> ## Documentation Index > Fetch the complete documentation index at: https://docs.bfl.ml/llms.txt > Use this file to discover all available pages before exploring further. # Generate an image with FLUX 3 Klein > Generate or edit images with FLUX 3 Klein and retrieve the asynchronous result. ```bash Text to image theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "Ultra-wide cinematic shot of a fog-drenched coastal highway at dawn, cliffs on one side, turquoise sea on the other, a single vintage car with headlights on, soft golden rim light", "aspect_ratio": "21:9" }' ``` ```bash Edit an image theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "change the color of only one bird in the middle to #e01075", "images": [ "https://cdn.sanity.io/images/2gpum2i6/production/4792198dfeba9223bf3ecf020fed2942de7f0bd7-1800x1200.webp" ] }' ``` ```bash Multi reference theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "Turn Image 1 in the Style of Image 2", "images": [ "https://cdn.sanity.io/images/2gpum2i6/production/ababcf5c9cf86074d71c92d6362ff63545d90661-1800x1201.webp", "https://cdn.sanity.io/images/2gpum2i6/production/dc642f5b01040c4afc46c1b4f8c4945152932683-1350x1800.webp" ] }' ``` ```bash Layout with boxes theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "Minimalist graphic illustration featuring a black silhouette of a person centered against a solid, vibrant chartreuse background . The figure is captured in a dynamic, mid-stride running pose, facing toward the left side of the frame. The image relies entirely on the high-contrast relationship between the two colors, mimicking a digital recreation of a screen-printed or risograph aesthetic, with no discernible light source or shadow. [{\"id\":\"background_1\",\"bbox\":[0,0,1000,1000],\"desc\":\"A flat field of neon yellow-green possessing a subtle, tactile paper texture with fine, organic grain and slight variations in color saturation, giving the flat surface a sense of physical depth.\"},{\"id\":\"silhouette_1\",\"bbox\":[150,150,850,850],\"desc\":\"A black silhouette of a person in motion, composed of a dense, stippled texture that resembles physical ink on paper or a low-resolution digital dither. The leading edges, including the front of the head, chest, and forward leg, are relatively solid and opaque. The trailing edges, such as the back, outstretched rear arm, and lifted back leg, dissolve into a spray of coarse, square-shaped pixels and scattered dots. The black ink shows a slight textural irregularity, as if pressed onto a porous surface.\"}]", "aspect_ratio": "1:1" }' ``` ```bash Edit with boxes theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "In , change the large tiger and the small glowing butterfly to be pink. Keep the massive fallen log , the falling snow , and the dark background trees exactly unchanged. [{\"id\":\"animal_1\",\"from\":null,\"src_bbox\":null,\"tgt_bbox\":[250,50,850,650],\"desc\":\"Make both pink.\"},{\"id\":\"insect_1\",\"from\":null,\"src_bbox\":null,\"tgt_bbox\":[650,680,750,750],\"desc\":\"Make both pink.\"},{\"id\":\"log_1\",\"from\":\"ref_image_0\",\"src_bbox\":[600,0,1000,1000],\"tgt_bbox\":[600,0,1000,1000],\"desc\":\"A massive, fallen tree log stretching horizontally across the foreground. The surface features deep, rough-textured bark, weathered cracks, and small pockets of frost.\"},{\"id\":\"snow_1\",\"from\":\"ref_image_0\",\"src_bbox\":[0,0,1000,1000],\"tgt_bbox\":[0,0,1000,1000],\"desc\":\"Numerous white snowflakes of varying sizes falling across the scene. Some flakes are sharp and distinct, while others closer to the lens appear as blurred white streaks.\"},{\"id\":\"trees_1\",\"from\":\"ref_image_0\",\"src_bbox\":[0,0,650,1000],\"tgt_bbox\":[0,0,650,1000],\"desc\":\"A dense stand of tall, dark, vertical tree trunks receding into the distance. A cool, blue misty light permeates the spaces between the trees, glowing most intensely from the right edge.\"}]", "images": [ "https://cdn.sanity.io/images/2gpum2i6/production/b6476b163e11444d6d5490ac1fa1e610d4eab85e-1360x768.webp" ] }' ``` ```bash Move with boxes theme={null} curl --request POST \ --url https://api.bfl.ai/v1/flux-3-image-klein \ --header "x-key: $BFL_API_KEY" \ --header "Content-Type: application/json" \ --data '{ "prompt": "In , move the miniature grey amigurumi knight figure upwards and to the left along the yarn cliff . Leave the polished steel tapestry needle in its original position in the air. Keep the rest of the image completely unchanged, preserving the blurred yarn backdrop , the large knitted dragon , and the fiery orange thread suspended between them. [{\"id\":\"knight_1\",\"from\":\"ref_image_0\",\"src_bbox\":[500,150,850,350],\"tgt_bbox\":[194,55,544,255],\"desc\":\"A miniature amigurumi knight figure crocheted from thick grey woolen yarn. It has visible, intricate stitches forming a rounded helmet shape and a cylindrical body, with tiny stubby arms reaching upwards against the cliff.\"},{\"id\":\"backdrop_1\",\"from\":\"ref_image_0\",\"src_bbox\":[0,0,1000,1000],\"tgt_bbox\":[0,0,1000,1000],\"desc\":\"A soft, out-of-focus expanse of cream ivory and melange indigo knitted yarn, providing a blurred studio backdrop with tangible fiber fuzz catching the ambient light.\"},{\"id\":\"cliff_1\",\"from\":\"ref_image_0\",\"src_bbox\":[300,0,1000,450],\"tgt_bbox\":[300,0,1000,450],\"desc\":\"A steep, uneven cliff face constructed from stacked, thick yarn skeins in rich shades of mustard yellow, terracotta, and melange indigo, featuring visible woven wool textures and loose, stray fiber strands.