From 6a477c4cf5afbaff939b93ed57925fe97c0d011c Mon Sep 17 00:00:00 2001
From: LukeParkerDev <10430890+Hona@users.noreply.github.com>
Date: Sat, 23 May 2026 14:14:30 +1000
Subject: [PATCH 1/2] feat(mcp): start configured servers asynchronously

---
 .../app/src/components/dialog-select-mcp.tsx  |   5 +-
 .../src/components/status-popover-body.tsx    |   8 +-
 packages/app/src/context/global-sync.tsx      |   2 +
 .../src/context/global-sync/event-reducer.ts  |   6 +
 packages/app/src/i18n/en.ts                   |   1 +
 packages/opencode/src/cli/cmd/mcp.ts          |   3 +
 .../opencode/src/cli/cmd/tui/context/sync.tsx |   7 +
 packages/opencode/src/config/mcp.ts           |   4 +-
 packages/opencode/src/mcp/index.ts            | 195 +++++++++++++-----
 .../opencode/test/cli/cmd/tui/sync.test.tsx   |  44 +++-
 packages/opencode/test/mcp/lifecycle.test.ts  | 119 ++++++++++-
 packages/sdk/js/src/v2/gen/types.gen.ts       |  74 ++++---
 12 files changed, 369 insertions(+), 99 deletions(-)

diff --git a/packages/app/src/components/dialog-select-mcp.tsx b/packages/app/src/components/dialog-select-mcp.tsx
index 5a28173ead..f6046fb625 100644
--- a/packages/app/src/components/dialog-select-mcp.tsx
+++ b/packages/app/src/components/dialog-select-mcp.tsx
@@ -11,6 +11,7 @@ import { pathKey } from "@/utils/path-key"
 
 const statusLabels = {
   connected: "mcp.status.connected",
+  connecting: "mcp.status.connecting",
   failed: "mcp.status.failed",
   needs_auth: "mcp.status.needs_auth",
   needs_client_registration: "mcp.status.needs_client_registration",
@@ -79,6 +80,7 @@ export const DialogSelectMcp: Component = () => {
             if (s?.status === "failed" || s?.status === "needs_client_registration") return s.error
           }
           const enabled = () => status() === "connected"
+          const connecting = () => status() === "connecting"
           return (
             <div class="w-full flex items-center justify-between gap-x-3">
               <div class="flex flex-col gap-0.5 min-w-0">
@@ -95,8 +97,9 @@ export const DialogSelectMcp: Component = () => {
               <div onClick={(e) => e.stopPropagation()}>
                 <Switch
                   checked={enabled()}
-                  disabled={toggle.isPending && toggle.variables === i.name}
+                  disabled={connecting() || (toggle.isPending && toggle.variables === i.name)}
                   onChange={() => {
+                    if (connecting()) return
                     if (toggle.isPending) return
                     toggle.mutate(i.name)
                   }}
diff --git a/packages/app/src/components/status-popover-body.tsx b/packages/app/src/components/status-popover-body.tsx
index b38c98f141..678f5b665f 100644
--- a/packages/app/src/components/status-popover-body.tsx
+++ b/packages/app/src/components/status-popover-body.tsx
@@ -321,15 +321,17 @@ export function StatusPopoverBody(props: { shown: Accessor<boolean> }) {
                   {(name) => {
                     const status = () => mcpStatus(name)
                     const enabled = () => status() === "connected"
+                    const connecting = () => status() === "connecting"
                     return (
                       <button
                         type="button"
                         class="flex items-center gap-2 w-full min-h-8 pl-3 pr-2 py-1 rounded-md hover:bg-surface-raised-base-hover transition-colors text-left"
                         onClick={() => {
+                          if (connecting()) return
                           if (toggleMcp.isPending) return
                           toggleMcp.mutate(name)
                         }}
-                        disabled={toggleMcp.isPending && toggleMcp.variables === name}
+                        disabled={connecting() || (toggleMcp.isPending && toggleMcp.variables === name)}
                       >
                         <div
                           classList={{
@@ -337,6 +339,7 @@ export function StatusPopoverBody(props: { shown: Accessor<boolean> }) {
                             "bg-icon-success-base": status() === "connected",
                             "bg-icon-critical-base": status() === "failed",
                             "bg-border-weak-base": status() === "disabled",
+                            "bg-icon-warning-base animate-pulse": status() === "connecting",
                             "bg-icon-warning-base":
                               status() === "needs_auth" || status() === "needs_client_registration",
                           }}
@@ -354,8 +357,9 @@ export function StatusPopoverBody(props: { shown: Accessor<boolean> }) {
                         <div onClick={(event) => event.stopPropagation()}>
                           <Switch
                             checked={enabled()}
-                            disabled={toggleMcp.isPending && toggleMcp.variables === name}
+                            disabled={connecting() || (toggleMcp.isPending && toggleMcp.variables === name)}
                             onChange={() => {
+                              if (connecting()) return
                               if (toggleMcp.isPending) return
                               toggleMcp.mutate(name)
                             }}
diff --git a/packages/app/src/context/global-sync.tsx b/packages/app/src/context/global-sync.tsx
index 2e9ac17071..a40cbb0667 100644
--- a/packages/app/src/context/global-sync.tsx
+++ b/packages/app/src/context/global-sync.tsx
@@ -49,6 +49,8 @@ export const loadMcpQuery = (directory: string, sdk: OpencodeClient) =>
   queryOptions({
     queryKey: [directory, "mcp"] as const,
     queryFn: () => sdk.mcp.status().then((r) => r.data ?? {}),
+    refetchInterval: (query) =>
+      Object.values(query.state.data ?? {}).some((status) => status.status === "connecting") ? 1000 : false,
   })
 
