# Generate Mask by Prompt

Generates a segmentation mask video based on a text prompt.
Response behavior:
- Returns HTTP 202 with `request_id` and `status_url`
- The final result (via status endpoint) will contain a `mask_url`.

Constraints:
- Max Duration: 5 seconds (Truncated if `auto_trim`=true).
- Max Resolution: 750p.

Endpoint: POST /mask_by_prompt
Security: api_token

## Request fields (application/json):

  - `video` (string, required)
    Publicly accessible URL for the input video file.

  - `prompt` (string, required)
    The text instruction describing the object to be masked.

  - `auto_trim` (boolean)
    If true, trims the video to the 5s limit.

  - `output_container_and_codec` (string)
    Enum: "mp4_h264", "mp4_h265", "webm_vp9", "mov_h265", "mov_proresks", "mkv_h264", "mkv_h265", "mkv_vp9", "gif"

  - `webhook_url` (string)
    Optional URL for receiving the result via webhook when the async job completes. See [webhooks](/getting-started/async-requests#webhooks).

## Response 202 fields (application/json):

  - `request_id` (string, required)

  - `status_url` (string, required)

## Response 400 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 403 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 405 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 415 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 422 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 429 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)

## Response 500 fields (application/json):

  - `error` (object, required)

  - `error.code` (integer, required)
    Example: 123

  - `error.message` (string, required)

  - `error.details` (string, required)

  - `request_id` (string, required)