feat(mcp): support client roots (#32230)

packages/opencode/test/mcp/lifecycle.test.ts

@@ -1,6 +1,7 @@
 import path from "node:path"
+import { pathToFileURL } from "node:url"
 import { expect, mock, beforeEach } from "bun:test"
-import { ToolListChangedNotificationSchema } from "@modelcontextprotocol/sdk/types.js"
+import { ListRootsRequestSchema, ToolListChangedNotificationSchema } from "@modelcontextprotocol/sdk/types.js"
 import { Cause, Effect, Exit } from "effect"
 import type { MCP as MCPNS } from "../../src/mcp/index"
 import { testEffect } from "../lib/effect"
@@ -38,6 +39,8 @@ interface MockClientState {
     { resources: Array<{ name: string; uri: string; description?: string }>; nextCursor?: string }
   >
   closed: boolean
+  clientOptions?: { capabilities?: { roots?: { listChanged?: boolean } } }
+  requestHandlers: Map<unknown, (...args: any[]) => Promise<any>>
   notificationHandlers: Map<unknown, (...args: any[]) => any>
 }
 
@@ -75,6 +78,7 @@ function getOrCreateClientState(name?: string): MockClientState {
       promptPages: {},
       resourcePages: {},
       closed: false,
+      requestHandlers: new Map(),
       notificationHandlers: new Map(),
     }
     clientStates.set(key, state)
@@ -149,8 +153,10 @@ void mock.module("@modelcontextprotocol/sdk/client/index.js", () => ({
     _state!: MockClientState
     transport: any
 
-    constructor(_opts: any) {
+    constructor(_info: any, options?: MockClientState["clientOptions"]) {
       clientCreateCount++
+      this._state = getOrCreateClientState(lastCreatedClientName)
+      this._state.clientOptions = options
     }
 
     async connect(transport: { start: () => Promise<void> }) {
@@ -160,6 +166,10 @@ void mock.module("@modelcontextprotocol/sdk/client/index.js", () => ({
       this._state = getOrCreateClientState(lastCreatedClientName)
     }
 
+    setRequestHandler(schema: unknown, handler: (...args: any[]) => Promise<any>) {
+      this._state.requestHandlers.set(schema, handler)
+    }
+
     setNotificationHandler(schema: unknown, handler: (...args: any[]) => any) {
       this._state?.notificationHandlers.set(schema, handler)
     }
@@ -251,6 +261,28 @@ function statusName(status: Record<string, MCPNS.Status> | MCPNS.Status, server:
   return status[server]?.status
 }
 
+it.instance(
+  "advertises and lists the instance directory as its root",
+  () =>
+    MCP.Service.use((mcp: MCPNS.Interface) =>
+      Effect.gen(function* () {
+        const { directory } = yield* TestInstance
+        lastCreatedClientName = "roots"
+        yield* mcp.add("roots", { type: "local", command: ["echo", "test"] })
+
+        const state = getOrCreateClientState("roots")
+        expect(state.clientOptions?.capabilities?.roots).toEqual({})
+        expect(state.clientOptions?.capabilities?.roots?.listChanged).toBeUndefined()
+
+        const handler = state.requestHandlers.get(ListRootsRequestSchema)
+        expect(handler).toBeDefined()
+        const result = yield* Effect.promise(() => handler?.() ?? Promise.reject(new Error("roots handler missing")))
+        expect(result).toEqual({ roots: [{ uri: pathToFileURL(directory).href }] })
+      }),
+    ),
+  { config: { mcp: {} } },
+)
+
 it.instance(
   "local mcp cwd resolves relative paths against instance directory",
   () =>

packages/opencode/test/mcp/oauth-auto-connect.test.ts

@@ -87,6 +87,8 @@ void mock.module("@modelcontextprotocol/sdk/client/sse.js", () => ({
 // Mock the MCP SDK Client
 void mock.module("@modelcontextprotocol/sdk/client/index.js", () => ({
   Client: class MockClient {
+    setRequestHandler() {}
+
     async connect(transport: { start: () => Promise<void> }) {
       await transport.start()
     }

packages/opencode/test/mcp/oauth-browser.test.ts

@@ -89,6 +89,8 @@ void mock.module("@modelcontextprotocol/sdk/client/sse.js", () => ({
 // Mock the MCP SDK Client to trigger OAuth flow
 void mock.module("@modelcontextprotocol/sdk/client/index.js", () => ({
   Client: class MockClient {
+    setRequestHandler() {}
+
     async connect(transport: { start: () => Promise<void> }) {
       await transport.start()
     }