News · Claude
Claude Developers: A Sonnet 5.5 guide covers migration, effort settings and model selection
Posted on X by Claude Developers (@ClaudeDevs) on 28 September 2026. The headline is our summary; the post itself is quoted below.
Claude Developers@ClaudeDevs ·
Claude Sonnet 5.5 is out! We wrote a guide for building with it: • choosing between Sonnet 5.5 and Opus 5.5 • migrating from Sonnet…
The quote is the post as published on X; the original may include images, links or a thread.
Context
- Claude Code 2.1.284Released the same day (UTC). Added Claude Sonnet 5.5 (claude-sonnet-5-5), now the default Sonnet model on the Anthropic API — 1M context, $2/$10 per Mtok with $0.20/Mtok cache reads…
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