name: Chempirical plans
generated: '2026-10-09'
method: searched
source: https://chempirical.com/api/
audience: developer-api
pricing_basis: free
published: false
delivery:
  delivery: managed
plans:
- name: Free JSON API
  description: Read-only JSON for the compounds, reactions and physical data behind the site.
  price_text: No key, no sign-up.
  features: [No API key required, CORS open to every origin]
  limits: [Please keep it to a few requests per second.]