Opus 4.8 shows substantially lower rates of misaligned behavior compared to 4.7, with approximately 4x improvement in catching code flaws. Fast mode API pricing reduced by 3x.
SDK adds support for Claude Opus 4-8 model with mid-conversation system blocks and granular output token usage details.
Anthropic closed a $65 billion Series H at a $965 billion valuation, making it the most valuable AI startup globally and surpassing OpenAI's $852 billion March valuation. The company simultaneously released Claude Opus 4.8 and announced plans to bring its Mythos cyber-focused model to all customers within weeks.
Anthropic released Claude Opus 4.8 on May 28, 2026, replacing Opus 4.7 at unchanged pricing. The company claims the model's misalignment rates match those of Claude Mythos Preview, the experimental model deemed too dangerous for public release in April 2026. Opus 4.8 delivers faster thinking modes at one-third the cost of version 4.7.
Anthropic released Claude Opus 4.8 on May 28, 2026, with improved performance in agentic coding, computer use, and reasoning benchmarks. Pricing remains at $5 per million input tokens and $25 per million output tokens, while the model's fast mode is now three times cheaper than previous versions.
Anthropic's Claude Opus 4.8 is now available on Amazon Bedrock and Claude Platform on AWS. The model is designed for autonomous multi-stage tasks, agentic coding, and long-running workflows with reduced supervision.
Anthropic released Claude Opus 4.8 on May 28, 2026, six weeks after version 4.7. The model achieves 69.2% on agentic coding benchmarks (up from 64.3%), runs 2.5 times faster in fast mode at one-third the cost, while maintaining the same pricing as version 4.7.
Anthropic released version 0.105.0 of its Python SDK on May 28, 2026, adding support for the Claude Opus 4-8 model. The update includes mid-conversation system blocks and detailed output token usage tracking.
Anthropic released Claude Opus 4.8 on Thursday, its fastest upgrade cycle at 41 days since the previous Opus 4.7. The model includes a new Dynamic Workflows feature designed to manage complex tasks across hundreds of parallel subagents, with pricing unchanged from previous Opus releases.