# NousResearch/hermes-agent · Claude Opus 5.5 thinking-disabled 400 error fix

## Open now

- 0 issues, 2 PRs open on GitHub.
- PR #120075: fix(anthropic): keep claude-opus-5-5 on the mandatory-thinking omission list
- PR #121016: Thinking-off turns no longer 400 on Claude Opus 5.5 (fixes #120069, salvage #119419)

Claude Opus 5.5 rejects the thinking.type=disabled parameter, causing HTTP 400 errors on title generation and reasoning-off requests. These members address omitting that parameter for this model to prevent the failures.

## TL;DR

- 3 member(s): 0 open issue(s), 1 closed issue(s), 2 open PR(s), 0 merged PR(s), 0 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.67`: 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

- #120069: Anthropic adapter: claude-opus-5-5 rejects thinking.type=disabled, so title generation and /reasoning none fail with HTTP 400

## Prior & competing PRs

- **#120075: fix(anthropic): keep claude-opus-5-5 on the mandatory-thinking omission list**. open
  - maintainer direction: category `superseded_by_pr`; implication `superseded`; refs `#121016`, `#119419`
  - files: `agent/anthropic_adapter.py`, `tests/agent/test_anthropic_thinking_disable.py`
- **#121016: Thinking-off turns no longer 400 on Claude Opus 5.5 (fixes #120069, salvage #119419)**. open
  - maintainer direction: category `stale_abandoned`; implication `active`; refs `#119419`, `#120069`
  - files: `agent/anthropic_adapter.py`, `contributors/emails/acadine@users.noreply.github.com`, `tests/agent/test_anthropic_thinking_disable.py`

## Fix status

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