChallenge(ChallengeContext {
            challenge: challenge.clone(),
            key: pubkey,
        }))?;
        info!(
            ?pubkey,
            ?challenge,
            "Sent authentication challenge to client"
        );
        Ok(response(ClientResponsePayload::AuthChallenge(challenge)))
    }
    fn verify_challenge_solution(
        &self,
        solution: &AuthChallengeSolution,
    ) -> Result<(bool, &ChallengeContext), ClientError> {
        let ClientStates::WaitingForChallengeSolution(challenge_context) = self.state.state()
        else {
            error!("Received challenge solution in invalid state");
            return Err(ClientError::InvalidStateForChallengeSolution);
        };
        let formatted_challenge = arbiter_proto::format_challenge(
            challenge_context.challenge.nonce,
            &challenge_context.challenge.pubkey,
        );
        let signature = solution.signature.as_slice().try_into().map_err(|_| {
            error!(?solution, "Invalid signature length");
            ClientError::InvalidSignatureLength
        })?;
        let valid = challenge_context
            .key
            .verify_strict(&formatted_challenge, &signature)
            .is_ok();
        Ok((valid, challenge_context))
    }
    async fn handle_auth_challenge_solution(
        &mut self,
        solution: AuthChallengeSolution,
    ) -> Output {
        let (valid, challenge_context) = self.verify_challenge_solution(&solution)?;
        if valid {
            info!(
                ?challenge_context,
                "Client provided valid solution to authentication challenge"
            );
            self.transition(ClientEvents::ReceivedGoodSolution)?;
            Ok(response(ClientResponsePayload::AuthOk(AuthOk {})))
        } else {
            error!("Client provided invalid solution to authentication challenge");
            self.transition(ClientEvents::ReceivedBadSolution)?;
            Err(ClientError::InvalidChallengeSolution)
        }
    }
 }
 type Output = Result<ClientResponse, ClientError>;
 fn response(payload: ClientResponsePayload) -> ClientResponse {
    ClientResponse {
        payload: Some(payload),
    }
 }
 impl<Transport> Actor for ClientActor<Transport>
 where
    Transport: Bi<ClientRequest, Result<ClientResponse, ClientError>>,
 {
    type Args = Self;
    type Error = ();
    async fn on_start(
        args: Self::Args,
        _: kameo::prelude::ActorRef<Self>,
    ) -> Result<Self, Self::Error> {
        Ok(args)
    }
    async fn next(
        &mut self,
        _actor_ref: kameo::prelude::WeakActorRef<Self>,
        mailbox_rx: &mut kameo::prelude::MailboxReceiver<Self>,
    ) -> Option<kameo::mailbox::Signal<Self>> {
        loop {
            select! {
                signal = mailbox_rx.recv() => {
                    return signal;
                }
                msg = self.transport.recv() => {
                    match msg {
                        Some(request) => {
                            match self.process_transport_inbound(request).await {
                                Ok(resp) => {
                                    if self.transport.send(Ok(resp)).await.is_err() {
                                        error!(actor = "client", reason = "channel closed", "send.failed");
                                        return Some(kameo::mailbox::Signal::Stop);
                                    }
                                }
                                Err(err) => {
                                    let _ = self.transport.send(Err(err)).await;
                                    return Some(kameo::mailbox::Signal::Stop);
                                }
                            }
                        }
                        None => {
                            info!(actor = "client", "transport.closed");
                            return Some(kameo::mailbox::Signal::Stop);
                        }
                    }
                }
            }
        }
    }
 }
 impl ClientActor<DummyTransport<ClientRequest, Result<ClientResponse, ClientError>>> {
    pub fn new_manual(db: db::DatabasePool) -> Self {
        Self {
            db,
            state: ClientStateMachine::new(DummyContext),
            transport: DummyTransport::new(),
        }
    }
 }
--- a/server/crates/arbiter-server/src/actors/client/state.rs
+++ b/server/crates/arbiter-server/src/actors/client/state.rs
@@ -0,0 +1,31 @@
 use arbiter_proto::proto::client::AuthChallenge;
 use ed25519_dalek::VerifyingKey;
 /// Context for state machine with validated key and sent challenge
 #[derive(Clone, Debug)]
 pub struct ChallengeContext {
    pub challenge: AuthChallenge,
    pub key: VerifyingKey,
 }
 smlang::statemachine!(
    name: Client,
    custom_error: false,
    transitions: {
        *Init + AuthRequest = ReceivedAuthRequest,
        ReceivedAuthRequest + SentChallenge(ChallengeContext) / move_challenge = WaitingForChallengeSolution(ChallengeContext),
        WaitingForChallengeSolution(ChallengeContext) + ReceivedGoodSolution = Idle,
        WaitingForChallengeSolution(ChallengeContext) + ReceivedBadSolution = AuthError,
    }
 );
 pub struct DummyContext;
 impl ClientStateMachineContext for DummyContext {
    #[allow(missing_docs)]
    #[allow(clippy::unused_unit)]
    fn move_challenge(&mut self, event_data: ChallengeContext) -> Result<ChallengeContext, ()> {
        Ok(event_data)
    }
 }
--- a/server/crates/arbiter-server/src/actors/user_agent/error.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/error.rs
@@ -1,57 +0,0 @@
 use tonic::Status;
 use crate::db;
 #[derive(Debug, thiserror::Error)]
 pub enum UserAgentError {
    #[error("Missing payload in request")]
    MissingPayload,
    #[error("Invalid bootstrap token")]
    InvalidBootstrapToken,
    #[error("Public key not registered")]
    PubkeyNotRegistered,
    #[error("Invalid public key format")]
    InvalidPubkey,
    #[error("Invalid signature length")]
    InvalidSignatureLength,
    #[error("Invalid challenge solution")]
    InvalidChallengeSolution,
    #[error("Invalid state for operation")]
    InvalidState,
    #[error("Actor unavailable")]
    ActorUnavailable,
    #[error("Database error")]
    Database(#[from] diesel::result::Error),
    #[error("Database pool error")]
    DatabasePool(#[from] db::PoolError),
 }
 impl From<UserAgentError> for Status {
    fn from(err: UserAgentError) -> Self {
        match err {
            UserAgentError::MissingPayload
            | UserAgentError::InvalidBootstrapToken
            | UserAgentError::InvalidPubkey
            | UserAgentError::InvalidSignatureLength => Status::invalid_argument(err.to_string()),
            UserAgentError::PubkeyNotRegistered | UserAgentError::InvalidChallengeSolution => {
                Status::unauthenticated(err.to_string())
            }
            UserAgentError::InvalidState => Status::failed_precondition(err.to_string()),
            UserAgentError::ActorUnavailable
            | UserAgentError::Database(_)
            | UserAgentError::DatabasePool(_) => Status::internal(err.to_string()),
        }
    }
 }
--- a/server/crates/arbiter-server/src/actors/user_agent/mod.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/mod.rs
@@ -1,23 +1,21 @@
 use std::{ops::DerefMut, sync::Mutex};
-use arbiter_proto::proto::{
+use arbiter_proto::{
-    UnsealEncryptedKey, UnsealResult, UnsealStart, UnsealStartResponse, UserAgentRequest,
+    proto::user_agent::{
-    UserAgentResponse,
+        AuthChallenge, AuthChallengeRequest, AuthChallengeSolution, AuthOk, UnsealEncryptedKey,
-    auth::{
+        UnsealResult, UnsealStart, UnsealStartResponse, UserAgentRequest, UserAgentResponse,
        self, AuthChallengeRequest, AuthOk, ClientMessage as ClientAuthMessage,
        ServerMessage as AuthServerMessage,
