Anthropic (Claude API)UpdateConfigChecked against the official docs, Nov 9, 2026

Fast mode for Claude Opus 4.8 is deprecated and will be removed on November 30, 2026 (October 30, 2026)

From Nov 30, 2026, Claude Opus 4.8 requests with speed "fast" return an error. Move fast mode traffic to Claude Opus 5.5.