> ## Documentation Index > Fetch the complete documentation index at: https://docs.vidgo.ai/llms.txt > Use this file to discover all available pages before exploring further. # VEO 3.1 Official Video Generation > Official VEO 3.1 video generation with duration, audio control, and image-guided modes 1. After submission, a `task_id` will be returned. If you provided a `callback_url`, when the task status becomes `finished` or `failed`, a POST request will be sent to the `callback_url`. 2. Regardless of whether `callback_url` is provided, you can retrieve the result through the unified [Query Task Status](/api-manual/task-management/status) endpoint. # VEO 3.1 Official Video Generation Generate videos with the official VEO 3.1 model family through one async API. The generation models support text-to-video, image-to-video, first/last-frame video, and three-image reference generation depending on the selected model and input. ## Available Models * **veo3.1-fast-official** - Fast official generation with `4`, `6`, or `8` second duration options * **veo3.1-lite-official** - Lightweight official generation with lower per-second pricing * **veo3.1-quality-official** - Higher-quality official generation with 4K support ## Input Modes * No `image_urls`: text-to-video * One image: image-to-video * Two images: first/last-frame video. The first image is the start frame and the second image is the end frame * Three images: reference generation. Use `generation_type: "reference"` and `duration: 8` * `veo3.1-lite-official` supports at most two images and does not support `generation_type: "reference"` ## Parameters * **model**: Required model identifier. Use `veo3.1-fast-official`, `veo3.1-lite-official`, or `veo3.1-quality-official` * **prompt**: Required text prompt for video generation, up to `1000` characters * **image\_urls**: Optional image URL array. Supports up to `3` public image URLs * **generation\_type**: Optional `frame` or `reference`. If omitted, the mode is inferred from `image_urls` * **duration**: `4`, `6`, or `8`. Default is `8`. Reference generation and `veo3.1-lite-official` with `resolution: "1080p"` support `8` only * **aspect\_ratio**: `16:9` or `9:16`. `auto` is also supported for one-image and two-image workflows. Default is `16:9` * **resolution**: `720p`, `1080p`, or `4k`. Default is `1080p`. `veo3.1-lite-official` does not support `4k` * **sound**: Boolean audio switch. Default is `true`; set `false` for silent output * **callback\_url**: Optional webhook URL for completion or failure notifications ## Pricing Pricing is charged per generated second and varies by model, resolution, and whether audio is generated. See the model page for the current credit table. ## OpenAPI ````yaml api-manual/video-series/veo-3-1-official.json POST /api/generate/submit openapi: 3.0.0 info: title: Vidgo API - VEO 3.1 Official API description: >- Official VEO 3.1 video generation with duration, audio control, and image-guided modes version: 1.0.0 servers: - url: https://api.vidgo.ai description: Production server security: - BearerAuth: [] paths: /api/generate/submit: post: tags: - VEO 3.1 Official summary: Submit VEO 3.1 Official Task description: >- Submit an async official VEO 3.1 video generation task. Use Fast, Lite, or Quality variants with text-to-video, image-to-video, first/last-frame, or reference generation workflows. operationId: submitVeo31OfficialTask requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SubmitRequest' examples: fast: summary: veo3.1-fast-official value: model: veo3.1-fast-official callback_url: https://your-domain.com/callback input: prompt: >- A cinematic close-up of a paper boat drifting through a neon-lit canal duration: 6 aspect_ratio: '16:9' resolution: 1080p sound: true lite: summary: veo3.1-lite-official value: model: veo3.1-lite-official callback_url: https://your-domain.com/callback input: prompt: >- A warm handheld shot of a ceramic coffee cup on a windowsill as morning light moves across the steam image_urls: - https://example.com/veo31-official-lite-source.png duration: 8 aspect_ratio: '16:9' resolution: 1080p sound: true quality: summary: veo3.1-quality-official value: model: veo3.1-quality-official callback_url: https://your-domain.com/callback input: prompt: >- A high-detail aerial view of a futuristic coastal city at dusk, cinematic camera movement, realistic lighting, crisp architectural detail image_urls: - >- https://example.com/veo31-official-reference-character.png - >- https://example.com/veo31-official-reference-environment.png - https://example.com/veo31-official-reference-detail.png generation_type: reference duration: 8 aspect_ratio: '16:9' resolution: 4k sound: true responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/SubmitResponse' example: code: 200 data: task_id: task-unified-1780000000-veo31official status: not_started created_time: '2026-05-20T10:30:00' '400': description: Invalid request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: lite-4k: summary: Lite does not support 4K value: code: 400 message: veo3.1-lite-official does not support 4k resolution lite-reference: summary: Lite does not support reference generation value: code: 400 message: veo3.1-lite-official does not support reference mode reference-duration: summary: Reference generation requires 8 seconds value: code: 400 message: reference mode supports 8s duration only auto-aspect-ratio: summary: auto aspect ratio requires one or two images value: code: 400 message: >- aspect_ratio auto is supported only with one or two image_urls prompt-too-long: summary: Prompt length exceeds limit value: code: 400 message: >- prompt must be 1000 characters or fewer for veo-3.1-official '401': description: Unauthorized - invalid API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 401 message: Unauthorized components: schemas: SubmitRequest: type: object required: - model - input properties: model: type: string description: VEO 3.1 official model identifier enum: - veo3.1-fast-official - veo3.1-lite-official - veo3.1-quality-official example: veo3.1-fast-official callback_url: type: string format: uri description: Webhook callback URL for result notifications example: https://your-domain.com/callback input: type: object required: - prompt description: Input parameters for generation properties: prompt: type: string description: Required text prompt describing the desired video. example: >- A cinematic close-up of a paper boat drifting through a neon-lit canal. image_urls: type: array items: type: string format: uri minItems: 1 maxItems: 3 description: >- Optional image URL array. No images creates text-to-video, one image creates image-to-video, two images create first/last-frame generation, and three images require reference generation. Lite supports at most two images. generation_type: type: string enum: - frame - reference description: >- Optional generation mode. Use frame for two image URLs and reference for three image URLs. If omitted, the mode is inferred from image_urls. duration: type: integer description: >- Output duration in seconds. Supports 4, 6, or 8. Defaults to 8. Reference generation and Lite 1080p support 8 only. enum: - 4 - 6 - 8 default: 8 example: 8 aspect_ratio: type: string description: >- Video aspect ratio. auto is supported only for one-image and two-image workflows. enum: - auto - '16:9' - '9:16' default: '16:9' example: '16:9' resolution: type: string description: Output resolution. Lite does not support 4k. enum: - 720p - 1080p - 4k default: 1080p example: 1080p sound: type: boolean description: >- Generate native audio. Defaults to true; set false for silent output. default: true example: true SubmitResponse: type: object required: - code - data properties: code: type: integer description: Response code example: 200 data: type: object description: Submitted task metadata required: - task_id - status - created_time properties: task_id: type: string description: Unique task identifier for status tracking example: task-unified-1780000000-veo31official status: type: string description: Initial task status enum: - not_started example: not_started created_time: type: string format: date-time description: ISO 8601 timestamp when the task was created example: '2026-05-20T10:30:00' ErrorResponse: type: object required: - code - message properties: code: type: integer description: Error code example: 400 message: type: string description: Error message describing what went wrong example: duration must be one of [4, 6, 8] for veo-3.1-official securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: API Key description: >- All API endpoints require Bearer Token authentication Get your API Key: Visit the [API Key Management Page](https://vidgo.ai/apis/dashboard/api-key) to get your API Key Add it to the request header: ``` Authorization: Bearer YOUR_API_KEY ``` ````