pingdotgg · atarantino · Aug 12, 2026 · Aug 12, 2026 · Aug 12, 2026 · Aug 12, 2026
diff --git a/README.md b/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, GitHub Copilot, Cursor, Grok Build, and OpenCode. If they're set up on your computer, T3 Code can control them.
 
 ## "Wait, what are you selling me?"
 
@@ -13,10 +13,11 @@ 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, GitHub Copilot (Early Access), Cursor, 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`
+> - GitHub Copilot: install [Copilot CLI](https://github.com/github/copilot-cli) and run `copilot login`
 > - Cursor: install [Cursor CLI](https://cursor.com/cli) and run `agent login`
 > - 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`
@@ -74,6 +75,7 @@ Full docs live in [docs/](./docs). There's no docs site yet.
 - [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)
+- [GitHub Copilot provider](./docs/user/providers-copilot.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).

diff --git a/apps/mobile/src/components/ProviderIcon.tsx b/apps/mobile/src/components/ProviderIcon.tsx
@@ -49,6 +49,17 @@ export function ProviderIcon(props: ProviderIconProps) {
     );
   }
 
+  if (props.provider === "copilot") {
+    return (
+      <Svg width={size} height={size} viewBox="0 0 256 208" fill="none">
+        <Path
+          fill={mono}
+          d="M205.3 31.4c14 14.8 20 35.2 22.5 63.6 6.6 0 12.8 1.5 17 7.2l7.8 10.6c2.2 3 3.4 6.6 3.4 10.4v28.7a12 12 0 0 1-4.8 9.5C215.9 187.2 172.3 208 128 208c-49 0-98.2-28.3-123.2-46.6a12 12 0 0 1-4.8-9.5v-28.7c0-3.8 1.2-7.4 3.4-10.5l7.8-10.5c4.2-5.7 10.4-7.2 17-7.2 2.5-28.4 8.4-48.8 22.5-63.6C77.3 3.2 112.6 0 127.6 0h.4c14.7 0 50.4 2.9 77.3 31.4ZM128 78.7c-3 0-6.5.2-10.3.6a27.1 27.1 0 0 1-6 12.1 45 45 0 0 1-32 13c-6.8 0-13.9-1.5-19.7-5.2-5.5 1.9-10.8 4.5-11.2 11-.5 12.2-.6 24.5-.6 36.8 0 6.1 0 12.3-.2 18.5 0 3.6 2.2 6.9 5.5 8.4C79.9 185.9 105 192 128 192s48-6 74.5-18.1a9.4 9.4 0 0 0 5.5-8.4c.3-18.4 0-37-.8-55.3-.4-6.6-5.7-9.1-11.2-11-5.8 3.7-13 5.1-19.7 5.1a45 45 0 0 1-32-12.9 27.1 27.1 0 0 1-6-12.1c-3.4-.4-6.9-.5-10.3-.6Zm-27 44c5.8 0 10.5 4.6 10.5 10.4v19.2a10.4 10.4 0 0 1-20.8 0V133c0-5.8 4.6-10.4 10.4-10.4Zm53.4 0c5.8 0 10.4 4.6 10.4 10.4v19.2a10.4 10.4 0 0 1-20.8 0V133c0-5.8 4.7-10.4 10.4-10.4Zm-73-94.4c-11.2 1.1-20.6 4.8-25.4 10-10.4 11.3-8.2 40.1-2.2 46.2A31.2 31.2 0 0 0 75 91.7c6.8 0 19.6-1.5 30.1-12.2 4.7-4.5 7.5-15.7 7.2-27-.3-9.1-2.9-16.7-6.7-19.9-4.2-3.6-13.6-5.2-24.2-4.3Zm69 4.3c-3.8 3.2-6.4 10.8-6.7 19.9-.3 11.3 2.5 22.5 7.2 27a41.7 41.7 0 0 0 30 12.2c8.9 0 17-2.9 21.3-7.2 6-6.1 8.2-34.9-2.2-46.3-4.8-5-14.2-8.8-25.4-9.9-10.6-1-20 .7-24.2 4.3ZM128 56c-2.6 0-5.6.2-9 .5.4 1.7.5 3.7.7 5.7 0 1.5 0 3-.2 4.5 3.2-.3 6-.3 8.5-.3 2.6 0 5.3 0 8.5.3-.2-1.6-.2-3-.2-4.5.2-2 .3-4 .7-5.7-3.4-.3-6.4-.5-9-.5Z"
+        />
+      </Svg>
+    );
+  }
+
   if (props.provider === "opencode") {
     return (
       <Svg width={size} height={size} viewBox="0 0 32 40" fill="none">

diff --git a/apps/server/scripts/acp-mock-agent.ts b/apps/server/scripts/acp-mock-agent.ts
@@ -74,10 +74,11 @@ const permissionOptionIds = {
   allowAlways: process.env.T3_ACP_ALLOW_ALWAYS_OPTION_ID ?? "allow-always",
   rejectOnce: process.env.T3_ACP_REJECT_ONCE_OPTION_ID ?? "reject-once",
 };
+const permissionToolKind = process.env.T3_ACP_PERMISSION_TOOL_KIND === "edit" ? "edit" : "execute";
 const sessionId = "mock-session-1";
 
