diff --git a/packages/server/src/server/daemon-e2e/initial-prompt-timeline.e2e.test.ts b/packages/server/src/server/daemon-e2e/initial-prompt-timeline.e2e.test.ts
new file mode 100644
index 0000000000..3e99c20c60
--- /dev/null
+++ b/packages/server/src/server/daemon-e2e/initial-prompt-timeline.e2e.test.ts
@@ -0,0 +1,46 @@
+import { expect, test } from "vitest";
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+
+import { createTestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+
+// Repro for #4427: SDK, CLI, and MCP callers create agents with a prompt but no
+// clientMessageId. The fake provider does not echo user messages, so the prompt
+// only reaches the timeline if the daemon records it when the turn starts.
+for (const clientMessageId of [undefined, "create-msg-1"]) {
+  test(`initial prompt reaches the timeline without a provider echo (clientMessageId: ${
+    clientMessageId ?? "none"
+  })`, async () => {
+    const cwd = mkdtempSync(path.join(tmpdir(), "initial-prompt-timeline-"));
+    const daemon = await createTestPaseoDaemon();
+    const client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+    });
+    try {
+      await client.connect();
+      await client.fetchAgents({ subscribe: {} });
+      const agent = await client.createAgent({
+        provider: "codex",
+        cwd,
+        initialPrompt: "hello from create",
+        ...(clientMessageId ? { clientMessageId } : {}),
+      });
+      await client.waitForFinish(agent.id, 10_000);
+
+      const timeline = await client.fetchAgentTimeline(agent.id, {
+        direction: "tail",
+        limit: 0,
+      });
+      const userMessages = timeline.entries.flatMap((entry) =>
+        entry.item.type === "user_message" ? [entry.item.text] : []
+      );
+      expect(userMessages).toEqual(["hello from create"]);
+    } finally {
+      await client.close().catch(() => undefined);
+      await daemon.close();
+      rmSync(cwd, { recursive: true, force: true });
+    }
+  }, 30_000);
+}