 export const loadLspQuery = (directory: string, sdk: OpencodeClient) =>
diff --git a/packages/app/src/context/global-sync/event-reducer.ts b/packages/app/src/context/global-sync/event-reducer.ts
index 5b72d37f9d..8b4e4dcd71 100644
--- a/packages/app/src/context/global-sync/event-reducer.ts
+++ b/packages/app/src/context/global-sync/event-reducer.ts
@@ -2,6 +2,7 @@ import { Binary } from "@opencode-ai/core/util/binary"
 import { produce, reconcile, type SetStoreFunction, type Store } from "solid-js/store"
 import type {
   Message,
+  McpStatus,
   Part,
   PermissionRequest,
   Project,
@@ -182,6 +183,11 @@ export function applyDirectoryEvent(input: {
       input.setStore("session_status", props.sessionID, reconcile(props.status))
       break
     }
+    case "mcp.status.changed": {
+      const props = event.properties as { name: string; status: McpStatus }
+      input.setStore("mcp", props.name, reconcile(props.status))
+      break
+    }
     case "message.updated": {
       const info = clean((event.properties as { info: Message }).info)
       const messages = input.store.message[info.sessionID]
diff --git a/packages/app/src/i18n/en.ts b/packages/app/src/i18n/en.ts
index bc4bf07b1f..eaaedd3c00 100644
--- a/packages/app/src/i18n/en.ts
+++ b/packages/app/src/i18n/en.ts
@@ -303,6 +303,7 @@ export const dict = {
   "dialog.plugins.empty": "Plugins configured in opencode.json",
 
   "mcp.status.connected": "connected",
+  "mcp.status.connecting": "connecting",
   "mcp.status.failed": "failed",
   "mcp.status.needs_auth": "needs auth",
   "mcp.status.disabled": "disabled",
diff --git a/packages/opencode/src/cli/cmd/mcp.ts b/packages/opencode/src/cli/cmd/mcp.ts
index f7ea030aa9..beba9345dd 100644
--- a/packages/opencode/src/cli/cmd/mcp.ts
+++ b/packages/opencode/src/cli/cmd/mcp.ts
@@ -143,6 +143,9 @@ export const McpListCommand = effectCmd({
       } else if (status.status === "disabled") {
         statusIcon = "○"
         statusText = "disabled"
+      } else if (status.status === "connecting") {
+        statusIcon = "…"
+        statusText = "connecting"
       } else if (status.status === "needs_auth") {
         statusIcon = "⚠"
         statusText = "needs authentication"
diff --git a/packages/opencode/src/cli/cmd/tui/context/sync.tsx b/packages/opencode/src/cli/cmd/tui/context/sync.tsx
index 9f8a384f77..2d25ed3462 100644
--- a/packages/opencode/src/cli/cmd/tui/context/sync.tsx
+++ b/packages/opencode/src/cli/cmd/tui/context/sync.tsx
@@ -363,6 +363,13 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
           break
         }
 
