← Every issue
No. 1 · 4 October 2026

This week in Claude

  1. 1.1
    All · 2026-09-28

    Claude Sonnet 5.5 is out

    Anthropic describes it as a faster, lower-cost complement to Claude Opus 5.5, so everyday tasks can run quicker.

    Try it: Use it for one quick everyday task this week and compare it with the model you normally pick.

    support.claude.com ↗
  2. 1.2
    API · 2026-09-28

    Code written for Sonnet 5 can break on Sonnet 5.5

    The API notes list five breaking differences, including how to turn off up-front thinking and forced tool use now returning an error.

    Try it: Before switching a model id in an app, read "What's new in Claude Sonnet 5.5" linked from the release notes.

    platform.claude.com ↗
  3. 1.3
    API · 2026-09-30 · act by 30 November 2026

    Claude Sonnet 4.5 retires from the API on 30 November 2026

    Anything still calling claude-sonnet-4-5-20250929 will stop working after that date.

    Try it: Search your projects for that model id and plan the move to Sonnet 5.5.

    platform.claude.com ↗
  4. 1.4
    Cowork · 2026-09-29

    Make a Google Doc, Sheet or deck straight from a chat

    With Google Drive connected, the new chat's Output picker can create the file for you instead of you copying text across.

    Try it: Ask for a one-page brief and choose a Google Doc as the output.

    claude.com ↗
Worth a look