HeyGen Video Agent V3

Generate videos with a single prompt. Describe what you want in plain text, and the agent handles avatar selection, scripting, scene composition - all in one.

Pricing: $0.034/second. Endpoint: POST /v1/models/heygen/v3/video-agent/runs.

Generate videos with a single prompt. Describe what you want in plain text, and the agent handles avatar selection, scripting, scene composition - all in one.

Overview

• Endpoint: https://api.runflow.io/v1/models/heygen/v3/video-agent/runs
• Model ID: heygen/v3/video-agent
• Provider: HeyGen
• License: commercial
• Last Updated: 2026-04-21

Pricing

• Base price: $0.034/second
• Note: Usage-based, per second of generated video

HeyGen Video Agent V3 API

Endpoint: POST /v1/models/heygen/v3/video-agent/runs

Run the model

Python

import requests

response = requests.post(
    "https://api.runflow.io/v1/models/heygen/v3/video-agent/runs",
    headers={"Authorization": "Bearer RUNFLOW_API_KEY"},
    json={
        "input": {
            "prompt": "Create a 20-second professional product announcement video from a CTO introducing a new AI video platform to prospective customers. Modern office backdrop, warm professional lighting, confident tone, medium shot, minimal graphics. End with call-to-action."
        },
        "callback_url": "https://your-server.com/webhook"
    },
)

data = response.json()
print(data)

Node.js

const response = await fetch(
  "https://api.runflow.io/v1/models/heygen/v3/video-agent/runs",
  {
    method: "POST",
    headers: {
      "Authorization": "Bearer RUNFLOW_API_KEY",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
        "input": {
            "prompt": "Create a 20-second professional product announcement video from a CTO introducing a new AI video platform to prospective customers. Modern office backdrop, warm professional lighting, confident tone, medium shot, minimal graphics. End with call-to-action."
        },
        "callback_url": "https://your-server.com/webhook"
    }),
  }
);

const data = await response.json();
console.log(data);

cURL

curl -X POST https://api.runflow.io/v1/models/heygen/v3/video-agent/runs \
  -H "Authorization: Bearer $RUNFLOW_API_KEY" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'JSON'
{
    "input": {
        "prompt": "Create a 20-second professional product announcement video from a CTO introducing a new AI video platform to prospective customers. Modern office backdrop, warm professional lighting, confident tone, medium shot, minimal graphics. End with call-to-action."
    },
    "callback_url": "https://your-server.com/webhook"
}
JSON

Request parameters

Parameter	Type	Required	Description
input	object	required	Model input parameters. See “Input schema” below.
callback_url	string | null	optional	Webhook URL - POSTed when the run reaches a terminal state.
metadata	object | null	optional	Arbitrary key-value pairs attached to the run.

Input schema

Field	Type	Required	Allowed values	Description
prompt	string	required	Any	Natural language prompt describing the video to generate. The agent handles avatar selection, script, and production automatically.
orientation	string	optional	landscape, portrait	Video orientation. Auto-detected from the prompt if omitted.
avatar	string	optional	Any	Avatar to use in the video. Set to ‘auto’ to let the agent auto-select based on the prompt.
file_urls	file_list	optional	Any	URLs of files to include as assets in the video (images, videos, audio, PDFs). Maximum 20 files.
incognito_mode	boolean	optional	Any	When enabled, disables the agent’s memory functions.
style_id	string	optional	Any	Style template ID from the /v3/video-agent/styles endpoint.
voice	string	optional	Any	Voice for narration. Set to ‘auto’ to let the agent auto-select.

Output schema

Field	Type	Description
outputs	json	Unified output array.
seed	json	Seed used for generation, or null.
timing	json	Provider timing info, or null.
nsfw_detected	json	NSFW flag, or null.

Callback payload

When you provide a callback_url, Runflow POSTs to it once the run reaches a terminal state.

Field	Type	Description
event	string	Event type: “run.completed”, “run.failed”, or “run.cancelled”.
run_id	string	The unique identifier of the run.
status	string	Terminal status: “succeeded”, “failed”, or “cancelled”.
output	object | null	The run output. Null if the run failed or was cancelled.
duration_ms	number | null	Total run duration in milliseconds.
created_at	string | null	ISO 8601 timestamp when the run was created.
completed_at	string | null	ISO 8601 timestamp when the run reached terminal state.
metadata	object | null	The metadata object passed at run creation, if any.

• Retries: 3 attempts with exponential backoff (1s, 2s). Retries on 5xx / network errors only.
• Headers: Runflow-Request-Id is always sent. Runflow-Signature is sent if a signing secret is configured.

Additional Resources

• Playground
• API Reference
• Documentation
• OpenAPI

Related

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Run lifecycle

Callbacks, polling, statuses.

Callbacks

Handle async results.

Pricing

How requests bill out.