+        case "mcp.status.changed": {
+          if (workspace === project.workspace.current()) {
+            setStore("mcp", event.properties.name, reconcile(event.properties.status))
+          }
+          break
+        }
+
         case "vcs.branch.updated": {
           if (workspace === project.workspace.current()) {
             setStore("vcs", { branch: event.properties.branch })
diff --git a/packages/opencode/src/config/mcp.ts b/packages/opencode/src/config/mcp.ts
index 2a49745dd8..ccad0507ba 100644
--- a/packages/opencode/src/config/mcp.ts
+++ b/packages/opencode/src/config/mcp.ts
@@ -13,7 +13,7 @@ export const Local = Schema.Struct({
     description: "Enable or disable the MCP server on startup",
   }),
   timeout: Schema.optional(PositiveInt).annotate({
-    description: "Timeout in ms for MCP server requests. Defaults to 5000 (5 seconds) if not specified.",
+    description: "Timeout in ms for MCP server requests. Defaults to 30000 (30 seconds) if not specified.",
   }),
 }).annotate({ identifier: "McpLocalConfig" })
 export type Local = Schema.Schema.Type<typeof Local>
@@ -49,7 +49,7 @@ export const Remote = Schema.Struct({
     description: "OAuth authentication configuration for the MCP server. Set to false to disable OAuth auto-detection.",
   }),
   timeout: Schema.optional(PositiveInt).annotate({
-    description: "Timeout in ms for MCP server requests. Defaults to 5000 (5 seconds) if not specified.",
+    description: "Timeout in ms for MCP server requests. Defaults to 30000 (30 seconds) if not specified.",
   }),
 }).annotate({ identifier: "McpRemoteConfig" })
 export type Remote = Schema.Schema.Type<typeof Remote>
diff --git a/packages/opencode/src/mcp/index.ts b/packages/opencode/src/mcp/index.ts
index 85985876e7..22d316e755 100644
--- a/packages/opencode/src/mcp/index.ts
+++ b/packages/opencode/src/mcp/index.ts
@@ -26,7 +26,7 @@ import { BusEvent } from "../bus/bus-event"
 import { Bus } from "@/bus"
 import { TuiEvent } from "@/cli/cmd/tui/event"
 import open from "open"
-import { Effect, Exit, Layer, Option, Context, Schema, Stream } from "effect"
+import { Effect, Exit, Layer, Option, Context, Schema, Stream, Scope, Semaphore } from "effect"
 import { EffectBridge } from "@/effect/bridge"
 import { InstanceState } from "@/effect/instance-state"
 import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process"
@@ -79,6 +79,9 @@ const StatusConnected = Schema.Struct({ status: Schema.Literal("connected") }).a
 const StatusDisabled = Schema.Struct({ status: Schema.Literal("disabled") }).annotate({
   identifier: "MCPStatusDisabled",
 })
+const StatusConnecting = Schema.Struct({ status: Schema.Literal("connecting") }).annotate({
+  identifier: "MCPStatusConnecting",
+})
 const StatusFailed = Schema.Struct({ status: Schema.Literal("failed"), error: Schema.String }).annotate({
   identifier: "MCPStatusFailed",
 })
@@ -93,12 +96,21 @@ const StatusNeedsClientRegistration = Schema.Struct({
 export const Status = Schema.Union([
   StatusConnected,
   StatusDisabled,
+  StatusConnecting,
   StatusFailed,
   StatusNeedsAuth,
   StatusNeedsClientRegistration,
 ]).annotate({ identifier: "MCPStatus", discriminator: "status" })
 export type Status = Schema.Schema.Type<typeof Status>
 
+export const StatusChanged = BusEvent.define(
+  "mcp.status.changed",
+  Schema.Struct({
+    name: Schema.String,
+    status: Status,
+  }),
+)
+
 // Store transports for OAuth servers to allow finishing auth
 type TransportWithAuth = StreamableHTTPClientTransport | SSEClientTransport
 const pendingOAuthTransports = new Map<string, TransportWithAuth>()
@@ -237,6 +249,7 @@ interface State {
   status: Record<string, Status>
   clients: Record<string, MCPClient>
   defs: Record<string, MCPToolDef[]>
+  revision: Record<string, number>
 }
 
 export interface Interface {
@@ -480,6 +493,7 @@ export const layer = Layer.effect(
       return { mcpClient, status, defs: listed } satisfies CreateResult
     })
     const cfgSvc = yield* Config.Service
+    const startupLock = Semaphore.makeUnsafe(1)
 
     const descendants = Effect.fnUntraced(
       function* (pid: number) {
@@ -519,43 +533,133 @@ export const layer = Layer.effect(
       })
     }
 
+    function failedStatus(error: unknown): Status {
+      return { status: "failed", error: error instanceof Error ? error.message : String(error) }
+    }
+
+    function bump(s: State, name: string) {
+      const next = (s.revision[name] ?? 0) + 1
+      s.revision[name] = next
+      return next
+    }
+
+    function closeClient(s: State, name: string) {
+      const client = s.clients[name]
+      delete s.defs[name]
+      if (!client) return Effect.void
+      return Effect.tryPromise(() => client.close()).pipe(Effect.ignore)
+    }
+
+    function closeCreateResult(result: CreateResult) {
+      const client = result.mcpClient
+      if (!client) return Effect.void
+      return Effect.tryPromise(() => client.close()).pipe(Effect.ignore)
+    }
+
+    const setStatus = Effect.fnUntraced(function* (s: State, name: string, status: Status) {
+      s.status[name] = status
+      yield* bus.publish(StatusChanged, { name, status }).pipe(Effect.ignore)
+      return status
+    })
+
+    const storeClient = Effect.fnUntraced(function* (
+      s: State,
+      name: string,
+      client: MCPClient,
+      listed: MCPToolDef[],
+      timeout?: number,
+    ) {
+      const bridge = yield* EffectBridge.make()
+      yield* closeClient(s, name)
+      s.clients[name] = client
+      s.defs[name] = listed
+      watch(s, name, client, bridge, timeout)
+      return yield* setStatus(s, name, { status: "connected" })
+    })
+
+    const applyCreateResult = Effect.fnUntraced(function* (
+      s: State,
+      name: string,
+      result: CreateResult,
+      timeout?: number,
+    ) {
+      const client = result.mcpClient
+      if (!client) {
+        yield* closeClient(s, name)
+        delete s.clients[name]
+        return yield* setStatus(s, name, result.status)
+      }
+
+      if (!result.defs) {
+        yield* closeCreateResult(result)
+        yield* closeClient(s, name)
+        delete s.clients[name]
+        return yield* setStatus(s, name, { status: "failed", error: "Failed to get tools" })
+      }
+
+      return yield* storeClient(s, name, client, result.defs, timeout)
+    })
+
+    const createSafely = (key: string, mcp: ConfigMCP.Info) =>
+      create(key, mcp).pipe(
+        Effect.catch((error) => {
+          log.error("mcp startup failed", { key, error })
+          return Effect.succeed({ status: failedStatus(error) } satisfies CreateResult)
+        }),
+      )
+
+    const startConfigured = Effect.fn("MCP.startConfigured")(function* (
+      s: State,
+      entries: ReadonlyArray<readonly [string, ConfigMCP.Info]>,
+    ) {
+      yield* startupLock.withPermits(1)(
+        Effect.forEach(
+          entries,
+          ([key, mcp]) =>
+            Effect.gen(function* () {
+              const revision = s.revision[key] ?? 0
+              const result = yield* createSafely(key, mcp)
+              if ((s.revision[key] ?? 0) !== revision) {
+                yield* closeCreateResult(result)
+                return
+              }
+              yield* applyCreateResult(s, key, result, mcp.timeout)
+            }),
+          { concurrency: "unbounded", discard: true },
+        ),
+      )
+    })
+
     const state = yield* InstanceState.make<State>(
       Effect.fn("MCP.state")(function* () {
         const cfg = yield* cfgSvc.get()
-        const bridge = yield* EffectBridge.make()
+        const scope = yield* Scope.Scope
         const config = cfg.mcp ?? {}
         const s: State = {
           status: {},
           clients: {},
           defs: {},
+          revision: {},
         }
 
