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fittings PubChem Compound Lookup
x402
fittings PubChem Compound Lookup is a paid API for AI agents from fittings.sh, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).
Returns structure and computed physicochemical properties (formula, molecular weight, InChI, logP, TPSA, H-bond counts) for a chemical compound identified by name, CAS number, PubChem CID, or SMILES.
Price / call$0.004
Success—
StatusUnknown
How this service works
Structure and computed properties for a compound by name, CAS number, PubChem CID or SMILES: formula, weight, InChI, logP, TPSA and H-bond counts.
Output
Returns a JSON object containing the compound's molecular formula, molecular weight, canonical SMILES, InChI, InChIKey, logP (XLogP3), topological polar surface area (TPSA), H-bond donor count, H-bond acceptor count, and PubChem CID.
Example use cases
Drug-likeness screening for lead compound
“Can you pull the logP, TPSA, molecular weight, and H-bond donor and acceptor counts for the compound with SMILES CC(=O)Oc1ccccc1C(=O)O? I want to check if it passes Lipinski's rule of five.”
Pharmacology research data enrichment
“I have a list of drug names and I need their molecular formulas and InChI strings. Start with caffeine — can you look it up by name and return its structure and computed properties?”
CAS number to structure resolution
“Look up the compound with CAS number 50-78-2 and give me its molecular formula, molecular weight, and InChI string.”
Technical details
Endpoint
GEThttps://fittings.sh/v1/chem/pubchem-compoundWhen to prefer
Use this endpoint when you need fast, structured physicochemical property data for a known compound identified by name, CAS number, PubChem CID, or SMILES — especially for drug-likeness checks, cheminformatics pipelines, or any workflow needing logP, TPSA, or H-bond counts without spinning up a local chemistry toolkit. Prefer this over raw PubChem API calls for its simplicity, consistent JSON schema, and pay-per-call pricing with no API key management.
Side effects
- Compound name not found in PubChem — returns an error or empty result
- Invalid SMILES string causes a parse failure
- Ambiguous compound name matching multiple records may return the most common entry
- CAS number not indexed in PubChem returns no result
- Missing all query parameters (name, cid, smiles) results in a 400-style validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Tags
x402
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