ByteDance Seedance 2.0 (Fast)

ByteDance Seedance 2.0 on the EachLabs Predictions API. Seedance 2.0 generates cinematic video with native synchronized audio (sound effects, ambient sound, lip-synced speech), realistic physics, and director-level camera control.

Two model slugs:

Slug	Category	Use
`bytedance-seedance-2-0-text-to-video-fast`	Text to Video	Generate a video from a prompt
`bytedance-seedance-2-0-image-to-video-fast`	Image to Video	Animate a starting frame (optionally to an end frame)

The "Fast" tier prioritizes rapid turnaround for high-throughput pipelines while keeping the family's character consistency and physics.

When to use

User asks for "Seedance 2.0", "ByteDance video", or wants a Seedance-style look.
Native audio required in the same pass (dialogue, SFX, ambience) — no separate TTS/lipsync step.
Cinematic motion, realistic physics, or director-level camera language ("slow push in", "rack focus").
Durations of 4–15 seconds at 480p or 720p.
Image-to-video with an end frame to control where the clip lands.

For a wider video-model comparison (Veo, Kling, Sora, Pixverse, Hailuo, etc.) see

eachlabs-video-generation

Authentication

Header: X-API-Key: <your-api-key>

Set the

EACHLABS_API_KEY

environment variable. Get your key at eachlabs.ai/dashboard/api-keys.

Prediction Flow

(Recommended) Check schema —

GET https://api.eachlabs.ai/v1/model?slug=bytedance-seedance-2-0-text-to-video-fast

(or the i2v slug).

POST

https://api.eachlabs.ai/v1/prediction

with

model

version: "0.0.1"

, and

input

Poll

GET https://api.eachlabs.ai/v1/prediction/{id}

until

status

"success"

"error"

, or use a webhook.

Extract the video URL from
```
output
```
(string).

Quick Start — Text to Video

bash

curl -X POST https://api.eachlabs.ai/v1/prediction \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "model": "bytedance-seedance-2-0-text-to-video-fast",
    "version": "0.0.1",
    "input": {
      "prompt": "Cinematic slow push-in on a lone astronaut standing at the edge of a Martian canyon at dusk, dust drifting across their boots, distant wind, subtle helmet reflections",
      "resolution": "720p",
      "duration": "6",
      "aspect_ratio": "16:9",
      "generate_audio": true
    }
  }'

Typical processing time: ~120 seconds.

Quick Start — Image to Video

bash

curl -X POST https://api.eachlabs.ai/v1/prediction \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $EACHLABS_API_KEY" \
  -d '{
    "model": "bytedance-seedance-2-0-image-to-video-fast",
    "version": "0.0.1",
    "input": {
      "prompt": "Camera slowly pushes from wide to medium close-up as the lion roars at golden hour. Warm amber light rakes across the mane. Narrator (weathered British male, 50s): \"He has ruled this land for seven years.\"",
      "image_url": "https://your-cdn.example.com/lion.jpg",
      "resolution": "720p",
      "duration": "8",
      "aspect_ratio": "16:9",
      "generate_audio": true
    }
  }'

Typical processing time: ~150 seconds.

Start-to-end transition

Pass

end_image_url

to lock the final frame and let the model interpolate motion between the two:

json

{
  "model": "bytedance-seedance-2-0-image-to-video-fast",
  "version": "0.0.1",
  "input": {
    "prompt": "Smooth parallax zoom through the scene, crossfading into the second look",
    "image_url": "https://your-cdn.example.com/frame-start.jpg",
    "end_image_url": "https://your-cdn.example.com/frame-end.jpg",
    "duration": "6",
    "resolution": "720p"
  }
}

Polling

bash

curl https://api.eachlabs.ai/v1/prediction/{PREDICTION_ID} \
  -H "X-API-Key: $EACHLABS_API_KEY"

Status	Meaning
`processing`	Still running — poll again
`success`	Done — read `output` (video URL)
`error`	Failed — read `message` / `details`

Webhook (alternative to polling)

Pass

"webhook_url": "https://your.host/path"

in the create body. EachLabs POSTs:

json

{
  "exec_id": "prediction-uuid",
  "status": "succeeded",
  "output": "https://...",
  "error": ""
}

status

"succeeded"

"failed"

. Return 2xx within 30 seconds.

