> ## 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. # FLUX 3 Max Keyframes to Video > The FLUX 3 Max Keyframes to Video API places 1–10 images on a 24 fps timeline with frame_index and generates the 5–20 second motion between them. > [!TIP] > > 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](https://docs.vidgo.ai/api-manual/task-management/status.md) endpoint. FLUX 3 Max Keyframes to Video lets you pin up to 10 images to exact positions on a 24 fps timeline and generates the motion between them. It is built for storyboard animatics, product transformations and time-lapse style sequences where specific shots must appear at specific moments. FLUX 3 Max is a video model post-trained by fal in collaboration with Black Forest Labs on the FLUX 3 video base. Vidgo exposes it as three model IDs: [Text to Video](https://docs.vidgo.ai/api-manual/video-series/blackforestlabs-flux-3-max-text-to-video.md), [Image to Video](https://docs.vidgo.ai/api-manual/video-series/blackforestlabs-flux-3-max-image-to-video.md) and [Keyframes to Video](https://docs.vidgo.ai/api-manual/video-series/blackforestlabs-flux-3-max-keyframes-to-video.md). ## Models * **blackforestlabs/flux-3-max/keyframes-to-video** — Keyframes-to-video with FLUX 3 Max, 1–10 images placed by `frame_index`. ## Features * Keyframe control with 1–10 images, each placed on a frame of a 24 fps timeline. * Integer durations from 5 to 20 seconds at 720p or 1080p. * Eight aspect ratios; `auto` follows the first keyframe image. * Native audio on by default. ## Required parameters * `keyframes` (object\[]): 1–10 objects, each with exactly two fields: * `image_url` (string): Public HTTP(S) URL of the keyframe image (PNG, JPEG or WebP). * `frame_index` (integer): Position of that image on the 24 fps timeline, from `0` to `duration × 24`. Indexes must be unique. * `prompt` (string): The motion and transitions between keyframes, the camera movement and, with `sound` on, the audio. Must not be blank. ## Optional parameters * `duration` (integer): Output length in seconds, `5`–`20`. Default `5`. * `resolution` (string): `720p` or `1080p`. Default `720p`. * `aspect_ratio` (string): `auto`, `21:9`, `2:1`, `16:9`, `4:3`, `1:1`, `3:4` or `9:16`. Default `auto`. * `sound` (boolean): Generate native audio with the video. Default `true`; set `false` for silent footage. ## Duration `frame_index` counts frames at 24 fps, so the last valid index depends on `duration`: | `duration` | Valid `frame_index` range | | - | - | | 5 | 0–120 | | 10 | 0–240 | | 15 | 0–360 | | 20 | 0–480 | To place an image at second *t*, use `frame_index = t × 24` (for example 2.5 s → 60). ## Output The finished task returns one MP4 video in the `files` array of [Query Task Status](https://docs.vidgo.ai/api-manual/task-management/status.md) and the callback payload. ## Examples * **Three keyframes over 5 seconds**: seed, sapling and blossom at frames `0`, `60` and `120` (start, middle and end of a 5-second clip). * **10-second 1080p storyboard with callback**: four shots at frames `0`, `96`, `168` and `240`, `21:9`, silent, with a `callback_url`. ## Notes * A `frame_index` above `duration × 24`, a repeated index, or extra fields inside a keyframe object return 400. If you shorten `duration`, check that every index still fits. * Fields not listed above, such as `image_urls`, return 400. For a simple start/end frame clip, use [FLUX 3 Max Image to Video](https://docs.vidgo.ai/api-manual/video-series/blackforestlabs-flux-3-max-image-to-video.md). * Credits are reserved at submission and depend on `resolution` and `duration`. The rate is the same for text-to-video, image-to-video and keyframes-to-video, and `sound` does not change it. A failed task is refunded in full. See the [pricing page](https://vidgo.ai/apis/api-pricing) for current rates. * There is no 4K tier, no `seed` and no output longer than 20 seconds on this model. ## OpenAPI ````yaml api-manual/video-series/blackforestlabs-flux-3-max-keyframes-to-video.json POST /api/generate/submit openapi: 3.0.0 info: title: Vidgo API - FLUX 3 Max Keyframes to Video description: >- The FLUX 3 Max Keyframes to Video API places 1–10 images on a 24 fps timeline with frame_index and generates the 5–20 second motion between them. version: 1.0.0 servers: - url: https://api.vidgo.ai description: Production server security: - BearerAuth: [] paths: /api/generate/submit: post: tags: - Video Series summary: FLUX 3 Max Keyframes to Video description: >- Send only the `input` fields listed for this model. Any other field, including `image_urls`, returns 400. Each keyframe needs a public HTTP(S) `image_url` and a unique `frame_index` between 0 and `duration × 24`. operationId: submit_blackforestlabs_flux_3_max_keyframes_to_video requestBody: required: true content: application/json: schema: type: object required: - model - input properties: model: type: string description: >- Model ID. Use `blackforestlabs/flux-3-max/keyframes-to-video`. example: blackforestlabs/flux-3-max/keyframes-to-video callback_url: type: string format: uri nullable: true description: >- Optional public HTTP(S) endpoint that receives a POST when the task becomes `finished` or `failed`. HTTPS is recommended. Omit