Seedance 2.5 Edit API

ByteDancevideo$2.34 / run

Submit a Seedance 2.5 Edit run over HTTP, then poll it or take a webhook. Results are files on media.ezflows.io. Try it in the playground first.

Async: the POST answers at once with a request id. Poll it, or take the webhook.

Docs

Submit

Parameters at the top level of the JSON body. Answers 202 with a request id.

curlPOST /v1/models/seedance-2.5-edit

curl -X POST https://api.ezflows.io/v1/models/seedance-2.5-edit \
  -H "Authorization: Bearer $EZFLOWS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "video": "https://media.ezflows.io/inputs/<account>/<upload-id>.mp4",
    "prompt": "a wide shot of a desert at dusk",
    "resolution": "720p"
  }'

# 202 Accepted, at once — it never waits for the model:
# {"request_id": "req_8f2a41c9b70e4d15", "status": "queued",
#  "poll_url": "https://api.ezflows.io/v1/requests/req_8f2a41c9b70e4d15"}

Poll

Same bearer header, every few seconds, until the status is final.

curlGET /v1/requests/:id

REQUEST_ID=req_8f2a41c9b70e4d15   # from the POST

while :; do
  BODY=$(curl -s https://api.ezflows.io/v1/requests/$REQUEST_ID \
    -H "Authorization: Bearer $EZFLOWS_API_KEY")
  STATUS=$(echo "$BODY" | jq -r .data.status)
  case "$STATUS" in succeeded|failed|cancelled) break ;; esac
  sleep 3
done

echo "$BODY" | jq -r '.data.output.artifacts[].url'   # media.ezflows.io, kept 90 days

Response

Files are on media.ezflows.io, kept 90 days. A failed run says why and costs nothing.

json200 · succeeded

{
  "data": {
    "id": "req_8f2a41c9b70e4d15",
    "model_slug": "seedance-2.5-edit",
    "status": "succeeded",
    "http_status": 200,
    "cost": 2.338065,
    "auth_method": "api_key",
    "error": null,
    "submitted_at": "2026-09-12T18:07:21.114Z",
    "queue_started_at": "2026-09-12T18:07:21.402Z",
    "execution_started_at": "2026-09-12T18:07:22.010Z",
    "first_byte_at": "2026-09-12T18:07:52.871Z",
    "finished_at": "2026-09-12T18:07:55.203Z",
    "io_deleted_at": null,
    "canvas_id": null,
    "canvas_node_id": null,
    "client_attempt_id": null,
    "idempotency_key": null,
    "input": {
      "video": "https://media.ezflows.io/inputs/<account>/<upload-id>.mp4",
      "prompt": "a wide shot of a desert at dusk",
      "resolution": "720p"
    },
    "output": {
      "artifacts": [
        {
          "index": 0,
          "kind": "video",
          "contentType": "video/mp4",
          "url": "https://media.ezflows.io/outputs/<account>/req_8f2a41c9b70e4d15/0.mp4"
        }
      ]
    }
  }
}

Webhook

Skip polling: we POST the result to your endpoint, at least once.

Register: Create an endpoint under Webhooks in the dashboard; the signing secret is shown once.
Events: request.succeeded · request.failed · request.cancelled
Headers: ezflows-event-id (dedupe on it) · ezflows-timestamp (unix seconds) · ezflows-signature t=<ts>,v1=<hex HMAC-SHA256 of "<ts>.<raw body>">
Verify: Over the exact bytes received, in constant time; reject anything older than five minutes.
Respond: Any 2xx within 10 s. Redirects are not followed.
Retries: Five, with backoff: 30 s · 60 s · 2 min · 4 min · 8 min. Disabled after five consecutive dead deliveries.

jsonDelivery body

{
  "id": "82cf46a4-841e-41d6-b3c7-facc937d3252",
  "type": "request.succeeded",
  "created_at": "2026-09-12T18:07:55Z",
  "data": {
    "id": "req_8f2a41c9b70e4d15",
    "model_slug": "seedance-2.5-edit",
    "status": "succeeded",
    "cost": 2.338065,
    "output": {
      "artifacts": [
        {
          "url": "https://media.ezflows.io/…/0.mp4"
        }
      ]
    }
  }
}

curlverify.sh

# Create the endpoint under Webhooks in the dashboard; the signing secret is shown once.
# ezflows-signature: t=<ts>,v1=<hex HMAC-SHA256 of "<ts>.<raw body>">
# body.json = the exact bytes received. Reject anything older than five minutes.
EXPECTED=$({ printf '%s.' "$TS"; cat body.json; } \
  | openssl dgst -sha256 -hmac "$EZFLOWS_WEBHOOK_SECRET" -r | cut -d' ' -f1)

