[eric] agents: a silent quit at high context compacts history and goes fresh before the nudge; re-sending the bloat just burned a nudge (ENG-354)

backend/apps/agents/manager/run/empty_finish.py

@@ -55,6 +55,13 @@ def maybe_nudge_empty_finish(session: AgentSession, session_id: str) -> bool:
     if session.empty_finish_nudges >= 1 and p_tool_calls <= session.empty_finish_progress_mark:
         return False
     session.empty_finish_progress_mark = p_tool_calls
+    # At high context the silent quit is usually the model choking on the prompt itself, so
+    # re-sending the same bloat just burns a nudge; compact FIRST and retry distilled (ENG-354).
+    from backend.apps.agents.manager.context_budget import compact_trigger_tokens, maybe_compact
+    p_input = int(session.tokens.get("input", 0) or 0)
+    if p_input >= int(0.8 * compact_trigger_tokens(session)) and maybe_compact(session, force=True):
+        session.needs_fresh_session = True
+        logger.warning(f"Agent {session_id}: empty finish at {p_input} input tokens; compacted history before the nudge")
     session.empty_finish_nudges += 1
     session.pending_continuation = True
     p_final = session.empty_finish_nudges >= NUDGE_HARD_CAP
@@ -72,6 +79,8 @@ def maybe_nudge_empty_finish(session: AgentSession, session_id: str) -> bool:
             "kind": "empty_finish_nudge",
             "session_id": session_id,
             "model": session.model,
+            "input_tokens": p_input,
+            "compacted": bool(session.needs_fresh_session),
             "tool_calls": p_tool_calls,
             "nudge": session.empty_finish_nudges,
             "flight": p_fr.build_envelope(

backend/tests/test_empty_finish.py

@@ -134,3 +134,32 @@ def test_stalled_continuation_is_not_renudged() -> None:
     s.pending_continuation = False
     assert maybe_nudge_empty_finish(s, "sid") is True
     assert s.empty_finish_nudges == 2
+
+
+def test_high_context_empty_finish_compacts_before_nudge():
+    """ENG-354: a silent quit at high context must compact + go fresh, not just re-send the bloat."""
+    from backend.apps.agents.manager.run.empty_finish import maybe_nudge_empty_finish
+    s = p_session(("user", "long task"),
+                  ("tool_call", {"tool": "Bash", "input": {"command": "ls"}}),
+                  ("tool_result", {"text": "ok"}),
+                  ("tool_call", {"tool": "Bash", "input": {"command": "pwd"}}),
+                  ("tool_result", {"text": "/tmp"}),
+                  ("tool_call", {"tool": "Bash", "input": {"command": "date"}}),
+                  ("tool_result", {"text": "now"}))
+    s.context_window = 200_000
+    s.tokens["input"] = 190_000
+    assert maybe_nudge_empty_finish(s, "sid-high") is True
+    assert s.compacted_through_msg_id is not None
+    assert s.needs_fresh_session is True
+
+
+def test_low_context_empty_finish_nudges_without_compacting():
+    from backend.apps.agents.manager.run.empty_finish import maybe_nudge_empty_finish
+    s = p_session(("user", "small task"),
+                  ("tool_call", {"tool": "Bash", "input": {"command": "ls"}}),
+                  ("tool_result", {"text": "ok"}))
+    s.context_window = 1_000_000
+    s.tokens["input"] = 30_000
+    assert maybe_nudge_empty_finish(s, "sid-low") is True
+    assert s.compacted_through_msg_id is None
+    assert getattr(s, "needs_fresh_session", False) is False