> ## Documentation Index > Fetch the complete documentation index at: https://docs.anyfast.ai/llms.txt > Use this file to discover all available pages before exploring further. # Seedance 2.0 > ByteDance's Seedance 2.0 video generation model with multimodal reference, video editing, extension, audio generation, and web search. Seedance 2.0 is ByteDance's latest video generation model available through Anyfast API. It supports text-to-video, image-to-video, multimodal reference input, video editing, video extension, and synchronized audio generation. ## Key capabilities | Feature | Description | | ----------------------------------- | ------------------------------------------------------------------------------------------------- | | Text-to-video | Generate video from text prompts | | Image-to-video (first frame) | Use an image as the first frame | | Image-to-video (first + last frame) | Use two images as first and last frames | | Multimodal reference | Combine images, videos, and audio as references (0–9 images, up to 3 videos, up to 3 audio clips) | | Video editing | Modify elements in an existing video using reference images | | Video extension | Extend and concatenate reference videos | | Audio generation | Auto-generate synchronized voice, sound effects, and background music | | Web search | Enhance generation with real-time internet content (text-to-video only) | | Return last frame | Retrieve the last frame of generated video | ## Output specifications | Property | Value | | ------------ | ----------------------------------------- | | Resolution | 480p, 720p, 1080p, 4k | | Aspect ratio | 16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive | | Duration | 4–15 seconds | | Format | mp4 | | Frame rate | 24 fps | ## Workflow ``` 1. POST /v1/video/generations → task_id 2. Poll GET /v1/video/generations/{task_id} → status 3. When status = "succeeded" → download video URL (valid 24 hours) ``` ## Asset management workflow To use persistent image, video, or audio assets (such as a fixed character reference), upload them via the Asset Management API and reference them with `asset://` in generation requests. ### Step 1: Create an asset group Create an asset group to get a group ID. ```bash theme={null} curl https://www.anyfast.ai/volc/asset/CreateAssetGroup \ -H 'Authorization: Bearer YOUR_KEY' \ -H 'Content-Type: application/json' \ -d '{ "model": "volc-asset", "Name": "your-custom-name" }' ``` Response example: ```json theme={null} { "Id": "group-20260427160000-xxxxx" } ``` *** ### Step 2: Create an asset in the group Use the group ID from Step 1 to upload an image asset (e.g., a character face reference photo). ```bash theme={null} curl https://www.anyfast.ai/volc/asset/CreateAsset \ -H 'Authorization: Bearer YOUR_KEY' \ -H 'Content-Type: application/json' \ -d '{ "model": "volc-asset", "GroupId": "group-20260427160000-xxxxx", "Name": "character-reference", "AssetType": "Image", "URL": "https://example.com/example.png" }' ``` Response example: ```json theme={null} { "Id": "asset-20260427160000-xxxxx" } ``` *** ### Step 3: Generate a video using the asset Reference the asset ID from Step 2 to generate a video. ```bash theme={null} curl https://www.anyfast.ai/v1/video/generations \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "seedance-2.0", "content": [ { "type": "text", "text": "The person from @image1 walks along a sunlit street, cinematic quality" }, { "type": "image_url", "image_url": { "url": "asset://asset-20260427160000-xxxxx" }, "role": "reference_image" } ], "resolution": "720p", "duration": 5 }' ``` The API returns an asynchronous task ID (prefixed with `asyn`). *** ### Step 4: Poll for the result Query the generation status using the task ID. ```bash theme={null} curl https://www.anyfast.ai/v1/video/generations/asynxxxx \ -H "Authorization: Bearer YOUR_API_KEY" ``` Once the task completes, the response includes a pre-signed S3 download link. > **Notes** > > * Download links expire after 12 hours; re-fetch after expiry. > * If the task reaches 100% but returns an error, the content was likely blocked by the provider's content moderation system (e.g., celebrity likeness or copyrighted content). Try modifying the prompt or replacing the reference image. ## Examples ### Text-to-video ```bash cURL theme={null} curl https://www.anyfast.ai/v1/video/generations \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "seedance-2.0", "content": [ { "type": "text", "text": "A cat playing piano in a sunlit room, cinematic lighting" } ], "generate_audio": true, "ratio": "16:9", "duration": 8 }' ``` ```python Python theme={null} import requests import time headers = {"Authorization": "Bearer YOUR_API_KEY", "Content-Type": "application/json"} # Step 1: create task resp = requests.post( "https://www.anyfast.ai/v1/video/generations", headers=headers, json={ "model": "seedance-2.0", "content": [ {"type": "text", "text": "A cat playing piano in a sunlit room, cinematic lighting"} ], "generate_audio": True, "ratio": "16:9", "duration": 8 } ) task_id = resp.json()["task_id"] # Step 2: poll for result while True: result = requests.get( f"https://www.anyfast.ai/v1/video/generations/{task_id}", headers=headers ).json() status = result["data"]["status"] if status == "SUCCESS": print("Video URL:", result["data"]["data"]["content"]["video_url"]) break elif status == "FAILED": print("Failed:", result["data"].get("fail_reason")) break time.sleep(5) ``` ### Multimodal reference (image + video + audio) Reference assets in the prompt with `@image1`, `@video1`, `@audio1` — numbered per media type by their order in the `content` array. > **Important:** Assets