Summary
On June 30, 2026 Anthropic released Claude Sonnet 5, its most agentic Sonnet model, positioned as a cheaper way to run agents with near-Opus performance; it is the default model in Claude Code with a 1M-token context window and introductory pricing of 2 USD per million input and 10 USD per million output tokens through August 31, 2026.
What changed
Anthropic shipped Claude Sonnet 5 on June 30, 2026 across the Claude API, Amazon Bedrock, and Microsoft Foundry (Google Cloud Vertex AI coming soon). It becomes the default model in Claude Code, supports a 1M-token context window, and launches with promotional pricing of 2 USD input and 10 USD output per million tokens through August 31.
Why it matters
A cheaper, strongly agentic mid-tier model lowers the cost of long-horizon, tool-using agent runs; making it the Claude Code default pushes that economics directly into developer coding workflows and pressures rival coding-model pricing.
Evidence excerpt
Claude Sonnet 5 is now the default model in Claude Code, with a native 1M-token context window and promotional pricing of 2/10 per Mtok through August 31.