Motion Transfer API Documentation

Overview

Transfer body motion captured in a source video onto a target subject, preserving the target's appearance and background.

Primary Endpoint

POST/api/v1/motionTransfer/start

Start a motion transfer task to transfer motion from video to image. ### Request - Send a valid bearer token. The server evaluates the operation in the authenticated caller's access context. - Send an `application/json` body. Required fields: `image_url`, `video_url`. - API-token callers may include `webhook_url` and `webhook_token` for best-effort terminal-state notifications; ordinary JWT/cookie calls ignore these fields. ### Behavior - This is an asynchronous operation: a successful submission creates a task and returns before processing finishes. - Persist the returned task identifier and use the corresponding detail or list operation to observe progress. - Treat the detail endpoint as the source of truth even when webhook delivery is enabled. ### Response - A `200` response confirms task acceptance; it does not by itself mean media generation has completed. - Retain the returned identifier and wait for a documented terminal status before using output URLs. - JSON object responses, including error responses, normally carry a top-level `trace_id` string for this request; include it when contacting support. It is not a task identifier. - Do not infer undocumented fields or statuses; clients should tolerate additional response properties. ### Errors - `400` — Bad Request - Invalid parameters. - `401` — Unauthorized - Invalid or missing JWT token. ### Related Operations - `GET /api/v1/motionTransfer/allRecords` — Get all motion transfer records. - `GET /api/v1/motionTransfer/{_id}` — Get motion transfer task detail. - `DELETE /api/v1/motionTransfer/{_id}` — Delete motion transfer task. Authentication: set header Authorization: Bearer <token> (supports user JWT or sk_ API token).

Request Parameters

Name	Type	Required	Description
name	string	No	Name of the motion transfer task; default: ""
image_url	string	Yes	Reference image URL for motion transfer
video_url	string	Yes	Control video URL for motion source
positive_prompt	string	No	Positive prompt for motion transfer
negative_prompt	string	No	Negative prompt for motion transfer
timeout	number	No	Processing timeout in seconds; default: 300
minor_suspected_skip	boolean	No	Set to true when retrying after error code 1004 to confirm and bypass the suspected-minor soft block.; default: false
webhook_url	string	No	HTTPS URL to receive task.completed / task.failed notifications. Best-effort delivery, single attempt, no retries; clients should treat the detail API as the source of truth.; maxLength: 2048
webhook_token	string	No	Optional plaintext token returned in the X-A2e-Webhook-Token header so receivers can verify the request originated from a2e.; maxLength: 256

Request schema and conditional rules

{
  "allOf": [
    {
      "type": "object",
      "properties": {
        "name": {
          "type": "string",
          "description": "Name of the motion transfer task",
          "default": "",
          "example": "Dance Motion Transfer"
        },
        "image_url": {
          "type": "string",
          "format": "uri",
          "pattern": "^https?://.*",
          "description": "Reference image URL for motion transfer",
          "example": "https://example.com/person.jpg"
        },
        "video_url": {
          "type": "string",
          "format": "uri",
          "pattern": "^https?://.*",
          "description": "Control video URL for motion source",
          "example": "https://example.com/dance.mp4"
        },
        "positive_prompt": {
          "type": "string",
          "description": "Positive prompt for motion transfer",
          "example": "high quality motion transfer, natural pose transition, smooth movement"
        },
        "negative_prompt": {
          "type": "string",
          "description": "Negative prompt for motion transfer",
          "example": "blurry, distorted limbs, unnatural poses, deformation"
        },
        "timeout": {
          "type": "number",
          "default": 300,
          "description": "Processing timeout in seconds",
          "example": 300
        },
        "minor_suspected_skip": {
          "type": "boolean",
          "default": false,
          "description": "Set to true when retrying after error code 1004 to confirm and bypass the suspected-minor soft block."
        }
      },
      "required": [
        "image_url",
        "video_url"
      ]
    },
    {
      "$ref": "#/components/schemas/WebhookInput"
    }
  ]
}

Response Fields

code: integer
data: object
data._id: string: Task ID
data.name: string: Task name
data.image_url: string: Reference image URL
data.video_url: string: Control video URL
data.positive_prompt: string: Positive prompt used
data.negative_prompt: string: Negative prompt used
data.current_status: string: Current task status
data.coins: number: Coins required for the task
data.createdAt: string: Task creation timestamp
trace_id: string: Trace ID of this HTTP request. Include it when contacting support about this request. It is generated per request and is not a task identifier; use the returned task `_id` to query results.

Request Example

curl -X POST "https://headswap.app/api/v1/motionTransfer/start" \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
  "image_url": "https://example.com/person.jpg",
  "video_url": "https://example.com/dance.mp4"
}'