# NousResearch/hermes-agent · Fix unparseable model_config overwriting session lineage

## Open now

- 1 issue, 1 PR open on GitHub.
- #126761: \[Bug\] \`_merge_model_config_json\` converts an unparseable \`model_config\` into a total overwrite, permanently destroying session lineage markers
- PR #126848: fix(state): refuse model_config merges over an unparseable row

A bug was identified where merging into an unparseable model_config JSON row would silently overwrite it entirely, destroying session lineage markers. These items address refusing or preserving the unparseable value to prevent that data loss.

## TL;DR

- 3 member(s): 1 open issue(s), 0 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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.

## Open related issues

- #126761: \[Bug\] \`_merge_model_config_json\` converts an unparseable \`model_config\` into a total overwrite, permanently destroying session lineage markers

## Prior & competing PRs

- **#126848: fix(state): refuse model_config merges over an unparseable row**. open
  - maintainer direction: category `uncategorized`; implication `needs_llm`; refs `3b987fd6a2`, `bf2aced873`
  - files: `hermes_state_messages.py`, `hermes_state_sessions.py`, `tests/hermes_state/test_model_config_merge_preserves_unparseable.py`
- **#130026: fix(state): preserve unparseable model_config to prevent lineage loss (#126761)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `0afa2b879d`

## Fix status

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