Anthropic guides

PricingUpdated Sep 28, 2026
AI API pricing explained: tokens, input vs output, caching and batch
How AI API pricing works, with dollar examples: tokens, why output costs more, caching and batch discounts, and DeepSeek's peak hours.
Language modelsUpdated Sep 28, 2026
Claude models explained: Fable 5.1, Opus 5.5, Sonnet 5 and Haiku 4.5
Anthropic's Claude lineup in plain English: what each model is for, what it costs through the API, what claude.ai plans include, and Fable vs Mythos.
BasicsUpdated Sep 28, 2026
Why does ChatGPT or Claude feel dumber? What's actually on the record
The documented reasons an AI model gets worse: confirmed bugs, changed defaults, outages and long chats. What providers admitted and how to test it.