# Cognition — Announcing Devin Agent Preview with Sonnet 4.5

- Company: Cognition (cognition.com)
- Announced: 2025-09-29
- Category: capability-change
- Coverage: not counted
- Announcement: yes
- Group: announcements
- Source: https://cognition.com/blog/devin-agent-preview-sonnet-4-5
- Record: https://forck.live/items/7690-announcing-devin-agent-preview-with-sonnet-4-5
- Subject: Devin / SWE
- Models affected: Claude Sonnet 4.5

Cognition announced that Claude Sonnet 4.5 is now available in Devin, delivering an 18% improvement in planning performance and a 12% improvement in end-to-end eval scores over the previous model. The model's new behaviors required changes to Devin's architecture.

## Evidence

Verbatim from https://cognition.com/blog/devin-agent-preview-sonnet-4-5:

> Claude Sonnet 4.5 increased planning performance by 18% and end-to-end eval scores by 12% - the biggest jump we've seen since the release of Claude Sonnet 3.6.

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