Every fal model in ComfyUI, one API key.
Custom nodes that bring the entire fal.ai catalog into ComfyUI: ~90 curated hand-written nodes for the most popular models, plus ~1,391 auto-generated nodes covering every live public model on fal — image, video, audio, 3D, LLMs and more. One FAL_KEY unlocks all of them. With a persistent result cache (never pay for the same call twice), spend guards, async fan-out, and zero-I/O fal→fal chaining. The full model catalog lives in MODELS.md.
- What's New
- Installation
- Configuration
- Screenshots
- Curated Nodes
- Auto-Generated Nodes
- Platform Utilities
- Utility Nodes
- Troubleshooting
- Contributing
- License
- Async execution — fal calls run asynchronously on modern ComfyUI, so the UI stays responsive while jobs are in flight.
- Typed builder nodes — build LoRA lists and reference-element configs with dedicated, connectable nodes instead of hand-typed JSON.
- Featured tier — hand-picked models surface under FAL/Featured in the node menu, and models superseded by newer versions are flagged.
- Registry freshness — the pack warns when the committed model registry snapshot is stale, and you can refresh it from the fal sidebar without leaving ComfyUI.
- MODELS.md — the full ~1,391-model catalog moved out of this README into MODELS.md.
Twenty utility nodes under FAL/Utils covering everything between your assets and a fal endpoint — dataset prep (images → captioned training ZIP), media loading from URLs/folders, video trim/concat/mux/frame-extract, image grids and resizing, and JSON/prompt/text data helpers. See Utility Nodes.
Durable job inbox (queued jobs survive ComfyUI restarts), provenance receipts (saved outputs carry endpoint + request id in a sidecar/PNG chunk and can be re-materialized for free), and the in-canvas web extension: cost badges above nodes, a fal sidebar with spend/balance/live jobs, and endpoint autocomplete.
Persistent result cache — identical fal calls are served from disk, free and instant, across restarts; uploads are deduplicated too. Spend guard — refuse to submit past a session budget or below a balance floor, before money moves. URL passthrough — wire a fal node's URL output into the next node's *_direct_url input and intermediate media never touches your machine.
Platform utilities under FAL/Platform: Fal Submit + Fal Collect for parallel fan-out (five video jobs run concurrently on fal, not back-to-back), Fal Result by Request ID to re-fetch any past result without re-paying, Fal Cost Estimator, and Fal Session Costs.
Every live public model on fal became a node: ~1,391 auto-generated nodes built at startup from the committed data/fal_registry.json, with native IMAGE/VIDEO/AUDIO sockets, schema-derived tooltips, and pricing in the help panel. Plus the generic Fal Any Endpoint node, visible errors (failed calls raise fal's actual error message instead of silently returning blanks), progress + cancellation, and full backward compatibility for all ~90 curated nodes.
- Navigate to your ComfyUI custom nodes directory:
cd custom_nodes - Clone this repository:
git clone https://github.com/gokayfem/ComfyUI-fal-API.git - Install the required dependencies:
pip install -r requirements.txt - Configure your API key (below) and restart ComfyUI. Curated nodes appear under the FAL category, auto-generated nodes under FAL/Models/<category> (e.g.
FAL/Models/text-to-image), and hand-picked models under FAL/Featured — or just search for any model by name.
- Get your fal API key from fal.ai
- Copy
config.ini.exampletoconfig.iniinsidecustom_nodes/ComfyUI-fal-API(config.iniis gitignored, so your key never ends up in a commit) - Replace
<your_fal_api_key_here>with your actual fal API key — or set theFAL_KEYenvironment variable instead:export FAL_KEY=your_actual_api_key
All sections besides [API] are optional; defaults shown.
[API]
FAL_KEY = your_actual_api_key
[dynamic_nodes]
; Set to false to load only the curated hand-written nodes.
enabled = true
; Comma-separated category filter; leave unset to load everything.
; categories = text-to-image,image-to-video
[cache]
; Persistent result cache: identical fal calls are served from disk (free)
; across ComfyUI restarts. Bypass per node with force_rerun.
enabled = true
ttl_days = 7
max_entries = 5000
[spend_guard]
; Refuse to submit jobs once the session's estimated spend reaches the
; budget, or when the account balance falls below the floor. 0 = disabled.
session_budget_usd = 0
min_balance_usd = 0
[archive]
; Safety caps for the dataset/folder → ZIP upload utilities.
max_files = 5000
max_total_mb = 2048
[registry]
; On startup a background thread compares the local model registry
; against fal's live catalog and logs how many new models are available;
; the fal sidebar shows them with a one-click refresh (restart required).
; startup_check = true
[MODELS.md](MODELS.md).**
Find them in the node browser under `FAL/Models/<category>`, or search by model name. Node keys are `FalAPI_<endpoint-id>` (slashes → dashes), so workflows stay stable across registry refreshes. Each generated node gives you:
- **Native inputs/outputs** — `IMAGE`/`VIDEO`/`AUDIO` sockets; connected media is uploaded to fal automatically, and video/audio/image models return native ComfyUI types (JSON-ish models return the raw result string).
- **Tooltips + pricing** — hover any input for fal's own parameter docs; the help panel shows the model's current pricing.
- **Seed semantics** — `seed = -1` means "random / omit seed".
- **force_rerun** — bypass result caching to re-roll identical inputs.
**Fal Any Endpoint (fal)** is the escape hatch: one generic node that calls *any* fal endpoint by id with free-form JSON arguments plus optional image/video/audio inputs (uploaded and merged into the matching keys). Outputs are extracted as `IMAGE`/`VIDEO`/`AUDIO`, with the raw result always available as `result_json`. Even brand-new models work the day they launch.
