Genie
Documentation

Video transitions

Frame-to-frame: animate from a start frame, optionally toward an end frame, with optional motion guidance — image-to-video / keyframe morph. Same async contract as video generation: 202 + job id, poll GET /v1/jobs/:id or supply a webhook.

Endpoint

POST https://api.genie.tech/v1/videos/transitions
Authorization: Bearer sk-genie-{your-key}
Content-Type: application/json

Try it

Submission accepts strict snake_case fields. On a runner that has the diffusion model loaded, the kickoff returns 202 + a polling URL and the eventual GET /v1/jobs/:id resolves to a WebM URL. When the model is not installed on the serving ComfyUI, the failed-poll response now carries code: "comfyui-model-missing" with the requested model and a upstreamError field so SDK clients can branch — instead of an opaque inference-failed with a deeply-escaped JSON wad in message.

Try it nowTransition kickoff (async)
Start frame preview
data URI (~12 KB)
End frame preview
data URI (~21 KB)

Upload a file (encoded inline as a data: URI) or paste an https image URL. Start is required; end is optional — omit it for single-keyframe animate.

Sign in to tryPOST /api/v1/videos/transitions

SDK + curl

# Submit (start frame -> optional end frame)
curl https://api.genie.tech/v1/videos/transitions \
  -H "Authorization: Bearer $GENIE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "wan-2.1",
    "start_image": "https://cdn.example/frame-a.png",
    "end_image": "https://cdn.example/frame-b.png",
    "prompt": "smooth cinematic morph",
    "duration_seconds": 3,
    "size": "512x512"
  }'

# Poll
curl https://api.genie.tech/v1/jobs/$JOB_ID \
  -H "Authorization: Bearer $GENIE_API_KEY"

Request body

  • model — wan-2.1 | ltx-video (free tier auto-substitutes to ltx-video).
  • start_image — required. An https:// URL or a data:image/... URI.
  • end_image — optional second keyframe. Omit for single-keyframe animate; supply for a frame-to-frame transition.
  • prompt — optional motion guidance (≤ 2000 chars). Empty = pure keyframe morph.
  • duration_seconds — 1–15, default 4.
  • size — 512x512 | 720x720 | 1280x720 | 1920x1080.
  • seed, negative_prompt — optional.
  • webhook — { url, secret? }; called when the job finishes.

Validation errors always include informative details (never an opaque {}).

Kickoff response

{
  "id": "vidgen-cmoz...",
  "object": "video.transition",
  "status": "queued",
  "poll_url": "/v1/jobs/cmoz...",
  "created": 1731020000
}

Completed response (poll)

{
  "id": "vidgen-cmoz...",
  "status": "completed",
  "result": {
    "url": "https://blob.genie.tech/.../transition.mp4",
    "duration_ms": 9800
  }
}
Frame URLs are SSRF-guarded. An https:// start_image/end_image pointing at link-local/metadata addresses (e.g. 169.254.169.254) is rejected before any job is enqueued — same defense as webhook.url. data: URIs are inert (never fetched).