fix(mcp): share MCP layer across prompt and command wiring

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <[email protected]>

Author: codeg-dev

packages/opencode/src/command/index.ts

@@ -181,7 +181,6 @@ export const layer = Layer.effect(
 
 export const defaultLayer = layer.pipe(
   Layer.provide(Config.defaultLayer),
-  Layer.provide(MCP.defaultLayer),
   Layer.provide(Skill.defaultLayer),
 )
 

packages/opencode/src/effect/app-runtime.ts

@@ -49,6 +49,10 @@ import { SessionShare } from "@/share"
 import { Npm } from "@/npm"
 import { memoMap } from "./memo-map"
 
+const mcpLayer = MCP.defaultLayer
+const commandLayer = Command.defaultLayer.pipe(Layer.provide(mcpLayer))
+const sessionPromptLayer = SessionPrompt.defaultLayer.pipe(Layer.provide(mcpLayer))
+
 export const AppLayer = Layer.mergeAll(
   Npm.defaultLayer,
   AppFileSystem.defaultLayer,
@@ -78,13 +82,13 @@ export const AppLayer = Layer.mergeAll(
   SessionCompaction.defaultLayer,
   SessionRevert.defaultLayer,
   SessionSummary.defaultLayer,
-  SessionPrompt.defaultLayer,
+  sessionPromptLayer,
   Instruction.defaultLayer,
   LLM.defaultLayer,
   LSP.defaultLayer,
-  MCP.defaultLayer,
+  mcpLayer,
   McpAuth.defaultLayer,
-  Command.defaultLayer,
+  commandLayer,
   Truncate.defaultLayer,
   ToolRegistry.defaultLayer,
   Format.defaultLayer,

packages/opencode/src/session/prompt.ts

@@ -1679,7 +1679,6 @@ export const defaultLayer = Layer.suspend(() =>
     Layer.provide(SessionProcessor.defaultLayer),
     Layer.provide(Command.defaultLayer),
     Layer.provide(Permission.defaultLayer),
-    Layer.provide(MCP.defaultLayer),
     Layer.provide(LSP.defaultLayer),
     Layer.provide(ToolRegistry.defaultLayer),
     Layer.provide(Truncate.defaultLayer),

packages/opencode/test/session/prompt-effect.test.ts

@@ -157,7 +157,7 @@ function makeHttp() {
     LLM.defaultLayer,
     Env.defaultLayer,
     AgentSvc.defaultLayer,
-    Command.defaultLayer,
+    Command.defaultLayer.pipe(Layer.provide(mcp)),
     Permission.defaultLayer,
     Plugin.defaultLayer,
     Config.defaultLayer,

packages/opencode/test/session/prompt.test.ts

@@ -5,6 +5,7 @@ import { fileURLToPath } from "url"
 import { Effect, Layer } from "effect"
 import { Instance } from "../../src/project/instance"
 import { ModelID, ProviderID } from "../../src/provider/schema"
+import { MCP } from "../../src/mcp"
 import { Session } from "../../src/session"
 import { MessageV2 } from "../../src/session/message-v2"
 import { SessionPrompt } from "../../src/session/prompt"
@@ -15,7 +16,10 @@ void Log.init({ print: false })
 
 function run<A, E>(fx: Effect.Effect<A, E, SessionPrompt.Service | Session.Service>) {
   return Effect.runPromise(
-    fx.pipe(Effect.scoped, Effect.provide(Layer.mergeAll(SessionPrompt.defaultLayer, Session.defaultLayer))),
+    fx.pipe(
+      Effect.scoped,
+      Effect.provide(Layer.mergeAll(SessionPrompt.defaultLayer.pipe(Layer.provide(MCP.defaultLayer)), Session.defaultLayer)),
+    ),
   )
 }
 

packages/opencode/test/session/snapshot-tool-race.test.ts

@@ -112,7 +112,7 @@ function makeHttp() {
     LLM.defaultLayer,
     Env.defaultLayer,
     AgentSvc.defaultLayer,
-    Command.defaultLayer,
+    Command.defaultLayer.pipe(Layer.provide(mcp)),
     Permission.defaultLayer,
     Plugin.defaultLayer,
     Config.defaultLayer,

packages/opencode/test/session/structured-output-integration.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, test } from "bun:test"
 import path from "path"
 import { Effect, Layer } from "effect"
 import { Session } from "../../src/session"
+import { MCP } from "../../src/mcp"
 import { SessionPrompt } from "../../src/session/prompt"
 import { Log } from "../../src/util"
 import { Instance } from "../../src/project/instance"
@@ -23,7 +24,10 @@ async function withInstance<T>(fn: () => Promise<T>): Promise<T> {
 
 function run<A, E>(fx: Effect.Effect<A, E, SessionPrompt.Service | Session.Service>) {
   return Effect.runPromise(
-    fx.pipe(Effect.scoped, Effect.provide(Layer.mergeAll(SessionPrompt.defaultLayer, Session.defaultLayer))),
+    fx.pipe(
+      Effect.scoped,
+      Effect.provide(Layer.mergeAll(SessionPrompt.defaultLayer.pipe(Layer.provide(MCP.defaultLayer)), Session.defaultLayer)),
+    ),
   )
 }