ai-video-gen

Video Generation (HeyGen API)

Generate AI videos from text prompts. Supports multiple providers (VEO 3.1, Kling, Sora, Runway, Seedance), configurable aspect ratios, and optional reference images for image-to-video generation.

Authentication

All requests require the X-Api-Key header. Set the HEYGEN_API_KEY environment variable.

curl -X POST "https://api.heygen.com/v1/workflows/executions" \
  -H "X-Api-Key: $HEYGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"workflow_type": "GenerateVideoNode", "input": {"prompt": "A drone shot flying over a coastal city at sunset"}}'

Default Workflow

1. Call POST /v1/workflows/executions with workflow_type: "GenerateVideoNode" and your prompt
2. Receive a execution_id in the response
3. Poll GET /v1/workflows/executions/{id} every 10 seconds until status is completed
4. Use the returned video_url from the output

Execute Video Generation

Endpoint

POST https://api.heygen.com/v1/workflows/executions

Request Fields

Field	Type	Req	Description
workflow_type	string	Y	Must be "GenerateVideoNode"
input.prompt	string	Y	Text description of the video to generate
input.provider	string		Video generation provider (default: "veo_3_1"). See Providers below.
input.aspect_ratio	string		Aspect ratio (default: "16:9"). Common values: "16:9", "9:16", "1:1"
input.reference_image_url	string		Reference image URL for image-to-video generation
input.tail_image_url	string		Tail image URL for last-frame guidance
input.config	object		Provider-specific configuration overrides

Providers

Provider	Value	Description
VEO 3.1	"veo_3_1"	Google VEO 3.1 (default, highest quality)
VEO 3.1 Fast	"veo_3_1_fast"	Faster VEO 3.1 variant
VEO 3	"veo3"	Google VEO 3
VEO 3 Fast	"veo3_fast"	Faster VEO 3 variant
VEO 2	"veo2"	Google VEO 2
Kling Pro	"kling_pro"	Kling Pro model
Kling V2	"kling_v2"	Kling V2 model
Sora V2	"sora_v2"	OpenAI Sora V2
Sora V2 Pro	"sora_v2_pro"	OpenAI Sora V2 Pro
Runway Gen-4	"runway_gen4"	Runway Gen-4
Seedance Lite	"seedance_lite"	Seedance Lite
Seedance Pro	"seedance_pro"	Seedance Pro
LTX Distilled	"ltx_distilled"	LTX Distilled (fastest)

curl

curl -X POST "https://api.heygen.com/v1/workflows/executions" \
  -H "X-Api-Key: $HEYGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "workflow_type": "GenerateVideoNode",
    "input": {
      "prompt": "A drone shot flying over a coastal city at golden hour, cinematic lighting",
      "provider": "veo_3_1",
      "aspect_ratio": "16:9"
    }
  }'

TypeScript

interface GenerateVideoInput {
  prompt: string;
  provider?: string;
  aspect_ratio?: string;
  reference_image_url?: string;
  tail_image_url?: string;
  config?: Record<string, any>;
}

interface ExecuteResponse {
  data: {
    execution_id: string;
    status: "submitted";
  };
}

async function generateVideo(input: GenerateVideoInput): Promise<string> {
  const response = await fetch("https://api.heygen.com/v1/workflows/executions", {
    method: "POST",
    headers: {
      "X-Api-Key": process.env.HEYGEN_API_KEY!,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      workflow_type: "GenerateVideoNode",
      input,
    }),
  });

  const json: ExecuteResponse = await response.json();
  return json.data.execution_id;
}

