Black Forest Labs
Black Forest Labs makes the FLUX models. Brut calls their own API with your key, for two things:
- FLUX 3 Image, their flagship image model, in every image menu (Text → Image, Image → Image, Compose, Inpaint, Multi-Shot, the Storyboard's keyframes, the Sketchpad's generation layers).
- FLUX Outpaint, their outpainting tool, as a painter in Conform's extend. It is the one painter in Brut that holds your picture in place and generates only what the frame adds.
Get a key
Create an account on the Black Forest Labs dashboard, add credits, make an API key and paste it into ⚙ Settings → Black Forest Labs.
Billing is prepaid credits: 1 credit is $0.01, and a call on an empty balance answers "not enough credits". There is no subscription. Every answer says what the call cost, and that number is what Brut writes on the ledger row.
No key? FLUX 3 Image also runs through OpenRouter on an OpenRouter key (the node says "⇄ via OpenRouter"). FLUX Outpaint is on Black Forest Labs' own API only: no aggregator carries it.
FLUX 3 Image
| Sizes | 768, 1K, 1.5K, 2K, 4K. These are pixel budgets, the same at every ratio: about 0.6, 1, 2.4, 4 and 17 megapixels. |
| Ratios | Every ratio on Brut's menu, plus auto on an edit: the output keeps the first picture's framing. |
| Pictures in | Up to 10 per request, from 256 px a side to 16 megapixels each. Above 4 megapixels Black Forest Labs scales a reference down to 4 before it works on it. |
| Price | Per image, by size: $0.041 (768), $0.048 (1K), $0.07 (1.5K), $0.10 (2K), $0.607 (4K). Reference pictures and the prompt cost nothing extra; a refused request is not charged. |
Things worth knowing:
- It can look things up. By default FLUX 3 searches the web before it draws, which is how it gets a real building or a real product right. Brut leaves that on, except when Conform uses FLUX 3 to extend a picture (there is nothing to look up).
- It has no mask input. On the Inpaint node the mask steers the edit, as on Gemini. Like every mask in Brut it is guidance: the model redraws the frame.
- It is an edit model, not a fill model. Asked to extend a picture, it sometimes keeps your picture exactly where it was and sometimes recomposes the room. For an extension where the original must not move, use FLUX Outpaint.
- 4K is priced six times 2K. "Same as the picture" on a large frame lands on 4K; the frame editor shows the price before you paint, and 2K is one pick away.
FLUX Outpaint
A tool, not a model you prompt: it takes a picture, the size of the frame around it and where the picture sits in that frame, and paints the rest. It appears in one place, the painter menu of Conform's ✂ frame editor, when the method is extend, and it is the painter Conform starts on once your key is in.
- Your picture is held. Where the frame covers the picture, the output is the picture; the tool generates only the added part. That is the difference with every image model on the same menu, which redraw the whole frame.
- 4 megapixels at most. The tool's frame cannot exceed 4 megapixels. A larger frame is painted smaller: a 2048 × 3641 frame comes back at 1520 × 2704 (a frame can also lose a few pixels at its edges). Brut delivers that picture as it is and never scales it back up; Upscale Image is the way to more pixels. The frame editor says so under the picture before you paint.
- A size menu to paint smaller on purpose. Up to 4 MP is the default; up to 2 MP and up to 1 MP lower the limit, and the price with it.
- No prompt needed. The tool reads the picture and continues it. The still's optional note ("more lawn", "no new buildings") is passed along as a hint; the tool may or may not follow it.
- High or Fast. High (the default) gives the best continuation of the picture. Fast answers in seconds for about a sixth of the price; your picture is held just as well, but the painted part is rougher: on an interior, a grittier floor and a wall that stops at the seam where High carries it on. Fast suits a first look, and scenes that extend easily (sky, lawn, water, a plain background).
- Price. Black Forest Labs publishes no rate for this tool. Measured through Brut, counted on the whole frame, your picture included: High, $0.10 per megapixel ($0.10 at 1 MP, $0.20 at 2 MP, $0.40 at 4 MP); Fast, about $0.05 ($0.045 at 1 MP, $0.051 at 2 MP, $0.063 at 4 MP). The frame editor shows the price for your frame, size and mode before the paint; the ledger row carries the billed amount after it.
Limits
- Results are saved to your project as soon as they're ready.
- Their moderation can stop a request (the prompt or a picture) or a result. The node shows which, with their reason; a moderated call is not charged.
Privacy
Calls go from your machine to Black Forest Labs' servers with your key, and nowhere else. With web lookup on, FLUX 3 itself sends search queries drawn from your prompt: that happens inside Black Forest Labs' service.