name: IMF Data API Rate Limits
description: The IMF Data API enforces application-based rate limiting at 50 requests per second, identified by the User-Agent header. There are no per-user or per-key limits since authentication is not required. Clients are encouraged to set a descriptive User-Agent string to avoid being throttled collectively with other anonymous clients.
url: https://datahelp.imf.org/knowledgebase/articles/667294-using-json-restful-web-service
created: '2026-06-13'
modified: '2026-06-13'

rateLimits:
  - name: Application Rate Limit
    description: The IMF API limits requests at 50 per second, tracked by the application User-Agent header string. Applications that do not set a custom User-Agent share the same rate limit bucket, which increases the chance of being throttled. Setting a descriptive User-Agent is strongly recommended.
    limit: 50
    period: second
    unit: requests
    scope: application (User-Agent based)
    enforcement: HTTP 429 Too Many Requests

  - name: Retry Policy
    description: When rate limited or encountering transient errors, clients should implement exponential backoff retry logic. The recommended maximum retry attempts is 10 before failing permanently.
    maxRetries: 10
    strategy: exponential backoff
    timeout: 30 seconds per request

notes:
  - Authentication is not required for any public IMF data endpoints.
  - Rate limits are enforced at the application level based on the User-Agent HTTP header.
  - Setting a unique, descriptive User-Agent string for each application is recommended to avoid sharing rate limit quota with other anonymous clients.
  - There are no daily or monthly request volume caps documented for the public API.
  - The legacy SDMX_JSON service at dataservices.imf.org may have different rate limiting behavior.

legacyApi:
  name: Legacy SDMX JSON Service
  baseUrl: http://dataservices.imf.org/REST/SDMX_JSON.svc
  description: The older IMF SDMX JSON 2.1 service. Now superseded by the SDMX 3.0 API but still operational. Rate limits are not explicitly documented for this service.
  status: Deprecated (still operational)