feat(devin): add and harden CLI provider support

README.md

@@ -2,7 +2,7 @@
 
 T3 Code is an "agent harness control surface". It enables control of the agents on your machine with a best-in-class mobile app ([iOS](https://apps.apple.com/us/app/t3-code-remote-claude-more/id6787819824), [Android](https://play.google.com/store/apps/details?id=com.t3tools.t3code)), [web app](https://app.t3.codes) and [Electron-based desktop app](https://t3.codes).
 
-Works with your subscriptions on Claude Code, Codex, Cursor, Grok Build, and OpenCode. If they're set up on your computer, T3 Code can control them.
+Works with your subscriptions on Claude Code, Codex, Cursor, Devin, Grok Build, and OpenCode. If they're set up on your computer, T3 Code can control them.
 
 ## "Wait, what are you selling me?"
 
@@ -13,11 +13,12 @@ We wanted something performant, remote-ready, and truly open. If we ever go the
 ## Installation
 
 > [!WARNING]
-> T3 Code currently supports Codex, Claude, Cursor, Grok Build and OpenCode. Install and authenticate at least one provider before use:
+> T3 Code currently supports Codex, Claude, Cursor, Devin, Grok Build and OpenCode. Install and authenticate at least one provider before use:
 >
 > - Codex: install [Codex CLI](https://developers.openai.com/codex/cli) and run `codex login`
 > - Claude: install [Claude Code](https://claude.com/product/claude-code) and run `claude auth login`
 > - Cursor: install [Cursor CLI](https://cursor.com/cli) and run `agent login`
+> - Devin: install the [Devin CLI](https://devin.ai) and follow the Devin CLI documentation to authenticate
 > - Grok Build: install [Grok Build CLI](https://x.ai/cli) and run `grok login`
 > - OpenCode: install [OpenCode](https://opencode.ai) and run `opencode auth login`
 
@@ -82,7 +83,7 @@ Full docs live in [docs/](./docs). There's no docs site yet.
 - [Remote access from a phone or another machine](./docs/user/remote-access.md)
 - [Keeping app and server in sync](./docs/user/updating.md)
 - [Source control integrations](./docs/user/source-control.md)
-- Multiple accounts: [Codex](./docs/user/providers-codex.md) · [Claude](./docs/user/providers-claude.md)
+- Multiple accounts: [Codex](./docs/user/providers-codex.md) · [Claude](./docs/user/providers-claude.md) · [Devin](./docs/user/providers-devin.md)
 - Linux: [run T3 Code as a background service](./docs/user/background-service.md)
 
 Building from source? Start at [docs/internals/overview.md](./docs/internals/overview.md).

apps/marketing/src/pages/index.astro

@@ -41,6 +41,9 @@ const mobileEndorsementRows = [
       <span class="hero-float-mark hf-grok" title="Grok">
         <img src="/harnesses/grok-dark.svg" alt="" />
       </span>
+      <span class="hero-float-mark hf-devin" title="Devin">
+        <img src="/harnesses/devin.svg" alt="" />
+      </span>
     </div>
 
     <div class="container hero-inner">
@@ -49,7 +52,7 @@ const mobileEndorsementRows = [
       </h1>
 
       <p class="hero-sub">
-        Orchestrate Claude Code, Codex, OpenCode, Cursor, and Grok from one surface.
+        Orchestrate Claude Code, Codex, OpenCode, Cursor, Grok, and Devin from one surface.
         Bring your own subscription. Fork the whole thing.
       </p>
 
@@ -228,6 +231,13 @@ const mobileEndorsementRows = [
             <div class="harness-tag">grok login</div>
           </div>
         </div>
+        <div class="harness">
+          <div class="harness-mark"><img src="/harnesses/devin.svg" alt="" /></div>
+          <div class="harness-meta">
+            <div class="harness-name">Devin</div>
+            <div class="harness-tag">devin auth login</div>
+          </div>
+        </div>
       </div>
 
       <div class="harness-footer">
@@ -661,6 +671,7 @@ const mobileEndorsementRows = [
   .hero-float-mark.hf-opencode { background: radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.06), rgba(20, 20, 24, 0.92) 65%); top: 30%; left: 5%;  animation-delay: -5s;   transform: rotate(4deg); }
   .hero-float-mark.hf-cursor   { background: radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.08), rgba(20, 20, 24, 0.92) 65%); top: 30%; right: 5%; animation-delay: -7s;   transform: rotate(-5deg); }
   .hero-float-mark.hf-grok     { background: radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.08), rgba(20, 20, 24, 0.92) 65%); top: 52%; left: 6%;  animation-delay: -1.2s; transform: rotate(3deg); }
+  .hero-float-mark.hf-devin    { background: radial-gradient(circle at 30% 25%, rgba(255, 255, 255, 0.06), rgba(20, 20, 24, 0.92) 65%); top: 52%; right: 6%; animation-delay: -4s;   transform: rotate(-3deg); }
 
