Claude Sonnet 5.5 is out! We wrote a guide for building with it:
• choosing between Sonnet 5.5 and Opus 5.5
• migrating from Sonnet 5 and tuning effort
• using it in Claude Code
Claude can now help you build evaluations and hillclimb on them.
In this article, we share guidance on eval design & skills that Claude Code can use to improve your applications.
Built completely for free on Codex 🤯
We built this game (and video!) with DeepSeek V4 Flash through Antseed on Codex.
Over 400,000 tokens used, $0 in costs.
Connect Codex to Antseed, pick a free model, and start building.
Try it:
Opus 5.5 is 20% cheaper per input and output token than Opus 5, and 60% cheaper on cache reads. So what does that actually do to the cost of a task in Claude Code?
We ran the numbers, and built a calculator so you can run yours from /usage:
You don’t need permission to sell AI.
Run a model or build an AI service? Offer it directly to buyers on Antseed. Set your own price. No platform approval queue.
Your stall. Your service. Your price. 🐜