> ## Documentation Index
> Fetch the complete documentation index at: https://docs.convertly.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Merge multiple audio files into one

> Concatenate two or more audio files end-to-end in the order they are uploaded.



## OpenAPI

````yaml /openapi.json post /api/media/concat-audio
openapi: 3.1.0
info:
  title: Convertly API
  version: 1.0.0
  description: >-
    Convertly provides production API endpoints for media conversion,
    compression, Image CDN delivery, Forma AI, HLS/DASH video streaming, media
    tools, async jobs, workflows, webhooks, and Convertly Storage.
  license:
    name: Proprietary
    url: https://convertly.sh/terms
servers:
  - url: https://convertly.sh
security:
  - bearerAuth: []
  - apiKeyAuth: []
paths:
  /api/media/concat-audio:
    post:
      tags:
        - Media Tools
      summary: Merge multiple audio files into one
      description: >-
        Concatenate two or more audio files end-to-end in the order they are
        uploaded.
      operationId: concatenateAudio
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/ConcatAudioRequest'
      responses:
        '200':
          description: Generated file or queued media tool job
          content:
            application/json:
              schema:
                oneOf:
                  - $ref: '#/components/schemas/MediaToolFilesResponse'
                  - $ref: '#/components/schemas/AsyncMediaToolJobResponse'
        '400':
          $ref: '#/components/responses/Error'
        '401':
          $ref: '#/components/responses/Error'
        '402':
          $ref: '#/components/responses/Error'
        '413':
          $ref: '#/components/responses/Error'
        '415':
          $ref: '#/components/responses/Error'
        '429':
          $ref: '#/components/responses/Error'
components:
  schemas:
    ConcatAudioRequest:
      type: object
      description: >-
        Merge two or more audio files end-to-end into a single output. Send each
        input under the `file` form field (repeated).
      properties:
        file:
          type: array
          items:
            type: string
            format: binary
          minItems: 2
          description: Two or more audio files in playback order.
        format:
          type: string
          enum:
            - mp3
            - m4a
            - wav
          default: mp3
        async:
          type: string
          enum:
            - 'true'
            - 'false'
          default: 'false'
        callbackUrl:
          type: string
          format: uri
      required:
        - file
    MediaToolFilesResponse:
      type: object
      properties:
        files:
          type: array
          items:
            $ref: '#/components/schemas/MediaToolFile'
      required:
        - files
    AsyncMediaToolJobResponse:
      type: object
      properties:
        jobId:
          type: string
          format: uuid
        status:
          const: pending
        tool:
          type: string
          enum:
            - thumbnail
            - pdf-preview
            - image-to-pdf
            - strip-metadata
            - poster-frame
            - extract-audio
            - watermark
            - inspect
            - trim
            - gif
            - storyboard
            - transform
      required:
        - jobId
        - status
        - tool
    MediaToolFile:
      type: object
      properties:
        filename:
          type: string
        mimeType:
          type: string
        originalSize:
          type: integer
        finalSize:
          type: integer
        downloadUrl:
          type: string
      required:
        - filename
        - mimeType
        - originalSize
        - finalSize
        - downloadUrl
    Error:
      type: object
      properties:
        error:
          type: string
        upgradeUrl:
          type: string
      required:
        - error
  responses:
    Error:
      description: Error response
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Dashboard-generated Convertly API key. Keys currently begin with
        `cvly_`.
    apiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: Alternative API key header for server-side clients.

````