Functions Overview

Functions are serverless compute units that run on the Falcon platform. They process requests, call APIs, read and write data, and return responses — all without managing infrastructure.

Supported languages

Language	FDK	SDK Integration
Python 3.10–3.12	Built-in	FalconPy (context authentication)
Go 1.21+	foundry-fn-go	goFalcon

Development environments

Environment	Languages	Features
Foundry CLI	Python, Go	Full local development, testing, debugging
Browser Editor	Python only	In-console editing, handler registration, one-click testing

Handler structure

Every function implements a handler that receives a request and returns a response.

Python

from crowdstrike.foundry.function import Function, Request, Response

func = Function.instance()

@func.handler(method='POST', path='/my-endpoint')
def on_post(request: Request) -> Response:
    body = request.body
    # Process the request
    return Response(body={"message": "success"}, code=200)

if __name__ == '__main__':
    func.run()

Go

package main

import (
    fdk "github.com/CrowdStrike/foundry-fn-go"
)

func handler(ctx context.Context, request fdk.Request) fdk.Response {
    return fdk.Response{
        Body: map[string]interface{}{"message": "success"},
        Code: 200,
    }
}

Request format

Field	Type	Description
body	object	The request payload
params	object	Query parameters
url	string	The request URL
method	string	HTTP method
context	object	Execution context (app ID, CID, user info)

Response format

Field	Type	Description
body	object	The response payload
code	integer	HTTP status code
errors	array	Optional error messages
headers	object	Optional response headers

Limitations

Limit	Value
Maximum request payload	124 KB (JSON portion; files in requests may be larger)
Maximum response payload	120 KB
Default execution timeout	30 seconds (configurable up to 900 seconds)
Default memory	256 MB (configurable up to 1 GB)
Maximum concurrent executions	100
Maximum package size (including dependencies)	50 MB

Next steps

• Functions: Foundry CLI — Full development guide for all languages
• Functions: UI Editor — Browser-based Python editor