        client_message::Payload as ClientAuthPayload,
        server_message::Payload as ServerAuthPayload,
    },
        user_agent_request::Payload as UserAgentRequestPayload,
        user_agent_response::Payload as UserAgentResponsePayload,
    },
    transport::{Bi, DummyTransport},
 };
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, dsl::update};
 use diesel_async::RunQueryDsl;
 use ed25519_dalek::VerifyingKey;
-use kameo::{Actor, actor::Recipient, error::SendError, messages, prelude::Message};
+use kameo::{Actor, error::SendError};
 use memsafe::MemSafe;
 use tokio::select;
 use tracing::{error, info};
 use x25519_dalek::{EphemeralSecret, PublicKey};
@@ -35,24 +33,59 @@ use crate::{
    db::{self, schema},
 };
 mod error;
 mod state;
-pub use error::UserAgentError;
+#[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
 pub enum UserAgentError {
    #[error("Expected message with payload")]
    MissingRequestPayload,
    #[error("Expected message with payload")]
    UnexpectedRequestPayload,
    #[error("Invalid state for challenge solution")]
    InvalidStateForChallengeSolution,
    #[error("Invalid state for unseal encrypted key")]
    InvalidStateForUnsealEncryptedKey,
    #[error("client_pubkey must be 32 bytes")]
    InvalidClientPubkeyLength,
    #[error("Expected pubkey to have specific length")]
    InvalidAuthPubkeyLength,
    #[error("Failed to convert pubkey to VerifyingKey")]
    InvalidAuthPubkeyEncoding,
    #[error("Invalid signature length")]
    InvalidSignatureLength,
    #[error("Invalid bootstrap token")]
    InvalidBootstrapToken,
    #[error("Public key not registered")]
    PublicKeyNotRegistered,
    #[error("Invalid challenge solution")]
    InvalidChallengeSolution,
    #[error("State machine error")]
    StateTransitionFailed,
    #[error("Bootstrap token consumption failed")]
    BootstrapperActorUnreachable,
    #[error("Vault is not available")]
    KeyHolderActorUnreachable,
    #[error("Database pool error")]
    DatabasePoolUnavailable,
    #[error("Database error")]
    DatabaseOperationFailed,
 }
-#[derive(Actor)]
+pub struct UserAgentActor<Transport>
-pub struct UserAgentActor {
+where
    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
 {
    db: db::DatabasePool,
    actors: GlobalActors,
    state: UserAgentStateMachine<DummyContext>,
-    transport: Recipient<Result<UserAgentResponse, UserAgentError>>,
+    transport: Transport,
 }
-impl UserAgentActor {
+impl<Transport> UserAgentActor<Transport>
-    pub(crate) fn new(
+where
-        context: ServerContext,
+    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
-        transport: Recipient<Result<UserAgentResponse, UserAgentError>>,
+{
-    ) -> Self {
+    pub(crate) fn new(context: ServerContext, transport: Transport) -> Self {
        Self {
            db: context.db.clone(),
            actors: context.actors.clone(),
@@ -61,55 +94,42 @@ impl UserAgentActor {
        }
    }
-    pub fn new_manual(
+    fn transition(&mut self, event: UserAgentEvents) -> Result<(), UserAgentError> {
-        db: db::DatabasePool,
+        self.state.process_event(event).map_err(|e| {
-        actors: GlobalActors,
+            error!(?e, "State transition failed");
-        transport: Recipient<Result<UserAgentResponse, UserAgentError>>,
+            UserAgentError::StateTransitionFailed
-    ) -> Self {
+        })?;
-        Self {
+        Ok(())
            db,
            actors,
            state: UserAgentStateMachine::new(DummyContext),
            transport,
        }
    }
-    async fn process_request(&mut self, req: UserAgentRequest) -> Output {
+    pub async fn process_transport_inbound(&mut self, req: UserAgentRequest) -> Output {
        let msg = req.payload.ok_or_else(|| {
            error!(actor = "useragent", "Received message with no payload");
-            UserAgentError::MissingPayload
+            UserAgentError::MissingRequestPayload
        })?;
        match msg {
-            UserAgentRequestPayload::AuthMessage(ClientAuthMessage {
+            UserAgentRequestPayload::AuthChallengeRequest(req) => {
-                payload: Some(ClientAuthPayload::AuthChallengeRequest(req)),
+                self.handle_auth_challenge_request(req).await
-            }) => self.handle_auth_challenge_request(req).await,
+            }
-            UserAgentRequestPayload::AuthMessage(ClientAuthMessage {
+            UserAgentRequestPayload::AuthChallengeSolution(solution) => {
-                payload: Some(ClientAuthPayload::AuthChallengeSolution(solution)),
+                self.handle_auth_challenge_solution(solution).await
-            }) => self.handle_auth_challenge_solution(solution).await,
+            }
            UserAgentRequestPayload::UnsealStart(unseal_start) => {
                self.handle_unseal_request(unseal_start).await
            }
            UserAgentRequestPayload::UnsealEncryptedKey(unseal_encrypted_key) => {
                self.handle_unseal_encrypted_key(unseal_encrypted_key).await
            }
-            _ => Err(UserAgentError::MissingPayload),
+            _ => Err(UserAgentError::UnexpectedRequestPayload),
        }
    }
    fn transition(&mut self, event: UserAgentEvents) -> Result<(), UserAgentError> {
        self.state.process_event(event).map_err(|e| {
            error!(?e, "State transition failed");
            UserAgentError::InvalidState
        })?;
        Ok(())
    }
    async fn auth_with_bootstrap_token(
        &mut self,
        pubkey: ed25519_dalek::VerifyingKey,
        token: String,
-    ) -> Output {
+    ) -> Result<UserAgentResponse, UserAgentError> {
        let token_ok: bool = self
            .actors
            .bootstrapper
@@ -117,7 +137,7 @@ impl UserAgentActor {
            .await
            .map_err(|e| {
                error!(?pubkey, "Failed to consume bootstrap token: {e}");
-                UserAgentError::ActorUnavailable
+                UserAgentError::BootstrapperActorUnreachable
            })?;
        if !token_ok {
@@ -126,7 +146,10 @@ impl UserAgentActor {
        }
        {
-            let mut conn = self.db.get().await?;
+            let mut conn = self.db.get().await.map_err(|e| {
                error!(error = ?e, "Database pool error");
                UserAgentError::DatabasePoolUnavailable
            })?;
            diesel::insert_into(schema::useragent_client::table)
                .values((
@@ -134,17 +157,24 @@ impl UserAgentActor {
                    schema::useragent_client::nonce.eq(1),
                ))
                .execute(&mut conn)
-                .await?;
+                .await
                .map_err(|e| {
                    error!(error = ?e, "Database error");
                    UserAgentError::DatabaseOperationFailed
                })?;
        }
        self.transition(UserAgentEvents::ReceivedBootstrapToken)?;
-        Ok(auth_response(ServerAuthPayload::AuthOk(AuthOk {})))
+        Ok(response(UserAgentResponsePayload::AuthOk(AuthOk {})))
    }
    async fn auth_with_challenge(&mut self, pubkey: VerifyingKey, pubkey_bytes: Vec<u8>) -> Output {
        let nonce: Option<i32> = {
-            let mut db_conn = self.db.get().await?;
+            let mut db_conn = self.db.get().await.map_err(|e| {
                error!(error = ?e, "Database pool error");
                UserAgentError::DatabasePoolUnavailable
            })?;
            db_conn
                .exclusive_transaction(|conn| {
                    Box::pin(async move {
@@ -168,15 +198,19 @@ impl UserAgentActor {
                    })
                })
                .await
-                .optional()?
+                .optional()
                .map_err(|e| {
                    error!(error = ?e, "Database error");
                    UserAgentError::DatabaseOperationFailed
                })?