**Keeping the catalog fresh:** a weekly GitHub Action refreshes `data/fal_registry.json` and opens a PR; you can also run `python scripts/build_registry.py` yourself (then `python scripts/build_readme.py` to regenerate MODELS.md), or use the refresh button in the fal sidebar. If ~1,391 extra nodes is more than you want, the `[dynamic_nodes]` config section disables or filters them — see [Configuration](#configuration).
## Platform Utilities
Nodes built on fal's platform primitives (queue, request ids, per-model pricing), under `FAL/Platform`:
| Node | What it does |
| --- | --- |
| **Fal Submit** / **Fal Collect** | Queue a job on any endpoint and collect it later — wire N Submits into N Collects and all N jobs run **in parallel** on fal, so the graph takes as long as the slowest one, not the sum. |
| **Fal Result by Request ID** | Paste any past request id (console log, sidebar, or [fal dashboard](https://fal.ai/dashboard/requests)) to re-fetch its result **without re-generating or re-paying**. |
| **Fal Cost Estimator** | Endpoint id + run count → cost report and `total_usd` float from fal's published pricing, *before* you queue anything. |
| **Fal Session Costs** | Running ledger of every fal call this session (endpoint, duration, request id, estimated cost), with optional reset. |
| **Fal Account Balance** | Your live fal balance (needs an admin-scoped key; scoped keys degrade gracefully). |
| **Fal Job Inbox** | Every Submit is journaled to disk, so queued jobs **survive ComfyUI restarts** — lists pending/collected jobs and outputs the newest pending `request_id` + `endpoint_id`. |
| **Fal Save Media from URL** | fal result URLs eventually expire; this downloads any result into your `output/` directory and writes a provenance receipt (`<file>.fal.json` sidecar + PNG text chunk with endpoint, request id, source URL). |
| **Fal Provenance from File** | Read a saved file's receipt back into `endpoint_id` + `request_id` — re-materialize a generation for free, months later. |
Behind the nodes, three always-on platform features:
- **Persistent result cache** — identical fal calls are served from a disk cache, free and instant, across restarts; input uploads are deduplicated. Bypass per node with `force_rerun`; tune via `[cache]`.
- **Spend guard** — with `[spend_guard]` configured, the pack refuses to submit once estimated session spend hits your budget or your balance drops below the floor — the node errors *before* money moves.
- **URL passthrough** — every generated node's media input has a `*_direct_url` twin and image nodes output `image_urls`; chain fal→fal by URL and intermediate media never touches your machine.
And a web extension (degrades silently on older ComfyUI): **cost badges** above every priced fal node with live estimates on free-typed endpoint fields, a **fal sidebar** (session spend, balance, live job list with per-job Cancel, registry freshness/refresh), and **endpoint autocomplete** with prices when editing any `endpoint_id` field.
## Utility Nodes
Twenty nodes under `FAL/Utils` covering everything between your assets and a fal endpoint — no other packs needed:
| Category | Nodes |
| --- | --- |
| `FAL/Utils/Dataset` | *Images → Training ZIP URL* (standard LoRA caption layout), *Folder → ZIP URL*, *Video → Frame Dataset ZIP URL*, *Batch Caption Images* (parallel VLM captioning) |
| `FAL/Utils/Load` | *Load Image from URL* (multi-URL batching), *Load Audio from URL*, *Load Image Folder*, *Upload Folder as ZIP URL* |
| `FAL/Utils/Video` | *Extract Frames* (efficient last-frame seek — chain into image-to-video for endless extension), *Trim* (keyframe remux, no re-encode), *Concat* (auto resolution/fps normalize), *Mux Audio + Video*, *Video → Audio* |
| `FAL/Utils/Image` | *Image Grid with Labels*, *Resize to fal Preset* (cover/contain/stretch to standard image_size dims), *Image ↔ Base64* |
| `FAL/Utils/Data` | *JSON Extract* (dot/bracket path queries against any `result_json`), *Prompt Lines* (cycling line picker), *Text Template* |
The full LoRA-training pipeline needs nothing else: Load Image Folder → Batch Caption → Images→ZIP → any trainer node.
## Troubleshooting
1. Ensure you have the latest version of ComfyUI installed
2. Update this custom node package:cd custom_nodes/ComfyUI-fal-API git pull pip install -r requirements.txt
3. If you're using ComfyUI Windows Portable, you may need to install fal-client manually:
ComfyUI_windows_portable>.\python_embeded\python.exe -m pip install fal-client
4. **Dynamic nodes not appearing?** Check the ComfyUI console for a line like `Registered N dynamic fal nodes` at startup. If it says the nodes are disabled, remove `enabled = false` from the `[dynamic_nodes]` section of your `config.ini` (and check the `categories` filter isn't excluding what you're looking for). Any registry loading error is also printed there.
5. **`VIDEO` output is `None` or video sockets are missing?** Update ComfyUI — native `VIDEO`/`AUDIO` types require a recent ComfyUI version.
6. **API calls failing?** Failed fal requests raise visible errors that include fal's actual error message (validation issues, content policy, quota). Read the error text in ComfyUI — it usually tells you exactly which parameter to fix.
## Contributing
Contributions are welcome — but note that **a new fal model usually needs no code at all**: it appears automatically via the registry. Read [CONTRIBUTING.md](CONTRIBUTING.md) before opening a PR; it covers when a hand-written node is (and isn't) justified, the compatibility rules, and dev setup.
## License
This project is licensed under the Apache License 2.0. See the [LICENSE](LICENSE) file for details.
If you encounter any issues or have questions, please open an issue on the [GitHub repository](https://github.com/gokayfem/ComfyUI-fal-API/issues).