> ## Documentation Index > Fetch the complete documentation index at: https://evolink.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Kling-4.0 Image to Video > - Kling-4.0 Image to Video (kling-v4-image-to-video) generates videos from images - Supports first and last frames, as well as intermediate frames between them - The aspect ratio is determined by the first-frame image, **`aspect_ratio` is not accepted** - Asynchronous processing mode, use the returned task ID to [query status](/en/api-manual/task-management/get-task-detail) - Generated video links are valid for 24 hours, please save them promptly ## OpenAPI ````yaml en/api-manual/video-series/kling/kling-v4-image-to-video.json POST /v1/videos/generations openapi: 3.1.0 info: title: kling-v4-image-to-video API description: Create image-to-video tasks using AI models license: name: MIT version: 1.0.0 servers: - url: https://api.evolink.ai description: Production security: - bearerAuth: [] tags: - name: Video Generation description: AI video generation APIs paths: /v1/videos/generations: post: tags: - Video Generation summary: kling-v4-image-to-video API description: >- - Kling-4.0 Image to Video (kling-v4-image-to-video) generates videos from images - Supports first and last frames, as well as intermediate frames between them - The aspect ratio is determined by the first-frame image, **`aspect_ratio` is not accepted** - Asynchronous processing mode, use the returned task ID to [query status](/en/api-manual/task-management/get-task-detail) - Generated video links are valid for 24 hours, please save them promptly operationId: createVideoGeneration requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/VideoGenerationRequest' examples: basic: summary: First Frame Image to Video value: model: kling-v4-image-to-video prompt: The person in the image slowly turns their head and smiles image_start: https://example.com/portrait.jpg duration: 5 quality: 720p first_last_frame: summary: First Frame + Last Frame value: model: kling-v4-image-to-video prompt: Transition from daytime to nighttime image_start: https://example.com/day.jpg image_end: https://example.com/night.jpg duration: 10 quality: 1080p with_keyframes: summary: First frame + intermediate frames + last frame value: model: kling-v4-image-to-video prompt: The flower bud slowly blooms, then the camera pulls back image_start: https://example.com/bud.jpg keyframes: - image_url: https://example.com/half-open.jpg - image_url: https://example.com/open.jpg image_end: https://example.com/wide.jpg duration: 5 quality: 720p keyframes_without_end: summary: First frame + intermediate frames (no last frame) value: model: kling-v4-image-to-video prompt: >- The camera moves from a street in the early morning to a square at dusk as the light gradually warms image_start: https://example.com/morning.jpg keyframes: - image_url: https://example.com/noon.jpg - image_url: https://example.com/afternoon.jpg duration: 8 quality: 1080p responses: '200': description: Video generation task created successfully content: application/json: schema: $ref: '#/components/schemas/VideoGenerationResponse' '400': description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: invalid_request message: Invalid request parameters type: invalid_request_error '401': description: Unauthenticated, token invalid or expired content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: unauthorized message: Invalid or expired token type: authentication_error '402': description: Insufficient quota, top-up required content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: insufficient_quota message: Insufficient quota. Please top up your account. type: insufficient_quota '403': description: Access denied content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: model_access_denied message: 'Token does not have access to model: kling-v4-image-to-video' type: invalid_request_error '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: rate_limit_exceeded message: Too many requests, please try again later type: rate_limit_error '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: internal_error message: Internal server error type: api_error components: schemas: VideoGenerationRequest: type: object required: - model - image_start - prompt properties: model: type: string description: Video generation model name enum: - kling-v4-image-to-video default: kling-v4-image-to-video example: kling-v4-image-to-video image_start: type: string format: uri description: >- First frame image URL for image-to-video generation (**required**) **Note:** - Image size: up to `10MB` - Supported formats: `.jpg`, `.jpeg`, `.png` - Image dimensions: width and height >= `300px`, aspect ratio between `1:2.5` and `2.5:1` - Image URL must be directly accessible by