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API Reference
API Reference

Suno Replace-Section

Use the replace section endpoint to create an asynchronous Task.

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01

Overview

Use the replace section endpoint with a supported model. Use the returned Task ID to retrieve its state, or provide callback_url for the deliveries documented below.

Quick start

  1. Create an API key and set it as RUNAPI_API_KEY.
  2. Choose a supported model and send a POST request whose body matches that model's schema.
  3. Store the returned task ID, then poll until a terminal state or handle the callbacks documented below.

Endpoint

POST /api/v1/suno/replace_section
Base URL
https://runapi.ai
API version
v1
Authentication
Authorization: Bearer YOUR_API_TOKEN
02

Supported models

Open a model page for current pricing, rate limits, and commercial-usage details.

03

Request schema

JSON body

Fields and allowed values depend on the selected model. When supplied, callback_url receives the Task deliveries documented below.

Request body12 fields
audio_idstring
Optional

Audio ID within the source task. Use with task_id; do not combine with upload_url/model.

callback_urlstring
Optional

Webhook URL for async notifications.

full_lyricsstring
Required

Complete song lyrics for context.

Bound: 5000
infill_end_timenumber
Required

Section end time in seconds; must be greater than infill_start_time and produce a replacement duration of at least 10 seconds.

infill_start_timenumber
Required

Section start time in seconds; the replacement duration must be at least 10 seconds.

lyricsstring
Required

Replacement section lyrics.

Bound: 5000
modelstring
Optional

Model slug for uploaded source audio.

Allowed values: suno-v6, suno-v6-wild, suno-v6-mini, suno-v4, suno-v4.5, suno-v4.5-all, suno-v4.5-plus, suno-v5, suno-v5.5
negative_tagsstring
Optional

Styles to avoid.

tagsstring
Required

Style or genre tags.

Bound: 1000
task_idstring
Optional

Source task ID. Use with audio_id; do not combine with upload_url/model.

titlestring
Required

Song title.

Bound: 80
upload_urlstring
Optional

Uploaded source audio URL. Use with model; do not combine with task_id/audio_id.

04

Create acceptance

HTTP 202

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "billing": {
      "properties": {
        "refund": {
          "oneOf": [
            {
              "properties": {
                "refunded_at": {
                  "type": "string"
                }
              },
              "required": [
                "refunded_at"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "reservation": {
          "oneOf": [
            {
              "properties": {
                "amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "amount_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "settlement": {
          "oneOf": [
            {
              "properties": {
                "amount_micro_cents": {
                  "type": "integer"
                },
                "charged_amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "charged_amount_cents",
                "amount_micro_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        }
      },
      "required": [
        "reservation",
        "settlement",
        "refund"
      ],
      "type": "object",
      "unevaluatedProperties": false
    },
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "processing"
      ],
      "type": "string"
    },
    "task_replayed": {
      "type": "boolean"
    }
  },
  "required": [
    "id",
    "status",
    "billing"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "billing": {
    "refund": null,
    "reservation": null,
    "settlement": null
  },
  "id": "tsk_reference_demo",
  "status": "processing"
}
05

Polling processing

HTTP 200

GET /api/v1/suno/replace_section/:id

Response schema
JSON 
{
  "properties": {
    "billing": {
      "properties": {
        "refund": {
          "oneOf": [
            {
              "properties": {
                "refunded_at": {
                  "type": "string"
                }
              },
              "required": [
                "refunded_at"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "reservation": {
          "oneOf": [
            {
              "properties": {
                "amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "amount_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "settlement": {
          "oneOf": [
            {
              "properties": {
                "amount_micro_cents": {
                  "type": "integer"
                },
                "charged_amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "charged_amount_cents",
                "amount_micro_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        }
      },
      "required": [
        "reservation",
        "settlement",
        "refund"
      ],
      "type": "object",
      "unevaluatedProperties": false
    },
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "processing"
      ],
      "type": "string"
    },
    "track": {
      "properties": {
        "audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "duration": {
          "type": "number"
        },
        "id": {
          "type": "string"
        },
        "image_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "lyrics": {
          "type": "string"
        },
        "model_name": {
          "type": "string"
        },
        "stream_audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "tags": {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "title": {
          "type": "string"
        }
      },
      "required": [
        "id"
      ],
      "type": "object",
      "unevaluatedProperties": false
    }
  },
  "required": [
    "id",
    "status",
    "billing"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "billing": {
    "refund": null,
    "reservation": null,
    "settlement": null
  },
  "id": "tsk_reference_demo",
  "status": "processing"
}
06

