Add worktree handoff and status tools to the t3-code MCP server

apps/server/src/git/GitWorkflowService.ts

@@ -65,6 +65,7 @@ export class GitWorkflowService extends Context.Service<
     readonly createWorktree: (
       input: VcsCreateWorktreeInput,
     ) => Effect.Effect<VcsCreateWorktreeResult, GitCommandError>;
+    readonly listLocalBranchNames: (cwd: string) => Effect.Effect<string[], GitCommandError>;
     readonly fetchRemote: (input: {
       readonly cwd: string;
       readonly remoteName: string;
@@ -299,6 +300,10 @@ export const make = Effect.gen(function* () {
       ensureGitCommand("GitWorkflowService.createWorktree", input.cwd).pipe(
         Effect.andThen(git.createWorktree(input)),
       ),
+    listLocalBranchNames: (cwd) =>
+      ensureGitCommand("GitWorkflowService.listLocalBranchNames", cwd).pipe(
+        Effect.andThen(git.listLocalBranchNames(cwd)),
+      ),
     fetchRemote: (input) =>
       ensureGitCommand("GitWorkflowService.fetchRemote", input.cwd).pipe(
         Effect.andThen(git.fetchRemote(input)),

apps/server/src/mcp/McpHttpServer.ts

@@ -25,6 +25,9 @@ import {
   PreviewSnapshotToolkit,
   PreviewStandardToolkit,
 } from "./toolkits/preview/tools.ts";
+import { WorktreeToolkitHandlersLive } from "./toolkits/worktree/handlers.ts";
+import { WorktreeToolkit } from "./toolkits/worktree/tools.ts";
+import * as WorktreeMcpService from "./WorktreeMcpService.ts";
 
 const unauthorized = HttpServerResponse.jsonUnsafe(
   {
@@ -216,6 +219,11 @@ export const OrchestratorToolkitRegistrationLive = McpServer.toolkit(Orchestrato
   Layer.provide(OrchestratorMcpService.layer),
 );
 
+export const WorktreeToolkitRegistrationLive = McpServer.toolkit(WorktreeToolkit).pipe(
+  Layer.provide(WorktreeToolkitHandlersLive),
+  Layer.provide(WorktreeMcpService.layer),
+);
+
 const McpTransportLive = McpServer.layerHttp({
   name: "T3 Code",
   version: packageJson.version,
@@ -225,4 +233,5 @@ const McpTransportLive = McpServer.layerHttp({
 export const layer = Layer.mergeAll(
   PreviewToolkitRegistrationLive,
   OrchestratorToolkitRegistrationLive,
+  WorktreeToolkitRegistrationLive,
 ).pipe(Layer.provideMerge(McpTransportLive));

apps/server/src/mcp/McpInvocationContext.ts

@@ -7,7 +7,8 @@ import {
 import * as Context from "effect/Context";
 import * as Effect from "effect/Effect";
 
-export type McpCapability = "preview" | "orchestration";
+export const ALL_MCP_CAPABILITIES = ["preview", "orchestration", "worktree"] as const;
+export type McpCapability = (typeof ALL_MCP_CAPABILITIES)[number];
 
 export interface McpInvocationScope {
   readonly environmentId: EnvironmentId;

apps/server/src/mcp/McpSessionRegistry.test.ts

@@ -43,7 +43,7 @@ it.effect("stores only a token hash, resolves the bearer token, and revokes by t
 
     const resolved = yield* registry.resolve(token);
     expect(resolved?.threadId).toBe(threadId);
-    expect(resolved?.capabilities).toEqual(new Set(["preview", "orchestration"]));
+    expect(resolved?.capabilities).toEqual(new Set(["preview", "orchestration", "worktree"]));
 
     yield* registry.revokeThread(threadId);
     expect(yield* registry.resolve(token)).toBeUndefined();

apps/server/src/mcp/McpSessionRegistry.ts

@@ -94,7 +94,7 @@ const makeWithOptions = Effect.fn("McpSessionRegistry.make")(function* (
         threadId: ThreadId.make(request.threadId),
         providerSessionId,
         providerInstanceId: ProviderInstanceId.make(request.providerInstanceId),
-        capabilities: new Set(["preview", "orchestration"]),
+        capabilities: new Set(McpInvocationContext.ALL_MCP_CAPABILITIES),
         issuedAt,
       };
       yield* SynchronizedRef.update(state, ({ records }) => {