-        yield* Effect.forEach(
-          Object.entries(config),
-          ([key, mcp]) =>
-            Effect.gen(function* () {
-              if (!isMcpConfigured(mcp)) {
-                log.error("Ignoring MCP config entry without type", { key })
-                return
-              }
+        const configured = Object.entries(config).flatMap(([key, mcp]) => {
+          if (!isMcpConfigured(mcp)) {
+            log.error("Ignoring MCP config entry without type", { key })
+            return []
+          }
 
-              if (mcp.enabled === false) {
-                s.status[key] = { status: "disabled" }
-                return
-              }
+          if (mcp.enabled === false) {
+            s.status[key] = { status: "disabled" }
+            return []
+          }
 
-              const result = yield* create(key, mcp).pipe(Effect.catch(() => Effect.void))
-              if (!result) return
+          s.status[key] = { status: "connecting" }
+          return [[key, mcp] as const]
+        })
 
-              s.status[key] = result.status
-              if (result.mcpClient) {
-                s.clients[key] = result.mcpClient
-                s.defs[key] = result.defs!
-                watch(s, key, result.mcpClient, bridge, mcp.timeout)
-              }
-            }),
-          { concurrency: "unbounded" },
-        )
+        if (configured.length > 0) {
+          yield* startConfigured(s, configured).pipe(Effect.ignore, Effect.forkIn(scope), Effect.asVoid)
+        }
 
         yield* Effect.addFinalizer(() =>
           Effect.gen(function* () {
@@ -584,29 +688,6 @@ export const layer = Layer.effect(
       }),
     )
 
-    function closeClient(s: State, name: string) {
-      const client = s.clients[name]
-      delete s.defs[name]
-      if (!client) return Effect.void
-      return Effect.tryPromise(() => client.close()).pipe(Effect.ignore)
-    }
-
-    const storeClient = Effect.fnUntraced(function* (
-      s: State,
-      name: string,
-      client: MCPClient,
-      listed: MCPToolDef[],
-      timeout?: number,
-    ) {
-      const bridge = yield* EffectBridge.make()
-      yield* closeClient(s, name)
-      s.status[name] = { status: "connected" }
-      s.clients[name] = client
-      s.defs[name] = listed
-      watch(s, name, client, bridge, timeout)
-      return s.status[name]
-    })
-
     const status = Effect.fn("MCP.status")(function* () {
       const s = yield* InstanceState.get(state)
 
@@ -629,16 +710,15 @@ export const layer = Layer.effect(
 
     const createAndStore = Effect.fn("MCP.createAndStore")(function* (name: string, mcp: ConfigMCP.Info) {
       const s = yield* InstanceState.get(state)
-      const result = yield* create(name, mcp)
-
-      s.status[name] = result.status
-      if (!result.mcpClient) {
-        yield* closeClient(s, name)
-        delete s.clients[name]
-        return result.status
+      const revision = bump(s, name)
+      yield* setStatus(s, name, mcp.enabled === false ? { status: "disabled" } : { status: "connecting" })
+      const result = yield* createSafely(name, mcp)
+      if ((s.revision[name] ?? 0) !== revision) {
+        yield* closeCreateResult(result)
+        return s.status[name] ?? result.status
       }
 
