# PubChem Compound Lookup

> PubChem Compound Lookup is a paid API for AI agents from bio.memoryapi.org, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Retrieves drug and chemical compound data from PubChem (NIH), including CID, IUPAC name, molecular formula, molecular weight, SMILES, InChI, description, and synonyms.

## Facts

- Endpoint: GET https://bio.memoryapi.org/x402/bio/compound
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bio-memoryapi-org-b17575a7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_B_8yv35WwHohlV89b8ElI

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability bio-memoryapi-org-b17575a7
```

Example prompt: Can you look up the PubChem compound data for ibuprofen — I need the CID, molecular formula, molecular weight, SMILES, and IUPAC name?

## When to prefer this

Use this endpoint when you need structured chemical or pharmaceutical compound data (CID, SMILES, InChI, molecular weight, IUPAC name) sourced directly from NIH's PubChem database. Prefer this over general web search when you need machine-readable chemical identifiers and properties for a known drug or compound name.

## Known failure modes

- Compound name not found in PubChem — returns empty result or 404
- Ambiguous compound name matching multiple CIDs — may return primary match only
- Payment of $0.005 USDC not provided or failed — returns 402 Payment Required
- Rate limiting or upstream PubChem API downtime — returns 503 or timeout

## How this service works

Biomedical drug and compound data API with x402 micropayments. Powered by PubChem (NIH), OpenFDA, and ChEMBL (EMBL-EBI).

## Output

Returns structured compound data from PubChem including the PubChem CID, IUPAC name, molecular formula, molecular weight, canonical SMILES, InChI string, a text description of the compound, and a list of known synonyms.

## Example request

```json
{
 "name": "aspirin",
 "type": "label"
}
```

## Response schema (JSON Schema)

```json
{
 "example": {
  "cid": 2244,
  "name": "aspirin",
  "smiles": "CC(=O)Oc1ccccc1C(=O)O",
  "source": "PubChem / NIH",
  "formula": "C9H8O4",
  "success": true,
  "molecular_weight": "180.16"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bio-memoryapi-org-b17575a7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bio.memoryapi.org](https://www.zero.xyz/host/bio.memoryapi.org/llms.txt)