> ## Documentation Index > Fetch the complete documentation index at: https://evolink.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Seedance 2.5 Flash Reference-to-Video > - Input reference images (0–10) + reference videos (0–5) + reference audio (0–5) + a text prompt to generate video; provide at least one image, video, or audio reference - Best suited for generating new footage: images, videos, and audio act as style, subject, camera-movement, and soundtrack references - **To edit an existing video, use [Seedance 2.5 Flash Video Edit](/en/api-manual/video-series/seedance2.5/seedance-2.5-flash-video-edit)**: do not put editing or extension intent in this model's prompt (see the `prompt` description) - Asynchronous processing mode, use the returned task ID to [query status](/en/api-manual/task-management/get-task-detail) - Generated video links are valid for 24 hours, please save them promptly ## OpenAPI ````yaml en/api-manual/video-series/seedance2.5/seedance-2.5-flash-reference-to-video.json POST /v1/videos/generations openapi: 3.1.0 info: title: Seedance 2.5 Flash Reference-to-Video API description: >- Seedance 2.5 Flash multimodal reference-to-video API, supports mixed generation from image, video, and audio reference materials license: name: MIT version: 1.0.0 servers: - url: https://api.evolink.ai description: Production security: - bearerAuth: [] tags: - name: Video Generation description: AI video generation endpoints paths: /v1/videos/generations: post: tags: - Video Generation summary: Seedance 2.5 Flash Reference-to-Video description: >- - Input reference images (0–10) + reference videos (0–5) + reference audio (0–5) + a text prompt to generate video; provide at least one image, video, or audio reference - Best suited for generating new footage: images, videos, and audio act as style, subject, camera-movement, and soundtrack references - **To edit an existing video, use [Seedance 2.5 Flash Video Edit](/en/api-manual/video-series/seedance2.5/seedance-2.5-flash-video-edit)**: do not put editing or extension intent in this model's prompt (see the `prompt` description) - Asynchronous processing mode, use the returned task ID to [query status](/en/api-manual/task-management/get-task-detail) - Generated video links are valid for 24 hours, please save them promptly operationId: createSeedance25FlashReferenceToVideo requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/VideoGenerationRequest' examples: multimodal: summary: Multimodal reference (image + video + audio) value: model: seedance-2.5-flash-reference-to-video prompt: >- Use the first-person perspective framing of @video1 throughout, and use @audio1 as background music throughout. First-person perspective fruit tea promotional video... image_urls: - https://example.com/ref1.jpg - https://example.com/ref2.jpg video_urls: - https://example.com/reference.mp4 audio_urls: - https://example.com/bgm.mp3 duration: 10 quality: 720p aspect_ratio: '16:9' generate_audio: true subject_reference: summary: Image + video reference (subject + camera movement) value: model: seedance-2.5-flash-reference-to-video prompt: >- Make the face cream in @image1 the hero product, and follow the camera rhythm and lighting mood of @video1 to generate a clean product commercial image_urls: - https://example.com/cream.jpg video_urls: - https://example.com/reference.mp4 duration: 5 quality: 720p aspect_ratio: '16:9' multi_video: summary: Multi-video reference (multi-shot narrative) value: model: seedance-2.5-flash-reference-to-video prompt: >- The arched window in @video1 opens into the art gallery interior, continuing with @video2; then the camera enters the painting, continuing with @video3 video_urls: - https://example.com/part1.mp4 - https://example.com/part2.mp4 - https://example.com/part3.mp4 duration: 8 quality: 720p aspect_ratio: '16:9' generate_audio: true responses: '200': description: Video generation task created successfully content: application/json: schema: $ref: '#/components/schemas/VideoGenerationResponse' '400': description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: invalid_parameter message: Invalid request parameters type: invalid_request_error '401': description: Unauthenticated, token invalid or expired content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: unauthorized message: Invalid or expired token type: authentication_error '402': description: Insufficient quota, top-up required content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: insufficient_quota message: Insufficient quota. Please top up your account. type: insufficient_quota '403': description: Access denied content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: model_access_denied message: >- Token does not have access to model: seedance-2.5-flash-reference-to-video type: invalid_request_error '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: rate_limit_exceeded message: Too many requests, please try again later type: rate_limit_error '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: internal_error message: Internal server error type: api_error components: schemas: VideoGenerationRequest: type: object required: - model - prompt properties: model: type: string description: Video generation model name enum: - seedance-2.5-flash-reference-to-video default: seedance-2.5-flash-reference-to-video example: seedance-2.5-flash-reference-to-video prompt: type: string description: >- Text prompt describing the desired video. Supports both Chinese and English, recommended no more than 500 characters for Chinese. Maximum prompt length: 10000 tokens **Details:** - When referring to input materials in the prompt, prefer explicit tags such as `@image1`, `@video1`, and `@audio1` instead of relying only on natural-language references such as "image 1", "video 1", or "audio 1" - Tag numbers follow the order of the corresponding URL array and start at 1: the first `image_urls` item is `@image1`, the first `video_urls` item is `@video1`, and the first `audio_urls` item is `@audio1` - Natural-language numbering may still be understood, but explicit tags provide a clearer mapping between each material and its intended use **Avoid being classified as an edit / extend task:** - The task type is inferred from the prompt intent: wording such as "edit the video", "add", "remove / delete", "change / replace" is treated as video editing; wording such as "extend forward / backward", "continue" is treated as video extension - Once classified this way, the request is accepted without an error, but the task may fail later. The pre-authorized quota is refunded, but the waiting time is wasted - If you really need editing, use `seedance-2.5-flash-video-edit` instead - For pure reference generation, rephrase words like "replace" or "remove" descriptively, e.g. "the shot features ..." or "rendered in the style of @image1" example: >- Use the first-person perspective framing of @video1 throughout, and use @audio1 as background music throughout. First-person perspective fruit tea promotional video... image_urls: type: array description: >- Reference image URL array, **optional; 1–10 images when provided** **Requirement:** At least one of `image_urls`, `video_urls`, or `audio_urls` must be provided. **Role description:** | Media Type | Role | Typical Usage | |---------|------|----------| | Image | `reference_image` | Style reference, product image, first/last frame (specified via prompt) | **Image requirements:** - Supported formats: `.jpeg`, `.png`, `.webp` - Aspect ratio (width/height): `0.4` ~ `2.5` - Width/height pixels: `300` ~ `6000` px - Max size per image: `30MB` - Total request body size must not exceed `64MB`, do not use Base64 encoding - Image URLs must be directly accessible by the server items: type: string format: uri minItems: 1 maxItems: 10 example: - https://example.com/ref1.jpg - https://example.com/ref2.jpg video_urls: type: array description: >- Reference video URL array, **optional; 1–5 videos when provided** **Requirement:** At least one of `image_urls`, `video_urls`, or `audio_urls` must be provided. **Role description:** | Media Type | Role | Typical Usage | |---------|------|----------| | Video | `reference_video` | Camera movement reference, motion reference | **Video requirements:** - Supported formats: `.mp4`, `.mov` - Resolution: 480p, 720p, 1080p, 4K - Duration per video: `2` ~ `30` seconds, max 5 videos, total duration of all videos ≤ `30` seconds - Aspect ratio (width/height): `0.4` ~ `2.5` - Width/height pixels: `300` ~ `6000` px - Frame pixels (width × height): `409,600` ~ `8,295,044` (e.g., 640×640 ~ 3326×2494) - Max size per video: `200MB` - Frame rate: `24` ~ `60` FPS - Total request body size must not exceed `64MB`, do not use Base64 encoding - Specific codec, resolution, and other media validity checks are performed by the model - Using video references will increase costs (input video duration is counted in billing) - Video URLs must be directly accessible by the server items: type: string format: uri minItems: 1 maxItems: 5 example: - https://example.com/reference.mp4 audio_urls: type: array description: >- Reference audio URL array, **optional; 1–5 clips when provided** **Requirement:** At least one of `image_urls`, `video_urls`, or `audio_urls` must be provided. **Role description:** | Media Type | Role | Typical Usage | |---------|------|----------| | Audio | `reference_audio` | Background music, sound effects, voice/dialogue reference | **Audio requirements:** - Supported formats: `.wav`, `.mp3` - Duration per clip: `2` ~ `30` seconds, max 5 clips, total duration of all audio ≤ `30` seconds - Max size per clip: `15MB` - Total request body size must not exceed `64MB`, do not use Base64 encoding - Audio URLs must be directly