        };
        let Some(nonce) = nonce else {
            error!(?pubkey, "Public key not found in database");
-            return Err(UserAgentError::PubkeyNotRegistered);
+            return Err(UserAgentError::PublicKeyNotRegistered);
        };
-        let challenge = auth::AuthChallenge {
+        let challenge = AuthChallenge {
            pubkey: pubkey_bytes,
            nonce,
        };
@@ -192,19 +226,22 @@ impl UserAgentActor {
            "Sent authentication challenge to client"
        );
-        Ok(auth_response(ServerAuthPayload::AuthChallenge(challenge)))
+        Ok(response(UserAgentResponsePayload::AuthChallenge(challenge)))
    }
    fn verify_challenge_solution(
        &self,
-        solution: &auth::AuthChallengeSolution,
+        solution: &AuthChallengeSolution,
    ) -> Result<(bool, &ChallengeContext), UserAgentError> {
        let UserAgentStates::WaitingForChallengeSolution(challenge_context) = self.state.state()
        else {
            error!("Received challenge solution in invalid state");
-            return Err(UserAgentError::InvalidState);
+            return Err(UserAgentError::InvalidStateForChallengeSolution);
        };
-        let formatted_challenge = arbiter_proto::format_challenge(&challenge_context.challenge);
+        let formatted_challenge = arbiter_proto::format_challenge(
            challenge_context.challenge.nonce,
            &challenge_context.challenge.pubkey,
        );
        let signature = solution.signature.as_slice().try_into().map_err(|_| {
            error!(?solution, "Invalid signature length");
@@ -222,31 +259,24 @@ impl UserAgentActor {
 type Output = Result<UserAgentResponse, UserAgentError>;
-fn auth_response(payload: ServerAuthPayload) -> UserAgentResponse {
+fn response(payload: UserAgentResponsePayload) -> UserAgentResponse {
    UserAgentResponse {
        payload: Some(UserAgentResponsePayload::AuthMessage(AuthServerMessage {
            payload: Some(payload),
        })),
    }
 }
 fn unseal_response(payload: UserAgentResponsePayload) -> UserAgentResponse {
    UserAgentResponse {
        payload: Some(payload),
    }
 }
-#[messages]
+impl<Transport> UserAgentActor<Transport>
-impl UserAgentActor {
+where
-    #[message]
+    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
-    pub async fn handle_unseal_request(&mut self, req: UnsealStart) -> Output {
+{
    async fn handle_unseal_request(&mut self, req: UnsealStart) -> Output {
        let secret = EphemeralSecret::random();
        let public_key = PublicKey::from(&secret);
        let client_pubkey_bytes: [u8; 32] = req
            .client_pubkey
            .try_into()
-            .map_err(|_| UserAgentError::InvalidPubkey)?;
+            .map_err(|_| UserAgentError::InvalidClientPubkeyLength)?;
        let client_public_key = PublicKey::from(client_pubkey_bytes);
@@ -255,18 +285,17 @@ impl UserAgentActor {
            client_public_key,
        }))?;
-        Ok(unseal_response(
+        Ok(response(
            UserAgentResponsePayload::UnsealStartResponse(UnsealStartResponse {
                server_pubkey: public_key.as_bytes().to_vec(),
            }),
        ))
    }
-    #[message]
+    async fn handle_unseal_encrypted_key(&mut self, req: UnsealEncryptedKey) -> Output {
    pub async fn handle_unseal_encrypted_key(&mut self, req: UnsealEncryptedKey) -> Output {
        let UserAgentStates::WaitingForUnsealKey(unseal_context) = self.state.state() else {
            error!("Received unseal encrypted key in invalid state");
-            return Err(UserAgentError::InvalidState);
+            return Err(UserAgentError::InvalidStateForUnsealEncryptedKey);
        };
        let ephemeral_secret = {
            let mut secret_lock = unseal_context.secret.lock().unwrap();
@@ -277,7 +306,7 @@ impl UserAgentActor {
                    drop(secret_lock);
                    error!("Ephemeral secret already taken");
                    self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                    return Ok(unseal_response(UserAgentResponsePayload::UnsealResult(
+                    return Ok(response(UserAgentResponsePayload::UnsealResult(
                        UnsealResult::InvalidKey.into(),
                    )));
                }
@@ -310,49 +339,48 @@ impl UserAgentActor {
                    Ok(_) => {
                        info!("Successfully unsealed key with client-provided key");
                        self.transition(UserAgentEvents::ReceivedValidKey)?;
-                        Ok(unseal_response(UserAgentResponsePayload::UnsealResult(
+                        Ok(response(UserAgentResponsePayload::UnsealResult(
                            UnsealResult::Success.into(),
                        )))
                    }
                    Err(SendError::HandlerError(keyholder::Error::InvalidKey)) => {
                        self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                        Ok(unseal_response(UserAgentResponsePayload::UnsealResult(
+                        Ok(response(UserAgentResponsePayload::UnsealResult(
                            UnsealResult::InvalidKey.into(),
                        )))
                    }
                    Err(SendError::HandlerError(err)) => {
                        error!(?err, "Keyholder failed to unseal key");
                        self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                        Ok(unseal_response(UserAgentResponsePayload::UnsealResult(
+                        Ok(response(UserAgentResponsePayload::UnsealResult(
                            UnsealResult::InvalidKey.into(),
                        )))
                    }
                    Err(err) => {
                        error!(?err, "Failed to send unseal request to keyholder");
                        self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                        Err(UserAgentError::ActorUnavailable)
+                        Err(UserAgentError::KeyHolderActorUnreachable)
                    }
                }
            }
            Err(err) => {
                error!(?err, "Failed to decrypt unseal key");
                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Ok(unseal_response(UserAgentResponsePayload::UnsealResult(
+                Ok(response(UserAgentResponsePayload::UnsealResult(
                    UnsealResult::InvalidKey.into(),
                )))
            }
        }
    }
-    #[message]
+    async fn handle_auth_challenge_request(&mut self, req: AuthChallengeRequest) -> Output {
    pub async fn handle_auth_challenge_request(&mut self, req: AuthChallengeRequest) -> Output {
        let pubkey = req
            .pubkey
            .as_array()
-            .ok_or(UserAgentError::InvalidPubkey)?;
+            .ok_or(UserAgentError::InvalidAuthPubkeyLength)?;
        let pubkey = VerifyingKey::from_bytes(pubkey).map_err(|_err| {
            error!(?pubkey, "Failed to convert to VerifyingKey");
-            UserAgentError::InvalidPubkey
+            UserAgentError::InvalidAuthPubkeyEncoding
        })?;
        self.transition(UserAgentEvents::AuthRequest)?;
@@ -363,10 +391,9 @@ impl UserAgentActor {
        }
    }
-    #[message]
+    async fn handle_auth_challenge_solution(
    pub async fn handle_auth_challenge_solution(
        &mut self,
-        solution: auth::AuthChallengeSolution,
+        solution: AuthChallengeSolution,
    ) -> Output {
        let (valid, challenge_context) = self.verify_challenge_solution(&solution)?;
@@ -376,7 +403,7 @@ impl UserAgentActor {
                "Client provided valid solution to authentication challenge"
            );
            self.transition(UserAgentEvents::ReceivedGoodSolution)?;
-            Ok(auth_response(ServerAuthPayload::AuthOk(AuthOk {})))
+            Ok(response(UserAgentResponsePayload::AuthOk(AuthOk {})))
        } else {
            error!("Client provided invalid solution to authentication challenge");
            self.transition(UserAgentEvents::ReceivedBadSolution)?;
@@ -385,17 +412,67 @@ impl UserAgentActor {
    }
 }
 impl Message<UserAgentRequest> for UserAgentActor {
    type Reply = ();
-    async fn handle(
+impl<Transport> Actor for UserAgentActor<Transport>
 where
    Transport: Bi<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>,
 {
    type Args = Self;
    type Error = ();
    async fn on_start(
        args: Self::Args,
        _: kameo::prelude::ActorRef<Self>,
    ) -> Result<Self, Self::Error> {
        Ok(args)
    }
    async fn next(
        &mut self,
-        msg: UserAgentRequest,
+        _actor_ref: kameo::prelude::WeakActorRef<Self>,
-        _ctx: &mut kameo::prelude::Context<Self, Self::Reply>,
+        mailbox_rx: &mut kameo::prelude::MailboxReceiver<Self>,
-    ) -> Self::Reply {
+    ) -> Option<kameo::mailbox::Signal<Self>> {
-        let result = self.process_request(msg).await;
+        loop {
-        if let Err(e) = self.transport.tell(result).await {
+            select! {
-            error!(actor = "useragent", "Failed to send response to transport: {}", e);
+                signal = mailbox_rx.recv() => {
                    return signal;
                }
                msg = self.transport.recv() => {
                    match msg {
                        Some(request) => {
                            match self.process_transport_inbound(request).await {
                                Ok(response) => {
                                    if self.transport.send(Ok(response)).await.is_err() {
                                        error!(actor = "useragent", reason = "channel closed", "send.failed");
                                        return Some(kameo::mailbox::Signal::Stop);
                                    }
                                }
                                Err(err) => {
                                    let _ = self.transport.send(Err(err)).await;
                                    return Some(kameo::mailbox::Signal::Stop);
                                }
                            }
                        }
                        None => {
                            info!(actor = "useragent", "transport.closed");
                            return Some(kameo::mailbox::Signal::Stop);
                        }
                    }
                }
            }
        }
    }
 }
 impl UserAgentActor<DummyTransport<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>> {
    pub fn new_manual(db: db::DatabasePool, actors: GlobalActors) -> Self {
        Self {
            db,
            actors,
            state: UserAgentStateMachine::new(DummyContext),
            transport: DummyTransport::new(),
        }
    }
 }
--- a/server/crates/arbiter-server/src/actors/user_agent/state.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/state.rs
@@ -1,6 +1,6 @@
 use std::sync::Mutex;
-use arbiter_proto::proto::auth::AuthChallenge;
+use arbiter_proto::proto::user_agent::AuthChallenge;
 use ed25519_dalek::VerifyingKey;
 use x25519_dalek::{EphemeralSecret, PublicKey};
--- a/server/crates/arbiter-server/src/lib.rs
+++ b/server/crates/arbiter-server/src/lib.rs
@@ -1,19 +1,23 @@
 #![forbid(unsafe_code)]
 use arbiter_proto::{
-    proto::{ClientRequest, ClientResponse, UserAgentRequest, UserAgentResponse},
+    proto::{
-    transport::{BiStream, GrpcTransportActor, wire},
+        client::{ClientRequest, ClientResponse},
        user_agent::{UserAgentRequest, UserAgentResponse},
    },
    transport::{IdentityRecvConverter, SendConverter, grpc},
 };
 use async_trait::async_trait;
-use kameo::actor::PreparedActor;
+use kameo::actor::Spawn;
 use tokio_stream::wrappers::ReceiverStream;
 use tokio::sync::mpsc;
 use tonic::{Request, Response, Status};
 use tracing::info;
 use crate::{
    actors::{
-        client::handle_client,
+        client::{ClientActor, ClientError},
-        user_agent::UserAgentActor,
+        user_agent::{UserAgentActor, UserAgentError},
    },
    context::ServerContext,
 };
@@ -24,6 +28,119 @@ pub mod db;
 const DEFAULT_CHANNEL_SIZE: usize = 1000;
 /// Converts User Agent domain outbounds into the tonic stream item emitted by
 /// the server.§
 ///
 /// The conversion is defined at the server boundary so the actor module remains
 /// focused on domain semantics and does not depend on tonic status encoding.
 struct UserAgentGrpcSender;
 impl SendConverter for UserAgentGrpcSender {
    type Input = Result<UserAgentResponse, UserAgentError>;
    type Output = Result<UserAgentResponse, Status>;
    fn convert(&self, item: Self::Input) -> Self::Output {
        match item {
            Ok(message) => Ok(message),
            Err(err) => Err(user_agent_error_status(err)),
        }
    }
 }
 /// Converts Client domain outbounds into the tonic stream item emitted by the
 /// server.