Python

import requests
import os

def generate_video(
    prompt: str,
    provider: str = "veo_3_1",
    aspect_ratio: str = "16:9",
    reference_image_url: str | None = None,
    tail_image_url: str | None = None,
) -> str:
    payload = {
        "workflow_type": "GenerateVideoNode",
        "input": {
            "prompt": prompt,
            "provider": provider,
            "aspect_ratio": aspect_ratio,
        },
    }

    if reference_image_url:
        payload["input"]["reference_image_url"] = reference_image_url
    if tail_image_url:
        payload["input"]["tail_image_url"] = tail_image_url

    response = requests.post(
        "https://api.heygen.com/v1/workflows/executions",
        headers={
            "X-Api-Key": os.environ["HEYGEN_API_KEY"],
            "Content-Type": "application/json",
        },
        json=payload,
    )

    data = response.json()
    return data["data"]["execution_id"]

Response Format

{
  "data": {
    "execution_id": "node-gw-v1d2e3o4",
    "status": "submitted"
  }
}

Check Status

Endpoint

GET https://api.heygen.com/v1/workflows/executions/{execution_id}

curl

curl -X GET "https://api.heygen.com/v1/workflows/executions/node-gw-v1d2e3o4" \
  -H "X-Api-Key: $HEYGEN_API_KEY"

Response Format (Completed)

{
  "data": {
    "execution_id": "node-gw-v1d2e3o4",
    "status": "completed",
    "output": {
      "video": {
        "video_url": "https://resource.heygen.ai/generated/video.mp4",
        "video_id": "abc123"
      },
      "asset_id": "asset-xyz789"
    }
  }
}

Polling for Completion

async function generateVideoAndWait(
  input: GenerateVideoInput,
  maxWaitMs = 600000,
  pollIntervalMs = 10000
): Promise<{ video_url: string; video_id: string; asset_id: string }> {
  const executionId = await generateVideo(input);
  console.log(`Submitted video generation: ${executionId}`);

  const startTime = Date.now();
  while (Date.now() - startTime < maxWaitMs) {
    const response = await fetch(
      `https://api.heygen.com/v1/workflows/executions/${executionId}`,
      { headers: { "X-Api-Key": process.env.HEYGEN_API_KEY! } }
    );
    const { data } = await response.json();

    switch (data.status) {
      case "completed":
        return {
          video_url: data.output.video.video_url,
          video_id: data.output.video.video_id,
          asset_id: data.output.asset_id,
        };
      case "failed":
        throw new Error(data.error?.message || "Video generation failed");
      case "not_found":
        throw new Error("Workflow not found");
      default:
        await new Promise((r) => setTimeout(r, pollIntervalMs));
    }
  }

  throw new Error("Video generation timed out");
}

Usage Examples

Simple Text-to-Video

curl -X POST "https://api.heygen.com/v1/workflows/executions" \
  -H "X-Api-Key: $HEYGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "workflow_type": "GenerateVideoNode",
    "input": {
      "prompt": "A person walking through a sunlit park, shallow depth of field"
    }
  }'

Image-to-Video

{
  "workflow_type": "GenerateVideoNode",
  "input": {
    "prompt": "Animate this product photo with a slow zoom and soft particle effects",
    "reference_image_url": "https://example.com/product-photo.png",
    "provider": "kling_pro"
  }
}

Vertical Format for Social Media

{
  "workflow_type": "GenerateVideoNode",
  "input": {
    "prompt": "A trendy coffee shop interior, camera slowly panning across the counter",
    "aspect_ratio": "9:16",
    "provider": "veo_3_1"
  }
}

Fast Generation with LTX

{
  "workflow_type": "GenerateVideoNode",
  "input": {
    "prompt": "Abstract colorful shapes morphing and flowing",
    "provider": "ltx_distilled"
  }
}

Best Practices

1. Be descriptive in prompts — include camera movement, lighting, style, and mood details
2. Default to VEO 3.1 for highest quality; use ltx_distilled or veo3_fast when speed matters
3. Use reference images for image-to-video generation — great for animating product photos or still images
4. Video generation is the slowest workflow — allow up to 5 minutes, poll every 10 seconds
5. Aspect ratio matters — use 9:16 for social media stories/reels, 16:9 for landscape, 1:1 for square
6. Output includes asset_id — use this to reference the generated video in other HeyGen workflows
7. Output URLs are temporary — download or save generated videos promptly