Anthropic ships Sonnet 5 as Claude Code's default

Anthropic shipped Claude Sonnet 5 as Claude Code's default model, adding a native 1M-token context window, per the company.

The swap covers Free and Pro users by default. Anthropic calls Sonnet 5 its most agentic Sonnet yet, and says it logs measurably fewer undesirable behaviors in agentic settings than Sonnet 4.6. That matters most for anyone running long autonomous coding sessions, where a single drift can send a whole run sideways.

Intro pricing is $2 per million input tokens and $10 per million output tokens, through August 31. It'll rise to $3 and $15 on September 1, a 50% jump on both ends.

I use Claude Code every day in my personal projects. Here's the win: bigger context and fewer agentic missteps mean longer sessions before things go off track.

The likely effect: a rush of heavy agent work before the price jump, then a drop in usage once September pricing kicks in.