# Provenance stamped 2026-10-07 (roadmap#943): written by an API Evangelist sweep (undated — the file carries no date and git cannot supply one), not
# harvested from the provider. `method: generated` so the economics campaign may replace it with a
# dated, verbatim transcription; every figure below is unverified until it does.
method: generated
rateLimits:
  documented: false
  summary: >
    ChEMBL does not publish explicit rate limits for its public REST API. As a
    publicly funded EMBL-EBI resource, the API is intended for open access without
    quotas or throttling. However, EMBL-EBI's general terms of service prohibit
    usage patterns that would prevent other users from accessing services. Abusive
    or excessive usage may result in IP-level blocking at the discretion of the
    ChEMBL team.
  policies:
    - name: Fair Use Policy
      description: Users must not employ methods that interfere with service availability for other users. Any attempt to use EMBL-EBI Data Resources and Tools to a level that prevents EMBL-EBI from providing services to others will result in the user being blocked.
      source: https://www.ebi.ac.uk/about/terms-of-use/
      enforcement: IP blocking for abusive usage
    - name: Bulk Access Recommendation
      description: For large-scale or bulk data access, EMBL-EBI recommends using FTP downloads rather than the REST API to reduce load on the API service.
      source: https://www.ebi.ac.uk/chembl/
      recommendation: Use FTP bulk downloads for large datasets
  pagination:
    defaultPageSize: 20
    description: Results are paginated with a default of 20 records per page. Page size can be adjusted via the limit parameter.
  recommendations:
    - Use the official Python client (chembl_webresource_client) which handles pagination and retries gracefully
    - For bulk data needs, prefer FTP downloads over repeated API calls
    - Use POST with X-HTTP-Method-Override header for complex queries instead of very long GET URLs
    - Cache responses locally when performing repeated lookups of the same entities
  contact: chembl-help@ebi.ac.uk
  termsUrl: https://www.ebi.ac.uk/about/terms-of-use/