 ///
 /// The conversion is defined at the server boundary so the actor module remains
 /// focused on domain semantics and does not depend on tonic status encoding.
 struct ClientGrpcSender;
 impl SendConverter for ClientGrpcSender {
    type Input = Result<ClientResponse, ClientError>;
    type Output = Result<ClientResponse, Status>;
    fn convert(&self, item: Self::Input) -> Self::Output {
        match item {
            Ok(message) => Ok(message),
            Err(err) => Err(client_error_status(err)),
        }
    }
 }
 /// Maps Client domain errors to public gRPC transport errors for the `client`
 /// streaming endpoint.
 fn client_error_status(value: ClientError) -> Status {
    match value {
        ClientError::MissingRequestPayload | ClientError::UnexpectedRequestPayload => {
            Status::invalid_argument("Expected message with payload")
        }
        ClientError::InvalidStateForChallengeSolution => {
            Status::invalid_argument("Invalid state for challenge solution")
        }
        ClientError::InvalidAuthPubkeyLength => {
            Status::invalid_argument("Expected pubkey to have specific length")
        }
        ClientError::InvalidAuthPubkeyEncoding => {
            Status::invalid_argument("Failed to convert pubkey to VerifyingKey")
        }
        ClientError::InvalidSignatureLength => {
            Status::invalid_argument("Invalid signature length")
        }
        ClientError::PublicKeyNotRegistered => {
            Status::unauthenticated("Public key not registered")
        }
        ClientError::InvalidChallengeSolution => {
            Status::unauthenticated("Invalid challenge solution")
        }
        ClientError::StateTransitionFailed => Status::internal("State machine error"),
        ClientError::DatabasePoolUnavailable => Status::internal("Database pool error"),
        ClientError::DatabaseOperationFailed => Status::internal("Database error"),
    }
 }
 /// Maps User Agent domain errors to public gRPC transport errors for the
 /// `user_agent` streaming endpoint.
 fn user_agent_error_status(value: UserAgentError) -> Status {
    match value {
        UserAgentError::MissingRequestPayload | UserAgentError::UnexpectedRequestPayload => {
            Status::invalid_argument("Expected message with payload")
        }
        UserAgentError::InvalidStateForChallengeSolution => {
            Status::invalid_argument("Invalid state for challenge solution")
        }
        UserAgentError::InvalidStateForUnsealEncryptedKey => {
            Status::failed_precondition("Invalid state for unseal encrypted key")
        }
        UserAgentError::InvalidClientPubkeyLength => {
            Status::invalid_argument("client_pubkey must be 32 bytes")
        }
        UserAgentError::InvalidAuthPubkeyLength => {
            Status::invalid_argument("Expected pubkey to have specific length")
        }
        UserAgentError::InvalidAuthPubkeyEncoding => {
            Status::invalid_argument("Failed to convert pubkey to VerifyingKey")
        }
        UserAgentError::InvalidSignatureLength => {
            Status::invalid_argument("Invalid signature length")
        }
        UserAgentError::InvalidBootstrapToken => {
            Status::invalid_argument("Invalid bootstrap token")
        }
        UserAgentError::PublicKeyNotRegistered => {
            Status::unauthenticated("Public key not registered")
        }
        UserAgentError::InvalidChallengeSolution => {
            Status::unauthenticated("Invalid challenge solution")
        }
        UserAgentError::StateTransitionFailed => Status::internal("State machine error"),
        UserAgentError::BootstrapperActorUnreachable => {
            Status::internal("Bootstrap token consumption failed")
        }
        UserAgentError::KeyHolderActorUnreachable => Status::internal("Vault is not available"),
        UserAgentError::DatabasePoolUnavailable => Status::internal("Database pool error"),
        UserAgentError::DatabaseOperationFailed => Status::internal("Database error"),
    }
 }
 pub struct Server {
    context: ServerContext,
 }
@@ -39,44 +156,44 @@ impl arbiter_proto::proto::arbiter_service_server::ArbiterService for Server {
    type UserAgentStream = ReceiverStream<Result<UserAgentResponse, Status>>;
    type ClientStream = ReceiverStream<Result<ClientResponse, Status>>;
    #[tracing::instrument(level = "debug", skip(self))]
    async fn client(
        &self,
        request: Request<tonic::Streaming<ClientRequest>>,
    ) -> Result<Response<Self::ClientStream>, Status> {
        let req_stream = request.into_inner();
        let (tx, rx) = mpsc::channel(DEFAULT_CHANNEL_SIZE);
-        tokio::spawn(handle_client(
+
-            self.context.clone(),
+        let transport = grpc::GrpcAdapter::new(
-            BiStream {
+            tx,
-                request_stream: req_stream,
+            req_stream,
-                response_sender: tx,
+            IdentityRecvConverter::<ClientRequest>::new(),
-            },
+            ClientGrpcSender,
-        ));
+        );
        ClientActor::spawn(ClientActor::new(self.context.clone(), transport));
        info!(event = "connection established", "grpc.client");
        Ok(Response::new(ReceiverStream::new(rx)))
    }
    #[tracing::instrument(level = "debug", skip(self))]
    async fn user_agent(
        &self,
        request: Request<tonic::Streaming<UserAgentRequest>>,
    ) -> Result<Response<Self::UserAgentStream>, Status> {
        let req_stream = request.into_inner();
        let (tx, rx) = mpsc::channel(DEFAULT_CHANNEL_SIZE);
        let context = self.context.clone();
-        wire(
+        let transport = grpc::GrpcAdapter::new(
            |prepared: PreparedActor<UserAgentActor>, recipient| {
                prepared.spawn(UserAgentActor::new(context, recipient));
            },
            |prepared: PreparedActor<GrpcTransportActor<_, _, _>>, business_recipient| {
                prepared.spawn(GrpcTransportActor::new(
            tx,
            req_stream,
-                    business_recipient,
+            IdentityRecvConverter::<UserAgentRequest>::new(),
-                ));
+            UserAgentGrpcSender,
-            },
+        );
-        )
+        UserAgentActor::spawn(UserAgentActor::new(self.context.clone(), transport));
-        .await;
+
        info!(event = "connection established", "grpc.user_agent");
        Ok(Response::new(ReceiverStream::new(rx)))
    }
--- a/server/crates/arbiter-server/tests/client.rs
+++ b/server/crates/arbiter-server/tests/client.rs
@@ -0,0 +1,2 @@
 #[path = "client/auth.rs"]
 mod auth;
--- a/server/crates/arbiter-server/tests/client/auth.rs
+++ b/server/crates/arbiter-server/tests/client/auth.rs
@@ -0,0 +1,102 @@
 use arbiter_proto::proto::client::{
    AuthChallengeRequest, AuthChallengeSolution, AuthOk, ClientRequest, ClientResponse,
    client_request::Payload as ClientRequestPayload,
    client_response::Payload as ClientResponsePayload,
 };
 use arbiter_server::{
    actors::client::{ClientActor, ClientError},
    db::{self, schema},
 };
 use diesel::{ExpressionMethods as _, insert_into};
 use diesel_async::RunQueryDsl;
 use ed25519_dalek::Signer as _;
 #[tokio::test]
 #[test_log::test]
 pub async fn test_unregistered_pubkey_rejected() {
    let db = db::create_test_pool().await;
    let mut client = ClientActor::new_manual(db.clone());
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
    let result = client
        .process_transport_inbound(ClientRequest {
            payload: Some(ClientRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: pubkey_bytes,
                },
            )),
        })
        .await;
    match result {
        Err(err) => {
            assert_eq!(err, ClientError::PublicKeyNotRegistered);
        }
        Ok(_) => {
            panic!("Expected error due to unregistered pubkey, but got success");
        }
    }
 }
 #[tokio::test]
 #[test_log::test]
 pub async fn test_challenge_auth() {
    let db = db::create_test_pool().await;
    let mut client = ClientActor::new_manual(db.clone());
    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::program_client::table)
            .values(schema::program_client::public_key.eq(pubkey_bytes.clone()))
            .execute(&mut conn)
            .await
            .unwrap();
    }
    let result = client
        .process_transport_inbound(ClientRequest {
            payload: Some(ClientRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: pubkey_bytes,
                },
            )),
        })
        .await
        .expect("Shouldn't fail to process message");
    let ClientResponse {
        payload: Some(ClientResponsePayload::AuthChallenge(challenge)),
    } = result
    else {
        panic!("Expected auth challenge response, got {result:?}");
    };
    let formatted_challenge = arbiter_proto::format_challenge(challenge.nonce, &challenge.pubkey);
    let signature = new_key.sign(&formatted_challenge);
    let serialized_signature = signature.to_bytes().to_vec();
    let result = client
        .process_transport_inbound(ClientRequest {
            payload: Some(ClientRequestPayload::AuthChallengeSolution(
                AuthChallengeSolution {
                    signature: serialized_signature,
                },
            )),
        })
        .await
        .expect("Shouldn't fail to process message");
    assert_eq!(
        result,
        ClientResponse {
            payload: Some(ClientResponsePayload::AuthOk(AuthOk {})),
        }
    );
 }
--- a/server/crates/arbiter-server/tests/user_agent.rs
+++ b/server/crates/arbiter-server/tests/user_agent.rs
@@ -1,30 +1,5 @@
 mod common;
 use arbiter_proto::proto::UserAgentResponse;
 use arbiter_server::actors::user_agent::UserAgentError;
 use kameo::{Actor, actor::Recipient, actor::Spawn, prelude::Message};
 /// A no-op actor that discards any messages it receives.