-      return yield* storeClient(s, name, result.mcpClient, result.defs!, mcp.timeout)
+      return yield* applyCreateResult(s, name, result, mcp.timeout)
     })
 
     const add = Effect.fn("MCP.add")(function* (name: string, mcp: ConfigMCP.Info) {
@@ -655,9 +735,10 @@ export const layer = Layer.effect(
     const disconnect = Effect.fn("MCP.disconnect")(function* (name: string) {
       yield* requireMcpConfig(name)
       const s = yield* InstanceState.get(state)
+      bump(s, name)
       yield* closeClient(s, name)
       delete s.clients[name]
-      s.status[name] = { status: "disabled" }
+      yield* setStatus(s, name, { status: "disabled" })
     })
 
     const tools = Effect.fn("MCP.tools")(function* () {
diff --git a/packages/opencode/test/cli/cmd/tui/sync.test.tsx b/packages/opencode/test/cli/cmd/tui/sync.test.tsx
index 714c39a781..683836b9aa 100644
--- a/packages/opencode/test/cli/cmd/tui/sync.test.tsx
+++ b/packages/opencode/test/cli/cmd/tui/sync.test.tsx
@@ -2,7 +2,7 @@
 import { describe, expect, test } from "bun:test"
 import { Global } from "@opencode-ai/core/global"
 import { tmpdir } from "../../../fixture/fixture"
-import { mount, wait } from "./sync-fixture"
+import { json, mount, wait } from "./sync-fixture"
 import type { GlobalEvent } from "@opencode-ai/sdk/v2"
 
 function branchEvent(branch: string, workspace?: string): GlobalEvent {
@@ -18,6 +18,19 @@ function branchEvent(branch: string, workspace?: string): GlobalEvent {
   }
 }
 
+function mcpStatusEvent(status: "connecting" | "connected", workspace?: string): GlobalEvent {
+  return {
+    directory: "/tmp/other",
+    project: "proj_test",
+    workspace,
+    payload: {
+      id: `evt_mcp_${status}`,
+      type: "mcp.status.changed",
+      properties: { name: "playwright", status: { status } },
+    },
+  }
+}
+
 describe("tui sync", () => {
   test("refresh scopes sessions by default and lists project sessions when disabled", async () => {
     const previous = Global.Path.state
@@ -67,4 +80,33 @@ describe("tui sync", () => {
       Global.Path.state = previous
     }
   })
+
+  test("mcp status changes update the active workspace", async () => {
+    const previous = Global.Path.state
+    await using tmp = await tmpdir()
+    Global.Path.state = tmp.path
+    await Bun.write(`${tmp.path}/kv.json`, "{}")
+    const { app, emit, project, sync } = await mount((url) => {
+      if (url.pathname === "/mcp") return json({ playwright: { status: "connecting" } })
+      return undefined
+    })
+
+    try {
+      expect(sync.data.mcp.playwright?.status).toBe("connecting")
+
+      project.workspace.set("ws_a")
+      emit(mcpStatusEvent("connected", "ws_b"))
+      await Bun.sleep(30)
+
+      expect(sync.data.mcp.playwright?.status).toBe("connecting")
+
+      emit(mcpStatusEvent("connected", "ws_a"))
+      await wait(() => sync.data.mcp.playwright?.status === "connected")
+
+      expect(sync.data.mcp.playwright?.status).toBe("connected")
+    } finally {
+      app.renderer.destroy()
+      Global.Path.state = previous
+    }
+  })
 })
diff --git a/packages/opencode/test/mcp/lifecycle.test.ts b/packages/opencode/test/mcp/lifecycle.test.ts
index dddfd9875e..a7ff40006d 100644
--- a/packages/opencode/test/mcp/lifecycle.test.ts
+++ b/packages/opencode/test/mcp/lifecycle.test.ts
@@ -1,7 +1,9 @@
 import { expect, mock, beforeEach } from "bun:test"
 import { Cause, Effect, Exit } from "effect"
+import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import type { MCP as MCPNS } from "../../src/mcp/index"
-import { testEffect } from "../lib/effect"
+import { provideInstance, tmpdirScoped } from "../fixture/fixture"
+import { awaitWithTimeout, pollWithTimeout, testEffect } from "../lib/effect"
 
 // --- Mock infrastructure ---
 
@@ -25,6 +27,10 @@ let lastCreatedClientName: string | undefined
 let connectShouldFail = false
 let connectShouldHang = false
 let connectError = "Mock transport cannot connect"
+let connectHook: (() => Promise<void>) | undefined
+let activeConnects = 0
+let maxActiveConnects = 0
+let connectStarts = 0
 // Tracks how many Client instances were created (detects leaks)
 let clientCreateCount = 0
 // Tracks how many times transport.close() is called across all mock transports
@@ -52,6 +58,19 @@ function getOrCreateClientState(name?: string): MockClientState {
   return state
 }
 
