Generate Video from Template

Generates a video from a template by filling its variables. Use scene_ids to select, reorder or repeat the template’s existing scenes. Poll GET /v3/videos/ or use webhooks for completion. An idempotent replay returns the original response, not the video’s current state.

POST /v3/templates/{template_id}

Generate Video from Template

cURL

curl --request POST \
  --url https://api.heygen.com/v3/templates/{template_id} \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "variables": {},
  "title": "<string>",
  "caption": false,
  "subtitles": {
    "preset_name": "<string>",
    "alignment": 2,
    "disable_highlight": false,
    "font_size": 123,
    "position": {
      "x": 0,
      "y": 0
    }
  },
  "callback_id": "<string>",
  "callback_url": "<string>",
  "folder_id": "<string>",
  "brand_voice_id": "<string>",
  "brand_glossary_id": "<string>",
  "dimension": {
    "width": 2112,
    "height": 2112
  },
  "fps": 25,
  "scene_ids": [
    "<string>"
  ],
  "reorder_music": true,
  "keep_text_vertically_centered": false,
  "include_gif": false,
  "enable_sharing": false
}
'

200

{
  "data": {
    "id": "v_abc123def456",
    "status": "completed",
    "title": "My Generated Video",
    "created_at": 1711929600,
    "completed_at": 1711930200,
    "video_url": "https://files.heygen.ai/video/abc123.mp4",
    "thumbnail_url": "https://files.heygen.ai/thumb/abc123.jpg",
    "gif_url": "https://files.heygen.ai/gif/abc123.gif",
    "captioned_video_url": "https://files.heygen.ai/video/abc123_captioned.mp4",
    "subtitle_url": "https://files.heygen.ai/srt/abc123.srt",
    "duration": 30.5,
    "folder_id": "folder_abc123",
    "output_language": "en-US",
    "failure_code": "rendering_failed",
    "failure_message": "Avatar rendering timed out",
    "video_page_url": "https://app.heygen.com/video/abc123"
  }
}

Authorizations

ApiKeyAuthBearerAuth

x-api-key · string · header · required

HeyGen API key. Obtain from your HeyGen dashboard.

Headers

Idempotency-Key · string

Optional client-supplied key for safely retrying mutations. Subsequent calls within 24 hours that share this key replay the original response — even if the request body differs slightly (a warning is logged). A retry that arrives while the original is still in flight gets a 409 request_in_progress. Keys must be 1–255 characters from [A-Za-z0-9_:.-]; a UUID is a safe default. Scope is per-endpoint and per-resource: the same key on a different route or path parameter is independent.

Required string length: 1 - 255

Pattern: ^[A-Za-z0-9_\-:.]{1,255}$

Path Parameters

template_id · string · required

Unique template identifier

Body

application/json

Request body for POST /v3/templates/{template_id}.

variables · Variables · object · required

Template variable replacements, keyed by the variable name defined in the template. Supply every text variable you want filled: an omitted text variable is not substituted, so its literal {{variable_name}} placeholder remains in the text it is bound to, whether that is a spoken script or an on-screen text element. Omitting an image, video, audio, character or voice variable is safe and keeps the value the template already holds. The defaults returned by GET /v3/templates/{template_id} are the template's current values, not fallbacks applied at generation time.

Show child attributes

title · string | null

Title for the generated video

caption · boolean · default: false

Whether to burn captions into the video

subtitles · TemplateSubtitleSettings · object | null

Subtitle style settings. Implies captions when provided.

Show child attributes

callback_id · string | null

Opaque ID echoed back in webhook events for this video

callback_url · string | null

URL called with the video result in addition to registered webhook endpoints

folder_id · string | null

Destination folder ID in the caller's workspace, for example one returned by POST /v3/folders. Omit, pass null, or pass an empty string to place the result at the workspace root. The id must name a folder that is not in the trash and that the caller can write to. Assets library folders are accepted, but the HeyGen app files only assets in them, so a result placed there may not appear in the Assets library view. An unknown id, a folder in another workspace, a project of another kind such as a brand kit, or a trashed folder is rejected with 404 before anything is created. Supported only for single-video creation; batch video items cannot set their own destination folder.

brand_voice_id · string | null · deprecated

Legacy field name for brand_glossary_id. Both are accepted and resolve to the same workspace record. Prefer brand_glossary_id.

brand_glossary_id · string | null

Brand glossary controlling how custom terms are pronounced in generated speech. Discover IDs via GET /v3/brand-glossaries.

dimension · TemplateVideoDimension · object | null

Output resolution override. Must match the template's aspect ratio.

Show child attributes

fps · number · default: 25

Output frame rate. One of 25, 30, or 60.

scene_ids · string[] | null

Scene IDs to render, in order (repeats allowed). Scenes must already exist in the template; the API can select, reorder, and repeat scenes but cannot create new ones. Omit to render all scenes in template order.

reorder_music · boolean · default: true

When true (default), background audio tracks move with their scenes. When false, tracks stay pinned to layout positions.

keep_text_vertically_centered · boolean · default: false

When true, replaced text elements are vertically re-centered based on their rendered height

include_gif · boolean · default: false

Whether to include a GIF preview in the webhook payload

enable_sharing · boolean · default: false

Whether the generated video's share page is publicly accessible

Response

200

application/json

Successful response

data · VideoDetail · object

Video resource returned by list and detail endpoints.

If output_language is present the video is a translated video; otherwise it is a generated video.

Show child attributes