accessible by the server items: type: string format: uri minItems: 1 maxItems: 5 example: - https://example.com/bgm.mp3 duration: type: integer description: >- Output video duration (seconds), defaults to `5` seconds **Details:** - Supports any integer value between `4`–`30` seconds - Automatic duration (`-1`) is not supported; passing it returns a 400 parameter error - Duration directly affects billing **Billing rules:** - Billed per second - Billable duration: without reference videos, the output duration; with reference videos, `output duration + max(total reference video duration, output duration)` - The total reference video duration is rounded up to the next whole second default: 5 example: 10 minimum: 4 maximum: 30 quality: type: string description: |- Video resolution, defaults to `720p` **Options:** - `480p`: Lower clarity, lower cost - `720p`: Standard clarity, this is the default enum: - 480p - 720p default: 720p example: 720p aspect_ratio: type: string description: >- Video aspect ratio, defaults to `16:9` **Options:** - `16:9` (landscape), `9:16` (portrait), `1:1` (square), `4:3`, `3:4`, `21:9` (ultrawide) - Automatic aspect ratio (`adaptive`) is not supported; passing it returns a 400 parameter error **Pixel values per resolution:** | Aspect Ratio | 480p | 720p | |:------:|:----:|:----:| | 16:9 | 854×480 | 1280×720 | | 4:3 | 752×560 | 1112×834 | | 1:1 | 640×640 | 960×960 | | 3:4 | 560×752 | 834×1112 | | 9:16 | 480×854 | 720×1280 | | 21:9 | 992×432 | 1470×630 | enum: - '16:9' - '9:16' - '1:1' - '4:3' - '3:4' - '21:9' default: '16:9' example: '16:9' generate_audio: type: boolean description: |- Whether to generate synchronized audio, defaults to `true` **Options:** - `true`: Video includes synchronized audio at no additional charge - `false`: Output silent video default: true example: true callback_url: type: string description: >- HTTPS callback URL for task completion **Callback timing:** - Triggered when the task is completed or failed - Sent after billing confirmation is complete **Security restrictions:** - Only HTTPS protocol is supported - Callbacks to private IP addresses are prohibited (127.0.0.1, 10.x.x.x, 172.16-31.x.x, 192.168.x.x, etc.) - URL length must not exceed `2048` characters **Callback mechanism:** - Timeout: `10` seconds - Up to `3` retries after failure (at `1`/`2`/`4` seconds after failure respectively) - Callback response body format is consistent with the task query endpoint response format - A 2xx status code is considered successful; other status codes trigger retries format: uri example: https://your-domain.com/webhooks/video-task-completed VideoGenerationResponse: type: object properties: created: type: integer description: Task creation timestamp example: 1761313744 id: type: string description: Task ID example: task-unified-1774857405-abc123 model: type: string description: Actual model name used example: seedance-2.5-flash-reference-to-video object: type: string enum: - video.generation.task description: Specific type of the task progress: type: integer description: Task progress percentage (0-100) minimum: 0 maximum: 100 example: 0 status: type: string description: Task status enum: - pending - processing - completed - failed example: pending task_info: $ref: '#/components/schemas/VideoTaskInfo' description: Video task details type: type: string enum: - text - image - audio - video description: Output type of the task example: video usage: $ref: '#/components/schemas/VideoUsage' description: Usage and billing information ErrorResponse: type: object properties: error: type: object properties: code: type: string description: Error code identifier message: type: string description: Error description message type: type: string description: Error type VideoTaskInfo: type: object properties: can_cancel: type: boolean description: >- Whether the task can be cancelled. Seedance 2.5 Flash does not support user cancellation; this field always returns `false`. example: false estimated_time: type: integer description: Estimated completion time (seconds) minimum: 0 example: 165 video_duration: type: integer description: Video duration (seconds) example: 8 VideoUsage: type: object description: Usage and billing information properties: billing_rule: type: string description: Billing rule enum: - per_call - per_token - per_second example: per_second credits_reserved: type: number description: Estimated credits consumed minimum: 0 example: 50 user_group: type: string description: User group category example: default securitySchemes: bearerAuth: type: http scheme: bearer description: >- ##All endpoints require Bearer Token authentication## **Get API Key:** Visit the [API Key Management Page](https://evolink.ai/dashboard/keys) to obtain your API Key **Add to request header:** ``` Authorization: Bearer YOUR_API_KEY ``` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.