arkennemasis fal · Flux Pro Kontext Text to Image · $0.04/image

Straight text-to-image on the Kontext Pro endpoint, $0.04 per image. Worth knowing what this actually is before you wire it up: Kontext's reputation is editing, and the interesting thing about the text-to-image variant is that it inherits the same prompt-following and in-image text rendering - just without a reference to edit. Think of it as the mid-tier alternative to local Flux when you can't run 12B or don't want to.

The inputs

• prompt - write it as a description, in sentences.
• aspect_ratio - defaults to 1:1. Options: 21:9, 16:9, 4:3, 3:2, 1:1, 2:3, 3:4, 9:16, 9:21. Pick deliberately; a landscape scene in a square frame is a choice you probably didn't mean to make.
• guidance_scale 3.5 (1–20) - adherence to the prompt. seed for repeats, num_images 1–4.
• output_format (jpeg/png), enhance_prompt (off by default; fal rewrites your prompt when it's on), safety_tolerance default 2 with 1–6 available, 1 strictest.

And the pack-wide widgets that come on every fal node here: max_cost_usd (default $20 - checked before upload, so a bad setting can't bill you), reuse_identical_run (on; identical settings plus identical connected media return the earlier files), extra_json (JSON merged last into the request, for anything the node has no box for), max_concurrent (default 1 - one paid fal call at a time across the run).

Outputs

images → preview or save. image_paths → the files under output/fal/fal-ai_flux-pro_kontext_text-to-image/. seed for reproducibility, prompt echoing the text sent, has_nsfw_concepts, timings, and info with the request id, cost estimate and fal's answer.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/Hishamahmer/comfyui-arkennemasis

Or search comfyui-arkennemasis in ComfyUI-Manager. Restart, then find it at arkennemasis/fal/Image/Flux. Nothing to download locally.

# .env, beside run_nvidia_gpu.bat
FAL_KEY=your-key-from-fal.ai/dashboard/keys

No key field on the node - the pack reads the .env file and nothing else, so an FAL_KEY set as an environment variable won't be picked up.

Worth knowing before you spend

Pro is closed weights. There's no local download at any VRAM, which is the honest justification for paying per image here at all. If you can run Flux Dev locally, the Pro route is mostly a convenience and a quality-tier choice rather than a necessity.

No acceleration or step controls. This endpoint gives you prompt, guidance, ratio, seed and count. Iteration means rewriting the prompt, not turning a dial - which is a real difference from the local Flux experience where you'd sit there adjusting steps.

Text in images is a strength here, and it's the main reason to reach for Kontext's t2i over other hosted endpoints: signs, labels and short headlines come out legible far more often. Long strings still break.

Censorship lives in the model, not the node. The Kontext-era license and the weights put explicit content off the table; raising safety_tolerance doesn't change what the model will render.