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

packages/opencode/src/mcp/index.ts

@@ -1,4 +1,5 @@
 import path from "node:path"
+import { pathToFileURL } from "node:url"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { type Tool } from "ai"
 import { ConfigV1 } from "@opencode-ai/core/v1/config/config"
@@ -9,6 +10,7 @@ import { SSEClientTransport } from "@modelcontextprotocol/sdk/client/sse.js"
 import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js"
 import { UnauthorizedError } from "@modelcontextprotocol/sdk/client/auth.js"
 import {
+  ListRootsRequestSchema,
   type LoggingMessageNotification,
   LoggingMessageNotificationSchema,
   type Tool as MCPToolDef,
@@ -42,7 +44,7 @@ const CLIENT_OPTIONS = {
     // https://github.com/anomalyco/opencode/issues/23066
     // elicitation: {},
     // https://github.com/anomalyco/opencode/issues/2308
-    // roots: {},
+    roots: {},
     // https://github.com/anomalyco/opencode/issues/28567
     // tasks: {},
   },
@@ -82,6 +84,14 @@ export class NotFoundError extends Schema.TaggedErrorClass<NotFoundError>()("MCP
 
 type MCPClient = Client
 
+function createClient(directory: string) {
+  const client = new Client({ name: "opencode", version: InstallationVersion }, CLIENT_OPTIONS)
+  client.setRequestHandler(ListRootsRequestSchema, () =>
+    Promise.resolve({ roots: [{ uri: pathToFileURL(directory).href }] }),
+  )
+  return client
+}
+
 const StatusConnected = Schema.Struct({ status: Schema.Literal("connected") }).annotate({
   identifier: "MCPStatusConnected",
 })
@@ -192,19 +202,21 @@ export const layer = Layer.effect(
      * Connect a client via the given transport with resource safety:
      * on failure the transport is closed; on success the caller owns it.
      */
-    const connectTransport = (transport: Transport, timeout: number) =>
-      Effect.acquireUseRelease(
+    const connectTransport = Effect.fn("MCP.connectTransport")(function* (transport: Transport, timeout: number) {
+      const directory = yield* InstanceState.directory
+      return yield* Effect.acquireUseRelease(
         Effect.succeed(transport),
         (t) =>
           Effect.tryPromise({
             try: () => {
-              const client = new Client({ name: "opencode", version: InstallationVersion }, CLIENT_OPTIONS)
+              const client = createClient(directory)
               return withTimeout(client.connect(t), timeout).then(() => client)
             },
             catch: (e) => (e instanceof Error ? e : new Error(String(e))),
           }),
         (t, exit) => (Exit.isFailure(exit) ? Effect.tryPromise(() => t.close()).pipe(Effect.ignore) : Effect.void),
       )
+    })
 
     const DISABLED_RESULT: CreateResult = { status: { status: "disabled" } }
 
@@ -777,10 +789,11 @@ export const layer = Layer.effect(
         authProvider,
         requestInit: mcpConfig.headers ? { headers: mcpConfig.headers } : undefined,
       })
+      const directory = yield* InstanceState.directory
 
       return yield* Effect.tryPromise({
         try: () => {
-          const client = new Client({ name: "opencode", version: InstallationVersion }, CLIENT_OPTIONS)
+          const client = createClient(directory)
           return client
             .connect(transport)
             .then(() => ({ authorizationUrl: "", oauthState, client }) satisfies AuthResult)