[eric] agents: the unwedge envelope carries each child's status and age, so a lost result can be told from a dead child

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012G8kyALnPjsA7aJFmMBq3R

backend/apps/agents/manager/streaming/delegation_watchdog.py

@@ -14,7 +14,7 @@ from typing import Set
 from typeguard import typechecked
 
 from backend.apps.agents.manager.streaming.unwedge_sidecar import (
-    HEARTBEAT_FRESH_S, CORE_PREFIX, RETRY_PROMPT, arm_retry, heartbeat_age, unwedge,
+    HEARTBEAT_FRESH_S, CORE_PREFIX, RETRY_PROMPT, arm_retry, delegation_children_born_after, heartbeat_age, unwedge,
 )
 
 logger = logging.getLogger(__name__)
@@ -49,17 +49,7 @@ def delegation_children_settled(session_id: str, since: float) -> bool:
     p_parent = agent_manager.sessions.get(session_id)
     if p_parent is not None and getattr(p_parent, "ended_by_user", False):
         return False
-    kids = []
-    for s in agent_manager.sessions.values():
-        if getattr(s, "parent_session_id", None) != session_id or getattr(s, "mode", "") != "browser-agent":
-            continue
-        born = getattr(s, "created_at", None)
-        try:
-            if born is None or born.timestamp() < since:
-                continue
-        except Exception:
-            continue
-        kids.append(s)
+    kids = delegation_children_born_after(session_id, since)
     if not kids:
         return False
     return all(getattr(s, "status", "") in ("completed", "error", "failed", "stopped") for s in kids)

backend/apps/agents/manager/streaming/unwedge_sidecar.py

@@ -14,7 +14,7 @@ import os
 import subprocess
 import threading
 import time
-from typing import Set
+from typing import Dict, List, Set
 
 from typeguard import typechecked
 
@@ -146,6 +146,42 @@ def arm_retry(session: object) -> bool:
         return False
 
 
+@typechecked
+def delegation_children_born_after(session_id: str, since: float) -> List[object]:
+    """The browser/app children this session spawned after `since`. One definition, shared by the
+    watchdog's settled test and the unwedge envelope, so the two can never count different children."""
+    from backend.apps.agents.agent_manager import agent_manager
+    kids: List[object] = []
+    for s in agent_manager.sessions.values():
+        if getattr(s, "parent_session_id", None) != session_id or getattr(s, "mode", "") != "browser-agent":
+            continue
+        born = getattr(s, "created_at", None)
+        try:
+            if born is None or born.timestamp() < since:
+                continue
+        except Exception:
+            continue
+        kids.append(s)
+    return kids
+
+
+@typechecked
+def children_summary(session_id: str, since: float) -> List[Dict[str, object]]:
+    """What the children looked like at the moment of a kill: status plus how long ago each was born.
+    Haik's 154 CreateBrowserAgent kills could not be split into "child finished, result lost" versus
+    "child died first" because the envelope carried only tool, seconds and pids (read 2026-09-01)."""
+    now = time.time()
+    out: List[Dict[str, object]] = []
+    for s in delegation_children_born_after(session_id, since):
+        born = getattr(s, "created_at", None)
+        try:
+            age = round(now - born.timestamp(), 1) if born is not None else None
+        except Exception:
+            age = None
+        out.append({"status": str(getattr(s, "status", "") or ""), "age_s": age, "tools": len(getattr(s, "tool_latencies", {}) or {})})
+    return out
+
+
 @typechecked
 def unwedge(session_id: str, tool_name: str, outstanding_s: float) -> int:
     """CONT first: a STOPPED process queues TERM forever (the ghost-reaper lesson, ENG-196), so
@@ -169,6 +205,7 @@ def unwedge(session_id: str, tool_name: str, outstanding_s: float) -> int:
                 "tool": tool_name,
                 "outstanding_s": round(outstanding_s, 1),
                 "pids": pids,
+                "children": children_summary(session_id, time.time() - outstanding_s),
             })
         except Exception:
             pass

backend/tests/test_unwedge_envelope_children.py

@@ -0,0 +1,48 @@
+"""The unwedge envelope must say what the children looked like at the kill.
+
+Haik's install: 154 CreateBrowserAgent kills in 14 days at a 150 s floor, and the envelope carried
+only tool, seconds and pids, so nobody could tell "child finished, result lost" (recovery by design)
+from "child died first" (a different bug). One shared helper feeds the watchdog's settled test AND the
+envelope, so the two can never disagree about which children count."""
+import datetime
+from backend.apps.agents.agent_manager import agent_manager
+from backend.apps.agents.core.models import AgentSession
+from backend.apps.agents.manager.streaming import unwedge_sidecar as us
+from backend.apps.agents.manager.streaming.delegation_watchdog import delegation_children_settled
+from backend.apps.service import client as svc
+
+
+def p_child(parent_id: str, status: str, born_ago_s: float) -> AgentSession:
+    s = AgentSession(name="Browser Agent", model="sonnet", mode="browser-agent", status=status)
+    s.parent_session_id = parent_id
+    s.created_at = datetime.datetime.now() - datetime.timedelta(seconds=born_ago_s)
+    return s
+
+
+def test_the_envelope_carries_each_child_status_and_age(monkeypatch) -> None:
+    parent = AgentSession(name="p", model="sonnet")
+    agent_manager.sessions.clear(); agent_manager.sessions[parent.id] = parent
+    for kid in (p_child(parent.id, "completed", 30), p_child(parent.id, "error", 10), p_child(parent.id, "running", 5), p_child(parent.id, "completed", 900)):
+        agent_manager.sessions[kid.id] = kid
+    sent: list = []
+    monkeypatch.setattr(svc, "submit_diagnostic", lambda d: sent.append(d))
+    monkeypatch.setattr(us, "find_sidecar_pids", lambda sid: [424242])
+    monkeypatch.setattr(us.subprocess, "run", lambda *a, **k: None)
+    monkeypatch.setattr(us.time, "sleep", lambda s: None)
+    us.unwedge(parent.id, "mcp__openswarm-core__CreateBrowserAgent", 150.0)
+    env = [d for d in sent if isinstance(d, dict) and d.get("kind") == "mcp_sidecar_unwedged"]
+    assert len(env) == 1
+    kids = env[0]["children"]
+    assert sorted(k["status"] for k in kids) == ["completed", "error", "running"], "only children born after the call started; the 900 s one is an earlier delegation's"
+    assert all(isinstance(k["age_s"], float) for k in kids)
+
+
+def test_the_watchdog_and_the_envelope_count_the_same_children() -> None:
+    parent = AgentSession(name="p", model="sonnet")
+    agent_manager.sessions.clear(); agent_manager.sessions[parent.id] = parent
+    agent_manager.sessions.update({k.id: k for k in (p_child(parent.id, "completed", 20), p_child(parent.id, "completed", 600))})
+    import time
+    since = time.time() - 100
+    assert len(us.delegation_children_born_after(parent.id, since)) == 1
+    assert delegation_children_settled(parent.id, since) is True
+    assert len(us.children_summary(parent.id, since)) == 1