# PubChem on Onekey

> 4 endpoints for PubChem (4 stable, 0 beta), 1 to 5 credits each. Category: Science & research. One key, one JSON shape.

Base URL: https://api.onekey.dev
Auth: header `x-api-key: <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/pubchem
Reference (Markdown): https://onekey.dev/docs/api/pubchem.md
All docs: https://onekey.dev/llms.txt

## Canonical fields returned

Unified-schema fields (same names on every platform), with how many of the 4 mapped PubChem endpoints return each:

- `entity.id` (string): 3
- `entity.name` (string): 3
- `entity.description` (string): 1
- plus 5 platform-specific fields under `ext.`

## Endpoints

### pubchem.compound_by_cid

Chemical compound properties by PubChem CID.
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/pubchem/compound_by_cid?cid=2244` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `cid` (string, required): PubChem compound id
- Fields returned: `entity.id`, `entity.name`, `ext.formula`, `ext.molecularWeight`, `ext.inchiKey`, `ext.smiles`
- Reference: https://onekey.dev/docs/api/pubchem/compound_by_cid.md

### pubchem.compound_by_name

Chemical compound properties by name (PubChem).
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/pubchem/compound_by_name?name=aspirin` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `name` (string, required): Compound name, e.g. aspirin
- Fields returned: `entity.id`, `entity.name`, `ext.formula`, `ext.molecularWeight`, `ext.inchiKey`, `ext.smiles`
- Reference: https://onekey.dev/docs/api/pubchem/compound_by_name.md

### pubchem.description

Textual description of a compound (PubChem).
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/pubchem/description?name=aspirin` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `name` (string, required): Compound name
- Fields returned: `entity.id`, `entity.description`, `ext.source`
- Reference: https://onekey.dev/docs/api/pubchem/description.md

### pubchem.synonyms

Synonyms of a chemical compound (PubChem).
- Price: 5 credits per fresh call. Status: stable. Returns: a list.
- Request: `GET https://api.onekey.dev/v1/pubchem/synonyms?name=aspirin` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `name` (string, required): Compound name
- Fields returned: `entity.name`
- Reference: https://onekey.dev/docs/api/pubchem/synonyms.md

## Sample request

```bash
curl "https://api.onekey.dev/v1/pubchem/compound_by_cid?cid=2244" \
  -H "x-api-key: YOUR_API_KEY"
```