Claude API adds turn-scoped system messages in beta
Tech · Releases · Tue, September 1, 2026
Setting clear_at next_user_message on a mid-conversation system message renders it for the current turn only, then keeps it in history at no token cost. Per-turn reminders no longer accumulate or invalidate the prompt cache and later thinki
Every year
Also on Sep 1, 2026
| Date | Event | When |
|---|---|---|
| Tue, Sep 1, 2026 | Bear season opens (MN) | Now |
Source, method and history
- Source
- anthropic
- How we know
- From the Releases API (releases.fru.dev), which reads each vendor's changelog.
- Who
- anthropic
- Recurs
- one-off
- More on fru.dev
- releases.fru.dev
- Feed
- Subscribe to Releases
- Changes
- 2026-09-25: added to 2026-09-01