+async function runMockConnect() {
+  activeConnects++
+  connectStarts++
+  maxActiveConnects = Math.max(maxActiveConnects, activeConnects)
+  try {
+    await connectHook?.()
+    if (connectShouldHang) return new Promise<void>(() => {}) // never resolves
+    if (connectShouldFail) throw new Error(connectError)
+  } finally {
+    activeConnects--
+  }
+}
+
 // Mock transport that succeeds or fails based on connectShouldFail / connectShouldHang
 class MockStdioTransport {
   stderr: null = null
@@ -59,8 +78,7 @@ class MockStdioTransport {
   // oxlint-disable-next-line no-useless-constructor
   constructor(_opts: any) {}
   async start() {
-    if (connectShouldHang) return new Promise<void>(() => {}) // never resolves
-    if (connectShouldFail) throw new Error(connectError)
+    return runMockConnect()
   }
   async close() {
     transportCloseCount++
@@ -71,8 +89,7 @@ class MockStreamableHTTP {
   // oxlint-disable-next-line no-useless-constructor
   constructor(_url: URL, _opts?: any) {}
   async start() {
-    if (connectShouldHang) return new Promise<void>(() => {}) // never resolves
-    if (connectShouldFail) throw new Error(connectError)
+    return runMockConnect()
   }
   async close() {
     transportCloseCount++
@@ -84,8 +101,7 @@ class MockSSE {
   // oxlint-disable-next-line no-useless-constructor
   constructor(_url: URL, _opts?: any) {}
   async start() {
-    if (connectShouldHang) return new Promise<void>(() => {}) // never resolves
-    if (connectShouldFail) throw new Error(connectError)
+    return runMockConnect()
   }
   async close() {
     transportCloseCount++
@@ -173,6 +189,10 @@ beforeEach(() => {
   connectShouldFail = false
   connectShouldHang = false
   connectError = "Mock transport cannot connect"
+  connectHook = undefined
+  activeConnects = 0
+  maxActiveConnects = 0
+  connectStarts = 0
   clientCreateCount = 0
   transportCloseCount = 0
 })
@@ -188,6 +208,91 @@ function statusName(status: Record<string, MCPNS.Status> | MCPNS.Status, server:
   return status[server]?.status
 }
 
+function deferred() {
+  let resolve = () => {}
+  const promise = new Promise<void>((done) => {
+    resolve = done
+  })
+  return { promise, resolve }
+}
+
+it.instance(
+  "status() returns connecting without waiting for configured startup",
+  () =>
+    MCP.Service.use((mcp: MCPNS.Interface) =>
+      Effect.gen(function* () {
+        const connect = deferred()
+        connectHook = () => connect.promise
+
+        const status = yield* awaitWithTimeout(mcp.status(), "mcp status blocked on startup", "200 millis")
+        expect(status["slow-server"]?.status).toBe("connecting")
+
+        yield* pollWithTimeout(
+          Effect.sync(() => (connectStarts === 1 ? true : undefined)),
+          "configured mcp startup did not begin",
+        )
+
+        connect.resolve()
+
+        yield* pollWithTimeout(
+          Effect.gen(function* () {
+            const next = yield* mcp.status()
+            return next["slow-server"]?.status === "connected" ? true : undefined
+          }),
+          "configured mcp startup did not complete",
+        )
+      }),
+    ),
+  {
+    config: {
+      mcp: {
+        "slow-server": {
+          type: "local",
+          command: ["echo", "test"],
+        },
+      },
+    },
+  },
+)
+
+it.live("configured MCP startup runs for one project at a time", () =>
+  Effect.gen(function* () {
+    const connect = deferred()
+    connectHook = () => connect.promise
+    const config = {
+      mcp: {
+        "slow-server": {
+          type: "local" as const,
+          command: ["echo", "test"],
+        },
+      },
+    }
+
+    const first = yield* tmpdirScoped({ config })
+    const second = yield* tmpdirScoped({ config })
+    const mcp = yield* MCP.Service
+
+    yield* mcp.status().pipe(provideInstance(first))
+    yield* pollWithTimeout(
+      Effect.sync(() => (connectStarts === 1 ? true : undefined)),
+      "first configured mcp startup did not begin",
+    )
+
+    yield* mcp.status().pipe(provideInstance(second))
+    yield* Effect.sleep("100 millis")
+    expect(connectStarts).toBe(1)
+    expect(maxActiveConnects).toBe(1)
+
+    connect.resolve()
+
+    yield* pollWithTimeout(
+      Effect.sync(() => (connectStarts === 2 && activeConnects === 0 ? true : undefined)),
+      "second configured mcp startup did not run after first completed",
+    )
+    expect(maxActiveConnects).toBe(1)
+  }).pipe(Effect.provide(CrossSpawnSpawner.defaultLayer)),
+)
+
 // ========================================================================
 // Test: tools() are cached after connect
 // ========================================================================
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index aae1b06ad3..bc6249b5b5 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -29,6 +29,7 @@ export type Event =
   | EventSessionIdle
   | EventMcpToolsChanged
   | EventMcpBrowserOpenFailed
+  | EventMcpStatusChanged
   | EventCommandExecuted
   | EventProjectUpdated
   | EventSessionCompacted
@@ -352,6 +353,40 @@ export type SessionStatus =
       type: "busy"
     }
 
+export type McpStatusConnected = {
+  status: "connected"
+}
+
+export type McpStatusDisabled = {
+  status: "disabled"
+}
+
+export type McpStatusConnecting = {
+  status: "connecting"
+}
+
+export type McpStatusFailed = {
+  status: "failed"
+  error: string
+}
+
+export type McpStatusNeedsAuth = {
+  status: "needs_auth"
+}
+
+export type McpStatusNeedsClientRegistration = {
+  status: "needs_client_registration"
+  error: string
+}
+
+export type McpStatus =
+  | McpStatusConnected
+  | McpStatusDisabled
+  | McpStatusConnecting
+  | McpStatusFailed
+  | McpStatusNeedsAuth
+  | McpStatusNeedsClientRegistration
+
 export type Project = {
   id: string
   worktree: string
@@ -830,6 +865,7 @@ export type GlobalEvent = {
     | EventSessionIdle
     | EventMcpToolsChanged
     | EventMcpBrowserOpenFailed
+    | EventMcpStatusChanged
     | EventCommandExecuted
     | EventProjectUpdated
     | EventSessionCompacted
@@ -1661,35 +1697,6 @@ export type FormatterStatus = {
   enabled: boolean
 }
 