 let currentModeId = "ask";
-let currentModelId = "default";
+let currentModelId = process.env.T3_ACP_INITIAL_MODEL_ID?.trim() || "default";
 let parameterizedModelPicker = false;
 let currentReasoning = "medium";
 let currentContext = "272k";
@@ -982,7 +983,7 @@ const program = Effect.gen(function* () {
             sessionUpdate: "tool_call",
             toolCallId,
             title: "Terminal",
-            kind: "execute",
+            kind: permissionToolKind,
             status: "pending",
             rawInput: {
               command: ["cat", "server/package.json"],
@@ -1004,7 +1005,7 @@ const program = Effect.gen(function* () {
           toolCall: {
             toolCallId,
             title: "`cat server/package.json`",
-            kind: "execute",
+            kind: permissionToolKind,
             status: "pending",
             content: [
               {
@@ -1041,7 +1042,7 @@ const program = Effect.gen(function* () {
             sessionUpdate: "tool_call_update",
             toolCallId,
             title: "Terminal",
-            kind: "execute",
+            kind: permissionToolKind,
             status: "completed",
             rawOutput: {
               exitCode: 0,

diff --git a/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.ts b/apps/server/src/orchestration-v2/Adapters/AcpAdapterV2.ts
@@ -202,6 +202,12 @@ export interface AcpAdapterV2Flavor {
     Crypto.Crypto | Scope.Scope
   >;
   readonly resolveModelId?: (selection: ModelSelection) => string | undefined;
+  readonly configureSession?: (input: {
+    readonly runtime: AcpSessionRuntime.AcpSessionRuntime["Service"];
+    readonly startResult: AcpSessionRuntimeStartResult;
+    readonly modelSelection: ModelSelection;
+    readonly runtimePolicy: ProviderAdapterV2RuntimePolicy;
+  }) => Effect.Effect<void, EffectAcpErrors.AcpError>;
   readonly registerExtensions?: (
     context: AcpAdapterV2ExtensionContext,
   ) => Effect.Effect<void, EffectAcpErrors.AcpError>;
@@ -4597,6 +4603,14 @@ export function makeAcpAdapterV2(options: AcpAdapterV2Options): ProviderAdapterV
           modelSelection: ModelSelection,
           runtimePolicy: ProviderAdapterV2RuntimePolicy,
         ) {
+          if (flavor.configureSession !== undefined) {
+            return yield* flavor.configureSession({
+              runtime,
+              startResult,
+              modelSelection,
+              runtimePolicy,
+            });
+          }
           const requestedModel = flavor.resolveModelId?.(modelSelection) ?? modelSelection.model;
           if (
             requestedModel.length > 0 &&

