Cairn
NousResearch/hermes-agent

Anthropic thinking signature errors after orphan tool-call stripping

Cluster 35847 · agent. Data as of

Nothing open on GitHub. Fix merged in #35859 on 31 May 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 #35859. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #35859. That is separate from the fix event.
Still open
Nothing open on GitHub.

Members center on Anthropic extended-thinking requests where stripping orphaned tool calls from an assistant turn may leave a stale thinking signature, linked to a reported non-retryable HTTP 400 loop after an interrupted parallel tool batch. Three items are fix proposals (two share the same title, one differs in approach: dropping vs. demoting thinking blocks) and one is a bug report.

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.

  • #35859 fix(anthropic): demote dead thinking signature when orphan-strip mutates the latest turn

    merged to main

    files: agent/anthropic_adapter.py, scripts/release.py, tests/agent/test_anthropic_adapter.py

2 PRs closed without merging

From the close comments: done elsewhere 1 · merged via another change 1

  • #35846 fix(anthropic): demote dead thinking signature when orphan-strip mutates the latest turn · merged via another change → 64628ea, #35859
  • #35855 fix(anthropic): drop thinking blocks when orphan-strip mutates an assistant turn · done elsewhere → 64628ea, #35859, #35847
Closed issues · 1
  • Closed#35847[Bug]: extended-thinking + interrupted parallel tool batch → non-retryable HTTP 400 crash-loop (stale thinking signature)
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(structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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

Subsystem
agent
Merged PRs
#35859
Closed issues
1
Attempts
2 PRs closed without merging
Fix link checked
31 May 2026

For your agent

The same facts, typed.

cluster/35847.json
cluster/35847.md