> ## Documentation Index > Fetch the complete documentation index at: https://docs.ttapi.io/llms.txt > Use this file to discover all available pages before exploring further. # Suno Song Extension API Reference > Use the Suno song extension API to continue existing music with new sections, longer structure, or additional progression while keeping the original feel. Use the **Suno Extend API** when you already have a promising song segment and want to continue it with additional structure, length, or musical progression. ## OpenAPI ````yaml openapi/en/suno.json POST /suno/v1/extend openapi: 3.1.0 info: title: TTAPI API DOCS version: 1.0.0 description: Suno AI Music API servers: - url: https://api.ttapi.io security: [] paths: /suno/v1/extend: post: requestBody: required: true content: application/json: schema: allOf: - $ref: '#/components/schemas/Custom_Params' - $ref: '#/components/schemas/Gpt_description_prompt_Params' - $ref: '#/components/schemas/Prompt_Params' - $ref: '#/components/schemas/Title_Params' - $ref: '#/components/schemas/Tags_Params' - $ref: '#/components/schemas/Negative_tags_Params' - $ref: '#/components/schemas/Style_weight_Params' - $ref: '#/components/schemas/Weirdness_constraint_Params' - $ref: '#/components/schemas/Audio_weight_Params' - $ref: '#/components/schemas/Duration_Params' - $ref: '#/components/schemas/Auto_lyrics_Params' - $ref: '#/components/schemas/Vocal_gender_Params' - $ref: '#/components/schemas/Persona_id_Params' - $ref: '#/components/schemas/IsStorageParams' - $ref: '#/components/schemas/HookUrlParams' - type: object properties: music_id: type: string description: Audio ID of the track to extend. continue_at: type: number example: 10 description: >- Timestamp, in seconds, where the audio extension should begin. custom: type: boolean default: true description: >- Whether to use custom mode. - **true**: Generate audio from lyrics. - **false**: Generate audio from the inspiration-mode prompt. required: - custom - music_id - continue_at responses: '200': $ref: '#/components/responses/SuccessResponse' '400': $ref: '#/components/responses/400Response' '401': $ref: '#/components/responses/401Response' security: - CustomApiKey: [] components: schemas: Custom_Params: type: object properties: custom: type: boolean default: false description: >- Whether to use custom mode. - **true**: Audio will be generated from lyrics - **false**: Audio will be generated based on inspiration mode prompts Gpt_description_prompt_Params: type: object properties: gpt_description_prompt: type: string description: >- Prompt for inspiration mode. When not using custom mode (custom=false), this parameter is always required. Lyrics will be automatically generated from this prompt. Maximum length: 3000 characters. example: >- Night city lo-fi piano with rain ambience, soft vocal phrases, theme: "Under the city lights" Prompt_Params: type: object properties: prompt: type: string description: >- Lyrics. Used in custom mode (custom=true). Required when instrumental is false. The lyrics will be used and sung in the generated track. Maximum length: 5000 characters. Title_Params: type: object properties: title: type: string description: |- Music title. Used in custom mode (custom=true). Maximum length: 80 characters. Tags_Params: type: object properties: tags: type: string description: |- Music style or genre. Used in custom mode (custom=true). Maximum length: 1000 characters. example: rock, blues, hip-hop, r&b Negative_tags_Params: type: object properties: negative_tags: type: string description: |- Music styles or genres that should be excluded from generation. Used in custom mode (custom=true). Style_weight_Params: type: object properties: style_weight: type: number description: |- Music style weight, range: 0.00–1.00. Used in custom mode. Valid range: 0 <= x <= 1. example: 0.5 Weirdness_constraint_Params: type: object properties: weirdness_constraint: type: number description: |- Audio creativity (weirdness) weight, range: 0.00–1.00. Used in custom mode. Valid range: 0 <= x <= 1. example: 0.5 Audio_weight_Params: type: object properties: audio_weight: type: number description: |- Audio weight, range: 0.00–1.00. Used in custom mode. Valid range: 0 <= x <= 1. example: 0.5 Duration_Params: type: object properties: duration: type: int description: |- Audio duration, in seconds Used in custom mode. Valid range: 10 <= x <= 360. example: 120 Auto_lyrics_Params: type: object properties: auto_lyrics: type: boolean default: false description: >- Whether to automatically generate lyrics. Custom mode only. - **true**: The input lyrics will be creatively rewritten, similar to the inspiration mode prompt effect - **false**: Use the provided lyrics directly to generate the music Vocal_gender_Params: type: object properties: vocal_gender: type: string description: |- Vocal gender. - Male: Male voice - Female: Female voice enum: - Male - Female Persona_id_Params: type: object properties: persona_id: type: string description: |- Music style ID. Custom mode only. Use this parameter to generate music with a specific style. IsStorageParams: type: object properties: isStorage: type: boolean default: true description: >- Whether to store the generated audio. - **true**: The audio will be stored and a TTAPI CDN URL will be returned - **false**: The original source URL will be returned HookUrlParams: type: object properties: hookUrl: type: string description: Callback notification URL responses: SuccessResponse: description: Request successful content: application/json: schema: type: object properties: status: type: string example: SUCCESS message: type: string example: success data: type: object example: jobId: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx required: - status - message - data 400Response: description: Parameter error content: application/json: schema: type: object properties: status: type: string example: FAILED message: type: string data: type: object required: - status - message 401Response: description: Authorization failed content: application/json: schema: type: object properties: status: type: string example: FAILED message: type: string example: Wrong TT-API-KEY or email is not activated. required: - status - message securitySchemes: CustomApiKey: type: apiKey in: header name: TT-API-KEY description: >- You can obtain your API key from the TTAPI Dashboard. ````