> ## Documentation Index > Fetch the complete documentation index at: https://apidoc.cometapi.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a Runway image-to-video task > Use CometAPI to call Runway image_to_video and convert a still image URL into raw video output, with X-Runway-Version support for compatibility. Use this endpoint to animate one source image into a Runway video. ## Before you call it * Send the required `X-Runway-Version` header, for example `2024-11-06` * Use `model: gen3a_turbo` * Provide a stable HTTPS `promptImage` * Start with `duration: 5` and a supported ratio value for the selected Runway model/version ## Duration and ratio | Setting | Supported values | Default starting point | Boundary behavior | | ------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | ---------------------- | --------------------------------------------------------------------------------------------------------------- | | `duration` | Runway model/version dependent; use `5` or `10` for the broadest compatibility | `5` | CometAPI forwards the value to Runway. If the selected model/version rejects it, retry with `5`. | | `ratio` with `X-Runway-Version: 2024-11-06` | Runway model/version dependent resolution-style values such as `1280:768`, `768:1280`, `1280:720`, or `720:1280` | `1280:768` | Request values can normalize in the completed media; inspect the finished video before relying on exact pixels. | | `ratio` with older compatibility versions | `16:9`, `9:16`, or the resolution-style values accepted by the selected model/version | `16:9` or `1280:768` | Prefer the current Runway resolution-style values for production integrations. | Runway official-format requests use `ratio`, not `size`. Read resolution-style ratio values as their `WxH` equivalent: `1280:720` targets `1280x720`, `720:1280` targets `720x1280`, and `1280:768` can still render as `1280x720` depending on the selected model/version. ## Task flow Create the task with a source image and an optional short motion prompt. Save the task `id` for later polling. Use [Get a Runway task](./runway-to-get-task-details). If the first poll returns `task_not_exist`, wait a few seconds and retry. ## OpenAPI ````yaml api/openapi/video/runway/official-format/post-runway-images-raw-video.openapi.json POST /runwayml/v1/image_to_video openapi: 3.1.0 info: title: Image to Video API version: 1.0.0 description: >- Create a Runway image-to-video task through the official-format CometAPI route. servers: - url: https://api.cometapi.com security: - bearerAuth: [] paths: /runwayml/v1/image_to_video: post: summary: Create a Runway image-to-video task description: >- Submit a source image plus optional motion prompt and receive a task id for later polling. operationId: runway_images_raw_video parameters: - name: X-Runway-Version in: header required: true description: Runway version header, for example `2024-11-06`. schema: type: string requestBody: required: true content: application/json: schema: type: object required: - promptImage - model properties: promptImage: type: string description: Source image URL. default: >- https://cdn.britannica.com/70/234870-050-D4D024BB/Orange-colored-cat-yawns-displaying-teeth.jpg seed: type: integer description: 'Random seed for reproducible results. Range: 0–999999999.' model: type: string description: >- Runway image-to-video model ID. Choose an available model from the [Models page](/overview/models). default: gen3a_turbo promptText: type: string description: >- Text prompt describing the desired motion or scene. Maximum 512 characters. watermark: type: boolean description: Whether to add a watermark to the output video. default: false duration: type: integer description: >- Video duration in seconds. Runway support is model/version dependent; use 5 or 10 for the broadest compatibility. CometAPI forwards this value to Runway. default: 5 ratio: type: string description: >- Requested output ratio. Accepted values are Runway model/version dependent. With X-Runway-Version 2024-11-06, use a resolution-style value accepted by the selected model, such as 1280:768, 768:1280, 1280:720, or 720:1280. Read these as WxH targets, but completed media may normalize, so inspect the returned file before relying on exact pixels. default: '1280:768' default: promptImage: >- https://cdn.britannica.com/70/234870-050-D4D024BB/Orange-colored-cat-yawns-displaying-teeth.jpg seed: 1 model: gen3a_turbo promptText: A calm camera move. watermark: false duration: 5 ratio: '1280:768' examples: Default: summary: Default value: promptImage: >- https://cdn.britannica.com/70/234870-050-D4D024BB/Orange-colored-cat-yawns-displaying-teeth.jpg seed: 1 model: gen3a_turbo promptText: A calm camera move. watermark: false duration: 5 ratio: '1280:768' responses: '200': description: Task accepted. content: application/json: schema: type: object required: - id properties: id: type: string example: id: d0658ae1-bbdd-4adc-aaba-fd8070e14d79 x-codeSamples: - lang: Shell label: Default source: | curl https://api.cometapi.com/runwayml/v1/image_to_video \ -H "Authorization: Bearer $COMETAPI_KEY" \ -H "Content-Type: application/json" \ -d '{ "promptImage": "https://your-image-host/first-frame.png", "promptText": "A calm camera move.", "model": "gen3a_turbo", "ratio": "1280:768", "duration": 5 }' - lang: Python label: Default source: > import os import requests response = requests.post( "https://api.cometapi.com/runwayml/v1/image_to_video", headers={"Authorization": "Bearer " + os.environ["COMETAPI_KEY"]}, json={ "promptImage": "https://your-image-host/first-frame.png", "promptText": "A calm camera move.", "model": "gen3a_turbo", "ratio": "1280:768", "duration": 5 }, ) task = response.json() print(task["id"]) # poll GET /runwayml/v1/tasks/{id} until the output array appears - lang: JavaScript label: Default source: > const response = await fetch("https://api.cometapi.com/runwayml/v1/image_to_video", { method: "POST", headers: { Authorization: `Bearer ${process.env.COMETAPI_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ "promptImage": "https://your-image-host/first-frame.png", "promptText": "A calm camera move.", "model": "gen3a_turbo", "ratio": "1280:768", "duration": 5 }), }); const task = await response.json(); console.log(task.id); // poll GET /runwayml/v1/tasks/{id} until the output array appears components: securitySchemes: bearerAuth: type: http scheme: bearer description: Bearer token authentication. Use your CometAPI key. ````