-export type McpStatusConnected = {
-  status: "connected"
-}
-
-export type McpStatusDisabled = {
-  status: "disabled"
-}
-
-export type McpStatusFailed = {
-  status: "failed"
-  error: string
-}
-
-export type McpStatusNeedsAuth = {
-  status: "needs_auth"
-}
-
-export type McpStatusNeedsClientRegistration = {
-  status: "needs_client_registration"
-  error: string
-}
-
-export type McpStatus =
-  | McpStatusConnected
-  | McpStatusDisabled
-  | McpStatusFailed
-  | McpStatusNeedsAuth
-  | McpStatusNeedsClientRegistration
-
 export type McpUnsupportedOAuthError = {
   error: string
 }
@@ -2671,6 +2678,15 @@ export type EventMcpBrowserOpenFailed = {
   }
 }
 
+export type EventMcpStatusChanged = {
+  id: string
+  type: "mcp.status.changed"
+  properties: {
+    name: string
+    status: McpStatus
+  }
+}
+
 export type EventCommandExecuted = {
   id: string
   type: "command.executed"

From 4eab26aaaf82615518edd59af51ec61a8b6cd077 Mon Sep 17 00:00:00 2001
From: LukeParkerDev <10430890+Hona@users.noreply.github.com>
Date: Sat, 23 May 2026 14:30:51 +1000
Subject: [PATCH 2/2] fix(mcp): invalidate stale startup work

---
 packages/opencode/src/mcp/index.ts           |   8 +-
 packages/opencode/test/mcp/lifecycle.test.ts | 151 +++++++++----------
 2 files changed, 75 insertions(+), 84 deletions(-)

diff --git a/packages/opencode/src/mcp/index.ts b/packages/opencode/src/mcp/index.ts
index 22d316e755..dbfc0418d9 100644
--- a/packages/opencode/src/mcp/index.ts
+++ b/packages/opencode/src/mcp/index.ts
@@ -610,14 +610,14 @@ export const layer = Layer.effect(
 
     const startConfigured = Effect.fn("MCP.startConfigured")(function* (
       s: State,
-      entries: ReadonlyArray<readonly [string, ConfigMCP.Info]>,
+      entries: ReadonlyArray<readonly [string, ConfigMCP.Info, number]>,
     ) {
       yield* startupLock.withPermits(1)(
         Effect.forEach(
           entries,
-          ([key, mcp]) =>
+          ([key, mcp, revision]) =>
             Effect.gen(function* () {
-              const revision = s.revision[key] ?? 0
+              if ((s.revision[key] ?? 0) !== revision) return
               const result = yield* createSafely(key, mcp)
               if ((s.revision[key] ?? 0) !== revision) {
                 yield* closeCreateResult(result)
@@ -654,7 +654,7 @@ export const layer = Layer.effect(
           }
 
           s.status[key] = { status: "connecting" }
-          return [[key, mcp] as const]
+          return [[key, mcp, bump(s, key)] as const]
         })
 
         if (configured.length > 0) {
diff --git a/packages/opencode/test/mcp/lifecycle.test.ts b/packages/opencode/test/mcp/lifecycle.test.ts
index a7ff40006d..088495bc22 100644
--- a/packages/opencode/test/mcp/lifecycle.test.ts
+++ b/packages/opencode/test/mcp/lifecycle.test.ts
@@ -216,6 +216,15 @@ function deferred() {
   return { promise, resolve }
 }
 
+const waitConnected = (mcp: MCPNS.Interface, name: string) =>
+  pollWithTimeout(
+    Effect.gen(function* () {
+      const status = yield* mcp.status()
+      return status[name]?.status === "connected" ? true : undefined
+    }),
+    `configured mcp ${name} did not connect`,
+  )
+
 it.instance(
   "status() returns connecting without waiting for configured startup",
   () =>
@@ -255,42 +264,60 @@ it.instance(
   },
 )
 
