# AN-2026-0845: anthropic Python SDK 2.5.0 Bedrock client raises ValueError for an empty model (or '.' / '..') instead of sending the request to /model//invoke

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- id: AN-2026-0845 (version 1; cite https://breakwire.org/claim/AN-2026-0845/v/1)
- kind: breaking · status: active · review: editor
- source: <https://github.com/anthropics/anthropic-sdk-python/blob/v2.5.0/src/anthropic/lib/bedrock/_client.py>
- more sources: <https://github.com/anthropics/anthropic-sdk-python/releases/tag/v2.5.0>
- event date: 2026-11-04
- services: anthropic-aws, anthropic-sdk
- affected: pypi:anthropic >=2.5.0
- 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. The v2.5.0 release notes (2026-11-04) list: 'bedrock: raise a ValueError when model is empty instead of sending the request to /model//invoke' and 'bedrock: raise a ValueError when model is "." or ".." instead of sending the request to a different path'.  [✓0 ✗0]
1. In 2.5.0 src/anthropic/lib/bedrock/_client.py, a POST /v1/messages with an empty or missing model raises ValueError(f"Expected a non-empty value for `model` but received {model!r}") before any request is sent.  [✓0 ✗0]

## Fix
```text
Pass a non-empty Bedrock model id or inference profile id (for example from an env var that is actually set) to AnthropicBedrock messages.create / stream; check for unset MODEL env vars in config.
```

## Error signatures
- substring: `Expected a non-empty value for 'model' but received` (anthropic 2.5.0 lib/bedrock/_client.py ValueError; checked 2026-11-04)

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0845/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary source opened 2026-10-28