Anthropic has launched Claude Opus 4.8, an upgrade over Opus 4.7 with improvements across coding, agentic skills, reasoning, and practical knowledge. It is available now via the model ID claude-opus-4-8 on the Claude API and claude.ai.
Pricing is unchanged from Opus 4.7 at $5 per million input tokens and $25 per million output tokens. Fast mode runs at $10 per million input and $50 per million output tokens — three times cheaper than previous fast-mode models.
On capabilities, Opus 4.8 is roughly 4x less likely to overlook code flaws, reflecting enhanced honesty. A research-preview feature, dynamic workflows, supports hundreds of parallel subagents for large-scale tasks like codebase migrations. New effort control on claude.ai lets users trade off response quality against speed, and the Messages API now accepts system entries mid-task without breaking the prompt cache.
Benchmark highlights include being the only model to complete every case end-to-end on the Super-Agent benchmark, 84% on the Online-Mind2Web browser-agent benchmark, and the highest Legal Agent Benchmark score — the first to exceed 10% on the all-pass standard. Anthropic also reports improved prosocial traits and substantially lower misaligned behavior rates versus Opus 4.7.