openapi: 3.1.0
info:
  title: ExchangeRate Enriched Data Quota API
  description: ExchangeRate-API is a currency exchange rate API providing authoritative daily and intraday foreign exchange rates for 161 currencies. The v6 API surface includes Standard (Latest) rates, Pair conversion, Enriched data (locale, symbol, flag), Historical rates back to 1990, Supported codes, and an API request Quota endpoint. A separate no-key Open Access endpoint (open.er-api.com) provides once-daily rates with attribution.
  version: 6.0.0
  termsOfService: https://www.exchangerate-api.com/terms
  contact:
    name: ExchangeRate-API Support
    url: https://www.exchangerate-api.com/contact
    email: contact@exchangerate-api.com
  license:
    name: Proprietary
    url: https://www.exchangerate-api.com/terms
servers:
- url: https://v6.exchangerate-api.com/v6
  description: ExchangeRate-API v6 Production (API key required)
- url: https://open.er-api.com/v6
  description: ExchangeRate-API Open Access (no API key, attribution required)
security:
- apiKeyPath: []
tags:
- name: Quota
  description: Inspect the remaining request quota for the API key.
paths:
  /{api_key}/quota:
    get:
      tags:
      - Quota
      summary: Get Request Quota
      description: Returns the plan quota, number of requests remaining in the current billing window, and refresh metadata for the API key.
      operationId: getQuota
      parameters:
      - $ref: '#/components/parameters/ApiKey'
      responses:
        '200':
          description: Successful response with current quota information.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/QuotaResponse'
        '400':
          description: Error response.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    ErrorResponse:
      type: object
      description: Standard error envelope returned when a request cannot be fulfilled.
      properties:
        result:
          type: string
          description: Status indicator (error).
          example: error
        error-type:
          type: string
          description: Machine-readable error code.
          enum:
          - unsupported-code
          - malformed-request
          - invalid-key
          - inactive-account
          - quota-reached
          - plan-upgrade-required
          - no-data-available
    QuotaResponse:
      type: object
      description: Quota response showing remaining requests for the API key.
      properties:
        result:
          type: string
          description: Status indicator.
        documentation:
          type: string
          format: uri
          description: Link to the documentation.
        terms_of_use:
          type: string
          format: uri
          description: Link to the terms of use.
        plan_quota:
          type: integer
          description: The total monthly request quota for the plan.
        requests_remaining:
          type: integer
          description: Number of requests left until the quota resets.
        refresh_day_of_month:
          type: integer
          description: Day of the month when the quota refreshes.
  parameters:
    ApiKey:
      name: api_key
      in: path
      required: true
      description: Your ExchangeRate-API dashboard API key.
      schema:
        type: string
  securitySchemes:
    apiKeyPath:
      type: apiKey
      in: path
      name: api_key
      description: ExchangeRate-API uses an API key embedded in the URL path (after /v6/).