 #[derive(Actor)]
 struct NullSink;
 impl Message<Result<UserAgentResponse, UserAgentError>> for NullSink {
    type Reply = ();
    async fn handle(
        &mut self,
        _msg: Result<UserAgentResponse, UserAgentError>,
        _ctx: &mut kameo::prelude::Context<Self, Self::Reply>,
    ) -> Self::Reply {
    }
 }
 /// Creates a `Recipient` that silently discards all messages.
 fn null_recipient() -> Recipient<Result<UserAgentResponse, UserAgentError>> {
    let actor_ref = NullSink::spawn(NullSink);
    actor_ref.recipient()
 }
 #[path = "user_agent/auth.rs"]
 mod auth;
 #[path = "user_agent/unseal.rs"]
--- a/server/crates/arbiter-server/tests/user_agent/auth.rs
+++ b/server/crates/arbiter-server/tests/user_agent/auth.rs
@@ -1,55 +1,48 @@
-use arbiter_proto::proto::{
+use arbiter_proto::proto::user_agent::{
-    UserAgentResponse,
+    AuthChallengeRequest, AuthChallengeSolution, AuthOk, UserAgentRequest, UserAgentResponse,
-    auth::{self, AuthChallengeRequest, AuthOk},
+    user_agent_request::Payload as UserAgentRequestPayload,
    user_agent_response::Payload as UserAgentResponsePayload,
 };
 use arbiter_server::{
    actors::{
        GlobalActors,
        bootstrap::GetToken,
-        user_agent::{HandleAuthChallengeRequest, HandleAuthChallengeSolution, UserAgentActor},
+        user_agent::{UserAgentActor, UserAgentError},
    },
    db::{self, schema},
 };
 use diesel::{ExpressionMethods as _, QueryDsl, insert_into};
 use diesel_async::RunQueryDsl;
 use ed25519_dalek::Signer as _;
 use kameo::actor::Spawn;
 #[tokio::test]
 #[test_log::test]
 pub async fn test_bootstrap_token_auth() {
-    let db =db::create_test_pool().await;
+    let db = db::create_test_pool().await;
    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
    let token = actors.bootstrapper.ask(GetToken).await.unwrap().unwrap();
-    let user_agent =
+    let mut user_agent = UserAgentActor::new_manual(db.clone(), actors);
        UserAgentActor::new_manual(db.clone(), actors, super::null_recipient());
    let user_agent_ref = UserAgentActor::spawn(user_agent);
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
-    let result = user_agent_ref
+    let result = user_agent
-        .ask(HandleAuthChallengeRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: AuthChallengeRequest {
+            payload: Some(UserAgentRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: pubkey_bytes,
                    bootstrap_token: Some(token),
                },
            )),
        })
        .await
-        .expect("Shouldn't fail to send message");
+        .expect("Shouldn't fail to process message");
    assert_eq!(
        result,
        UserAgentResponse {
-            payload: Some(UserAgentResponsePayload::AuthMessage(
+            payload: Some(UserAgentResponsePayload::AuthOk(AuthOk {})),
                arbiter_proto::proto::auth::ServerMessage {
                    payload: Some(arbiter_proto::proto::auth::server_message::Payload::AuthOk(
                        AuthOk {},
                    )),
                },
            )),
        }
    );
@@ -68,31 +61,25 @@ pub async fn test_bootstrap_invalid_token_auth() {
    let db = db::create_test_pool().await;
    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let user_agent =
+    let mut user_agent = UserAgentActor::new_manual(db.clone(), actors);
        UserAgentActor::new_manual(db.clone(), actors, super::null_recipient());
    let user_agent_ref = UserAgentActor::spawn(user_agent);
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
-    let result = user_agent_ref
+    let result = user_agent
-        .ask(HandleAuthChallengeRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: AuthChallengeRequest {
+            payload: Some(UserAgentRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: pubkey_bytes,
                    bootstrap_token: Some("invalid_token".to_string()),
                },
            )),
        })
        .await;
    match result {
-        Err(kameo::error::SendError::HandlerError(err)) => {
+        Err(err) => {
-            assert!(
+            assert_eq!(err, UserAgentError::InvalidBootstrapToken);
                matches!(err, arbiter_server::actors::user_agent::UserAgentError::InvalidBootstrapToken),
                "Expected InvalidBootstrapToken, got {err:?}"
            );
        }
        Err(other) => {
            panic!("Expected SendError::HandlerError, got {other:?}");
        }
        Ok(_) => {
            panic!("Expected error due to invalid bootstrap token, but got success");
@@ -106,9 +93,7 @@ pub async fn test_challenge_auth() {
    let db = db::create_test_pool().await;
    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let user_agent =
+    let mut user_agent = UserAgentActor::new_manual(db.clone(), actors);
        UserAgentActor::new_manual(db.clone(), actors, super::null_recipient());
    let user_agent_ref = UserAgentActor::spawn(user_agent);
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
@@ -122,50 +107,44 @@ pub async fn test_challenge_auth() {
            .unwrap();
    }
-    let result = user_agent_ref
+    let result = user_agent
-        .ask(HandleAuthChallengeRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: AuthChallengeRequest {
+            payload: Some(UserAgentRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: pubkey_bytes,
                    bootstrap_token: None,
                },
            )),
        })
        .await
-        .expect("Shouldn't fail to send message");
+        .expect("Shouldn't fail to process message");
    let UserAgentResponse {
-        payload:
+        payload: Some(UserAgentResponsePayload::AuthChallenge(challenge)),
            Some(UserAgentResponsePayload::AuthMessage(arbiter_proto::proto::auth::ServerMessage {
                payload:
                    Some(arbiter_proto::proto::auth::server_message::Payload::AuthChallenge(challenge)),
            })),
    } = result
    else {
        panic!("Expected auth challenge response, got {result:?}");
    };
-    let formatted_challenge = arbiter_proto::format_challenge(&challenge);
+    let formatted_challenge = arbiter_proto::format_challenge(challenge.nonce, &challenge.pubkey);
    let signature = new_key.sign(&formatted_challenge);
    let serialized_signature = signature.to_bytes().to_vec();
-    let result = user_agent_ref
+    let result = user_agent
-        .ask(HandleAuthChallengeSolution {
+        .process_transport_inbound(UserAgentRequest {
-            solution: auth::AuthChallengeSolution {
+            payload: Some(UserAgentRequestPayload::AuthChallengeSolution(
                AuthChallengeSolution {
                    signature: serialized_signature,
                },
            )),
        })
        .await
-        .expect("Shouldn't fail to send message");
+        .expect("Shouldn't fail to process message");
    assert_eq!(
        result,
        UserAgentResponse {
-            payload: Some(UserAgentResponsePayload::AuthMessage(
+            payload: Some(UserAgentResponsePayload::AuthOk(AuthOk {})),
                arbiter_proto::proto::auth::ServerMessage {
                    payload: Some(arbiter_proto::proto::auth::server_message::Payload::AuthOk(
                        AuthOk {},
                    )),
                },
            )),
        }
    );
 }
--- a/server/crates/arbiter-server/tests/user_agent/unseal.rs
+++ b/server/crates/arbiter-server/tests/user_agent/unseal.rs
@@ -1,27 +1,32 @@
-use arbiter_proto::proto::{
+use arbiter_proto::proto::user_agent::{
-    UnsealEncryptedKey, UnsealResult, UnsealStart, auth::AuthChallengeRequest,
+    AuthChallengeRequest, UnsealEncryptedKey, UnsealResult, UnsealStart,
    UserAgentRequest, UserAgentResponse,
    user_agent_request::Payload as UserAgentRequestPayload,
    user_agent_response::Payload as UserAgentResponsePayload,
 };
 use arbiter_proto::transport::DummyTransport;
 use arbiter_server::{
    actors::{
