# NousResearch/hermes-agent · Structured output format compatibility across AI providers

## Open now

- Nothing open on GitHub.

These items address failures in session title generation and structured output handling when providers like vLLM or Anthropic reject certain response_format types (e.g., json_schema), including retry logic with fallback formats.

## TL;DR

- 4 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 2 merged PR(s), 1 PR(s) closed without merging.
- A fix was merged to main in PR #113966. Verify it addresses your case.
- **Recommended:** read PR #113966 (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: `resolved` · deciding PR(s): `pr-89589`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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 `0.50`: 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

- #82816: Session auto-title generation fails 100% of the time (HTTP 400) on OpenAI-compatible providers that reject response_format json_schema (vLLM guided_grammar / xgrammar)

## Prior & competing PRs

- **#89589: fix(aux): translate response_format for Anthropic wires and retry when providers reject structured output**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `agent/auxiliary_client.py`, `tests/agent/test_anthropic_structured_output.py`, `tests/agent/test_structured_output_rejection_retry.py`
- **#113966: fix(aux): structured-output 400s no longer kill fallback candidates or cost a doomed first request on DeepSeek (#83390, #105191, salvage #92908)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `agent/auxiliary_client.py`, `agent/auxiliary_structured_output.py`, `plugins/model-providers/deepseek/__init__.py`, `providers/base.py`, `tests/agent/conftest.py`, `tests/agent/test_auxiliary_structured_output.py`, `website/docs/developer-guide/model-provider-plugin.md`
- **#82868: fix(agent): retry title generation with json_object on HTTP 400**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `5cc81773b2b`, `#89589`, `#113966`, `#83390`

## Fix status

- Merged to main in PR #113966 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-09-17`.
- Subsystem: `agent`