Parameters (both slugs share most of these)

Parameter	Type	Required	Default	Options	Description
`prompt`	string	Yes	—	—	Text prompt. For i2v, describes the motion/action; supports timeline prompting and dialogue lines for native audio.
`image_url`	string	Yes (i2v only)	—	JPEG / PNG / WebP, max 30 MB	Starting frame. Publicly reachable HTTPS URL.
`end_image_url`	string	No (i2v only)	—	JPEG / PNG / WebP, max 30 MB	Final frame; model interpolates between `image_url` and this.
`resolution`	string	No	`720p`	`480p` , `720p`	480p = faster/cheaper, 720p = balanced.
`duration`	string	No	`auto`	`auto` , `4` … `15`	Clip length in seconds. `auto` lets the model pick from the prompt.
`aspect_ratio`	string	No	`auto`	`auto` , `21:9` , `16:9` , `4:3` , `1:1` , `3:4` , `9:16`	For i2v, `auto` infers from the input image.
`generate_audio`	boolean	No	`true`	—	Synchronized SFX, ambience, and lip-synced speech. Cost is the same whether on or off.
`seed`	string	No	—	—	Reproducibility hint — results may still drift slightly.
`end_user_id`	string	No	—	—	Your end-user identifier.

Pricing

Dynamic, charged per second of output video:

Resolution	Rate
480p	$0.1129 / second
720p (default)	$0.2419 / second

Audio generation does not change cost. A 6-second 720p clip ≈ $1.45; a 10-second 480p clip ≈ $1.13.

Prompt Tips

Timeline prompting: sequence beats with time or cut words — "Wide shot: … Cut to close-up: … Finally: …". Seedance 2.0 respects temporal structure better than single-sentence prompts.
Dialogue with native audio: write the line in quotes and describe the speaker ("Weathered British male narrator, 50s, calm authoritative voice, says: …"). Lip-sync and ambience are generated in the same pass.
Camera language: use real film vocabulary ("slow push-in", "rack focus", "dolly left", "handheld", "crane up"). The model follows director-level cues.
Physics cues: mention weight, momentum, and material interactions ("dust scatters as boot lands", "fabric settles after the spin") to unlock the realistic-physics behavior.

Rate Limits & Limits

Limit	Value
Create requests	100 / minute per key
Concurrent predictions	10 per key
File inputs	Publicly reachable HTTPS URLs only (JPEG/PNG/WebP, max 30 MB). No data-URIs, no localhost.

Errors

Error body:

{ "status": "error", "message": "...", "details": "..." }

Code	Meaning
400	Invalid input
401	Missing / invalid `X-API-Key`
404	Unknown model or prediction id
429	Rate limited — back off
5xx	Retry with exponential backoff

Security Constraints

No arbitrary URL loading:
```
image_url
```
/
```
end_image_url
```
must point to your own HTTPS-reachable storage (S3, GCS, CDN). Do not forward user-pasted URLs without validation.
No third-party API tokens: never forward provider tokens through
```
input
```
— authentication is exclusively via the EachLabs API key.
Validate before calling: resolve the live
```
request_schema
```
via
```
GET /v1/model?slug=<slug>
```
before constructing
```
input
```
.

Parameter Reference

See references/MODELS.md for the full per-slug table with defaults and options.

bytedance-seedance-2-0

NPX Install

Tags

SKILL.md Content

ByteDance Seedance 2.0 (Fast)

When to use

Authentication

Prediction Flow

Quick Start — Text to Video

Quick Start — Image to Video

Start-to-end transition

Polling

Webhook (alternative to polling)

Parameters (both slugs share most of these)

Pricing

Prompt Tips

Rate Limits & Limits

Errors

Security Constraints

Parameter Reference