        GlobalActors,
        bootstrap::GetToken,
        keyholder::{Bootstrap, Seal},
-        user_agent::{
+        user_agent::{UserAgentActor, UserAgentError},
            HandleAuthChallengeRequest, HandleUnsealEncryptedKey, HandleUnsealRequest,
            UserAgentActor,
        },
    },
    db,
 };
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use kameo::actor::{ActorRef, Spawn};
 use memsafe::MemSafe;
 use x25519_dalek::{EphemeralSecret, PublicKey};
 type TestUserAgent =
    UserAgentActor<DummyTransport<UserAgentRequest, Result<UserAgentResponse, UserAgentError>>>;
 async fn setup_authenticated_user_agent(
    seal_key: &[u8],
-) -> (arbiter_server::db::DatabasePool, ActorRef<UserAgentActor>) {
+) -> (
    arbiter_server::db::DatabasePool,
    TestUserAgent,
 ) {
    let db = db::create_test_pool().await;
    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
@@ -34,37 +39,37 @@ async fn setup_authenticated_user_agent(
        .unwrap();
    actors.key_holder.ask(Seal).await.unwrap();
-    let user_agent =
+    let mut user_agent = UserAgentActor::new_manual(db.clone(), actors.clone());
        UserAgentActor::new_manual(db.clone(), actors.clone(), super::null_recipient());
    let user_agent_ref = UserAgentActor::spawn(user_agent);
    let token = actors.bootstrapper.ask(GetToken).await.unwrap().unwrap();
    let auth_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-    user_agent_ref
+    user_agent
-        .ask(HandleAuthChallengeRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: AuthChallengeRequest {
+            payload: Some(UserAgentRequestPayload::AuthChallengeRequest(
                AuthChallengeRequest {
                    pubkey: auth_key.verifying_key().to_bytes().to_vec(),
                    bootstrap_token: Some(token),
                },
            )),
        })
        .await
        .unwrap();
-    (db, user_agent_ref)
+    (db, user_agent)
 }
 async fn client_dh_encrypt(
-    user_agent_ref: &ActorRef<UserAgentActor>,
+    user_agent: &mut TestUserAgent,
    key_to_send: &[u8],
 ) -> UnsealEncryptedKey {
    let client_secret = EphemeralSecret::random();
    let client_public = PublicKey::from(&client_secret);
-    let response = user_agent_ref
+    let response = user_agent
-        .ask(HandleUnsealRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: UnsealStart {
+            payload: Some(UserAgentRequestPayload::UnsealStart(UnsealStart {
                client_pubkey: client_public.as_bytes().to_vec(),
-            },
+            })),
        })
        .await
        .unwrap();
@@ -91,16 +96,22 @@ async fn client_dh_encrypt(
    }
 }
 fn unseal_key_request(req: UnsealEncryptedKey) -> UserAgentRequest {
    UserAgentRequest {
        payload: Some(UserAgentRequestPayload::UnsealEncryptedKey(req)),
    }
 }
 #[tokio::test]
 #[test_log::test]
 pub async fn test_unseal_success() {
    let seal_key = b"test-seal-key";
-    let (_db, user_agent_ref) = setup_authenticated_user_agent(seal_key).await;
+    let (_db, mut user_agent) = setup_authenticated_user_agent(seal_key).await;
-    let encrypted_key = client_dh_encrypt(&user_agent_ref, seal_key).await;
+    let encrypted_key = client_dh_encrypt(&mut user_agent, seal_key).await;
-    let response = user_agent_ref
+    let response = user_agent
-        .ask(HandleUnsealEncryptedKey { req: encrypted_key })
+        .process_transport_inbound(unseal_key_request(encrypted_key))
        .await
        .unwrap();
@@ -113,12 +124,12 @@ pub async fn test_unseal_success() {
 #[tokio::test]
 #[test_log::test]
 pub async fn test_unseal_wrong_seal_key() {
-    let (_db, user_agent_ref) = setup_authenticated_user_agent(b"correct-key").await;
+    let (_db, mut user_agent) = setup_authenticated_user_agent(b"correct-key").await;
-    let encrypted_key = client_dh_encrypt(&user_agent_ref, b"wrong-key").await;
+    let encrypted_key = client_dh_encrypt(&mut user_agent, b"wrong-key").await;
-    let response = user_agent_ref
+    let response = user_agent
-        .ask(HandleUnsealEncryptedKey { req: encrypted_key })
+        .process_transport_inbound(unseal_key_request(encrypted_key))
        .await
        .unwrap();
@@ -131,28 +142,26 @@ pub async fn test_unseal_wrong_seal_key() {
 #[tokio::test]
 #[test_log::test]
 pub async fn test_unseal_corrupted_ciphertext() {
-    let (_db, user_agent_ref) = setup_authenticated_user_agent(b"test-key").await;
+    let (_db, mut user_agent) = setup_authenticated_user_agent(b"test-key").await;
    let client_secret = EphemeralSecret::random();
    let client_public = PublicKey::from(&client_secret);
-    user_agent_ref
+    user_agent
-        .ask(HandleUnsealRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: UnsealStart {
+            payload: Some(UserAgentRequestPayload::UnsealStart(UnsealStart {
                client_pubkey: client_public.as_bytes().to_vec(),
-            },
+            })),
        })
        .await
        .unwrap();
-    let response = user_agent_ref
+    let response = user_agent
-        .ask(HandleUnsealEncryptedKey {
+        .process_transport_inbound(unseal_key_request(UnsealEncryptedKey {
            req: UnsealEncryptedKey {
            nonce: vec![0u8; 24],
            ciphertext: vec![0u8; 32],
            associated_data: vec![],
-            },
+        }))
        })
        .await
        .unwrap();
@@ -168,27 +177,22 @@ pub async fn test_unseal_start_without_auth_fails() {
    let db = db::create_test_pool().await;
    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let user_agent =
+    let mut user_agent = UserAgentActor::new_manual(db.clone(), actors);
        UserAgentActor::new_manual(db.clone(), actors, super::null_recipient());
    let user_agent_ref = UserAgentActor::spawn(user_agent);
    let client_secret = EphemeralSecret::random();
    let client_public = PublicKey::from(&client_secret);
-    let result = user_agent_ref
+    let result = user_agent
-        .ask(HandleUnsealRequest {
+        .process_transport_inbound(UserAgentRequest {
-            req: UnsealStart {
+            payload: Some(UserAgentRequestPayload::UnsealStart(UnsealStart {
                client_pubkey: client_public.as_bytes().to_vec(),
-            },
+            })),
        })
        .await;
    match result {
-        Err(kameo::error::SendError::HandlerError(err)) => {
+        Err(err) => {
-            assert!(
+            assert_eq!(err, UserAgentError::StateTransitionFailed);
                matches!(err, arbiter_server::actors::user_agent::UserAgentError::InvalidState),
                "Expected InvalidState, got {err:?}"
            );
        }
        other => panic!("Expected state machine error, got {other:?}"),
    }
@@ -198,13 +202,13 @@ pub async fn test_unseal_start_without_auth_fails() {
 #[test_log::test]
 pub async fn test_unseal_retry_after_invalid_key() {
    let seal_key = b"real-seal-key";
-    let (_db, user_agent_ref) = setup_authenticated_user_agent(seal_key).await;
+    let (_db, mut user_agent) = setup_authenticated_user_agent(seal_key).await;
    {
-        let encrypted_key = client_dh_encrypt(&user_agent_ref, b"wrong-key").await;
+        let encrypted_key = client_dh_encrypt(&mut user_agent, b"wrong-key").await;
-        let response = user_agent_ref
+        let response = user_agent
-            .ask(HandleUnsealEncryptedKey { req: encrypted_key })
+            .process_transport_inbound(unseal_key_request(encrypted_key))
            .await
            .unwrap();
@@ -215,10 +219,10 @@ pub async fn test_unseal_retry_after_invalid_key() {
    }
    {
-        let encrypted_key = client_dh_encrypt(&user_agent_ref, seal_key).await;
+        let encrypted_key = client_dh_encrypt(&mut user_agent, seal_key).await;
-        let response = user_agent_ref
+        let response = user_agent
-            .ask(HandleUnsealEncryptedKey { req: encrypted_key })
+            .process_transport_inbound(unseal_key_request(encrypted_key))
