openapi: 3.0.3
info:
  title: Fixer Conversion Fluctuation API
  description: 'Fixer is a lightweight JSON API for real-time and historical foreign exchange

    rates and currency conversion. Sourced primarily from the European Central Bank

    and 15+ other exchange rate data providers, Fixer supports 170+ world currencies.


    The API is delivered via the APILayer marketplace. All requests authenticate via

    an `apikey` HTTP header. The free tier is limited to 100 requests per month and

    is HTTP-only; HTTPS encryption and source-currency switching become available on

    the Basic plan and above.

    '
  version: 1.0.0
  contact:
    name: Fixer Support
    url: https://fixer.io/contact
  license:
    name: Commercial
    url: https://fixer.io/terms
  termsOfService: https://fixer.io/terms
  x-provider: fixer
  x-parent: apilayer
servers:
- url: https://api.apilayer.com/fixer
  description: APILayer-hosted production endpoint (current)
- url: http://data.fixer.io/api
  description: Legacy data.fixer.io endpoint (HTTP, free tier)
- url: https://data.fixer.io/api
  description: Legacy data.fixer.io endpoint (HTTPS, paid tiers)
security:
- ApiKeyAuth: []
tags:
- name: Fluctuation
  description: Currency fluctuation analysis between two dates.
paths:
  /fluctuation:
    get:
      operationId: getFluctuation
      summary: Get Fluctuation Data
      description: 'Returns fluctuation data (start rate, end rate, change, change_pct) between two

        dates for any supported currency pair. Available on Professional Plus and above.

        '
      tags:
      - Fluctuation
      parameters:
      - name: start_date
        in: query
        required: true
        description: Start date for the fluctuation window (YYYY-MM-DD).
        schema:
          type: string
          format: date
          example: '2018-02-25'
      - name: end_date
        in: query
        required: true
        description: End date for the fluctuation window (YYYY-MM-DD).
        schema:
          type: string
          format: date
          example: '2018-02-26'
      - $ref: '#/components/parameters/Base'
      - $ref: '#/components/parameters/Symbols'
      responses:
        '200':
          description: Per-currency fluctuation summary for the requested window.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FluctuationResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
        '429':
          $ref: '#/components/responses/RateLimited'
components:
  responses:
    RateLimited:
      description: Monthly request quota exhausted or per-minute rate limit hit.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    Unauthorized:
      description: Missing or invalid `apikey` header.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    Forbidden:
      description: The requested feature is not included in the current subscription plan.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  schemas:
    FluctuationEntry:
      type: object
      properties:
        start_rate:
          type: number
        end_rate:
          type: number
        change:
          type: number
        change_pct:
          type: number
    FluctuationResponse:
      type: object
      required:
      - success
      - fluctuation
      - start_date
      - end_date
      - base
      - rates
      properties:
        success:
          type: boolean
          example: true
        fluctuation:
          type: boolean
          example: true
        start_date:
          type: string
          format: date
          example: '2018-02-25'
        end_date:
          type: string
          format: date
          example: '2018-02-26'
        base:
          type: string
          example: EUR
        rates:
          type: object
          additionalProperties:
            $ref: '#/components/schemas/FluctuationEntry'
          example:
            USD:
              start_rate: 1.228952
              end_rate: 1.232735
              change: 0.0038
              change_pct: 0.3078
            JPY:
              start_rate: 131.587611
              end_rate: 131.651142
              change: 0.0635
              change_pct: 0.0483
    ErrorResponse:
      type: object
      required:
      - success
      - error
      properties:
        success:
          type: boolean
          example: false
        error:
          type: object
          properties:
            code:
              type: integer
              example: 104
            type:
              type: string
              example: monthly_limit_reached
            info:
              type: string
              example: Your monthly API request volume has been reached. Please upgrade your plan.
  parameters:
    Symbols:
      name: symbols
      in: query
      required: false
      description: Comma-separated list of ISO 4217 currency codes to limit the result set.
      schema:
        type: string
        example: USD,AUD,CAD,PLN,MXN
    Base:
      name: base
      in: query
      required: false
      description: 'Three-letter ISO 4217 base currency code. Defaults to EUR on the Free plan;

        any base currency may be selected on Basic plan and above.

        '
      schema:
        type: string
        example: USD
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: apikey
      description: APILayer API key provisioned at https://apilayer.com/marketplace/fixer-api.