Polling completed

HTTP 200

GET /api/v1/suno/replace_section/:id

Response schema
JSON 
{
  "properties": {
    "billing": {
      "properties": {
        "refund": {
          "oneOf": [
            {
              "properties": {
                "refunded_at": {
                  "type": "string"
                }
              },
              "required": [
                "refunded_at"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "reservation": {
          "oneOf": [
            {
              "properties": {
                "amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "amount_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "settlement": {
          "oneOf": [
            {
              "properties": {
                "amount_micro_cents": {
                  "type": "integer"
                },
                "charged_amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "charged_amount_cents",
                "amount_micro_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        }
      },
      "required": [
        "reservation",
        "settlement",
        "refund"
      ],
      "type": "object",
      "unevaluatedProperties": false
    },
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "completed"
      ],
      "type": "string"
    },
    "track": {
      "properties": {
        "audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "duration": {
          "type": "number"
        },
        "id": {
          "type": "string"
        },
        "image_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "lyrics": {
          "type": "string"
        },
        "model_name": {
          "type": "string"
        },
        "stream_audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "tags": {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "title": {
          "type": "string"
        }
      },
      "required": [
        "id"
      ],
      "type": "object",
      "unevaluatedProperties": false
    }
  },
  "required": [
    "id",
    "status",
    "track",
    "billing"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "billing": {
    "refund": null,
    "reservation": null,
    "settlement": null
  },
  "id": "tsk_reference_demo",
  "status": "completed",
  "track": {
    "audio_url": "https://file.runapi.ai/reference-audio.mp3",
    "id": "audio_replaced_section"
  }
}
07

Polling failed

HTTP 200

GET /api/v1/suno/replace_section/:id

Response schema
JSON 
{
  "properties": {
    "billing": {
      "properties": {
        "refund": {
          "oneOf": [
            {
              "properties": {
                "refunded_at": {
                  "type": "string"
                }
              },
              "required": [
                "refunded_at"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "reservation": {
          "oneOf": [
            {
              "properties": {
                "amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "amount_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        },
        "settlement": {
          "oneOf": [
            {
              "properties": {
                "amount_micro_cents": {
                  "type": "integer"
                },
                "charged_amount_cents": {
                  "type": "integer"
                }
              },
              "required": [
                "charged_amount_cents",
                "amount_micro_cents"
              ],
              "type": "object",
              "unevaluatedProperties": false
            },
            {
              "enum": [
                null
              ]
            }
          ]
        }
      },
      "required": [
        "reservation",
        "settlement",
        "refund"
      ],
      "type": "object",
      "unevaluatedProperties": false
    },
    "error": {
      "type": "string"
    },
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "failed"
      ],
      "type": "string"
    }
  },
  "required": [
    "id",
    "status",
    "error",
    "billing"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "billing": {
    "refund": null,
    "reservation": null,
    "settlement": null
  },
  "error": "Task processing failed.",
  "id": "tsk_reference_demo",
  "status": "failed"
}
08

Customer callback: completed

HTTP 200

POST callback_url

Response schema
JSON 
{
  "properties": {
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "completed"
      ],
      "type": "string"
    },
    "track": {
      "properties": {
        "audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "duration": {
          "type": "number"
        },
        "id": {
          "type": "string"
        },
        "image_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "lyrics": {
          "type": "string"
        },
        "model_name": {
          "type": "string"
        },
        "stream_audio_url": {
          "type": "string",
          "x-runapi-generated-media": true
        },
        "tags": {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "title": {
          "type": "string"
        }
      },
      "required": [
        "id"
      ],
      "type": "object",
      "unevaluatedProperties": false
    }
  },
  "required": [
    "id",
    "status",
    "track"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "id": "tsk_reference_demo",
  "status": "completed",
  "track": {
    "audio_url": "https://file.runapi.ai/reference-audio.mp3",
    "id": "audio_replaced_section"
  }
}
09