\"},{\"id\":\"needle_1\",\"from\":\"ref_image_0\",\"src_bbox\":[420,250,550,450],\"tgt_bbox\":[420,250,550,450],\"desc\":\"A real, oversized polished steel tapestry needle, gleaming under the studio lighting. It features a blunt tip and an elongated eye, grasped like a weapon in the knight'"'"'s yarn-stub hand.\"},{\"id\":\"dragon_1\",\"from\":\"ref_image_0\",\"src_bbox\":[100,600,950,1000],\"tgt_bbox\":[100,600,950,1000],\"desc\":\"A large, fluffy knitted dragon made of highly textured, fuzzy yarn in terracotta and mustard yellow. It has a rounded snout, large crocheted eyes, and a wide-open mouth, with visible loose fibers creating a soft, tactile surface.\"},{\"id\":\"fire_1\",\"from\":\"ref_image_0\",\"src_bbox\":[350,400,650,650],\"tgt_bbox\":[350,400,650,650],\"desc\":\"Curled, sculptural puffs of fiery orange angora thread, suspended in mid-air. The thread is highly textured, fuzzy, and chaotic, bursting from the dragon'"'"'s mouth and stretching horizontally across the center.\"}]", "images": [ "https://cdn.sanity.io/images/2gpum2i6/production/aa7b28af831835fcef86e770262c8c30fa308c2c-1360x768.webp" ] }' ``` ## OpenAPI ````yaml https://api.bfl.ai/openapi.json POST /v1/flux-3-image-klein openapi: 3.1.0 info: title: BFL API description: Authorize with an API key from your user profile. version: 0.0.1 servers: - url: https://api.bfl.ai description: BFL API security: [] tags: - name: Models description: >- Generation task endpoints. These endpoints allow you to submit generation tasks. - name: Utility description: >- These utility endpoints allow you to check the results of submitted tasks and to manage your finetunes. paths: /v1/flux-3-image-klein: post: tags: - Models summary: Generate an image with FLUX 3 Image Klein. description: Submits a text-to-image or image editing task with FLUX 3 Image Klein. operationId: flux_3_image_klein_v1_flux_3_image_klein_post requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/Flux3ImageKleinInputs' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/AsyncResponse' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' security: - APIKeyHeader: [] components: schemas: Flux3ImageKleinInputs: properties: prompt: type: string title: Prompt description: Free-form prompt describing the image. images: anyOf: - type: string - items: type: string type: array - type: 'null' title: Images description: >- Optional reference image(s), each an http(s) URL or base64, one to 10 total. The first is the image being edited and sets the default output size. aspect_ratio: anyOf: - type: string enum: - '21:9' - '2:1' - '16:9' - '3:2' - '7:5' - '4:3' - '5:4' - '1:1' - '4:5' - '3:4' - '5:7' - '2:3' - '9:16' - '1:2' - '9:21' - type: string const: auto title: Aspect Ratio description: >- Output aspect ratio, as in flux-3-image. `auto` (default): for edits, the first reference's exact aspect; for text-to-image, a ratio picked from the prompt (prompt rewrite, else ratio keywords, else 16:9) at the requested tier. Ignored when width and height are set. default: auto resolution: anyOf: - type: string enum: - 768sq - 1k - 1.5k - 2k - 4k - type: 'null' title: Resolution description: >- Equal-area size tier, as in flux-3-image: `768sq`, `1k`, `1.5k`, `2k` or `4k`. Omitted: `1k` for text-to-image; for edits the first reference's own size, or its nearest tier when aspect_ratio is set. Ignored when width and height are set. width: anyOf: - type: integer - type: 'null' title: Width description: >- Exact output width in pixels, [64, 6256]; set together with height. Overrides resolution and aspect_ratio. height: anyOf: - type: integer - type: 'null' title: Height description: >- Exact output height in pixels, [64, 6256]; width x height at most 16822272 pixels (16.8 MP, the largest 4k bin). seed: anyOf: - type: integer maximum: 4294967295 minimum: 0 - type: 'null' title: Seed description: Seed for reproducibility; random when omitted. safety_tolerance: type: integer maximum: 7 minimum: 0 title: Safety Tolerance description: >- Harm moderation tolerance from 0 to 7, with 0 the strictest. The route and organization determine the approved maximum and per-category ceilings. Unapproved levels return 422 with approved levels. default: 2 output_format: type: string enum: - jpeg - png title: Output Format description: 'Output image format: `jpeg` (default) or `png`.' default: jpeg steps: anyOf: - type: integer maximum: 16 minimum: 1 - type: 'null' title: Steps description: Denoising steps (default 16). additionalProperties: false type: object required: - prompt title: Flux3ImageKleinInputs description: >- FLUX 3 Image Klein: text-to-image, or editing with up to 10 reference images. AsyncResponse: properties: id: type: string title: Id polling_url: type: string title: Polling Url cost: anyOf: - type: number - type: 'null' title: Cost description: Cost in credits for this request input_mp: anyOf: - type: number - type: 'null' title: Input Mp description: Input megapixels (2 decimal places) output_mp: anyOf: - type: number - type: 'null' title: Output Mp description: Output megapixels (2 decimal places) type: object required: - id - polling_url title: AsyncResponse HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError securitySchemes: APIKeyHeader: type: apiKey in: header name: x-key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.