Claude API

Claude API loads current, correct reference material for building against the Messages API directly — request shapes, tool-use loops, streaming, prompt caching, and model selection — instead of relying on training-data knowledge that’s likely stale by the time it matters, given how frequently API surface and model lineups change.

It’s the skill to have active when you’re implementing a Claude integration by hand rather than through a higher-level SDK feature: a custom tool-use loop, a caching strategy for a long system prompt, or picking the right model for a cost/latency/quality tradeoff in a specific application.

Distinct from MCP Builder and Skill Creator in this catalog — those are for building the extensions Claude uses; this is for building software that calls Claude directly.