Claude Sonnet 5 with 1M token context becomes the default model in Claude Code 2.1.197 and costs $2 per 1M input tokens and $10 per 1M output tokens during the promotional phase.
Sonnet 5 significantly closes the performance gap to the more expensive Opus 4.8 in autonomous agent workloads while addressing existing weaknesses of its predecessor.
Anthropic launches Claude Sonnet 5 as an agentic-optimized standard mid-tier with 1M context and promotional pricing, promising previous high-end features at Sonnet cost, but showing benchmark weaknesses in tokenizer efficiency.
Sonnet 5 offers Opus 4.8-like performance at theoretically the same price as Sonnet 4.6, but a new tokenizer increases practical operating costs by approximately 30 percent.
Claude Code 2.1.197 integrates Claude Sonnet 5 with a 1M-token context window as the default model and offers promotional pricing of $2/$10 per million tokens through end of August.
Anthropic releases Sonnet 5, which approaches Opus 4.8 performance but is available at significantly lower prices, making autonomous agent tasks more cost-effective.