   @media (max-width: 1180px) {
     .hero-float-mark { width: 76px; height: 76px; border-radius: 20px; }
@@ -670,6 +681,7 @@ const mobileEndorsementRows = [
     .hero-float-mark.hf-opencode { top: 26%; left: 2%; }
     .hero-float-mark.hf-cursor   { top: 24%; right: 2%; }
     .hero-float-mark.hf-grok     { top: 48%; left: 2%;  transform: rotate(3deg); }
+    .hero-float-mark.hf-devin    { top: 48%; right: 2%; transform: rotate(-3deg); }
   }
 
   @media (max-width: 820px) {
@@ -731,6 +743,13 @@ const mobileEndorsementRows = [
       transform: rotate(8deg);
     }
 
+    .hero-float-mark.hf-devin {
+      top: 360px;
+      right: 4px;
+      left: auto;
+      transform: rotate(4deg);
+    }
+
     .hero-float-mark.hf-cursor {
       top: 474px;
       right: 4px;
@@ -748,6 +767,14 @@ const mobileEndorsementRows = [
       border-radius: 14px;
     }
 
+    .hero-float-mark.hf-grok {
+      left: 0;
+    }
+
+    .hero-float-mark.hf-devin {
+      right: 0;
+    }
+
     .hero-float-mark.hf-opencode,
     .hero-float-mark.hf-cursor {
       top: 580px;
@@ -765,6 +792,7 @@ const mobileEndorsementRows = [
     }
 
     .hero-float-mark.hf-grok img,
+    .hero-float-mark.hf-devin img,
     .hero-float-mark.hf-opencode img,
     .hero-float-mark.hf-cursor img {
       width: 30px;
@@ -811,7 +839,7 @@ const mobileEndorsementRows = [
 
   .harness-grid {
     display: grid;
-    grid-template-columns: repeat(5, 1fr);
+    grid-template-columns: repeat(6, 1fr);
     gap: 0;
     border: 1px solid var(--border);
     border-radius: var(--radius);
@@ -1266,7 +1294,7 @@ const mobileEndorsementRows = [
     .harness-grid { grid-template-columns: 1fr 1fr; }
     .harness { border-right: 0; border-bottom: 1px solid var(--border); }
     .harness:nth-child(odd) { border-right: 1px solid var(--border); }
-    .harness:nth-child(5):last-child {
+    .harness:nth-child(odd):last-child {
       grid-column: 1 / -1;
       border-right: 0;
     }

apps/mobile/src/features/usage/usageProviders.ts

@@ -5,11 +5,12 @@ import { useAppearancePreferences } from "../settings/appearance/AppearancePrefe
  * Series and table order. The chart stacks providers from the bottom in this
  * order, so it also fixes which band sits on top of the bars.
  */
-export const PROVIDER_ORDER: readonly UsageProviderKind[] = ["codex", "claude"];
+export const PROVIDER_ORDER: readonly UsageProviderKind[] = ["codex", "claude", "devin"];
 
 export const PROVIDER_LABEL: Record<UsageProviderKind, string> = {
   claude: "Claude Code",
   codex: "Codex",
+  devin: "Devin",
 };
 
 /**
@@ -21,5 +22,6 @@ export function useProviderColors(): Record<UsageProviderKind, string> {
   return {
     claude: "#d97757",
     codex: scheme === "dark" ? "#e6e6e6" : "#3c3c43",
+    devin: "#8a63d2",
   };
 }

apps/mobile/src/lib/modelOptions.ts

@@ -35,6 +35,7 @@ function providerDisplayLabel(provider: {
   if (provider.displayName) return provider.displayName;
   if (provider.driver === "codex") return "Codex";
   if (provider.driver === "claudeAgent") return "Claude";
+  if (provider.driver === "devin") return "Devin";
   return provider.instanceId;
 }
 

