hataa 80e031dcc6

fix(subagents): inherit LoopDetectionMiddleware to break tool loops (#3875) (#3931) ...

Subagents build their runtime chain via build_subagent_runtime_middlewares,
which attached none of the lead's runaway guards — no LoopDetectionMiddleware.
A degenerate subagent tool loop therefore ran unchecked until max_turns,
re-sending a growing context each turn (the #3875 4.4M-token burn).

Append LoopDetectionMiddleware.from_config(app_config.loop_detection) to the
subagent chain, gated by the existing loop_detection.enabled config (default
on) — no new config field. Registered before SafetyFinishReasonMiddleware to
match the lead's after-model ordering (the safety middleware requires placement
after LoopDetection). Subagents disallow task, so only the tool-loop heuristic
can fire here — no recursive-delegation false positives to worry about.

Phase 1 of #3875 (smallest blast radius). Phase 2 adds a deterministic
turn/token budget with a lead-visible stop reason; Phase 3 defers summarization.

Tests: enabled/disabled wiring + before-SafetyFinish ordering, mirroring the
lead chain's coverage.

Co-authored-by: Claude <noreply@anthropic.com>

2026-07-04 16:29:49 +08:00

..

harness

fix(subagents): inherit LoopDetectionMiddleware to break tool loops (#3875) (#3931)

2026-07-04 16:29:49 +08:00