openapi: 3.1.0
info:
  title: Loops OpenAPI Spec API key Email messages API
  description: This is the OpenAPI Spec for the [Loops API](https://loops.so/docs/api).
  version: 1.8.0
servers:
- url: https://app.loops.so/api/v1
tags:
- name: Email messages
  description: Manage email message content for campaigns
paths:
  /email-messages/{emailMessageId}:
    parameters:
    - name: emailMessageId
      in: path
      required: true
      description: The ID of the email message.
      schema:
        type: string
    get:
      tags:
      - Email messages
      summary: Get an email message
      description: Retrieve an email message, including its compiled LMX content.
      responses:
        '200':
          description: Successful.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageResponse'
        '400':
          description: Invalid `emailMessageId` or no sending domain configured.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '401':
          description: Invalid API key or content API not enabled for this team.
        '404':
          description: Email message not found.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '405':
          description: Wrong HTTP request method.
        '409':
          description: Email message uses MJML format or content cannot be parsed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
      security:
      - apiKey: []
    post:
      tags:
      - Email messages
      summary: Update an email message
      description: Update fields on an email message (subject, preview text, sender, LMX content). The campaign must be in draft status. Supply `expectedRevisionId` matching the current `contentRevisionId` — the server rejects mismatched revisions with 409.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UpdateEmailMessageRequest'
      responses:
        '200':
          description: Email message updated.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageResponse'
        '400':
          description: Invalid request body.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '401':
          description: Invalid API key or content API not enabled for this team.
        '404':
          description: Email message not found.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '405':
          description: Wrong HTTP request method.
        '409':
          description: Campaign is not in draft status, `contentRevisionId` is stale, content cannot be parsed, or email message uses MJML format.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '413':
          description: LMX payload exceeds the 100KB limit.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
        '422':
          description: LMX failed to compile.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EmailMessageFailureResponse'
      security:
      - apiKey: []
components:
  schemas:
    UpdateEmailMessageRequest:
      type: object
      properties:
        expectedRevisionId:
          type: string
          description: The `contentRevisionId` you last fetched. Used for optimistic concurrency — the request is rejected with 409 if the server's revision has advanced.
        subject:
          type: string
        previewText:
          type: string
        fromName:
          type: string
        fromEmail:
          type: string
          description: The sender username (without `@` or domain). The team's sending domain is appended automatically.
        replyToEmail:
          type: string
          description: Reply-to email. Must be empty or a valid email address.
        lmx:
          type: string
          description: The email body serialized as LMX. Styles must be embedded in the LMX `<Style />` tag.
      additionalProperties: false
    EmailMessageFailureResponse:
      type: object
      properties:
        success:
          type: boolean
          examples:
          - false
        message:
          type: string
      required:
      - success
      - message
    EmailMessageResponse:
      type: object
      properties:
        success:
          type: boolean
          examples:
          - true
        emailMessageId:
          type: string
        campaignId:
          type:
          - string
          - 'null'
        subject:
          type: string
        previewText:
          type: string
        fromName:
          type: string
        fromEmail:
          type: string
        replyToEmail:
          type: string
        lmx:
          type: string
          description: The email body serialized as LMX.
        contentRevisionId:
          type:
          - string
          - 'null'
          description: The current content revision. Pass this as `expectedRevisionId` on your next update.
        updatedAt:
          type: string
          format: date-time
        warnings:
          type: array
          description: Non-fatal issues raised while compiling the submitted LMX. Only present on update responses when warnings were produced.
          items:
            type: object
            properties:
              rule:
                type: string
              severity:
                type: string
                enum:
                - warning
              message:
                type: string
              path:
                type: string
            required:
            - rule
            - severity
            - message
      required:
      - success
      - emailMessageId
      - campaignId
      - subject
      - previewText
      - fromName
      - fromEmail
      - replyToEmail
      - lmx
      - contentRevisionId
      - updatedAt
  securitySchemes:
    apiKey:
      type: http
      scheme: bearer