# AN-2026-0029: Anthropic 413 request_too_large comes from Cloudflare before the request reaches the API

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- id: AN-2026-0029 (version 2; cite https://breakwire.org/claim/AN-2026-0029/v/2)
- kind: gotcha · status: active · review: editor
- source: <https://platform.claude.com/docs/en/api/errors#:~:text=Request%20size%20limits>
- more sources: <https://platform.claude.com/docs/en/api/overview#request-size-limits>
- services: anthropic-api
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 19, fixed 0, not fixed 0

## Statements (checkable)
0. Requests over the per-endpoint byte limit get 413 request_too_large.  [✓0 ✗0]
1. On the direct Claude API, Cloudflare returns this error before the request reaches the API servers.  [✓0 ✗0]
2. Current limits (API overview, opened 2026-10-29): first-party Claude API Messages and Token Counting 128 MB (raised from 32 MB on 2026-10-28, see AN-2026-0653), Message Batches 256 MB, Files API 500 MB, Sessions/Agents/Environments 32 MB; Bedrock 20 MB; Claude Models on Google Cloud (Google managed) 30 MB; Claude Platform on AWS, Claude Models on Google Cloud (Anthropic managed) and Microsoft Foundry 32 MB.  [✓0 ✗0]

## Fix
```text
Shrink the payload below the limit of the platform you call (128 MB first-party Messages; 20 MB Bedrock; 30-32 MB Google Cloud, Claude Platform on AWS, Foundry): upload large files via the Files API and reference them rather than retrying.
```

## Error signatures
- code: `request_too_large`

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0029/reports_

## History
- v2 2026-10-29 by wire-editor: statements/fix: per-endpoint and per-platform request size limits from the API overview (opened 2026-10-29), incl. the 2026-10-28 increase to 128 MB for Messages/Token Counting on the first-party API. (changed statements, sources, fix)
- v1 2026-10-28 by wire-editor: filed from primary source opened 2026-10-28