apps/server/scripts/acp-mock-agent.ts

@@ -21,9 +21,14 @@ const emitAskQuestion = process.env.T3_ACP_EMIT_ASK_QUESTION === "1";
 const emitXAiAskUserQuestion = process.env.T3_ACP_EMIT_XAI_ASK_USER_QUESTION === "1";
 const emitXAiPromptCompleteThenHang = process.env.T3_ACP_EMIT_XAI_PROMPT_COMPLETE_THEN_HANG === "1";
 const emitForeignSessionUpdates = process.env.T3_ACP_EMIT_FOREIGN_SESSION_UPDATES === "1";
+const emitStartupCommands = process.env.T3_ACP_EMIT_STARTUP_COMMANDS === "1";
 const hangPromptForever = process.env.T3_ACP_HANG_PROMPT_FOREVER === "1";
 const hangFirstPromptForever = process.env.T3_ACP_HANG_FIRST_PROMPT_FOREVER === "1";
 const emitLateUpdateAfterCancel = process.env.T3_ACP_EMIT_LATE_UPDATE_AFTER_CANCEL === "1";
+const emitDelayedCompactCompletion = process.env.T3_ACP_EMIT_DELAYED_COMPACT_COMPLETION === "1";
+const delayedCompactCompletionMs = Number(
+  process.env.T3_ACP_DELAYED_COMPACT_COMPLETION_MS ?? "1500",
+);
 const omitXAiPromptCompleteStopReason =
   process.env.T3_ACP_OMIT_XAI_PROMPT_COMPLETE_STOP_REASON === "1";
 const failLoadSession = process.env.T3_ACP_FAIL_LOAD_SESSION === "1";
@@ -36,10 +41,22 @@ const emitStaleXAiPromptCompleteBeforeSecondHang =
 const emitOverlappingXAiPromptCompleteOutOfOrder =
   process.env.T3_ACP_EMIT_OVERLAPPING_XAI_PROMPT_COMPLETE_OUT_OF_ORDER === "1";
 const failPrompt = process.env.T3_ACP_FAIL_PROMPT === "1";
+const requireAuthenticationForPrompt = process.env.T3_ACP_REQUIRE_AUTHENTICATION_FOR_PROMPT === "1";
 const failSetConfigOption = process.env.T3_ACP_FAIL_SET_CONFIG_OPTION === "1";
 const exitOnSetConfigOption = process.env.T3_ACP_EXIT_ON_SET_CONFIG_OPTION === "1";
 const promptResponseText = process.env.T3_ACP_PROMPT_RESPONSE_TEXT;
 const promptDelayMs = Number(process.env.T3_ACP_PROMPT_DELAY_MS ?? "0");
+const advertisedAuthMethods = (() => {
+  const raw = process.env.T3_ACP_AUTH_METHODS;
+  if (!raw) {
+    return undefined;
+  }
+  try {
+    return JSON.parse(raw) as ReadonlyArray<AcpSchema.AuthMethod>;
+  } catch {
+    return undefined;
+  }
+})();
 const permissionOptionIds = {
   allowOnce: process.env.T3_ACP_ALLOW_ONCE_OPTION_ID ?? "allow-once",
   allowAlways: process.env.T3_ACP_ALLOW_ALWAYS_OPTION_ID ?? "allow-always",
@@ -54,6 +71,7 @@ let currentReasoning = "medium";
 let currentContext = "272k";
 let currentFast = false;
 let promptCount = 0;
+let authenticated = false;
 let overlappingFirstPromptId: string | undefined;
 const cancelledSessions = new Set<string>();
 
@@ -79,6 +97,19 @@ function writeJsonRpcNotification(method: string, params: unknown): void {
   process.stdout.write(`${JSON.stringify({ jsonrpc: "2.0", method, params })}\n`);
 }
 
+function availableCommandsUpdate(targetSessionId: string): AcpSchema.SessionNotification {
+  return {
+    sessionId: targetSessionId,
+    update: {
+      sessionUpdate: "available_commands_update",
+      availableCommands: [
+        { name: "compact", description: "Compact the conversation" },
+        { name: "context", description: "Show context usage" },
+      ],
+    },
+  };
+}
+
 process.once("SIGTERM", () => {
   logExit("SIGTERM");
   process.exit(0);
@@ -218,7 +249,10 @@ function configOptions(): ReadonlyArray<AcpSchema.SessionConfigOption> {
         { value: "default", name: "Auto" },
         { value: "composer-2", name: "Composer 2" },
         { value: "composer-2[fast=true]", name: "Composer 2 Fast" },
-        { value: "gpt-5.3-codex[reasoning=medium,fast=false]", name: "Codex 5.3" },
+        {
+          value: "gpt-5.3-codex[reasoning=medium,fast=false]",
+          name: "Codex 5.3",
+        },
       ],
     },
   ];
@@ -303,18 +337,29 @@ const program = Effect.gen(function* () {
       return {
         protocolVersion: 1,
         agentCapabilities: { loadSession: true },
+        ...(advertisedAuthMethods !== undefined ? { authMethods: advertisedAuthMethods } : {}),
       };
     }),
   );
 
