MailPace Send Email API

openapi: 3.0.1
info:
  title: MailPace API
  description: >-
    The MailPace transactional email API. Send application email over HTTPS,
    manage DKIM-verified sending domains and their API tokens, and receive
    Ed25519-signed delivery event webhooks. Only HTTPS is supported.
  termsOfService: https://mailpace.com/terms
  contact:
    name: MailPace Support
    email: support@mailpace.com
    url: https://docs.mailpace.com
  version: '1.0'
servers:
  - url: https://app.mailpace.com/api/v1
    description: MailPace production API
tags:
  - name: Send
    description: Send transactional email.
  - name: Domains
    description: Manage sending domains and DKIM verification.
  - name: API Tokens
    description: Manage per-domain API tokens.
paths:
  /send:
    post:
      operationId: sendEmail
      tags:
        - Send
      summary: Send a transactional email
      description: >-
        Sends a single transactional email. Authenticated with the
        MailPace-Server-Token header. One of htmlbody or textbody is required.
        Up to 50 recipients are allowed across the to field, and the total
        message size may not exceed 50 MB.
      security:
        - ServerToken: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendRequest'
      responses:
        '200':
          description: Email accepted and queued for sending.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendResponse'
        '400':
          description: >-
            Bad request - invalid token/domain mismatch, unparseable sender,
            missing or invalid To field, blocked recipient, more than 50
            recipients, or disallowed attachment type.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Missing API token.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '403':
          description: >-
            Forbidden - domain not DKIM verified, no active subscription, or
            account disabled.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '429':
          description: Too many requests - sending rate limit exceeded.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
  /domains:
    get:
      operationId: listDomains
      tags:
        - Domains
      summary: List domains
      description: Returns an array of domains for the authenticated organization.
      security:
        - OrganizationToken: []
      responses:
        '200':
          description: An array of domains.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Domain'
        '401':
          description: Missing or invalid organization token.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
    post:
      operationId: createDomain
      tags:
        - Domains
      summary: Create a domain
      description: Creates a new sending domain for the authenticated organization.
      security:
        - OrganizationToken: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DomainCreateRequest'
      responses:
        '200':
          description: The created domain.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Domain'
        '422':
          description: Validation error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
  /domains/{id}:
    parameters:
      - $ref: '#/components/parameters/DomainId'
    get:
      operationId: getDomain
      tags:
        - Domains
      summary: Retrieve a domain
      description: Returns a single domain by ID.
      security:
        - OrganizationToken: []
      responses:
        '200':
          description: The requested domain.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Domain'
        '404':
          description: Domain not found.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
    patch:
      operationId: updateDomain
      tags:
        - Domains
      summary: Update a domain
      description: Updates the name or url of an existing domain.
      security:
        - OrganizationToken: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DomainUpdateRequest'
      responses:
        '200':
          description: The updated domain.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Domain'
  /domains/{id}/verify:
    parameters:
      - $ref: '#/components/parameters/DomainId'
    post:
      operationId: verifyDomain
      tags:
        - Domains
      summary: Verify a domain
      description: >-
        Triggers verification of the domain's DKIM and advanced DNS records.
      security:
        - OrganizationToken: []
      responses:
        '200':
          description: The domain with updated verification status.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Domain'
  /domains/{domain_id}/api_tokens:
    parameters:
      - $ref: '#/components/parameters/DomainIdPath'
    get:
      operationId: listApiTokens
      tags:
        - API Tokens
      summary: List API tokens
      description: Lists all API tokens for a domain.
      security:
        - OrganizationToken: []
      responses:
        '200':
          description: An array of API tokens.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/ApiToken'
    post:
      operationId: createApiToken
      tags:
        - API Tokens
      summary: Create an API token
      description: Creates a new API token for a domain.
      security:
        - OrganizationToken: []
      requestBody:
        required: false
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ApiTokenCreateRequest'
      responses:
        '200':
          description: The created API token.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiToken'
  /domains/{domain_id}/api_tokens/{id}:
    parameters:
      - $ref: '#/components/parameters/DomainIdPath'
      - $ref: '#/components/parameters/TokenId'
    get:
      operationId: getApiToken
      tags:
        - API Tokens
      summary: Retrieve an API token
      description: Returns a single API token by ID.
      security:
        - OrganizationToken: []
      responses:
        '200':
          description: The requested API token.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiToken'
    patch:
      operationId: updateApiToken
      tags:
        - API Tokens
      summary: Update an API token
      description: Updates attributes of an API token.
      security:
        - OrganizationToken: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ApiTokenCreateRequest'
      responses:
        '200':
          description: The updated API token.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ApiToken'
    delete:
      operationId: deleteApiToken
      tags:
        - API Tokens
      summary: Revoke an API token
      description: Revokes (deletes) an API token.
      security:
        - OrganizationToken: []
      responses:
        '204':
          description: Token revoked.
components:
  securitySchemes:
    ServerToken:
      type: apiKey
      in: header
      name: MailPace-Server-Token
      description: Per-domain server token used to authenticate send requests.
