Paper

DOI metadata lookup. 1 pay-per-call paper endpoint for AI agents — keyless, USDC via x402.

paper.doi-lookup$0.0012

Resolve a DOI to authoritative bibliographic metadata via Crossref.

GET /api/paper/doi-lookup

Discovery

/api/directory — full catalog of every endpoint
/openapi.json — OpenAPI 3.1 spec
/llms.txt — plain-text manifest for LLM ingestion