From 6b88f46c54ac6e43a8a1ba40b7f5175cc7be5f7f Mon Sep 17 00:00:00 2001
From: pander <>
Date: Mon, 27 Apr 2026 00:03:25 +0800
Subject: [PATCH] fix(compressor): trigger fallback on timeout errors alongside
 model-not-found

Previously only HTTP 404/503 and specific error strings triggered a fallback
to the main model when the summary model was unavailable. Timeout errors
(HTTP 408/429/502/504, or error strings containing 'timeout') entered a
short cooldown instead, leaving context to grow unbounded for the rest of
the session.

Add _is_timeout detection alongside _is_model_not_found so that transient
timeout errors on the summary model also trigger immediate fallback to the
main model, preventing compression failure from cascading.

Closes #15935
---
 agent/context_compressor.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/agent/context_compressor.py b/agent/context_compressor.py
index 6c177b9099..44d54d530c 100644
--- a/agent/context_compressor.py
+++ b/agent/context_compressor.py
@@ -906,15 +906,19 @@ The user has requested that this compaction PRIORITISE preserving all informatio
                 or "does not exist" in _err_str
                 or "no available channel" in _err_str
             )
+            _is_timeout = (
+                _status in (408, 429, 502, 504)
+                or "timeout" in _err_str
+            )
             if (
-                _is_model_not_found
+                (_is_model_not_found or _is_timeout)
                 and self.summary_model
                 and self.summary_model != self.model
                 and not getattr(self, "_summary_model_fallen_back", False)
             ):
                 self._summary_model_fallen_back = True
                 logging.warning(
-                    "Summary model '%s' not available (%s). "
+                    "Summary model '%s' unavailable (%s). "
                     "Falling back to main model '%s' for compression.",
                     self.summary_model, e, self.model,
                 )