diff --git a/packages/core/src/mcp/http.ts b/packages/core/src/mcp/http.ts
index 5673cd2..a81bf6d 100644
--- a/packages/core/src/mcp/http.ts
+++ b/packages/core/src/mcp/http.ts
@@ -3,7 +3,9 @@
  * Authenticated with per-run bearer tokens (mcp/tokens.ts) or, on `/mcp` only, the key of a connected app
  * (connect/connectors.ts) — never with the user's access token.
  * `tools/call` answers over SSE when the client accepts it, with keepalives, so long calls
- * (agent_delegate waiting for a peer) survive idle timeouts; everything else answers with JSON.
+ * (agent_delegate waiting for a peer) survive idle timeouts: progress notifications when the call carries a
+ * progressToken (Claude Code aborts a tool that sends neither a response nor progress for 5 minutes), comments
+ * otherwise. Everything else answers with JSON.
  */
 import type { Context, Hono } from "hono";
 import { VERSION } from "../config";
@@ -23,7 +25,7 @@ import { SSH_INSTRUCTIONS, UnknownSshToolError, callSshTool, listSshTools } from
 const log = logger("mcp");
 
 const DEFAULT_PROTOCOL_VERSION = "2025-06-18";
-const KEEPALIVE_MS = 15_000;
+let keepaliveMs = 15_000;
 const SLOW_TOOL_MS = 10_000;
 
 function toolResultText(result: Record<string, unknown>): string {
@@ -189,9 +191,21 @@ export function disableIdleTimeout(c: Context) {
   }
 }
 
-/** Answer one tools/call over SSE: headers go out immediately, keepalive comments until the result is ready. */
+export function __setKeepaliveForTests(ms: number | null) {
+  keepaliveMs = ms ?? 15_000;
+}
+
+function progressTokenOf(msg: unknown): string | number | null {
+  const meta = isObj(msg) && isObj(msg.params) && isObj(msg.params._meta) ? msg.params._meta : null;
+  const token = meta?.progressToken;
+  return typeof token === "string" || typeof token === "number" ? token : null;
+}
+
+/** Answer one tools/call over SSE: headers go out immediately, keepalives until the result is ready. */
 function sseCall(ctx: RunContext, msg: unknown, server: McpServerDef): Response {
   const encoder = new TextEncoder();
+  const progressToken = progressTokenOf(msg);
+  const started = Date.now();
   let keepalive: ReturnType<typeof setInterval> | null = null;
   let closed = false;
   const stream = new ReadableStream<Uint8Array>({
@@ -205,7 +219,13 @@ function sseCall(ctx: RunContext, msg: unknown, server: McpServerDef): Response
         }
       };
       send(": godmode\n\n");
-      keepalive = setInterval(() => send(": keepalive\n\n"), KEEPALIVE_MS);
+      let beats = 0;
+      keepalive = setInterval(() => {
+        if (progressToken === null) return send(": keepalive\n\n");
+        const seconds = Math.round((Date.now() - started) / 1000);
+        const params = { progressToken, progress: ++beats, message: `Still working (${seconds}s)` };
+        send(`event: message\ndata: ${JSON.stringify({ jsonrpc: "2.0", method: "notifications/progress", params })}\n\n`);
+      }, keepaliveMs);
       try {
         const response = await handleRpc(ctx, msg, server);
         if (response) send(`event: message\ndata: ${JSON.stringify(response)}\n\n`);
diff --git a/packages/core/test/mcp.test.ts b/packages/core/test/mcp.test.ts
index 4a9e3fe..159c7f2 100644
--- a/packages/core/test/mcp.test.ts
+++ b/packages/core/test/mcp.test.ts
@@ -16,6 +16,7 @@ import { createRoutine, listRoutines } from "../src/services/routines";
 import { updateSettings } from "../src/services/settings";
 import { createWorkspace } from "../src/services/workspaces";
 import { createMcpServer } from "../src/integrations/mcpServers";
+import { __setKeepaliveForTests } from "../src/mcp/http";
 
 const PASSPHRASE = "correct horse battery staple";
 const PASSWORD = "s3cret-Pass-9876";
@@ -394,6 +395,28 @@ describe("agents + delegation", () => {
     expect(child.prompt).toContain("Your final answer goes back to Delegator.]\n\nSay hello");
   });
 
+  test("a long agent_delegate sends progress for the caller's progressToken, so Claude Code's idle timeout doesn't fire", async () => {
+    __setKeepaliveForTests(50);
+    try {
+      const res = await post(tokens[delegator.id]!, {
+        jsonrpc: "2.0",
+        id: 11,
+        method: "tools/call",
+        params: { name: "agent_delegate", arguments: { agentId: worker.id, task: "SLOW_STREAM", timeoutSeconds: 60 }, _meta: { progressToken: 11 } },
+      });
+      const events = (await res.text()).split("\n").filter((l) => l.startsWith("data: ")).map((l) => JSON.parse(l.slice(6)));
+      const progress = events.filter((e) => e.method === "notifications/progress");
+      expect(progress.length).toBeGreaterThan(1);
+      expect(progress.every((e) => e.params.progressToken === 11)).toBe(true);
+      expect(progress.map((e) => e.params.progress)).toEqual(progress.map((_, i) => i + 1));
+      const last = events.at(-1);
+      expect(last.id).toBe(11);
+      expect(last.result.content[0].text).toContain("Worker finished the task");
+    } finally {
+      __setKeepaliveForTests(null);
+    }
+  });
+
   test("agent_delegate without waiting + delegation_status", async () => {
     const r = await call(tokens[delegator.id]!, "agent_delegate", { agentId: worker.id, task: "Background job", wait: false });
     const runId = /run (run_[A-Za-z0-9]+)/.exec(r.content[0]!.text)![1]!;