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NousResearch/hermes-agent

Anthropic blank text block validation bug fixes

Cluster 70909 · agent. Data as of

Nothing open on GitHub. Fix merged in #86643 on 15 Aug 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 #86643. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #86643. That is separate from the fix event.
Still open
Nothing open on GitHub.

These items address a bug where blank or whitespace-only text content blocks are synthesized during request assembly, causing HTTP 400 errors from the Anthropic API. Fixes target coercion of blank system blocks and enforcement that prepended user turns contain non-whitespace content.

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.

  • #77509 fix(anthropic): drop whitespace-only text blocks reaching the Messages API

    merged to main

    files: agent/anthropic_adapter.py, contributors/emails/[redacted:email], tests/agent/test_anthropic_adapter.py

  • #86643 fix(anthropic): coerce blank system text blocks at extraction (#70909)

    merged to main

    files: agent/anthropic_adapter.py, tests/agent/test_anthropic_request_blank_block_guard.py

1 PR closed without merging

From the close comments: merged via another change 1

  • #70910 fix(anthropic): prepended leading user turn must be non-whitespace (#70909) · merged via another change → #86643, #77509
Closed issues · 1
  • Closed#70909Session wedges on HTTP 400 'text content blocks must contain non-whitespace text' from a blank block synthesized during request assembly (compression/merge/pre-shaped content)
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(structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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.

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At a glance

Subsystem
agent
Merged PRs
#77509, #86643
Closed issues
1
Attempts
1 PR closed without merging
Fix link checked
15 Aug 2026

For your agent

The same facts, typed.

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