-it.live("configured MCP startup runs for one project at a time", () =>
-  Effect.gen(function* () {
-    const connect = deferred()
-    connectHook = () => connect.promise
-    const config = {
+it.instance(
+  "configured MCP startup runs for one project at a time",
+  () =>
+    MCP.Service.use((mcp: MCPNS.Interface) =>
+      Effect.gen(function* () {
+        const connect = deferred()
+        connectHook = () => connect.promise
+        const config = {
+          mcp: {
+            "slow-server": {
+              type: "local" as const,
+              command: ["echo", "test"],
+            },
+          },
+        }
+        const second = yield* tmpdirScoped({ config })
+
+        yield* mcp.status()
+        yield* pollWithTimeout(
+          Effect.sync(() => (connectStarts === 1 ? true : undefined)),
+          "first configured mcp startup did not begin",
+        )
+
+        yield* mcp.status().pipe(provideInstance(second))
+        yield* Effect.sleep("100 millis")
+        expect(connectStarts).toBe(1)
+        expect(maxActiveConnects).toBe(1)
+
+        connect.resolve()
+
+        yield* pollWithTimeout(
+          Effect.gen(function* () {
+            const first = yield* mcp.status()
+            const next = yield* mcp.status().pipe(provideInstance(second))
+            return first["slow-server"]?.status === "connected" && next["slow-server"]?.status === "connected"
+              ? true
+              : undefined
+          }),
+          "configured mcp startups did not complete",
+        )
+        expect(connectStarts).toBe(2)
+        expect(maxActiveConnects).toBe(1)
+      }),
+    ).pipe(Effect.provide(CrossSpawnSpawner.defaultLayer)),
+  {
+    config: {
       mcp: {
         "slow-server": {
-          type: "local" as const,
+          type: "local",
           command: ["echo", "test"],
         },
       },
-    }
-
-    const first = yield* tmpdirScoped({ config })
-    const second = yield* tmpdirScoped({ config })
-    const mcp = yield* MCP.Service
-
-    yield* mcp.status().pipe(provideInstance(first))
-    yield* pollWithTimeout(
-      Effect.sync(() => (connectStarts === 1 ? true : undefined)),
-      "first configured mcp startup did not begin",
-    )
-
-    yield* mcp.status().pipe(provideInstance(second))
-    yield* Effect.sleep("100 millis")
-    expect(connectStarts).toBe(1)
-    expect(maxActiveConnects).toBe(1)
-
-    connect.resolve()
-
-    yield* pollWithTimeout(
-      Effect.sync(() => (connectStarts === 2 && activeConnects === 0 ? true : undefined)),
-      "second configured mcp startup did not run after first completed",
-    )
-    expect(maxActiveConnects).toBe(1)
-  }).pipe(Effect.provide(CrossSpawnSpawner.defaultLayer)),
+    },
+  },
 )
 
 // ========================================================================
@@ -377,10 +404,8 @@ it.instance(
         lastCreatedClientName = "disc-server"
         getOrCreateClientState("disc-server")
 
-        yield* mcp.add("disc-server", {
-          type: "local",
-          command: ["echo", "test"],
-        })
+        yield* mcp.status()
+        yield* waitConnected(mcp, "disc-server")
 
         const statusBefore = yield* mcp.status()
         expect(statusBefore["disc-server"]?.status).toBe("connected")
@@ -418,10 +443,8 @@ it.instance(
           { name: "my_tool", description: "a tool", inputSchema: { type: "object", properties: {} } },
         ]
 
-        yield* mcp.add("reconn-server", {
-          type: "local",
-          command: ["echo", "test"],
-        })
+        yield* mcp.status()
+        yield* waitConnected(mcp, "reconn-server")
 
         yield* mcp.disconnect("reconn-server")
         expect((yield* mcp.status())["reconn-server"]?.status).toBe("disabled")
@@ -488,7 +511,7 @@ it.instance(
 // ========================================================================
 
 it.instance(
-  "init connects available servers even when one fails",
+  "connects available servers even when one fails",
   () =>
     MCP.Service.use((mcp: MCPNS.Interface) =>
       Effect.gen(function* () {
@@ -526,14 +549,8 @@ it.instance(
   {
     config: {
       mcp: {
-        "good-server": {
-          type: "local",
-          command: ["echo", "good"],
-        },
-        "bad-server": {
-          type: "local",
-          command: ["echo", "bad"],
-        },
+        "good-server": { type: "local", command: ["echo", "good"], enabled: false },
+        "bad-server": { type: "local", command: ["echo", "bad"], enabled: false },
       },
     },
   },
@@ -658,16 +675,7 @@ it.instance(
         expect(key).toContain("my-prompt")
       }),
     ),
-  {
-    config: {
-      mcp: {
-        "prompt-server": {
-          type: "local",
-          command: ["echo", "test"],
-        },
-      },
-    },
-  },
+  { config: { mcp: {} } },
 )
 
 it.instance(
@@ -691,16 +699,7 @@ it.instance(
         expect(key).toContain("my-resource")
       }),
     ),
-  {
-    config: {
-      mcp: {
-        "resource-server": {
-          type: "local",
-          command: ["echo", "test"],
-        },
-      },
-    },
-  },
+  { config: { mcp: {} } },
 )
 
 it.instance(
@@ -712,10 +711,8 @@ it.instance(
         const serverState = getOrCreateClientState("prompt-disc-server")
         serverState.prompts = [{ name: "hidden-prompt", description: "Should not appear" }]
 
-        yield* mcp.add("prompt-disc-server", {
-          type: "local",
-          command: ["echo", "test"],
-        })
+        yield* mcp.status()
+        yield* waitConnected(mcp, "prompt-disc-server")
 
         yield* mcp.disconnect("prompt-disc-server")
 
@@ -824,10 +821,7 @@ it.instance(
   {
     config: {
       mcp: {
-        "fail-connect": {
-          type: "local",
-          command: ["echo", "test"],
-        },
+        "fail-connect": { type: "local", command: ["echo", "test"], enabled: false },
       },
     },
   },
@@ -895,10 +889,7 @@ it.instance(
   {
     config: {
       mcp: {
-        "my.special-server": {
-          type: "local",
-          command: ["echo", "test"],
-        },
+        "my.special-server": { type: "local", command: ["echo", "test"], enabled: false },
       },
     },
   },