# Separate audio stems

Source: https://recoupable.dev/docs/api-reference/complete/content/post-music-stem-separation

Separate an audio file into individual stems (vocals, drums, bass, etc.). Upload an audio file via multipart/form-data. Choose between two-stem separation (vocals + instrumental) or six-stem separation (vocals, drums, bass, guitar, piano, other). Returns a ZIP archive containing the separated stems.

## POST /api/music/stem-separation

Full OpenAPI specification: https://recoupable.dev/docs/spec/content.json

## Authentication

This operation requires one of the security alternatives in the specification below. Security scheme definitions are included where present in the published specification.

[Authentication guide](https://recoupable.dev/docs/authentication)

## Operation and referenced schemas

```json
{
  "openapi": "3.1.0",
  "info": {
    "title": "Recoup API - Content",
    "description": "API documentation for the Recoup platform - an AI agent platform for the music industry",
    "license": {
      "name": "MIT"
    },
    "version": "1.0.0"
  },
  "servers": [
    {
      "url": "https://api.recoupable.dev"
    }
  ],
  "paths": {
    "/api/music/stem-separation": {
      "post": {
        "description": "Separate an audio file into individual stems (vocals, drums, bass, etc.). Upload an audio file via multipart/form-data. Choose between two-stem separation (vocals + instrumental) or six-stem separation (vocals, drums, bass, guitar, piano, other). Returns a ZIP archive containing the separated stems.",
        "security": [
          {
            "apiKeyAuth": []
          },
          {
            "bearerAuth": []
          }
        ],
        "requestBody": {
          "description": "Audio file and separation parameters",
          "required": true,
          "content": {
            "multipart/form-data": {
              "schema": {
                "type": "object",
                "properties": {
                  "file": {
                    "type": "string",
                    "format": "binary",
                    "description": "Audio file to separate into stems"
                  },
                  "stem_variation_id": {
                    "type": "string",
                    "enum": [
                      "two_stems_v1",
                      "six_stems_v1"
                    ],
                    "default": "six_stems_v1",
                    "description": "Stem separation mode. `two_stems_v1` produces vocals + instrumental. `six_stems_v1` produces vocals, drums, bass, guitar, piano, and other."
                  },
                  "sign_with_c2pa": {
                    "type": "boolean",
                    "default": false,
                    "description": "Sign the output with C2PA content credentials"
                  },
                  "output_format": {
                    "type": "string",
                    "description": "Audio output format (e.g. mp3_44100_192)"
                  }
                },
                "required": [
                  "file"
                ]
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Stems separated successfully. Returns a ZIP archive containing the individual stems.",
            "content": {
              "application/zip": {
                "schema": {
                  "type": "string",
                  "format": "binary"
                }
              }
            }
          },
          "400": {
            "description": "Validation failed — invalid or missing request body fields",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/MusicErrorResponse"
                }
              }
            }
          },
          "401": {
            "description": "Unauthorized — invalid or missing API key",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/MusicErrorResponse"
                }
              }
            }
          },
          "500": {
            "description": "Internal server error",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/MusicErrorResponse"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MusicErrorResponse": {
        "type": "object",
        "required": [
          "error"
        ],
        "description": "Error response from a music endpoint.",
        "properties": {
          "error": {
            "type": "string",
            "description": "Error message describing what went wrong."
          }
        }
      }
    },
    "securitySchemes": {
      "apiKeyAuth": {
        "type": "apiKey",
        "in": "header",
        "name": "x-api-key",
        "description": "Your Recoup API key. [Learn more](/quickstart#api-keys)."
      },
      "bearerAuth": {
        "type": "http",
        "scheme": "bearer"
      }
    }
  }
}
```