# NousResearch/hermes-agent · GPT-5 custom endpoints ignoring explicit api_mode setting

## Open now

- Nothing open on GitHub.

Reports and fixes around custom GPT-5 provider endpoints not respecting an explicitly configured api_mode, defaulting to codex_responses instead of chat_completions. Includes proposed fixes and a salvage attempt for a related prior change.

## TL;DR

- 5 member(s): 0 open issue(s), 3 closed issue(s), 0 open PR(s), 2 merged PR(s), 0 PR(s) closed without merging.
- A fix was merged to main in PR #10548. Verify it addresses your case.
- **Recommended:** read PR #10548 (and any competing PRs below) before filing. Confirm the merged change covers your symptom.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `partially_resolved` · deciding PR(s): `pr-10548,pr-115738`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_PARTIAL`): some members are connected by structural evidence (shared changed files, or a closing/superseded reference); the rest are joined by an automated relevance judgement over their text.
- Members outside that structural core may belong to a different underlying problem.
- Pairwise link density `0.31`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #5718: openai-codex provider should allow configurable api_mode (chat_completions vs codex_responses)
- #10473: \[Bug\]: custom GPT-5 endpoint is forced to codex_responses, ignoring explicit chat_completions
- #33062: \[Bug\]: Custom GPT-5 providers can ignore explicit api_mode

## Prior & competing PRs

- **#10548: fix: respect explicit api_mode for custom GPT-5 endpoints**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`; implication `superseded`
  - files: `gateway/run.py`, `run_agent.py`, `tests/gateway/test_background_process_notifications.py`
  - fix hunks:
  - `gateway/run.py`

    ```diff
    @@ -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":
    ```

    ```diff
    @@ -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`

    ```diff
    @@ -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`

    ```diff
    @@ -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 · fix tier `verified`
  - maintainer direction: category `merged`; implication `superseded`
  - files: `agent/chat_completion_helpers.py`, `tests/agent/test_fallback_api_mode_preservation.py`, `website/docs/integrations/providers.md`

## Fix status

- Merged to main in PR #10548 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-09-19`.
- Subsystem: `agent`