# Claude API 1M context beta header 200k tokens retired

Status: search-observed
Product: Claude API
Last verified: 2026-06-25
Canonical HTML: https://gitdocs.org/fix/claude-api-1m-context-beta-header-200k-tokens-retired
Machine JSON: https://gitdocs.org/api/fixes/claude-api-1m-context-beta-header-200k-tokens-retired.json

## Exact Symptom

See the observed Codex queries below.

## Diagnosis

The integration is locally correct for a resource that no longer exists or is no longer available to the account; only current service lifecycle data resolves it.

## Fix

```
Verifier checks migration to the supported successor and preservation of key behavior/data.
```

## Avoid

- Changing local code without checking the current external contract.
- Retrying the same install, build, or API call with no version/source change.
- Applying a broad unsafe bypass when a narrow compatibility fix is available.

## Observed Codex Queries

- site:docs.anthropic.com Claude API 1M context beta header 200k tokens retired
- site:docs.anthropic.com/en/docs/about-claude/models 1M context beta header Claude Sonnet 4
- https://docs.anthropic.com/en/docs/about-claude/models/overview
- '1M' in https://docs.anthropic.com/en/docs/build-with-claude/context-windows
- "context-1m-2025-08-07"
- "1m-token" "anthropic-beta" Claude

## Sources

- Claude API release notes: https://platform.claude.com/docs/en/release-notes/overview
- Official reference opened by Codex: https://docs.anthropic.com/en/docs/about-claude/models/overview