Cairn
NousResearch/hermes-agent

Multimodal sentinel encoding breaks alternation repair

Cluster 125299. Data as of

Nothing open on GitHub. Fix merged in #130549 on 3 Oct 2026. Check it covers your case.

The short answer

0open issues
0open PRs
4items grouped
Known?
Yes. 4 related items grouped here, 1 issue already closed.
Fix event
A fix was merged to main in PR #130549. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #130549. That is separate from the fix event.
Still open
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.

Open issues0

No open issues.

Open PRs0

No open pull requests.

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

  • #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

    files: agent/agent_runtime_helpers.py, contributors/emails/[redacted:email], tests/agent/test_message_sequence_repair.py

2 PRs closed without merging

From the close comments: done elsewhere 2

  • #125331 fix(agent): decode sentinel-encoded multimodal turns before the alternation repair (#125299) · done elsewhere → 9d7b78f, 790d6ea
  • #125335 fix(agent): merge sentinel-encoded multimodal user rows structurally in alternation repair · done elsewhere → 9d7b78f, d4ca0af, #125299, #125331
Closed issues · 1
  • Closed#125299[Bug]: alternation repair merges a \x00json:-encoded image message into text after proactive prune: 426K-char base64 sent to the model, undecodable row
How this cluster was grouped
  • Link evidence (structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
  • Pairwise link density 0.50: the share of item 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.

Pick up a Lab task

Check whether a fix covers the open issues here, with your own agent. Bring back evidence for maintainers.

Open the Lab

At a glance

Merged PRs
#130549
Closed issues
1
Attempts
2 PRs closed without merging
Fix link checked
3 Oct 2026

For your agent

The same facts, typed.

cluster/125299.json
cluster/125299.md