    OrganizationToken:
      type: apiKey
      in: header
      name: MailPace-Organization-Token
      description: Organization token used to authenticate domain and token management.
  parameters:
    DomainId:
      name: id
      in: path
      required: true
      description: The numeric ID of the domain.
      schema:
        type: integer
    DomainIdPath:
      name: domain_id
      in: path
      required: true
      description: The numeric ID of the domain.
      schema:
        type: integer
    TokenId:
      name: id
      in: path
      required: true
      description: The numeric ID of the API token.
      schema:
        type: integer
  schemas:
    SendRequest:
      type: object
      required:
        - from
        - to
      description: >-
        A transactional email. One of htmlbody or textbody must be supplied.
      properties:
        from:
          type: string
          description: Sender, as an email or "Name <email@domain.com>".
          example: Acme <noreply@acme.com>
        to:
          type: string
          description: Recipient(s), single or comma-separated, up to 50 addresses.
          example: user@example.com
        cc:
          type: string
          description: Comma-separated CC addresses.
        bcc:
          type: string
          description: Comma-separated BCC addresses.
        subject:
          type: string
          description: Email subject line.
          example: Welcome to Acme
        htmlbody:
          type: string
          description: HTML body. Required if textbody is absent.
        textbody:
          type: string
          description: Plain-text body. Required if htmlbody is absent.
        replyto:
          type: string
          description: Reply-To address.
        inreplyto:
          type: string
          description: Message-ID this email replies to.
        references:
          type: string
          description: Space-separated list of referenced Message-IDs.
        list_unsubscribe:
          type: string
          description: List-Unsubscribe header value.
        tags:
          description: A single tag or an array of tags.
          oneOf:
            - type: string
            - type: array
              items:
                type: string
        attachments:
          type: array
          description: Base64-encoded attachments.
          items:
            $ref: '#/components/schemas/Attachment'
    Attachment:
      type: object
      required:
        - name
        - content
      properties:
        name:
          type: string
          description: File name.
          example: invoice.pdf
        content:
          type: string
          description: Base64-encoded file content.
        content_type:
          type: string
          description: MIME type of the attachment.
          example: application/pdf
        cid:
          type: string
          description: Content-ID for inline embedding.
    SendResponse:
      type: object
      properties:
        id:
          type: integer
          description: Internal email identifier.
          example: 12345
        status:
          type: string
          description: Queue status of the email.
          example: pending
    Domain:
      type: object
      properties:
        id:
          type: integer
        name:
          type: string
          nullable: true
        url:
          type: string
        dkim_selector:
          type: string
        dkim_string:
          type: string
        dkim_verified:
          type: boolean
        advanced_verified:
          type: boolean
        webhook_public_key:
          type: string
          description: Base64-encoded Ed25519 public key used to verify webhook signatures.
        created_at:
          type: string
          format: date-time
        modified_at:
          type: string
          format: date-time
    DomainCreateRequest:
      type: object
      required:
        - domain
      properties:
        domain:
          type: object
          required:
            - url
          properties:
            url:
              type: string
              description: The domain to send from.
              example: acme.com
            name:
              type: string
              description: Optional display name.
    DomainUpdateRequest:
      type: object
      required:
        - domain
      properties:
        domain:
          type: object
          properties:
            url:
              type: string
            name:
              type: string
    ApiToken:
      type: object
      properties:
        id:
          type: integer
        name:
          type: string
          nullable: true
        token:
          type: string
          description: The server token value used in the MailPace-Server-Token header.
        created_at:
          type: string
          format: date-time
    ApiTokenCreateRequest:
      type: object
      properties:
        api_token:
          type: object
          properties:
            name:
              type: string
              description: Optional display name for the token.
    Error:
      type: object
      properties:
        error:
          type: string
          description: Human-readable error message.
        errors:
          type: object
          description: Field-level validation errors, when applicable.
          additionalProperties:
            type: array
            items:
              type: string