# AN-2026-0653: Anthropic raised the Messages and Token Counting API max request size from 32 MB to 128 MB on the first-party Claude API (Oct 28, 2026); Bedrock, Google Cloud and Foundry keep 20-32 MB

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- id: AN-2026-0653 (version 1; cite https://breakwire.org/claim/AN-2026-0653/v/1)
- kind: limit · status: active · review: editor
- source: <https://platform.claude.com/docs/en/release-notes/overview#:~:text=from%2032%20MB%20to%20128%20MB>
- more sources: <https://platform.claude.com/docs/en/api/overview#request-size-limits>
- event date: 2026-10-28
- services: anthropic-api, anthropic-aws, anthropic-google-cloud
- affected: anthropic-api:/v1/messages; anthropic-api:/v1/messages/count_tokens
- severity: low
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. Claude Platform release notes, October 28, 2026 (opened 2026-10-29): Anthropic raised the maximum request size for the Messages API and the Token Counting API from 32 MB to 128 MB on the first-party Claude API.  [✓0 ✗0]
1. The API overview's request size limits table (opened 2026-10-29) lists for the first-party Claude API: Messages and Token Counting 128 MB, Message Batches API 256 MB, Files API 500 MB, Sessions, Agents and Environments 32 MB; exceeding a limit returns a 413 request_too_large error.  [✓0 ✗0]
2. The same page says partner-operated platforms have their own limits: Bedrock 20 MB, Claude Models on Google Cloud (Google managed) 30 MB, and Claude Platform on AWS, Claude Models on Google Cloud (Anthropic managed) and Microsoft Foundry 32 MB for Messages and Token Counting requests.  [✓0 ✗0]
3. A payload that now succeeds on the first-party API (32-128 MB) can still get 413 when the same code is pointed at Bedrock, Google Cloud or Foundry.  [✓0 ✗0]

## Fix
```text
Size checks and chunking thresholds can use 128 MB only for Messages/Token Counting on api.anthropic.com; keep 20 MB (Bedrock), 30 MB (Google-managed Google Cloud) or 32 MB (Claude Platform on AWS, Anthropic-managed Google Cloud, Foundry) on partner platforms, and upload large files via the Files API instead of inlining them.
```

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0653/reports_

## History
- v1 2026-10-29 by wire-editor: promoted from candidate #89 (anthropic-release-notes) after review