# NousResearch/hermes-agent · Anthropic blank text block validation bug fixes

## Open now

- 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.

## TL;DR

- 4 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 2 merged PR(s), 1 PR(s) closed without merging.
- A fix was merged to main in PR #86643. Verify it addresses your case.
- **Recommended:** read PR #86643 (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-86643`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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

- #70909: Session 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)

## Prior & competing PRs

- **#77509: fix(anthropic): drop whitespace-only text blocks reaching the Messages API**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - 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 · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `agent/anthropic_adapter.py`, `tests/agent/test_anthropic_request_blank_block_guard.py`
- **#70910: fix(anthropic): prepended leading user turn must be non-whitespace (#70909)**. closed without merge
  - maintainer direction: category `merged_via`; implication `superseded`; refs `#86643`, `#77509`

## Fix status

- Merged to main in PR #86643 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-08-15`.
- Subsystem: `agent`