openapi: 3.1.0
info:
  title: Mailgun Domains Messages API
  description: Mailgun (by Sinch) is a transactional email API platform offering message send, inbound routing, suppression management, list management, webhooks, and event analytics. The HTTP API uses HTTP Basic Authentication with the literal username `api` and the account API key as the password. Regional endpoints are available for US (`api.mailgun.net`) and EU (`api.eu.mailgun.net`) data residency.
  version: 3.0.0
  contact:
    name: Mailgun
    url: https://documentation.mailgun.com/docs/mailgun/api-reference/
servers:
- url: https://api.mailgun.net/v3
  description: US region
- url: https://api.eu.mailgun.net/v3
  description: EU region
security:
- BasicAuth: []
tags:
- name: Messages
paths:
  /{domain}/messages:
    post:
      tags:
      - Messages
      summary: Send an email via the HTTP API
      operationId: sendMessage
      parameters:
      - name: domain
        in: path
        required: true
        description: Verified sending domain (e.g. mg.example.com)
        schema:
          type: string
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              required:
              - from
              - to
              - subject
              properties:
                from:
                  type: string
                to:
                  type: string
                cc:
                  type: string
                bcc:
                  type: string
                subject:
                  type: string
                text:
                  type: string
                html:
                  type: string
                template:
                  type: string
                o:tag:
                  type: string
                o:tracking:
                  type: string
      responses:
        '200':
          description: Message accepted; response includes Mailgun message ID.
  /{domain}/messages.mime:
    post:
      tags:
      - Messages
      summary: Send a pre-built MIME message
      operationId: sendMimeMessage
      parameters:
      - name: domain
        in: path
        required: true
        schema:
          type: string
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              required:
              - to
              - message
              properties:
                to:
                  type: string
                message:
                  type: string
                  format: binary
      responses:
        '200':
          description: Message accepted
components:
  securitySchemes:
    BasicAuth:
      type: http
      scheme: basic
      description: HTTP Basic with username `api` and your Mailgun API key as the password.