# NousResearch/hermes-agent · Multimodal sentinel encoding breaks alternation repair

## Open now

- Nothing open on GitHub.

A bug where alternation repair mishandles sentinel-encoded multimodal turns, causing raw base64 image data to be incorrectly merged into text. Two related fixes address decoding and structural merging of these encoded turns before repair runs.

## TL;DR

- 4 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 2 PR(s) closed without merging.
- A fix was merged to main in PR #130549. Verify it addresses your case.
- **Recommended:** read PR #130549 (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-130549`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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

- #125299: \[Bug\]: alternation repair merges a \\x00json:-encoded image message into text after proactive prune: 426K-char base64 sent to the model, undecodable row

## Prior & competing PRs

- **#130549: fix(agent): image turns restored from history are no longer sent to the model as raw base64 text (#125299, salvage #125331)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `agent/agent_runtime_helpers.py`, `contributors/emails/[redacted:email]`, `tests/agent/test_message_sequence_repair.py`
- **#125331: fix(agent): decode sentinel-encoded multimodal turns before the alternation repair (#125299)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `9d7b78f0c6`, `790d6eaf39`
- **#125335: fix(agent): merge sentinel-encoded multimodal user rows structurally in alternation repair**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `9d7b78f0c6`, `d4ca0af996`, `#125299`, `#125331`

## Fix status

- Merged to main in PR #130549 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-10-03`.