Use Veo3.1 Fast through Rivya Public API v1 with model id veo3-1-fast, supported inputs, parameters, Files API rules, credits, and response examples.

Available via APIText or URL ready; reference modes use Files APIVideo

API model id

veo3-1-fast

Inputs

text, file

Files API

Required for reference modes

Base credits

Capability

Video

Billing

FIXED

Prompt limit

5000 characters

Request contract

Send the model id at the top level. Model-specific controls belong in params.

Key	Type	Required	Default	Description
model	string	Yes	veo3-1-fast	Use the veo3-1-fast API model id.
prompt	string	Yes	-	Maximum 5000 characters for this model.
params	object	No	-	Model-specific parameter object. Use the rows below for allowed keys.
client_request_id	string	No	-	Optional client-side id for tracing requests in your system.

Model parameters

Key	Type	Required	Default	Range	Options	Description
generationType	select	No	FIRST_AND_LAST_FRAMES_2_VIDEO	-	FIRST_AND_LAST_FRAMES_2_VIDEO, REFERENCE_2_VIDEO	Generation mode
aspectRatio	select	No	16:9	-	16:9, 9:16, Auto	Aspect ratio
watermark	text	No	-	-	-	Watermark text
seeds	number	No	-	min 10000 / max 99999 / step 1	-	Leave it empty for a new random result each time. Reusing the same integer makes it easier to reproduce or fine-tune a previous result. It stays closer only when the prompt and other key settings also remain similar, and it is not a guaranteed 1:1 match.
enableTranslation	select	No	true	-	true, false	Prompt translation

Upload policy

Upload reference files first, then place the returned URL and duration token inside params.referenceMediaItems.

Reference rule

Reference image: Upload up to 3 image files for image and reference-driven projects.

Max files

Accepted file kinds

image

Duration token

Video and audio references should carry durationToken from /api/v1/files when duration verification is required.

kind	Max size	MIME types
image	10 MB	image/jpeg, image/png, image/webp

Minimal request

{
  "model": "veo3-1-fast",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "generationType": "FIRST_AND_LAST_FRAMES_2_VIDEO",
    "aspectRatio": "16:9",
    "watermark": "Optional watermark text",
    "seeds": 10000,
    "enableTranslation": "true"
  }
}

Reference-file request

{
  "model": "veo3-1-fast",
  "prompt": "A cinematic product reveal with smooth camera movement",
  "params": {
    "generationType": "FIRST_AND_LAST_FRAMES_2_VIDEO",
    "aspectRatio": "16:9",
    "watermark": "Optional watermark text",
    "seeds": 10000,
    "enableTranslation": "true",
    "referenceMediaItems": [
      {
        "url": "https://cdn.example.com/reference-image.png",
        "kind": "image",
        "name": "reference-image.png",
        "mimeType": "image/png"
      }
    ]
  }
}

Create response

The create endpoint returns a public task id. Poll the status endpoint until the task succeeds or fails.

{
  "id": "task_veo3_1_fast_example",
  "status": "queued",
  "model": "veo3-1-fast",
  "reserved_credits": 20,
  "final_credits": 0,
  "created_at": "2026-05-11T00:00:00.000Z",
  "updated_at": "2026-05-11T00:00:00.000Z",
  "result": null,
  "error": null
}

Common errors

validation_failed, insufficient_credits, idempotency_conflict, rate_limited, not_found

Some modes require Files API reference uploads.

Veo3.1 Fast API Integration