# NousResearch/hermes-agent · Gemini thinking_config malformed request causing 400 errors

## Open now

- 1 issue, 1 PR open on GitHub.
- #25123: fix: Fallback to gemini-3-flash-preview fails with 400 (thinking_config)
- PR #25124: fix: exclude gemini-3-flash-preview from thinking_config injection

Multiple issues and fixes related to incorrectly structured or inappropriately injected thinking_config in Gemini API requests, resulting in 400 Bad Request errors. Specific cases include double-nesting in extra_body, injection for unsupported models like Gemma and gemini-3-flash-preview, and OpenAI-compat path mismatches.

## TL;DR

- 4 member(s): 1 open issue(s), 1 closed issue(s), 1 open PR(s), 0 merged PR(s), 1 PR(s) closed without merging.
- No fix has been merged to main; one or more PRs were attempted (see below).
- **Recommended:** review the prior/competing PR(s) below. A fix was attempted but not merged; your case may extend or revive that work.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `unresolved`. 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evidence (`STRUCTURAL_PARTIAL`): some members are connected by structural evidence (shared changed files, or a closing/superseded reference); the rest are joined by an automated relevance judgement over their text.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 `0.39`: 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.

## Open related issues

- #25123: fix: Fallback to gemini-3-flash-preview fails with 400 (thinking_config)

## Closed / duplicate issues

- #26161: \[Bug\]: Gemini API Failed with 400 Bad Request

## Prior & competing PRs

- **#25124: fix: exclude gemini-3-flash-preview from thinking_config injection**. open
  - maintainer direction: category `wontfix_bydesign`; implication `wontfix`; refs `#25123`
  - files: `agent/transports/chat_completions.py`
- **#32353: fix(agent): exclude gemini-3-flash-preview from thinkingLevel injection (#25123)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`

## Fix status

- No merged fix on record.
- Subsystem: `agent`