Science API Guide

Cheminformatics endpoints for validation, normalization, similarity scoring, and substructure matching — built for pipelines and AI agents.

Base URLhttps://api.creatornode.io/science

What is the Science API?

The Science API focuses on cheminformatics: parsing and normalizing chemical notation, validating inputs, and comparing molecules with RDKit.

Chemistry Validate — validate SMILES, InChI, or Molfile and return canonical outputs.
Chemistry Compare — identity checks, similarity scoring (Tanimoto), and substructure relationships.

🧬 RDKit-powered

Canonical SMILES, Morgan fingerprints, Tanimoto similarity, and substructure matching — without installing RDKit locally.

⚡ Fast + deterministic

Designed for pipelines: stable outputs, predictable error handling, and millisecond-scale parsing/compare for typical molecules.

🧱 Pipeline-safe errors

Invalid molecules return HTTP 200 with structured parse/validation info — no crashes for expected bad inputs.

🔑 Free Tier

20 requests/day with no API key required. Add an API key to unlock higher limits and premium modes.

Endpoints

Click an endpoint to see the full guide — examples, tips & tricks, and limits.

POST/science/v1/chemistry/validate

Chemistry Validate

Validate chemical notation (SMILES/InChI/Mol) and extract molecular properties.

POST/science/v1/chemistry/compare

Chemistry Compare

Compare two molecules — structural similarity, fingerprint matching, property diff.

Credit Costs

🧪Science APICheminformatics endpoints (RDKit)

Endpoint	Cost	Description
`/science/v1/chemistry/validate`	1 credit	Validate chemical notation (SMILES, InChI, Molfile) and return normalized outputs.	Full guide →
`/science/v1/chemistry/compare`	3 credits	Compare two molecules for identity, similarity, and substructure matching.	Full guide →

See the Pricing page for credit packages and tier comparison.

Usage Example

Validate → Compare workflow

Validate both molecules first, then compare for identity or similarity:

// Node.js example
const headers = {
  'Content-Type': 'application/json',
  'X-API-Key': process.env.CREATORNODE_KEY,
};

// Step 1: Validate each molecule
const a = await fetch('https://api.creatornode.io/science/v1/chemistry/validate', {
  method: 'POST', headers,
  body: JSON.stringify({ input: 'CC(=O)Oc1ccccc1C(=O)O' }),
}).then(r => r.json());

const b = await fetch('https://api.creatornode.io/science/v1/chemistry/validate', {
  method: 'POST', headers,
  body: JSON.stringify({ input: 'OC(=O)c1ccccc1O' }),
}).then(r => r.json());

if (!a.data?.valid || !b.data?.valid) {
  throw new Error('One molecule is invalid');
}

// Step 2: Compare
const cmp = await fetch('https://api.creatornode.io/science/v1/chemistry/compare', {
  method: 'POST', headers,
  body: JSON.stringify({
    molecules: [{ input: a.data.canonicalSmiles }, { input: b.data.canonicalSmiles }],
    mode: 'similarity',
  }),
}).then(r => r.json());

console.log('Tanimoto:', cmp.data?.similarity?.tanimoto);
console.log('Interpretation:', cmp.data?.similarity?.interpretation);