[ "$EXPECTED" = "$V1" ] && echo "valid" || echo "reject"

Parameters 12

Name	Type	Default	Allowed	Description
videorequired	string	—	one video url	The clip to edit (@Video 1): 4-30 seconds, mp4 or mov, 480p-4k, up to 200MB. The output keeps its aspect ratio and length. Real human faces are blocked by the provider's content policy.
promptrequired	string	—	—	What to change in @Video 1: add, remove, replace or change something, or edit the audio. Everything you do not mention stays as it is. Cite extra references as '@Image 1', '@Audio 1'. If the prompt names no edit, 'Edit @Video 1:' is prepended.
reference_images	string[]	—	up to 30 image urls	Up to 30 reference images (max 30MB each) for character/style consistency. Cite as '@Image 1', '@Image 2' in your prompt. Cannot be used together with first_frame_url.
reference_audios	string[]	—	up to 10 audio urls	Up to 10 reference audio files (MP3, 2-30 seconds each, 30 seconds combined, max 15MB each). Cite as '@Audio 1' in your prompt. Audio-only reference is supported on seedance-2.5.
resolution	enum	720p	480p · 720p · 1080p	Output resolution. seedance-2.5 supports 480p, 720p and 1080p (24fps). Use 480p for drafts and fast iteration, 720p for final renders, 1080p for the highest fidelity (10-bit colour). Higher resolution costs more (token-based).
auto_resize	boolean	true	—	Automatically resizes an input image that falls outside the provider's accepted range (300-6000px per side, aspect ratio 0.4-2.5, 30MB) so the request succeeds instead of being rejected. Aspect ratio is preserved: oversized images are downscaled, undersized ones upscaled, and out-of-band ratios padded rather than cropped. On by default - set it to false to have the provider reject out-of-range images instead. When a resize happens the response carries an X-Input-Normalized header naming the field and the before/after dimensions.
bitrate_mode	enum	standard	standard · high	Output video encoding bitrate. 'standard' gives smaller files and faster downloads; 'high' produces ~5-6x higher bitrate for better visual fidelity and fewer compression artifacts (larger files). Does not affect price.
generate_audio	boolean	true	—	true keeps the clip's soundtrack (a silent clip gets generated sound; an audio edit in the prompt changes it). false delivers the video with no audio track at all, not the original audio.
output_codec	enum	auto	auto · h264	Codec of the delivered file. 'auto' returns the model's own encode untouched - for seedance-2.5 at 1080p that is 10-bit HEVC, the highest-fidelity master, which Chrome and Firefox on Windows cannot decode and will play as audio over a blank frame. 'h264' re-encodes it to H.264 High 8-bit yuv420p, which plays everywhere, at the cost of one additional generation of compression and half the bit depth; pick it for browser embeds and previews, and leave it on 'auto' when the file goes into an edit or grade. Output that is already H.264 (720p, 480p, the 2.0 series) is never re-encoded either way. Adds a few seconds when it applies, and does not affect price.
output_format	enum	mp4	mp4 · mov	mp4 = best compatibility. mov (H.264 + yuv444p + PCM) = higher color fidelity; recommended for video editing/extension round-trips.
return_last_frame	boolean	false	—	Returns the final video frame as a separate image, delivered in the response as `video.last_frame_url`. Chain shots by feeding that URL into the next generation's `first_frame_url`. Note this is an output: it is distinct from the `last_frame_url` input parameter, which is an image you supply to steer how the clip ends.
seed	integer	-1	-1–2147483647	Reproducibility seed. Use -1 for random output, set a fixed value to iterate on the same scene.

File inputs (video: one video url · reference_images: up to 30 image urls · reference_audios: up to 10 audio urls) take URLs. Upload the raw file to POST /v1/uploads with its own Content-Type and pass the url it returns. Inputs are kept 90 days.

Submit

Poll

Response

Webhook

Parameters 12

Related models