must be passed in strict order: `text`, `image_url`, `video_url`, `audio_url`. Do not reorder them — doing so may cause errors. When multiple assets are included, do not mix in other asset types. ```bash cURL theme={null} curl https://www.anyfast.ai/v1/video/generations \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "seedance-2.0", "content": [ { "type": "text", "text": "The character from @image1 dances in the scene from @video1, with @audio1 as background music" }, { "type": "image_url", "image_url": {"url": "https://example.com/character.jpg"}, "role": "reference_image" }, { "type": "video_url", "video_url": {"url": "https://example.com/clip.mp4"}, "role": "reference_video" }, { "type": "audio_url", "audio_url": {"url": "https://example.com/bgm.mp3"}, "role": "reference_audio" } ], "generate_audio": true, "ratio": "16:9", "duration": 11 }' ``` ### Video editing ```bash cURL theme={null} curl https://www.anyfast.ai/v1/video/generations \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "seedance-2.0", "content": [ { "type": "text", "text": "Replace the water bottle in @video1 with the perfume bottle from @image1, keep camera movement unchanged" }, { "type": "image_url", "image_url": {"url": "https://example.com/perfume.jpg"}, "role": "reference_image" }, { "type": "video_url", "video_url": {"url": "https://example.com/original.mp4"}, "role": "reference_video" } ], "generate_audio": true, "ratio": "16:9", "duration": 5 }' ``` ### Web search enhanced (text-to-video only) ```bash cURL theme={null} curl https://www.anyfast.ai/v1/video/generations \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "seedance-2.0", "content": [ { "type": "text", "text": "Macro shot of cherry blossoms in spring, petals falling slowly" } ], "generate_audio": true, "ratio": "16:9", "duration": 11, "tools": [{"type": "web_search"}] }' ``` ## Parameters | Parameter | Type | Required | Description | | ------------------------- | ------- | ----------- | ----------------------------------------------------------------------------------------- | | `model` | string | Yes | `seedance-2.0` | | `content` | array | Yes | Input content array (text, image\_url, video\_url, audio\_url items) | | `content[].type` | string | Yes | `text`, `image_url`, `video_url`, or `audio_url` | | `content[].text` | string | Text items | Text prompt (max 500 Chinese chars / 1000 English words) | | `content[].image_url.url` | string | Image items | Image URL, Base64 data URI, or `asset://` | | `content[].video_url.url` | string | Video items | Video URL or `asset://` (mp4/mov, max 50 MB, 2–15s) | | `content[].audio_url.url` | string | Audio items | Audio URL, Base64 data URI, or `asset://` (wav/mp3, max 15 MB) | | `content[].role` | string | Conditional | `first_frame`, `last_frame`, `reference_image`, `reference_video`, `reference_audio` | | `generate_audio` | boolean | No | Generate synchronized audio. Default: `true` | | `resolution` | string | No | `480p`, `720p`, `1080p`, or `4k`. Default: `720p`. (4k is supported only by Seedance 2.0) | | `ratio` | string | No | `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `adaptive`. Default: `adaptive` | | `duration` | integer | No | 4–15 seconds. Default: `5` | | `tools` | array | No | `[{"type": "web_search"}]` for web search (text-to-video only) | | `watermark` | boolean | No | Add watermark. Default: `false` | ### Input modes | Mode | Content items | `role` values | | ----------------------------------- | ----------------------------------- | ------------------------------------------------------- | | Text-to-video | 1× text | — | | Image-to-video (first frame) | text (optional) + 1× image\_url | `first_frame` or omit | | Image-to-video (first + last frame) | text (optional) + 2× image\_url | `first_frame` + `last_frame` | | Multimodal reference | text (optional) + image/video/audio | `reference_image`, `reference_video`, `reference_audio` | | Video editing | text + image\_url + video\_url | `reference_image` + `reference_video` | | Video extension | text + video\_url(s) | `reference_video` | > **Note:** First frame, first+last frame, and multimodal reference are mutually exclusive — do not mix them in the same request. ### Referencing assets in prompts Inside the text prompt, you can refer to media items using `@` placeholders — numbered **per media type by their order** in the `content` array: | Placeholder | Refers to | | ------------------------- | ---------------------------------- | | `@image1`, `@image2`, ... | The 1st, 2nd, ... `image_url` item | | `@video1`, `@video2`, ... | The 1st, 2nd, ... `video_url` item | | `@audio1`, `@audio2`, ... | The 1st, 2nd, ... `audio_url` item | Example: `"The character from @image1 walks through the scene in @video1 with @audio1 as background"`. > **Note:** Assets must be passed in strict order: `text`, `image_url`, `video_url`, `audio_url`. Do not reorder them — doing so may cause errors. When multiple assets are included, do not mix in other asset types. ### Resolution pixel values | Resolution | 16:9 | 4:3 | 1:1 | 3:4 | 9:16 | 21:9 | | ---------- | --------- | --------- | --------- | --------- | --------- | --------- | | 480p | 864x496 | 752x560 | 640x640 | 560x752 | 496x864 | 992x432 | | 720p | 1280x720 | 1112x834 | 960x960 | 834x1112 | 720x1280 | 1470x630 | | 1080p | 1920x1080 | 1664x1248 | 1440x1440 | 1248x1664 | 1080x1920 | 2208x944 | | 4k | 3840x2160 | 3326x2494 | 2880x2880 | 2494x3326 | 2160x3840 | 4398x1886 | > **Note:** 4k resolution is supported only by Seedance 2.0 (not Fast, Mini, or Ultra). View the interactive API playground for Seedance 2.0.