funcX - Federated Function as a Service

funcX is a distributed Function as a Service (FaaS) platform that enables flexible, scalable, and high performance remote function execution. Unlike centralized FaaS platforms, funcX allows users to execute functions on heterogeneous remote computers, from laptops to campus clusters, clouds, and supercomputers.

funcX is composed of two core components:

  • The funcX cloud-hosted service provides an available, reliable, and secure interface for registering, sharing, and executing functions on remote endpoints. It implements a fire-and-forget model via which the cloud service is responsible for securely communicating with endpoints to ensure functions are successfully executed.
  • funcX endpoints transform existing laptops, clouds, clusters, and supercomputers into function serving systems. Endpoints are registered by installing the funcX_endpoint software and configuring it for the target system.

funcX model

funcX works like other FaaS platforms: users first register a function with funcX by specifying the function body (in Python), they may then execute that function by specifying the function ID and input arguments. Unlike traditional FaaS platforms, users also specify the endpoint ID on which they wish to execute the function.

funcX endpoints are user-managed and may be configured on a wide range of resources from laptops and scientific instruments through to supercomputers. The funcX endpoint can be configured to execute functions locally (i.e., using multiple processes) or on connected computing resources (i.e., by provisioning and managing compute nodes from a batch scheduler or cloud API).

funcX implements a reliable fire-and-forget execution model. After invoking a function, a user can close their laptop and rely on funcX to manage the execution and store the results. funcX securely communicates with remote endpoints, waits for resources to become available, and can even retry execution upon failure. funcX stores results (or errors) in the cloud-hosted service until they are retrieved by the user.


Using funcX

funcX offers a Python SDK for registering, sharing, and executing functions. The following code shows how funcX can be used to register and run a “hello world” function on a remote endpoint.

from funcx.sdk.client import FuncXClient

fxc = FuncXClient()

def hello_world():
  return "Hello World!"

func_uuid = fxc.register_function(hello_world)

tutorial_endpoint = '4b116d3c-1703-4f8f-9f6f-39921e5864df'
result =, function_id=func_uuid)


Deploying an endpoint

A funcX endpoint can be created by installing the funcX endpoint software and configuring it for the target resources. The following steps show how to download and configure an endpoint for local (multi-process) execution.

$ python3 -m pip install funcx_endpoint

$ funcx-endpoint configure

$ funcx-endpoint start <ENDPOINT_NAME>


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