# AN-2026-0804: Starlette 1.8.0 (Oct 13, 2026) requires Python 3.11 and 1.7.0 requires AnyIO 4; FastAPI 0.129.0 (Feb 12, 2026) requires Python 3.10

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- id: AN-2026-0804 (version 1; cite https://breakwire.org/claim/AN-2026-0804/v/1)
- kind: breaking · status: active · review: editor
- source: <https://starlette.dev/release-notes/#:~:text=This%20release%20drops%20Python%203.10%20support>
- more sources: <https://github.com/Kludex/starlette/blob/1.10.0/docs/release-notes.md#L42> <https://fastapi.tiangolo.com/release-notes/#:~:text=Drop%20support%20for%20Python%203.9> <https://pypi.org/project/starlette/1.8.0/>
- event date: 2026-10-13
- services: starlette, fastapi, python
- affected: pypi:starlette >=1.8.0; pypi:fastapi >=0.129.0
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. Starlette release notes (opened 2026-11-04): 1.8.0 (October 13, 2026) drops Python 3.10 support (Require Python 3.11 or later, #3592); 1.7.0 (September 23, 2026) requires anyio>=4.0.0,<5 and raises WebSocketDisconnected (a RuntimeError subclass) for disconnected WebSocket operations. PyPI: starlette 1.8.0 Requires-Python >=3.11 (1.7.0 was >=3.10).  [✓0 ✗0]
1. FastAPI release notes: 0.129.0 (2026-02-12) Breaking Changes: drop support for Python 3.9 (PyPI Requires-Python >=3.10). fastapi 0.162.0 depends on starlette>=0.46.0 with no upper bound, so on Python 3.10 pip resolves Starlette 1.7.x and on 3.11+ Starlette 1.10.0.  [✓0 ✗0]

## Fix
```text
Use Python 3.11+ for current Starlette (3.10+ for FastAPI); on 3.10 pin `starlette<1.8` explicitly so lockfiles are reproducible. Upgrade anyio to 4.x before Starlette 1.7; catch `WebSocketDisconnected` where code expected a generic RuntimeError on closed sockets.
```

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0804/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary sources opened 2026-11-04 (FastAPI release notes + 0.162.0 source, Starlette release notes + 1.10.0 source; messages reproduced on fastapi 0.162.0 / starlette 1.10.0)