            .await
            .unwrap();
--- a/server/crates/arbiter-useragent/Cargo.toml
+++ b/server/crates/arbiter-useragent/Cargo.toml
@@ -9,7 +9,12 @@ arbiter-proto.path = "../arbiter-proto"
 kameo.workspace = true
 tokio = {workspace = true, features = ["net"]}
 tonic.workspace = true
 tonic.features = ["tls-aws-lc"]
 tracing.workspace = true
 ed25519-dalek.workspace = true
 smlang.workspace = true
 x25519-dalek.workspace = true
 thiserror.workspace = true
 tokio-stream.workspace = true
 http = "1.4.0"
 rustls-webpki = { version = "0.103.9", features = ["aws-lc-rs"] }
--- a/server/crates/arbiter-useragent/src/grpc.rs
+++ b/server/crates/arbiter-useragent/src/grpc.rs
@@ -0,0 +1,72 @@
 use arbiter_proto::{
    proto::{
        user_agent::{UserAgentRequest, UserAgentResponse},
        arbiter_service_client::ArbiterServiceClient,
    },
    transport::{IdentityRecvConverter, IdentitySendConverter, grpc},
    url::ArbiterUrl,
 };
 use ed25519_dalek::SigningKey;
 use kameo::actor::{ActorRef, Spawn};
 use tokio::sync::mpsc;
 use tokio_stream::wrappers::ReceiverStream;
 use tonic::transport::ClientTlsConfig;
 #[derive(Debug, thiserror::Error)]
 pub enum ConnectError {
    #[error("Could establish connection")]
    Connection(#[from] tonic::transport::Error),
    #[error("Invalid server URI")]
    InvalidUri(#[from] http::uri::InvalidUri),
    #[error("Invalid CA certificate")]
    InvalidCaCert(#[from] webpki::Error),
    #[error("gRPC error")]
    Grpc(#[from] tonic::Status),
 }
    use super::UserAgentActor;
 pub type UserAgentGrpc = ActorRef<
    UserAgentActor<
        grpc::GrpcAdapter<
            IdentityRecvConverter<UserAgentResponse>,
            IdentitySendConverter<UserAgentRequest>,
        >,
    >,
 >;
 pub async fn connect_grpc(
    url: ArbiterUrl,
    key: SigningKey,
 ) -> Result<UserAgentGrpc, ConnectError> {
    let bootstrap_token = url.bootstrap_token.clone();
    let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)?.to_owned();
    let tls = ClientTlsConfig::new().trust_anchor(anchor);
    // TODO: if `host` is localhost, we need to verify server's process authenticity
    let channel = tonic::transport::Channel::from_shared(format!("{}:{}", url.host, url.port))?
        .tls_config(tls)?
        .connect()
        .await?;
    let mut client = ArbiterServiceClient::new(channel);
    let (tx, rx) = mpsc::channel(16);
    let bistream = client.user_agent(ReceiverStream::new(rx)).await?;
    let bistream = bistream.into_inner();
    let adapter = grpc::GrpcAdapter::new(
        tx,
        bistream,
        IdentityRecvConverter::new(),
        IdentitySendConverter::new(),
    );
    let actor = UserAgentActor::spawn(UserAgentActor::new(key, bootstrap_token, adapter));
    Ok(actor)
 }
--- a/server/crates/arbiter-useragent/src/lib.rs
+++ b/server/crates/arbiter-useragent/src/lib.rs
@@ -1,66 +1,195 @@
-use arbiter_proto::{proto::UserAgentRequest, transport::TransportActor};
+use arbiter_proto::{
-use ed25519_dalek::SigningKey;
+    format_challenge,
-use kameo::{
+    proto::user_agent::{
-    Actor, Reply,
+        AuthChallengeRequest, AuthChallengeSolution, AuthOk,
-    actor::{ActorRef, WeakActorRef},
+        UserAgentRequest, UserAgentResponse,
-    prelude::Message,
+        user_agent_request::Payload as UserAgentRequestPayload,
        user_agent_response::Payload as UserAgentResponsePayload,
    },
    transport::Bi,
 };
 use ed25519_dalek::{Signer, SigningKey};
 use kameo::{Actor, actor::ActorRef};
 use smlang::statemachine;
-use tonic::transport::CertificateDer;
+use tokio::select;
-use tracing::{debug, error};
+use tracing::{error, info};
 struct Storage {
    pub identity: SigningKey,
    pub server_ca_cert: CertificateDer<'static>,
 }
 #[derive(Debug)]
 pub enum InitError {
    StorageError,
    Other(String),
 }
 statemachine! {
-    name: UserAgentStateMachine,
+    name: UserAgent,
    custom_error: false,
    transitions: {
-        *Init + SendAuthChallenge = WaitingForAuthSolution
+        *Init + SentAuthChallengeRequest = WaitingForServerAuth,
        WaitingForServerAuth + ReceivedAuthChallenge = WaitingForAuthOk,
        WaitingForServerAuth + ReceivedAuthOk = Authenticated,
        WaitingForAuthOk + ReceivedAuthOk = Authenticated,
    }
 }
 pub struct DummyContext;
 impl UserAgentStateMachineContext for DummyContext {}
-
+#[derive(Debug, thiserror::Error)]
-pub struct UserAgentActor<A: TransportActor<UserAgentRequest>> {
+pub enum InboundError {
-    key: SigningKey,
+    #[error("Invalid user agent response")]
-    server_ca_cert: CertificateDer<'static>,
+    InvalidResponse,
-    sender: ActorRef<A>,
+    #[error("Expected response payload")]
    MissingResponsePayload,
    #[error("Unexpected response payload")]
    UnexpectedResponsePayload,
    #[error("Invalid state for auth challenge")]
    InvalidStateForAuthChallenge,
    #[error("Invalid state for auth ok")]
    InvalidStateForAuthOk,
    #[error("State machine error")]
    StateTransitionFailed,
    #[error("Transport send failed")]
    TransportSendFailed,
 }
-impl<A: TransportActor<UserAgentRequest>> Actor for UserAgentActor<A> {
+
 pub struct UserAgentActor<Transport>
 where
    Transport: Bi<UserAgentResponse, UserAgentRequest>,
 {
    key: SigningKey,
    bootstrap_token: Option<String>,
    state: UserAgentStateMachine<DummyContext>,
    transport: Transport,
 }
 impl<Transport> UserAgentActor<Transport>
 where
    Transport: Bi<UserAgentResponse, UserAgentRequest>,
 {
    pub fn new(key: SigningKey, bootstrap_token: Option<String>, transport: Transport) -> Self {
        Self {
            key,
            bootstrap_token,
            state: UserAgentStateMachine::new(DummyContext),
            transport,
        }
    }
    fn transition(&mut self, event: UserAgentEvents) -> Result<(), InboundError> {
        self.state.process_event(event).map_err(|e| {
            error!(?e, "useragent state transition failed");
            InboundError::StateTransitionFailed
        })?;
        Ok(())
    }
    async fn send_auth_challenge_request(&mut self) -> Result<(), InboundError> {
        let req = AuthChallengeRequest {
            pubkey: self.key.verifying_key().to_bytes().to_vec(),
            bootstrap_token: self.bootstrap_token.take(),
        };
        self.transition(UserAgentEvents::SentAuthChallengeRequest)?;
        self.transport
            .send(UserAgentRequest {
                payload: Some(UserAgentRequestPayload::AuthChallengeRequest(req)),
            })
            .await
            .map_err(|_| InboundError::TransportSendFailed)?;
        info!(actor = "useragent", "auth.request.sent");
        Ok(())
    }
    async fn handle_auth_challenge(
        &mut self,
        challenge: arbiter_proto::proto::user_agent::AuthChallenge,
    ) -> Result<(), InboundError> {
        self.transition(UserAgentEvents::ReceivedAuthChallenge)?;
        let formatted = format_challenge(challenge.nonce, &challenge.pubkey);
        let signature = self.key.sign(&formatted);
        let solution = AuthChallengeSolution {
            signature: signature.to_bytes().to_vec(),
        };
        self.transport
            .send(UserAgentRequest {
                payload: Some(UserAgentRequestPayload::AuthChallengeSolution(solution)),
            })
            .await
            .map_err(|_| InboundError::TransportSendFailed)?;
        info!(actor = "useragent", "auth.solution.sent");
        Ok(())
    }
    fn handle_auth_ok(&mut self, _ok: AuthOk) -> Result<(), InboundError> {
        self.transition(UserAgentEvents::ReceivedAuthOk)?;
        info!(actor = "useragent", "auth.ok");
        Ok(())
    }
    pub async fn process_inbound_transport(
        &mut self,
        inbound: UserAgentResponse
    ) -> Result<(), InboundError> {
        let payload = inbound
            .payload
            .ok_or(InboundError::MissingResponsePayload)?;
        match payload {
            UserAgentResponsePayload::AuthChallenge(challenge) => {
