external-api-docs

Retrieving current, curated API documentation for external libraries and SDKs during development. Covers search strategies, token-aware fetching, annotation persistence, and provider fallback hierarchy. Use when writing code against an external API (Stripe, OpenAI, Anthropic Claude API, AWS, FastAPI, Supabase, etc.), debugging an integration issue, evaluating an SDK's capabilities, looking up current endpoint signatures or parameters, or when the agent may hallucinate API details due to training data staleness. Also activates for external API reference, SDK documentation, library docs lookup, current API signatures, and integration reference.