the server or trigger a direct download when accessed example: https://example.com/portrait.jpg image_end: type: string format: uri description: >- Last frame image URL **Note:** - `image_start` (first frame) must be provided when using last frame - Supported formats: `.jpg`, `.jpeg`, `.png` - Image size: up to `10MB` - Image URL must be directly accessible by the server or trigger a direct download when accessed example: https://example.com/night.jpg keyframes: type: array description: >- Intermediate frame images, evenly spaced in order between the first and last frames **Note:** - Count: `1` to `8` images - The first frame, intermediate frames, and last frame combined must not exceed `10` images or `duration` + 1 (for example, up to `4` images for `3` seconds or `6` images for `5` seconds) - The last frame is optional. If omitted, the model generates the ending frame - Image size: up to `10MB` - Supported formats: `.jpg`, `.jpeg`, `.png` - Image dimensions: width and height >= `300px`, aspect ratio between `1:2.5` and `2.5:1` - Image URL must be directly accessible by the server or trigger a direct download when accessed items: type: object properties: image_url: type: string format: uri description: Intermediate frame image URL required: - image_url additionalProperties: false minItems: 0 maxItems: 8 example: - image_url: https://example.com/half-open.jpg - image_url: https://example.com/open.jpg prompt: type: string description: |- Text prompt describing the video to generate **Note:** - Maximum `2500` characters example: The person in the image slowly turns their head and smiles maxLength: 2500 duration: type: integer description: |- Video duration in seconds. Defaults to `5` seconds **Range:** - Integer from `3` to `30` minimum: 3 maximum: 30 default: 5 example: 5 quality: type: string description: |- Resolution tier **Options:** - `720p`: Standard 720P - `1080p`: High quality 1080P enum: - 720p - 1080p default: 720p example: 720p callback_url: type: string description: >- HTTPS callback URL for task completion **Callback Timing:** - Triggered when task is completed, failed, or cancelled - Sent after billing confirmation **Security Restrictions:** - HTTPS protocol only - Internal IP addresses are prohibited (127.0.0.1, 10.x.x.x, 172.16-31.x.x, 192.168.x.x, etc.) - URL length must not exceed `2048` characters **Callback Mechanism:** - Timeout: `10` seconds - Maximum `3` retries after failure (at `1`/`2`/`4` seconds after failure) - Callback response format is consistent with task query API - 2xx status code is considered successful, other codes trigger retry format: uri example: https://your-domain.com/webhooks/video-task-completed VideoGenerationResponse: type: object properties: created: type: integer description: Task creation timestamp example: 1757169743 id: type: string description: Task ID example: task-unified-1757169743-7cvnl5zw model: type: string description: Actual model name used example: kling-v4-image-to-video object: type: string enum: - video.generation.task description: Task type progress: type: integer description: Task progress percentage (0-100) minimum: 0 maximum: 100 example: 0 status: type: string description: Task status enum: - pending - processing - completed - failed example: pending task_info: $ref: '#/components/schemas/VideoTaskInfo' description: Video task details type: type: string enum: - text - image - audio - video description: Task output type example: video usage: $ref: '#/components/schemas/VideoUsage' description: Usage and billing information ErrorResponse: type: object properties: error: type: object properties: code: type: string description: Error code identifier message: type: string description: Error description type: type: string description: Error type VideoTaskInfo: type: object properties: can_cancel: type: boolean description: Whether the task can be cancelled example: true estimated_time: type: integer description: Estimated completion time (seconds) minimum: 0 example: 300 video_duration: type: integer description: Video duration (seconds) example: 5 VideoUsage: type: object description: Usage and billing information properties: billing_rule: type: string description: Billing rule enum: - per_call - per_token - per_second example: per_second credits_reserved: type: number description: Estimated credits consumed minimum: 0 example: 53.38 user_group: type: string description: User group category example: default securitySchemes: bearerAuth: type: http scheme: bearer description: >- ## All APIs require Bearer Token authentication ## **Get API Key:** Visit [API Key Management Page](https://evolink.ai/dashboard/keys) to get your API Key **Add to request header:** ``` Authorization: Bearer YOUR_API_KEY ``` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.