# RCSB PDB on Onekey > 1 endpoint for RCSB PDB (1 stable, 0 beta), 1 credit each. Category: Science & research. One key, one JSON shape. Base URL: https://api.onekey.dev Auth: header `x-api-key: `. Call shape: `GET /v1/{platform}/{endpoint}?{params}`. Every response is `{success, data, metadata, error}`; check `success` first. Cost is in `metadata.credits_charged`. Free when served from cache (0.2 credit for a cached response over 100 KB). Failed and not-found calls are refunded. Status: stable = verified against the live source; beta = not yet verified, fields may be missing. Page: https://onekey.dev/platforms/rcsb Reference (Markdown): https://onekey.dev/docs/api/rcsb.md All docs: https://onekey.dev/llms.txt ## Canonical fields returned Unified-schema fields (same names on every platform), with how many of the 1 mapped RCSB PDB endpoints return each: - `entity.id` (string): 1 - `entity.name` (string): 1 - plus 3 platform-specific fields under `ext.` ## Endpoints ### rcsb.entry Protein Data Bank entry by PDB id. - Price: 1 credit per fresh call. Status: stable. Returns: one record. - Request: `GET https://api.onekey.dev/v1/rcsb/entry?id=4hhb` with header `x-api-key: YOUR_API_KEY` - Parameters: - `id` (string, required): PDB id, e.g. 4HHB - Fields returned: `entity.id`, `entity.name`, `ext.method`, `ext.depositDate`, `ext.molecularWeightKda` - Reference: https://onekey.dev/docs/api/rcsb/entry.md ## Sample request ```bash curl "https://api.onekey.dev/v1/rcsb/entry?id=4hhb" \ -H "x-api-key: YOUR_API_KEY" ```