GPT-5 custom endpoints ignoring explicit api_mode setting

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

• #10548 fix: respect explicit api_mode for custom GPT-5 endpoints

  merged to main

  files: gateway/run.py, run_agent.py, tests/gateway/test_background_process_notifications.py

  Show the diff

  • gateway/run.py

    @@ -486,9 +486,14 @@ def _parse_session_key(session_key: str) -> "dict | None":
         """Parse a session key into its component parts.
     
         Session keys follow the format
    -    ``agent:main:{platform}:{chat_type}:{chat_id}[:{thread_id}[:{user_id}]]``.
    +    ``agent:main:{platform}:{chat_type}:{chat_id}[:{extra}...]``.
         Returns a dict with ``platform``, ``chat_type``, ``chat_id``, and
         optionally ``thread_id`` keys, or None if the key doesn't match.
    +
    +    The 6th element is only returned as ``thread_id`` for chat types where
    +    it is unambiguous (``dm`` and ``thread``).  For group/channel sessions
    +    the suffix may be a user_id (per-user isolation) rather than a
    +    thread_id, so we leave ``thread_id`` out to avoid mis-routing.
         """
         parts = session_key.split(":")
         if len(parts) >= 5 and parts[0] == "agent" and parts[1] == "main":
    @@ -497,7 +502,7 @@ def _parse_session_key(session_key: str) -> "dict | None":
                 "chat_type": parts[3],
                 "chat_id": parts[4],
             }
    -        if len(parts) > 5:
    +        if len(parts) > 5 and parts[3] in ("dm", "thread"):
                 result["thread_id"] = parts[5]
             return result
         return None

  • run_agent.py

    @@ -721,8 +721,11 @@ def __init__(
             # Responses there. ACP runtimes are excluded: CopilotACPClient
             # handles its own routing and does not implement the Responses API
             # surface.
    +        # When api_mode was explicitly provided, respect it — the user
    +        # knows what their endpoint supports (#10473).
             if (
    -            self.api_mode == "chat_completions"
    +            api_mode is None
    +            and self.api_mode == "chat_completions"
                 and self.provider != "copilot-acp"
                 and not str(self.base_url or "").lower().startswith("acp://copilot")
                 and not str(self.base_url or "").lower().startswith("acp+tcp://")

  • tests/gateway/test_background_process_notifications.py

    @@ -383,15 +383,27 @@ def test_parse_session_key_valid():
     
     
     def test_parse_session_key_with_extra_parts():
    -    """Thread ID (6th part) is extracted; further parts are ignored."""
    +    """6th part in a group key may be a user_id, not a thread_id — omit it."""
         result = _parse_session_key("agent:main:discord:group:chan123:thread456")
    -    assert result == {"platform": "discord", "chat_type": "group", "chat_id": "chan123", "thread_id": "thread456"}
    +    assert result == {"platform": "discord", "chat_type": "group", "chat_id": "chan123"}
     
     
     def test_parse_session_key_with_user_id_part():
    -    """7th part (user_id) is ignored — only up to thread_id is extracted."""
    -    result = _parse_session_key("agent:main:telegram:group:chat1:thread42:user99")
    -    assert result == {"platform": "telegram", "chat_type": "group", "chat_id": "chat1", "thread_id": "thread42"}
    +    """Group keys with per-user isolation have user_id as 6th part — don't return as thread_id."""
    +    result = _parse_session_key("agent:main:telegram:group:chat1:user99")
    +    assert result == {"platform": "telegram", "chat_type": "group", "chat_id": "chat1"}
    +
    +
    +def test_parse_session_key_dm_with_thread():
    +    """DM keys use parts[5] as thread_id unambiguously."""
    +    result = _parse_session_key("agent:main:telegram:dm:chat1:topic42")
    +    assert result == {"platform": "telegram", "chat_type": "dm", "chat_id": "chat1", "thread_id": "topic42"}
    +
    +
    +def test_parse_session_key_thread_chat_type():
    +    """Thread-typed keys use parts[5] as thread_id unambiguously."""
    +    result = _parse_session_key("agent:main:discord:thread:chan1:thread99")
    +    assert result == {"platform": "discord", "chat_type": "thread", "chat_id": "chan1", "thread_id": "thread99"}
     
     
     def test_parse_session_key_too_short():

• #115738 fix(fallback): entries naming a providers block keep its declared transport on activation (#33062, #81932)

  merged to main

  files: agent/chat_completion_helpers.py, tests/agent/test_fallback_api_mode_preservation.py, website/docs/integrations/providers.md