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Deprecation & Migration Watch

Intermediate

Models get retired, parameters get renamed, behaviors shift. This page tracks breaking changes so upgrades don't surprise you. If you build on the API, skim it periodically.

Why this matters​

A pinned model ID will eventually be deprecated and then removed. Code that hard-codes it breaks. A little hygiene prevents 2am surprises.

Survival rules​

  • Read model IDs from config, never scatter literals across the codebase — then migrating is a one-line change.
  • Watch announcements for deprecation dates and recommended replacements.
  • Re-run your evals when you switch models — behavior can shift even on a "newer, better" model.
  • Test before the deadline, not after removal.

Common kinds of change​

ChangeExampleWhat to do
Model retiredAn older model ID stops workingMove to the recommended successor; re-eval
Parameter supersededA reasoning/budget knob replaced by effortUpdate calls; see Thinking & Effort
Default shiftA new default model/behaviorPin intentionally; verify your prompts still work
Endpoint/SDK updateNew SDK major versionRead the migration guide; bump deliberately

Current watch​

The authoritative schedule lives on the official model deprecations page — confirm dates there before you migrate. Anthropic gives at least 60 days' notice before retiring a publicly released model.

Deprecated models​

No publicly released Claude model is currently in the "deprecated, not yet retired" window. Confirm against the official model status table — Anthropic gives at least 60 days' notice before a retirement.

Recently retired​

  • claude-opus-4-1-20250805 (Opus 4.1) was retired August 5, 2026 — move to claude-opus-4-8 (or straight to claude-opus-5).
  • claude-opus-4-20250514 (Opus 4) and claude-sonnet-4-20250514 (Sonnet 4) were retired June 15, 2026 — move to claude-opus-4-8 and claude-sonnet-5 respectively.

Calls to any retired ID now return an API error. If your code still pins one of these, that's the first thing to fix.

Parameter deprecations​

On Claude Opus 4.7 and later (including Opus 4.8 and Opus 5) and on Claude Sonnet 5, the sampling knobs temperature, top_p, and top_k are deprecated: setting any of them to a non-default value returns a 400 error. Omit them and steer behavior with prompting and Thinking & Effort instead.

Always confirm your model IDs against the Current Models & Pricing table; if you're on an older ID, plan a migration.

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