-  yield* agent.handleAuthenticate(() => Effect.succeed({}));
+  yield* agent.handleAuthenticate(() =>
+    Effect.sync(() => {
+      authenticated = true;
+      return {};
+    }),
+  );
 
   yield* agent.handleCreateSession(() =>
-    Effect.succeed({
-      sessionId,
-      modes: modeState(),
-      models: modelState(),
-      configOptions: configOptions(),
+    Effect.gen(function* () {
+      if (emitStartupCommands) {
+        yield* agent.client.sessionUpdate(availableCommandsUpdate(sessionId));
+      }
+      return {
+        sessionId,
+        modes: modeState(),
+        models: modelState(),
+        configOptions: configOptions(),
+      };
     }),
   );
 
@@ -346,6 +391,9 @@ const program = Effect.gen(function* () {
       if (failLoadSession) {
         return yield* AcpError.AcpRequestError.internalError("Mock load session failure");
       }
+      if (emitStartupCommands) {
+        yield* agent.client.sessionUpdate(availableCommandsUpdate(requestedSessionId));
+      }
       if (hangLoadSessionAfterReplay || delayLoadSessionAfterReplay) {
         emitLoadReplayNotifications(requestedSessionId);
         yield* agent.client.sessionUpdate({
@@ -465,6 +513,44 @@ const program = Effect.gen(function* () {
         return yield* AcpError.AcpRequestError.internalError("Mock prompt failure");
       }
 
+      if (requireAuthenticationForPrompt && !authenticated) {
+        return yield* AcpError.AcpRequestError.internalError(
+          "Authentication failed: Please authenticate to continue. Run `/login` to log in.",
+        );
+      }
+
+      if (emitDelayedCompactCompletion) {
+        writeJsonRpcNotification("session/update", {
+          sessionId: requestedSessionId,
+          update: {
+            sessionUpdate: "agent_message_chunk",
+            content: { type: "text", text: "Compacting context…" },
+          },
+        });
+        yield* Effect.gen(function* () {
+          yield* Effect.sleep(
+            `${Number.isFinite(delayedCompactCompletionMs) ? delayedCompactCompletionMs : 1500} millis`,
+          );
+          yield* Effect.sync(() => {
+            writeJsonRpcNotification("session/update", {
+              sessionId: requestedSessionId,
+              update: {
+                sessionUpdate: "agent_message_chunk",
+                content: { type: "text", text: "Context comp" },
+              },
+            });
+            writeJsonRpcNotification("session/update", {
+              sessionId: requestedSessionId,
+              update: {
+                sessionUpdate: "agent_message_chunk",
+                content: { type: "text", text: "acted" },
+              },
+            });
+          });
+        }).pipe(Effect.forkDetach);
+        return { stopReason: "end_turn" };
+      }
+
       if (emitStaleXAiPromptCompleteBeforeSecondHang && promptCount === 1) {
         return {
           stopReason: "end_turn",
@@ -674,13 +760,21 @@ const program = Effect.gen(function* () {
             ],
           },
           options: [
-            { optionId: permissionOptionIds.allowOnce, name: "Allow once", kind: "allow_once" },
+            {
+              optionId: permissionOptionIds.allowOnce,
+              name: "Allow once",
+              kind: "allow_once",
+            },
             {
               optionId: permissionOptionIds.allowAlways,
               name: "Allow always",
               kind: "allow_always",
             },
-            { optionId: permissionOptionIds.rejectOnce, name: "Reject", kind: "reject_once" },
+            {
+              optionId: permissionOptionIds.rejectOnce,
+              name: "Reject",
+              kind: "reject_once",
+            },
           ],
         });
 
@@ -784,7 +878,10 @@ const program = Effect.gen(function* () {
                 question: "Which scope should Grok use?",
                 multiSelect: null,
                 options: [
-                  { label: "Workspace", description: "Use the current workspace" },
+                  {
+                    label: "Workspace",
+                    description: "Use the current workspace",
+                  },
                   { label: "Session", description: "Only use this session" },
                 ],
               },
@@ -869,7 +966,10 @@ const program = Effect.gen(function* () {
         sessionId: requestedSessionId,
         update: {
           sessionUpdate: "agent_message_chunk",
-          content: { type: "text", text: promptResponseText ?? "hello from mock" },
+          content: {
+            type: "text",
+            text: promptResponseText ?? "hello from mock",
+          },
         },
       });