{"uid":"cap_d2nYZc3IrIbJjOANln9a2","slug":"fittings-pubchem-compound-lookup-403be1fa","name":"fittings PubChem Compound Lookup","description":"Structure and computed properties for a compound by name, CAS number, PubChem CID or SMILES: formula, weight, InChI, logP, TPSA and H-bond counts.","url":"https://fittings.sh/v1/chem/pubchem-compound","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"cid":{"type":"number","description":"PubChem compound id"},"name":{"type":"string","description":"Compound name or CAS number, e.g. aspirin or 50-78-2"},"smiles":{"type":"string","description":"SMILES string"}}}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.004","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ONhx5gtTooe9dG1i6TOkw","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"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.","exampleAgentPrompt":"What are the molecular weight, logP, TPSA, and H-bond donor/acceptor counts for ibuprofen? You can look it up by its CAS number 15687-27-1.","exampleUseCases":[{"title":"Drug-likeness screening for lead compound","prompt":"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."},{"title":"Pharmacology research data enrichment","prompt":"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?"},{"title":"CAS number to structure resolution","prompt":"Look up the compound with CAS number 50-78-2 and give me its molecular formula, molecular weight, and InChI string."}],"resultDescription":"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.","failureModes":["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"],"whenToPreferThis":"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.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T19:13:46.597Z","isFirstParty":false}