Anthropic has introduced Claude Opus 5.5, its most rigorous reasoning model designed for mission-critical engineering and regulatory verification tasks. The model emphasizes mathematical correctness, formal logic and repository-scale security audits.

Opus 5.5 costs $15 per million input tokens and $75 per million output tokens, with prompt caching available at $1.50 per million tokens. It features a 500,000-token context window with enhanced needle-in-a-haystack precision across deep call stacks.

Anthropic has bundled direct integrations for Claude Code and popular CI/CD pipelines, allowing teams to run multi-hour automated code audits before production releases. For everyday chat, Sonnet 5.5 and Haiku 5.5 remain the cost-effective choices.

What this means

  • Opus 5.5 is optimized for large-scale codebase architecture and security reviews.
  • Pricing sits at $15 per million input tokens and $75 per million output tokens.
  • Native integration with Claude Code allows multi-hour unattended repository refactors.

Read the announcement

We explained the update in plain English. Use the original source below for the full announcement and any later changes.

Read the original source