diff --git a/tools/relay/server.ts b/tools/relay/server.ts
new file mode 100644
index 0000000..008f38e
--- /dev/null
+++ b/tools/relay/server.ts
@@ -0,0 +1,159 @@
+import { Server } from "@modelcontextprotocol/sdk/server/index.js";
+import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
+import {
+  CallToolRequestSchema,
+  ListToolsRequestSchema,
+} from "@modelcontextprotocol/sdk/types.js";
+import http from "node:http";
+import { RelayQueue, isRole } from "./queue.ts";
+
+const PORT = 7331;
+const queue = new RelayQueue();
+
+const mcpServer = new Server(
+  { name: "relay", version: "0.1.0" },
+  { capabilities: { tools: {} } }
+);
+
+const TOOLS = [
+  {
+    name: "post_message",
+    description:
+      "Push a message to a recipient's inbox. Returns the assigned message id.",
+    inputSchema: {
+      type: "object" as const,
+      properties: {
+        from: {
+          type: "string",
+          enum: ["pm", "dev-a", "dev-b"],
+          description: "Your role name",
+        },
+        to: {
+          type: "string",
+          enum: ["pm", "dev-a", "dev-b"],
+          description: "Recipient role name",
+        },
+        kind: {
+          type: "string",
+          enum: ["status", "question", "directive", "free"],
+          description: "Message type matching the coordination protocol",
+        },
+        body: {
+          type: "string",
+          description: "Message body — freeform markdown, typically the full formatted block",
+        },
+      },
+      required: ["from", "to", "kind", "body"],
+    },
+  },
+  {
+    name: "read_messages",
+    description:
+      "Pop and return all pending messages for this recipient. Inbox is empty after this call (consume-once).",
+    inputSchema: {
+      type: "object" as const,
+      properties: {
+        for: {
+          type: "string",
+          enum: ["pm", "dev-a", "dev-b"],
+          description: "Your role name",
+        },
+      },
+      required: ["for"],
+    },
+  },
+  {
+    name: "list_pending",
+    description:
+      "Return count and kinds of pending messages without consuming them.",
+    inputSchema: {
+      type: "object" as const,
+      properties: {
+        for: {
+          type: "string",
+          enum: ["pm", "dev-a", "dev-b"],
+          description: "Your role name",
+        },
+      },
+      required: ["for"],
+    },
+  },
+];
+
+mcpServer.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: TOOLS }));
+
+mcpServer.setRequestHandler(CallToolRequestSchema, async (request) => {
+  const { name, arguments: args } = request.params;
+  const a = args as Record<string, string>;
+
+  if (name === "post_message") {
+    if (!isRole(a.from)) {
+      return { content: [{ type: "text" as const, text: `Error: unknown role "${a.from}"` }], isError: true };
+    }
+    if (!isRole(a.to)) {
+      return { content: [{ type: "text" as const, text: `Error: unknown role "${a.to}"` }], isError: true };
+    }
+    const kind = a.kind as "status" | "question" | "directive" | "free";
+    const msg = queue.post(a.from, a.to, kind, a.body);
+    const ts = new Date(msg.ts).toTimeString().slice(0, 8);
+    const preview = a.body.slice(0, 60).replace(/\n/g, " ");
+    const ellipsis = a.body.length > 60 ? "..." : "";
+    process.stdout.write(`[${ts}] ${a.from} → ${a.to}  [${kind}]  "${preview}${ellipsis}"\n`);
+    return { content: [{ type: "text" as const, text: JSON.stringify({ id: msg.id }) }] };
+  }
+
+  if (name === "read_messages") {
+    if (!isRole(a.for)) {
+      return { content: [{ type: "text" as const, text: `Error: unknown role "${a.for}"` }], isError: true };
+    }
+    const messages = queue.read(a.for);
+    return { content: [{ type: "text" as const, text: JSON.stringify(messages) }] };
+  }
+
+  if (name === "list_pending") {
+    if (!isRole(a.for)) {
+      return { content: [{ type: "text" as const, text: `Error: unknown role "${a.for}"` }], isError: true };
+    }
+    const result = queue.pending(a.for);
+    return { content: [{ type: "text" as const, text: JSON.stringify(result) }] };
+  }
+
+  return {
+    content: [{ type: "text" as const, text: `Error: unknown tool "${name}"` }],
+    isError: true,
+  };
+});
+
+const transports = new Map<string, SSEServerTransport>();
+
+const httpServer = http.createServer(async (req, res) => {
+  try {
+    if (req.method === "GET" && req.url === "/sse") {
+      const transport = new SSEServerTransport("/message", res);
+      transports.set(transport.sessionId, transport);
+      transport.onclose = () => transports.delete(transport.sessionId);
+      await mcpServer.connect(transport);
+    } else if (req.method === "POST" && req.url?.startsWith("/message")) {
+      const url = new URL(req.url, `http://127.0.0.1:${PORT}`);
+      const sessionId = url.searchParams.get("sessionId") ?? "";
+      const transport = transports.get(sessionId);
+      if (transport) {
+        await transport.handlePostMessage(req, res);
+      } else {
+        res.writeHead(404, { "Content-Type": "application/json" });
+        res.end(JSON.stringify({ error: "session not found" }));
+      }
+    } else {
+      res.writeHead(404).end("not found");
+    }
+  } catch (err) {
+    console.error("[relay] error:", err);
+    if (!res.headersSent) res.writeHead(500).end(String(err));
+  }
+});
+
+httpServer.listen(PORT, "127.0.0.1", () => {
+  console.log(`[relay] server ready on :${PORT}`);
+  console.log(`[relay] tools: post_message, read_messages, list_pending`);
+  console.log(`[relay] waiting for connections — Ctrl-C to stop`);
+});