fal

fal is a serverless Python runtime that lets you run and scale code in the cloud with no infra management.

With fal, you can build pipelines, serve ML models and scale them up to many users. You scale down to 0 when you don't use any resources.

This repository contains the main Python packages for building on fal:

• fal (in projects/fal): define, test, and deploy serverless apps on fal
• fal-client (in projects/fal_client): call fal model APIs or your deployed endpoints from Python

For full product and platform documentation, see fal.ai/docs.

Which package should I use?

Use fal when you want to deploy Python code to fal

The fal package includes the Python SDK and CLI for building serverless apps, testing them with temporary URLs, and deploying them to production.

pip install fal
fal auth login

Create a minimal app:

import fal


class MyApp(fal.App):
    @fal.endpoint("/")
    def run(self) -> dict:
        return {"message": "Hello, World!"}

Run it on fal for testing:

fal run hello_world.py::MyApp

Deploy it to a persistent endpoint:

fal deploy hello_world.py::MyApp

Docs:

• Quick start
• Deploy to production
• Serverless documentation

Use fal-client when you want to call models or deployed endpoints

The fal-client package is the simplest way to call model APIs on fal from Python.

pip install fal-client
export FAL_KEY="your-api-key"

Call a model:

import fal_client

result = fal_client.subscribe(
    "fal-ai/flux/schnell",
    arguments={
        "prompt": "a futuristic cityscape at sunset",
        "image_size": "landscape_16_9",
    },
)

print(result["images"][0]["url"])

You can also use fal-client to call your own deployed fal apps by passing your endpoint ID instead of a model ID.

Docs:

• Client setup
• Inference methods
• Model APIs documentation

Install from source

From the repository root:

pip install -e 'projects/fal[dev]'
pip install -e 'projects/fal_client[dev]'
pip install -e 'projects/isolate_proto[dev]'

More resources

• Documentation index
• API reference
• Model gallery
• Dashboard