                self.handle_auth_challenge(challenge).await
            }
            UserAgentResponsePayload::AuthOk(ok) => self.handle_auth_ok(ok),
            _ => Err(InboundError::UnexpectedResponsePayload),
        }
    }
 }
 impl<Transport> Actor for UserAgentActor<Transport>
 where
    Transport: Bi<UserAgentResponse, UserAgentRequest>,
 {
    type Args = Self;
-    type Error = InitError;
+    type Error = ();
-    async fn on_start(args: Self::Args, actor_ref: ActorRef<Self>) -> Result<Self, Self::Error> {
+    async fn on_start(
-        todo!()
+        mut args: Self::Args,
        _actor_ref: ActorRef<Self>,
    ) -> Result<Self, Self::Error> {
        if let Err(err) = args.send_auth_challenge_request().await {
            error!(?err, actor = "useragent", "auth.start.failed");
            return Err(());
        }
        Ok(args)
    }
-    async fn on_link_died(
+    async fn next(
        &mut self,
-        _: WeakActorRef<Self>,
+        _actor_ref: kameo::prelude::WeakActorRef<Self>,
-        id: kameo::prelude::ActorId,
+        mailbox_rx: &mut kameo::prelude::MailboxReceiver<Self>,
-        _: kameo::prelude::ActorStopReason,
+    ) -> Option<kameo::mailbox::Signal<Self>> {
-    ) -> Result<std::ops::ControlFlow<kameo::prelude::ActorStopReason>, Self::Error> {
+        loop {
-        if id == self.sender.id() {
+            select! {
-            error!("Transport actor died, stopping UserAgentActor");
+                signal = mailbox_rx.recv() => {
-            Ok(std::ops::ControlFlow::Break(
+                    return signal;
-                kameo::prelude::ActorStopReason::Normal,
+                }
-            ))
+                inbound = self.transport.recv() => {
-        } else {
+                    match inbound {
-            debug!(
+                        Some(inbound) => {
-                "Linked actor {} died, but it's not the transport actor, ignoring",
+                            if let Err(err) = self.process_inbound_transport(inbound).await {
-                id
+                                error!(?err, actor = "useragent", "transport.inbound.failed");
-            );
+                                return Some(kameo::mailbox::Signal::Stop);
-            Ok(std::ops::ControlFlow::Continue(()))
+                            }
                        }
                        None => {
                            info!(actor = "useragent", "transport.closed");
                            return Some(kameo::mailbox::Signal::Stop);
                        }
                    }
                }
            }
        }
    }
 }
 mod grpc;
 pub use grpc::{connect_grpc, ConnectError};
--- a/server/crates/arbiter-useragent/tests/auth.rs
+++ b/server/crates/arbiter-useragent/tests/auth.rs
@@ -0,0 +1,139 @@
 use arbiter_proto::{
    format_challenge,
    proto::user_agent::{
        AuthChallenge, AuthOk,
        UserAgentRequest, UserAgentResponse,
        user_agent_request::Payload as UserAgentRequestPayload,
        user_agent_response::Payload as UserAgentResponsePayload,
    },
    transport::Bi,
 };
 use arbiter_useragent::UserAgentActor;
 use ed25519_dalek::SigningKey;
 use kameo::actor::Spawn;
 use tokio::sync::mpsc;
 use tokio::time::{Duration, timeout};
 struct TestTransport {
    inbound_rx: mpsc::Receiver<UserAgentResponse>,
    outbound_tx: mpsc::Sender<UserAgentRequest>,
 }
 impl Bi<UserAgentResponse, UserAgentRequest> for TestTransport {
    async fn send(&mut self, item: UserAgentRequest) -> Result<(), arbiter_proto::transport::Error> {
        self.outbound_tx
            .send(item)
            .await
            .map_err(|_| arbiter_proto::transport::Error::ChannelClosed)
    }
    async fn recv(&mut self) -> Option<UserAgentResponse> {
        self.inbound_rx.recv().await
    }
 }
 fn make_transport() -> (
    TestTransport,
    mpsc::Sender<UserAgentResponse>,
    mpsc::Receiver<UserAgentRequest>,
 ) {
    let (inbound_tx, inbound_rx) = mpsc::channel(8);
    let (outbound_tx, outbound_rx) = mpsc::channel(8);
    (
        TestTransport {
            inbound_rx,
            outbound_tx,
        },
        inbound_tx,
        outbound_rx,
    )
 }
 fn test_key() -> SigningKey {
    SigningKey::from_bytes(&[7u8; 32])
 }
 #[tokio::test]
 async fn sends_auth_request_on_start_with_bootstrap_token() {
    let key = test_key();
    let pubkey = key.verifying_key().to_bytes().to_vec();
    let bootstrap_token = Some("bootstrap-123".to_string());
    let (transport, inbound_tx, mut outbound_rx) = make_transport();
    let actor = UserAgentActor::spawn(UserAgentActor::new(key, bootstrap_token.clone(), transport));
    let outbound = timeout(Duration::from_secs(1), outbound_rx.recv())
        .await
        .expect("timed out waiting for auth request")
        .expect("channel closed before auth request");
    let UserAgentRequest {
        payload: Some(UserAgentRequestPayload::AuthChallengeRequest(req)),
    } = outbound
    else {
        panic!("expected auth challenge request");
    };
    assert_eq!(req.pubkey, pubkey);
    assert_eq!(req.bootstrap_token, bootstrap_token);
    drop(inbound_tx);
    drop(actor);
 }
 #[tokio::test]
 async fn challenge_flow_sends_solution_from_transport_inbound() {
    let key = test_key();
    let verify_key = key.verifying_key();
    let (transport, inbound_tx, mut outbound_rx) = make_transport();
    let actor = UserAgentActor::spawn(UserAgentActor::new(key, None, transport));
    let _initial_auth_request = timeout(Duration::from_secs(1), outbound_rx.recv())
        .await
        .expect("timed out waiting for initial auth request")
        .expect("missing initial auth request");
    let challenge = AuthChallenge {
        pubkey: verify_key.to_bytes().to_vec(),
        nonce: 42,
    };
    inbound_tx
        .send(UserAgentResponse {
            payload: Some(UserAgentResponsePayload::AuthChallenge(challenge.clone())),
        })
        .await
        .unwrap();
    let outbound = timeout(Duration::from_secs(1), outbound_rx.recv())
        .await
        .expect("timed out waiting for challenge solution")
        .expect("missing challenge solution");
    let UserAgentRequest {
        payload: Some(UserAgentRequestPayload::AuthChallengeSolution(solution)),
    } = outbound
    else {
        panic!("expected auth challenge solution");
    };
    let formatted = format_challenge(challenge.nonce, &challenge.pubkey);
    let sig: ed25519_dalek::Signature = solution
        .signature
        .as_slice()
        .try_into()
        .expect("signature bytes length");
    verify_key
        .verify_strict(&formatted, &sig)
        .expect("solution signature should verify");
    inbound_tx
        .send(UserAgentResponse {
            payload: Some(UserAgentResponsePayload::AuthOk(AuthOk {})),
        })
        .await
        .unwrap();
    drop(inbound_tx);
    drop(actor);
 }
Author	SHA1	Message	Date
hdbg	4169b2ba42	refactor: consolidate auth messages into client and user_agent packages Some checks failed ci/woodpecker/pr/server-lint Pipeline failed Details ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-test Pipeline was successful Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-03-01 12:49:38 +01:00
hdbg	3cc63474a8	chore(server): update Cargo.lock dependencies Some checks failed ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-lint Pipeline failed Details ci/woodpecker/pr/server-test Pipeline was successful Details ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-02-26 22:41:50 +01:00
hdbg	3478204b9f	tests(user-agent): basic auth tests similar to `server`	2026-02-26 22:41:24 +01:00
hdbg	61c65ddbcb	feat(useragent): initial connection impl	2026-02-26 22:22:44 +01:00
hdbg	3401205cbd	refactor(transport): simplify converters	2026-02-26 21:42:24 +01:00
hdbg	1799aef6f8	refactor(transport): implemented `Bi` stream based abstraction for actor communication with `next` loop override	2026-02-26 19:22:33 +01:00