feat(opencode): add MCP server for delegating sessions to external agents

packages/opencode/src/cli/cmd/mcp-server.ts

@@ -0,0 +1,71 @@
+import { Effect } from "effect"
+import { effectCmd } from "../effect-cmd"
+import { withNetworkOptions, resolveNetworkOptions } from "../network"
+import { ServerAuth } from "@/server/auth"
+import { createOpencodeClient } from "@opencode-ai/sdk/v2"
+
+export const McpServerCommand = effectCmd({
+  command: "mcp-server",
+  describe: "start opencode as an MCP server (for Claude Code and other MCP clients)",
+  builder: (yargs) =>
+    withNetworkOptions(yargs)
+      .option("transport", {
+        describe: "transport type",
+        type: "string",
+        choices: ["stdio", "streamable-http", "sse"] as const,
+        default: "stdio",
+      })
+      .option("path", {
+        describe: "HTTP path for streamable-http/sse transport",
+        type: "string",
+        default: "/mcp",
+      })
+      .option("cwd", {
+        describe: "working directory",
+        type: "string",
+        default: process.cwd(),
+      }),
+  handler: Effect.fn("Cli.mcp-server")(function* (args) {
+    const { Server } = yield* Effect.promise(() => import("@/server/server"))
+    const { McpServerAgent } = yield* Effect.promise(() => import("@/mcp-server/agent"))
+    process.env.OPENCODE_CLIENT = "mcp-server"
+    const opts = yield* resolveNetworkOptions(args)
+    const server = yield* Effect.promise(() => Server.listen(opts))
+
+    const sdk = createOpencodeClient({
+      baseUrl: `http://${server.hostname}:${server.port}`,
+      headers: ServerAuth.headers(),
+    })
+
+    const transport = args.transport ?? "stdio"
+    const mcpOptions = {
+      transport,
+      port: transport !== "stdio" ? (args.port ?? 3001) : undefined,
+      hostname: transport !== "stdio" ? opts.hostname : undefined,
+      path: args.path,
+    }
+
+    const agent = McpServerAgent.init({ sdk })
+    const handle = yield* Effect.promise(() => agent.start(mcpOptions))
+
+    yield* Effect.logInfo("MCP server started", { transport, hostname: handle.hostname, port: handle.port })
+
+    if (transport === "stdio") {
+      process.stdout.write(`MCP server started on stdio\n`)
+    } else {
+      process.stdout.write(`MCP server started on ${transport} at ${handle.hostname}:${handle.port}${args.path}\n`)
+      const authHeader = ServerAuth.header()
+      if (authHeader) process.stdout.write(`Authorization header: ${authHeader}\n`)
+    }
+
+    yield* Effect.promise(() =>
+      new Promise<void>((resolve, reject) => {
+        process.on("SIGINT", resolve)
+        process.on("SIGTERM", resolve)
+        process.on("unhandledRejection", reject)
+      }),
+    )
+
+    yield* Effect.promise(() => handle.stop())
+  }),
+})

packages/opencode/src/index.ts

@@ -15,6 +15,7 @@ import { ServeCommand } from "./cli/cmd/serve"
 import { DebugCommand } from "./cli/cmd/debug"
 import { StatsCommand } from "./cli/cmd/stats"
 import { McpCommand } from "./cli/cmd/mcp"
+import { McpServerCommand } from "./cli/cmd/mcp-server"
 import { GithubCommand } from "./cli/cmd/github"
 import { ExportCommand } from "./cli/cmd/export"
 import { ImportCommand } from "./cli/cmd/import"
@@ -80,6 +81,7 @@ const cli = yargs(args)
   .completion("completion", "generate shell completion script")
   .command(AcpCommand)
   .command(McpCommand)
+  .command(McpServerCommand)
   .command(TuiThreadCommand)
   .command(AttachCommand)
   .command(RunCommand)