From 07b983e82fcb808101593a5268c10e6e38ed9976 Mon Sep 17 00:00:00 2001
From: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>
Date: Wed, 10 Jun 2026 14:59:36 -0500
Subject: [PATCH] feat(mcp): support server log notifications (#31752)

---
 packages/opencode/src/mcp/index.ts           | 29 +++++++++++++++++++-
 packages/opencode/test/mcp/lifecycle.test.ts |  3 +-
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/packages/opencode/src/mcp/index.ts b/packages/opencode/src/mcp/index.ts
index 0ff39589a2..5a73322510 100644
--- a/packages/opencode/src/mcp/index.ts
+++ b/packages/opencode/src/mcp/index.ts
@@ -7,7 +7,12 @@ import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/
 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 { type Tool as MCPToolDef, ToolListChangedNotificationSchema } from "@modelcontextprotocol/sdk/types.js"
+import {
+  type LoggingMessageNotification,
+  LoggingMessageNotificationSchema,
+  type Tool as MCPToolDef,
+  ToolListChangedNotificationSchema,
+} from "@modelcontextprotocol/sdk/types.js"
 import { Config } from "@/config/config"
 import { ConfigMCPV1 } from "@opencode-ai/core/v1/config/mcp"
 import { NamedError } from "@opencode-ai/core/util/error"
@@ -391,6 +396,10 @@ export const layer = Layer.effect(
     )
 
     function watch(s: State, name: string, client: MCPClient, bridge: EffectBridge.Shape, timeout?: number) {
+      client.setNotificationHandler(LoggingMessageNotificationSchema, (notification) =>
+        bridge.promise(serverLog(name, notification.params)),
+      )
+
       if (!client.getServerCapabilities()?.tools) return
       client.setNotificationHandler(ToolListChangedNotificationSchema, async () => {
         if (s.clients[name] !== client || s.status[name]?.status !== "connected") return
@@ -404,6 +413,24 @@ export const layer = Layer.effect(
       })
     }
 
+    function serverLog(name: string, params: LoggingMessageNotification["params"]) {
+      const fields = { server: name, logger: params.logger, level: params.level, data: params.data }
+      switch (params.level) {
+        case "debug":
+          return Effect.logDebug("MCP server log", fields)
+        case "info":
+        case "notice":
+          return Effect.logInfo("MCP server log", fields)
+        case "warning":
+          return Effect.logWarning("MCP server log", fields)
+        case "error":
+        case "critical":
+        case "alert":
+        case "emergency":
+          return Effect.logError("MCP server log", fields)
+      }
+    }
+
     const state = yield* InstanceState.make<State>(
       Effect.fn("MCP.state")(function* () {
         const cfg = yield* cfgSvc.get()
diff --git a/packages/opencode/test/mcp/lifecycle.test.ts b/packages/opencode/test/mcp/lifecycle.test.ts
index 004909fb6e..0aef477d14 100644
--- a/packages/opencode/test/mcp/lifecycle.test.ts
+++ b/packages/opencode/test/mcp/lifecycle.test.ts
@@ -1,4 +1,5 @@
 import { expect, mock, beforeEach } from "bun:test"
+import { 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"
@@ -394,7 +395,7 @@ it.instance(
           { name: "next_tool", description: "next", inputSchema: { type: "object", properties: {} } },
         ]
 
-        const handler = Array.from(serverState.notificationHandlers.values())[0]
+        const handler = serverState.notificationHandlers.get(ToolListChangedNotificationSchema)
         expect(handler).toBeDefined()
         yield* Effect.promise(() => handler?.())