CriticalDeprecation
Anthropic Deprecating Manual Thinking and Prefilling in Claude Opus
Action Required
Users relying on manual thinking and prefilling in Claude Opus models will experience a break in functionality after the deprecation date, requiring code changes or model migration.
AI Impact Summary
Anthropic is deprecating manual thinking (budget_tokens) and prefilling assistant messages in Claude Opus models, transitioning to adaptive thinking. This change impacts users relying on these features, requiring them to migrate to Claude Opus 4.6 or newer models to maintain functionality. The move to adaptive thinking and the removal of prefilling capabilities represent a fundamental shift in how users interact with the model's reasoning process.
Anthropic Deprecating Manual Thinking and Prefilling in Claude Opus
Affected Systems
Claude Opus
- Date
- Date not specified
- Change type
- deprecation
- Severity
- critical