Add background jobs with Chat UI so long agent scripts can run for hours safely.

start_job/get_job/sleep replace blocked run_command for multi-hour work; Chat shows a live count badge and allows manual kill, with a reaper reclaiming timed-out or stale processes.

Co-authored-by: Cursor <cursoragent@cursor.com>

runtime/tools/public/sleep_tool.py

@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+import time
+from typing import Any
+
+from runtime.tools.base import ToolSpec
+
+_MAX_SLEEP_S = 120
+
+
+def sleep_tool() -> ToolSpec:
+    def _handler(args: dict[str, Any]) -> dict[str, Any]:
+        try:
+            seconds = float(args.get("seconds") or 0)
+        except Exception:
+            return {"ok": False, "error": "invalid_seconds"}
+        if seconds <= 0:
+            return {"ok": False, "error": "seconds_must_be_positive"}
+        if seconds > _MAX_SLEEP_S:
+            return {
+                "ok": False,
+                "error": "seconds_too_large",
+                "max_seconds": _MAX_SLEEP_S,
+                "hint": (
+                    "For multi-hour work use start_job + get_job, or schedule_create. "
+                    f"sleep is only for short poll gaps (max {_MAX_SLEEP_S}s)."
+                ),
+            }
+        started = time.time()
+        time.sleep(seconds)
+        return {
+            "ok": True,
+            "slept_seconds": round(time.time() - started, 3),
+            "requested_seconds": seconds,
+        }
+
+    return ToolSpec(
+        name="sleep",
+        description=(
+            f"Block the current turn for N seconds (max {_MAX_SLEEP_S}). "
+            "Use between get_job polls or after a change that needs a short settle time. "
+            "Do NOT use for multi-hour waits — use start_job or schedule_create instead."
+        ),
+        parameters={
+            "type": "object",
+            "properties": {
+                "seconds": {
+                    "type": "number",
+                    "description": f"Seconds to wait (1–{_MAX_SLEEP_S}).",
+                },
+            },
+            "required": ["seconds"],
+            "additionalProperties": False,
+        },
+        handler=_handler,
+        tags=frozenset({"public", "utility"}),
+        risk_level="low",
+        read_only=True,
+        timeout_s=float(_MAX_SLEEP_S + 5),
+    )
+
+
+__all__ = ["sleep_tool"]