it, or send `null` or an empty string, to disable callbacks. example: https://your-domain.com/callback input: type: object required: - keyframes - prompt properties: keyframes: type: array items: type: object required: - image_url - frame_index properties: image_url: type: string format: uri description: >- Public HTTP(S) URL of the keyframe image (PNG, JPEG or WebP). frame_index: type: integer minimum: 0 maximum: 480 description: >- Frame position on the 24 fps timeline, from `0` to `duration × 24` (for example 0–120 for a 5-second video). additionalProperties: false description: One keyframe. minItems: 1 maxItems: 10 description: >- 1–10 keyframes. Each object has exactly `image_url` and `frame_index`. Frame indexes must be unique. prompt: type: string minLength: 1 example: >- A seed sprouts, grows into a sapling and blossoms into a cherry tree, time-lapse, fixed camera description: >- Describe the motion and transitions between keyframes, the camera movement and, with `sound` on, the audio. Must not be blank. duration: type: integer minimum: 5 maximum: 20 default: 5 description: Output length in seconds (integer). resolution: type: string enum: - 720p - 1080p default: 720p description: Output resolution. It sets the billing rate. aspect_ratio: type: string enum: - auto - '21:9' - '2:1' - '16:9' - '4:3' - '1:1' - '3:4' - '9:16' default: auto description: >- Output aspect ratio. `auto` lets the model choose: 16:9 for text-only prompts, the shape of the first image when images are supplied. sound: type: boolean default: true description: >- Generate native audio in the same pass. Set `false` for a silent video. Does not change the price. additionalProperties: false description: Generation parameters. examples: three_keyframes: summary: Three keyframes over 5 seconds value: model: blackforestlabs/flux-3-max/keyframes-to-video input: keyframes: - image_url: https://example.com/seed.png frame_index: 0 - image_url: https://example.com/sapling.png frame_index: 60 - image_url: https://example.com/blossom.png frame_index: 120 prompt: >- A seed sprouts, grows into a sapling and blossoms into a cherry tree, time-lapse, fixed camera duration: 5 resolution: 720p aspect_ratio: auto sound: true storyboard: summary: 10-second 1080p storyboard with callback value: model: blackforestlabs/flux-3-max/keyframes-to-video callback_url: https://your-domain.com/callback input: keyframes: - image_url: https://example.com/shot-1.png frame_index: 0 - image_url: https://example.com/shot-2.png frame_index: 96 - image_url: https://example.com/shot-3.png frame_index: 168 - image_url: https://example.com/shot-4.png frame_index: 240 prompt: >- A courier cycles through a misty city at dawn, crosses a bridge and arrives at a lit doorway, smooth tracking shots duration: 10 resolution: 1080p aspect_ratio: '21:9' sound: false responses: '200': description: Task submitted content: application/json: schema: type: object required: - code - data properties: code: type: integer enum: - 200 description: HTTP status code. data: type: object required: - task_id - status - created_time properties: task_id: type: string description: >- Task ID. Use it with [Query Task Status](/api-manual/task-management/status). status: type: string enum: - not_started description: Initial task status. created_time: type: string format: date-time description: Time the task was created (ISO 8601). example: code: 200 data: task_id: task-unified-1762160000-abc123 status: not_started created_time: '2026-11-03T10:30:00' '400': description: >- Invalid input, unsupported field, inaccessible media, or insufficient credits content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '401': description: Invalid credentials content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '403': description: Access denied content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '404': description: Unknown or disabled model content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '408': description: Request timed out content: text/plain: schema: type: string example: Request timeout '422': description: Invalid JSON or non-object request body content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '429': description: Rate or API key credit limit exceeded content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '500': description: Internal error content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '502': description: Unable to create the upstream generation task content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. '503': description: The requested model is temporarily unavailable content: application/json: schema: type: object required: - detail properties: detail: oneOf: - type: string - type: object additionalProperties: true - type: array items: {} description: Error message. components: securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: API Key description: >- All API endpoints require Bearer Token authentication Get your API Key: Go to **Dashboard → API Key** ([API Key Management Page](https://vidgo.ai/apis/dashboard/api-key)) to get your API Key Add it to the request header: ``` Authorization: Bearer VIDGO_API_KEY ``` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.