CriticalDeprecation
Anthropic Deprecating Manual Thinking in Claude Opus 4.6
Action Required
Developers using manual token budgeting in Claude Opus 4.6 must migrate to the new adaptive thinking approach or risk application failures after April 30, 2026.
AI Impact Summary
Anthropic is deprecating manual thinking controls in Claude Opus 4.6, transitioning to adaptive thinking and a new `effort` parameter for managing token usage. Pre-filling assistant messages are no longer supported, and the 1M token context window is being sunset on April 30, 2026, requiring migration to Claude Sonnet 4.6 or Claude Opus 4.6. This change impacts developers who relied on manual token budgeting and requires a shift to the new adaptive thinking approach.
Anthropic Deprecating Manual Thinking in Claude Opus 4.6
Affected Systems
Claude Opus 4.6
- Date
- Date not specified
- Change type
- deprecation
- Severity
- critical