specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: ExchangeRate-API
providerId: exchangerate-api
created: '2026-05-29'
modified: '2026-05-29'
reconciled: true
tags:
  - Rate Limiting
  - Currency Exchange
  - Foreign Exchange
description: ExchangeRate-API enforces per-API-key monthly request quotas tied to plan tier rather
  than per-second / per-minute rate limits. Free uses 1,500/month, Pro 30,000/month, Business
  125,000/month, and Volume the largest allotment. When quota is exhausted the API returns an
  error envelope with error-type quota-reached. The no-key Open Access endpoint
  (open.er-api.com) is anti-abuse throttled and returns HTTP 429 with a 20-minute reset window.
sources:
  - https://www.exchangerate-api.com/docs/overview
  - https://www.exchangerate-api.com/docs/free
  - https://www.exchangerate-api.com/#pricing
responseCodes:
  quotaReached: 200
  quotaErrorType: quota-reached
  openAccessRateLimit: 429
limits:
  - name: Free plan monthly quota
    scope: api-key
    metric: requests_per_month
    limit: 1500
    timeFrame: month
  - name: Pro plan monthly quota
    scope: api-key
    metric: requests_per_month
    limit: 30000
    timeFrame: month
  - name: Business plan monthly quota
    scope: api-key
    metric: requests_per_month
    limit: 125000
    timeFrame: month
  - name: Volume plan monthly quota
    scope: api-key
    metric: requests_per_month
    limit: -1
    timeFrame: month
  - name: Open Access anti-abuse throttle
    scope: ip-or-account
    metric: requests
    limit: -1
    timeFrame: 20min
policies:
  - name: Quota refresh
    description: Monthly request quotas refresh on the day-of-month indicated by the quota endpoint
      response (refresh_day_of_month). Use the GET /v6/{key}/quota endpoint to programmatically
      track remaining requests.
  - name: Error envelope, not HTTP code
    description: When the monthly quota is exceeded the API returns HTTP 200 with a JSON error
      envelope where result is "error" and error-type is "quota-reached". Clients must inspect
      the JSON body rather than relying solely on HTTP status codes.
  - name: Open Access rate limiting
    description: The open.er-api.com endpoint is anti-abuse throttled. Excess traffic from an IP
      or account receives HTTP 429 with a 20-minute reset window. Caching responses for 24 hours
      is permitted and recommended.
  - name: Relaxed quota enforcement
    description: ExchangeRate-API documents a relaxed enforcement policy where transient spikes
      slightly over quota are typically tolerated, but sustained over-quota traffic triggers the
      quota-reached error.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com