tags:
  - Scheduled Messages
operationId: update-scheduled-message
summary: Update a Scheduled Message
description: |
  Update an existing scheduled message.
  
  Only messages with status 'draft' or 'pending' can be modified.
  Messages that have been sent or failed cannot be updated.
security:
  - userApiKey: []
requestBody:
  required: true
  content:
    application/json:
      schema:
        $ref: '#/components/schemas/scheduled_message_create_update_payload'
responses:
  '200':
    description: Success
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/scheduled_message'
  '404':
    description: Scheduled message not found
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/bad_request_error'
  '401':
    description: Unauthorized
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/bad_request_error'
  '403':
    description: Access denied
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/bad_request_error'
  '422':
    description: Unprocessable Entity - validation errors (e.g., message already sent)
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/bad_request_error'