diff --git a/apps/server/src/orchestration-v2/Adapters/CopilotAdapterV2.test.ts b/apps/server/src/orchestration-v2/Adapters/CopilotAdapterV2.test.ts
@@ -0,0 +1,168 @@
+import * as NodeServices from "@effect/platform-node/NodeServices";
+import { assert, describe, it } from "@effect/vitest";
+import { ProviderInstanceId, ProviderSessionId, ThreadId } from "@t3tools/contracts";
+import * as Crypto from "effect/Crypto";
+import * as Effect from "effect/Effect";
+import * as FileSystem from "effect/FileSystem";
+import * as Layer from "effect/Layer";
+import * as Path from "effect/Path";
+import { ChildProcessSpawner } from "effect/unstable/process";
+
+import { ServerConfig } from "../../config.ts";
+import * as AcpSessionRuntime from "../../provider/acp/AcpSessionRuntime.ts";
+import { layer as idAllocatorLayer, IdAllocatorV2 } from "../IdAllocator.ts";
+import { ProviderAdapterV2RuntimePolicy } from "../ProviderAdapter.ts";
+import { BUILT_IN_PROVIDER_ADAPTER_DRIVER_KINDS_V2 } from "../builtInProviderAdapterDrivers.ts";
+import type { AcpAdapterV2RuntimeInput } from "./AcpAdapterV2.ts";
+import {
+  COPILOT_DRIVER_KIND,
+  CopilotAdapterV2Driver,
+  makeCopilotAdapterV2,
+  makeCopilotAcpAdapterFlavor,
+  type CopilotAdapterV2Options,
+} from "./CopilotAdapterV2.ts";
+
+const serverConfigLayer = ServerConfig.layerTest(process.cwd(), {
+  prefix: "t3-copilot-v2-adapter-",
+}).pipe(Layer.provide(NodeServices.layer));
+
+const testLayer = Layer.mergeAll(NodeServices.layer, idAllocatorLayer, serverConfigLayer);
+
+function makeMockRuntime(input: {
+  readonly childProcessSpawner: ChildProcessSpawner.ChildProcessSpawner["Service"];
+  readonly mockAgentPath: string;
+}) {
+  return (runtimeInput: AcpAdapterV2RuntimeInput) =>
+    Effect.gen(function* () {
+      const context = yield* Layer.build(
+        AcpSessionRuntime.layer({
+          ...runtimeInput,
+          spawn: {
+            command: process.execPath,
+            args: [input.mockAgentPath],
+            cwd: runtimeInput.cwd,
+            env: { T3_ACP_SESSION_LIFECYCLE: "1" },
+          },
+          authMethodId: "test",
+        }).pipe(
+          Layer.provide(
+            Layer.succeed(ChildProcessSpawner.ChildProcessSpawner, input.childProcessSpawner),
+          ),
+        ),
+      );
+      const runtime = yield* Effect.service(AcpSessionRuntime.AcpSessionRuntime).pipe(
+        Effect.provide(context),
+      );
+      return runtime;
+    });
+}
+
+describe("CopilotAdapterV2", () => {
+  it("is registered with Copilot schema defaults", () => {
+    assert.isTrue(BUILT_IN_PROVIDER_ADAPTER_DRIVER_KINDS_V2.has(COPILOT_DRIVER_KIND));
+    assert.equal(CopilotAdapterV2Driver.driverKind, COPILOT_DRIVER_KIND);
+    assert.deepEqual(CopilotAdapterV2Driver.defaultConfig(), {
+      enabled: true,
+      binaryPath: "copilot",
+      customModels: [],
+    });
+  });
+
+  it.effect("keeps Copilot in agent mode even for a plan interaction request", () =>
+    Effect.gen(function* () {
+      const selectedModes: Array<string> = [];
+      const instanceId = ProviderInstanceId.make("copilot-mode-fixture");
+      const flavor = makeCopilotAcpAdapterFlavor({
+        makeRuntime: () => Effect.never,
+      } as unknown as CopilotAdapterV2Options);
+      const runtime = {
+        getConfigOptions: Effect.succeed([]),
+        getModeState: Effect.succeed({
+          currentModeId: "plan",
+          availableModes: [
+            { id: "agent", name: "Agent" },
+            { id: "plan", name: "Plan" },
+          ],
+        }),
+        setConfigOption: () => Effect.succeed({ configOptions: [] }),
+        setMode: (modeId: string) =>
+          Effect.sync(() => {
+            selectedModes.push(modeId);
+            return {};
+          }),
+        setModel: () => Effect.void,
+      } as unknown as AcpSessionRuntime.AcpSessionRuntime["Service"];
+      const configureSession = flavor.configureSession;
+      if (configureSession === undefined) {
+        return yield* Effect.die("Expected Copilot ACP session configuration");
+      }
+
+      yield* configureSession({
+        runtime,
+        startResult: {} as AcpSessionRuntime.AcpSessionRuntimeStartResult,
+        modelSelection: { instanceId, model: "auto" },
+        runtimePolicy: ProviderAdapterV2RuntimePolicy.make({
+          runtimeMode: "approval-required",
+          interactionMode: "plan",
+          cwd: process.cwd(),
+        }),
+      });
+
+      assert.deepEqual(selectedModes, ["agent"]);
+      assert.isFalse(flavor.capabilities.planning.emitsProposedPlan);
+    }),
+  );
+
+  it.effect("opens a Copilot V2 session through the shared ACP adapter", () =>
+    Effect.gen(function* () {
+      const childProcessSpawner = yield* ChildProcessSpawner.ChildProcessSpawner;
+      const fileSystem = yield* FileSystem.FileSystem;
+      const idAllocator = yield* IdAllocatorV2;
+      const path = yield* Path.Path;
+      const serverConfig = yield* ServerConfig;
+      const mockAgentPath = yield* path.fromFileUrl(
+        new URL("../../../scripts/acp-mock-agent.ts", import.meta.url),
+      );
+      const instanceId = ProviderInstanceId.make("copilot-fixture");
+      const adapter = makeCopilotAdapterV2({
+        instanceId,
+        settings: {
+          enabled: true,
+          binaryPath: "copilot",
+          customModels: [],
+        },
+        environment: {},
+        childProcessSpawner,
+        crypto: yield* Crypto.Crypto,
+        fileSystem,
+        idAllocator,
+        serverConfig,
+        makeRuntime: makeMockRuntime({
+          childProcessSpawner,
+          mockAgentPath,
+        }),
+      });
+      const threadId = ThreadId.make("thread-copilot-fixture");
+      const runtimePolicy = ProviderAdapterV2RuntimePolicy.make({
+        runtimeMode: "full-access",
+        interactionMode: "plan",
+        cwd: process.cwd(),
+      });
+      const modelSelection = { instanceId, model: "default" } as const;
+      const runtime = yield* adapter.openSession({
+        threadId,
+        providerSessionId: ProviderSessionId.make("provider-session-copilot-fixture"),
+        modelSelection,
+        runtimePolicy,
+      });
+      const providerThread = yield* runtime.ensureThread({
+        threadId,
+        modelSelection,
+        runtimePolicy,
+      });
+
+      assert.equal(runtime.providerSession.driver, "copilot");
+      assert.equal(providerThread.nativeThreadRef?.nativeId, "mock-session-1");
+    }).pipe(Effect.provide(testLayer), Effect.scoped),
+  );
+});