Anthropic releases Claude Opus 4.8, promising a more honest model

Anthropic released Claude Opus 4.8 as an incremental upgrade to Opus 4.7.

The model improves self-assessment, reduces coding-error leakage, and posts modest benchmark gains.

Claude Code adds dynamic workflows, while Claude.ai gets an effort slider for user control.

The Messages API now allows system instructions inside message arrays, with pricing unchanged.