fal.ai Backend

This is the smallest node in the pack, so let's not overthink it. The fal.ai Backend takes one thing - your fal.ai API key - and wraps it into a FAL_BACKEND value that the pack's cloud nodes can consume. Today exactly one node wants it: fal.ai Vision, which sends images to hosted vision models. Think of this as the key slot for the fal side of StudioDeep, the way LLM Backend is the key slot for Anthropic/OpenAI.

How it works

It builds {"api_key": ...} and passes it down the wire. Nothing is called here - no network, no models, nothing. If the key field is empty it raises ValueError("fal.ai API key is required") right away, which is honestly a nice touch: you find out before the expensive call, not during it.

The key thing to understand is that fal.ai is a paid cloud - the actual inference (in Vision's case) runs on fal's servers and you're billed per request. There's no local model, no VRAM pressure, no GGUF to download. If you'd rather not spend money, the answer isn't this node, it's the LLM Backend plus a local or free vision setup. This one is for when you want a specific hosted model without running it yourself.

Inputs and output

• api_key - from your fal.ai dashboard. Masked as a password field.
• Output: fal_backend (FAL_BACKEND), which wires straight into fal.ai Vision.

Installing

Same routine as every node in the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/studiodeep-ai/comfyui-studiodeep StudioDeep
pip install -r StudioDeep/requirements.txt

or search "StudioDeep" in ComfyUI Manager. Then restart. The pack's dependencies are just anthropic, openai, requests - no fal-specific SDK, because the Vision node calls fal's HTTP endpoint directly. No models, no .env.

Troubleshooting

• "fal.ai API key is required" - the field was empty. Grab a key from fal.ai/dashboard and re-run.
• A wrong or expired key won't error here; it'll surface as an HTTP 401 in fal.ai Vision with the status code and body in the error message.
• You don't configure model, temperature, or tokens on this node - those live on the consumer. If you're seeing surprises, check there, not here.

It's a boring node. That's the point: one place to paste a key, everything else stays tidy.