Griptape Driver: Black Forest Labs Image Generation

Most people run Flux locally in ComfyUI. This node is for when you want the same model family but don't want to host it - Griptape Driver: Black Forest Labs Image Generation talks to Black Forest Labs' hosted Flux API, giving you flux-pro, flux-dev, and the newer flux-pro-1.1 / flux-pro-1.1-ultra without a GPU, and billed per generation.

It's also the closest thing this pack has to a "full-featured" image driver, because BFL's API exposes every knob the service offers - and this node exposes all of them. It needs a BFL_API_KEY, which costs money at api.bfl.ai, so the honest framing is: use this if you're building a Griptape agent that generates images on a server you don't control, or if your local box can't run Flux at all.

How it works

Driver → task, like the rest of the pack: the DRIVER output feeds a Griptape Run: Prompt Image Generation Task, which calls the BFL API and returns the image. The node is where you configure the call, and there's a lot to configure.

The inputs worth knowing:

• image_generation_model - seven choices: flux-pro-1.1 (default), flux-pro-1.1-ultra, flux-pro, flux-dev, and the guidance-flavored flux-pro-1.0-canny, -depth, and -fill variants.
• width / height - dropdowns of values 256–1440 in 32px steps, plus separate aspect_ratio_width / aspect_ratio_height ints. You set either explicit dimensions or an aspect ratio.
• steps and guidance - optional. The tooltips are actually specific here: for flux-dev/flux-pro, guidance runs 1.5–5 (higher = better prompt adherence, less realism); for the canny/depth variants it's 1–100, where higher means "image over prompt."
• prompt_upsampling - BFL rewrites your prompt for more creative output when on. Fun, but it can drift from what you asked for.
• safety_tolerance - strict → none. BFL's safety filter; default medium.
• raw - "less processed, more natural-looking images."
• image_prompt_strength - 0.0–1.0, how strongly a reference image influences the result (relevant for the edit-style models).
• seed - reproducibility.
• api_key_env_var - the env-var name holding your key, BFL_API_KEY by default. Not the key itself.

Installing

Ships in the ComfyUI Griptape Nodes pack:

• ComfyUI Manager: search "Griptape" → install ComfyUI-Griptape.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/griptape-ai/ComfyUI-Griptape, then restart.

This driver is why the pack's requirements.txt carries a git dependency on griptape-black-forest - if the BFL driver is missing after install, that's the package to check. Manager installs everything automatically. And the torch caveat applies pack-wide (reinstall torch with the CUDA index if Griptape's install breaks ComfyUI's build - see the README).

Gotchas

Two things bite people. First, flux-pro-1.1-ultra and the canny/depth models don't all accept the same parameters - BFL rejects combos that don't apply (e.g., guidance on a model that doesn't take it). If a call errors with a parameter complaint, simplify the node to the defaults first. Second, the raw and prompt_upsampling toggles quietly change output character; if your results don't match your prompt, check those before blaming the model. Cost is the quiet killer too - each generation is a paid API call, and the ultra variants cost more.