Customer callback: failed

HTTP 200

POST callback_url

Response schema
JSON 
{
  "properties": {
    "error": {
      "oneOf": [
        {
          "type": "string"
        },
        {
          "properties": {
            "code": {
              "type": "string"
            },
            "limit_cents": {
              "type": "integer"
            },
            "message": {
              "type": "string"
            },
            "reset_at": {
              "format": "date-time",
              "type": [
                "string",
                "null"
              ]
            },
            "used_cents": {
              "type": "integer"
            },
            "window": {
              "enum": [
                "1h",
                "1d",
                "7d",
                "daily",
                "weekly",
                "monthly",
                "lifetime"
              ],
              "type": "string"
            }
          },
          "required": [
            "code",
            "message"
          ],
          "type": "object",
          "unevaluatedProperties": false
        }
      ]
    },
    "id": {
      "type": "string"
    },
    "status": {
      "enum": [
        "failed"
      ],
      "type": "string"
    }
  },
  "required": [
    "id",
    "status",
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": {
    "code": "generation_failed",
    "message": "Task processing failed."
  },
  "id": "tsk_reference_demo",
  "status": "failed"
}
10

Errors

HTTP 401

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Authentication required"
}
11

Errors

HTTP 401

GET /api/v1/suno/replace_section/:id

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Authentication required"
}
12

Errors

HTTP 400

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "oneOf": [
    {
      "properties": {
        "error": {
          "description": "Human-readable error message.",
          "type": "string"
        }
      },
      "required": [
        "error"
      ],
      "type": "object",
      "unevaluatedProperties": false
    },
    {
      "properties": {
        "error": {
          "description": "Human-readable validation summary.",
          "type": "string"
        },
        "errors": {
          "additionalProperties": {
            "items": {
              "type": "string"
            },
            "type": "array"
          },
          "description": "Validation messages keyed by public request field, with an array of human-readable strings for each field.",
          "type": "object"
        }
      },
      "required": [
        "error",
        "errors"
      ],
      "type": "object",
      "unevaluatedProperties": false
    }
  ]
}

Response example

JSON 
{
  "error": "model must be one of: "
}
13

Errors

HTTP 402

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Insufficient balance"
}
14

Errors

HTTP 429

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "API key credit limit exceeded"
}
15

Errors

HTTP 409

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "The request uses features that are not supported for the selected model"
}
16

Errors

HTTP 429

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Rate limit reached. Please retry later."
}
17

Errors

HTTP 503

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Service under maintenance, please try again later"
}
18

Errors

HTTP 504

POST /api/v1/suno/replace_section

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "The request timed out"
}
19

Errors

HTTP 404

GET /api/v1/suno/replace_section/:id

Response schema
JSON 
{
  "properties": {
    "error": {
      "description": "Human-readable error message.",
      "type": "string"
    }
  },
  "required": [
    "error"
  ],
  "type": "object",
  "unevaluatedProperties": false
}

Response example

JSON 
{
  "error": "Task with id 'tsk_reference_demo' not found"
}
20

Generated Code Samples

Use cURL directly, or install an SDK for your language. Each sample submits the validated request shown in this reference.

Install

Shell 
pip install runapi-suno
PYTHON 
import os
from runapi.suno import SunoClient

client = SunoClient(api_key=os.environ["RUNAPI_API_KEY"])
task = client.replace_section.create(
  upload_url="https://file.runapi.ai/source-audio.mp3",
  model="suno-v5",
  lyrics="New words for this section.",
  tags="acoustic pop",
  title="City Lights",
  infill_start_time=10,
  infill_end_time=20,
  full_lyrics="City lights reflect in the rain. New words for this section."
)