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Black Forest Labs · Image model
FLUX.2 Klein 4B
black-forest-labs/flux.2-klein-4b- Image
FLUX.2 [klein] 4B is the fastest and most cost-effective model in the FLUX.2 family, optimized for high-throughput use cases while maintaining excellent image quality. Pricing is based on the output...
Specifications
- Input
- text, image
- Output
- image
- Editing
- yes, up to 4 reference images
- Images per call
- 1
- Served by
- Black Forest Labs
Request options
Validated against these values; anything else returns 400 with the allowed list.
- aspect_ratio
- 1:1, 4:3, 3:4, 3:2, 2:3, 16:9, 9:16, 21:9, auto
- output_format
- png, jpeg
- seed
- boolean
Use it
POST /api/v1/images · /images/edits · MCP generate_image · edit_image · full reference
curl https://omnirail.org/api/v1/images \
-H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
-d '{"model":"black-forest-labs/flux.2-klein-4b","prompt":"a lighthouse at dawn, 35mm film","aspect_ratio":"1:1"}'