Tools for running Serverless CFML Lambda Functions

FuseLess Template FuseLess Core

built by:

Getting Started

Let's get right to it, you want to run your existing code on AWS Lambda...

Download the FuseLess Template

Start by downloading a zip of the FuseLess Template repository. Then extract it somewhere locally.

Download Lucee & FuseLess Jars

If you are on linux or a mac you can just run the init.sh script in the FuseLess Template zip and it will take care of it. If you are on Windows take a look at jars/README.md.

Currently only Lucee is supported, it may be possible to get Adobe ColdFusion running on Lambda as well, but the size of the jar files would really need to be trimmed down to fit in the 250mb code size limit. It would take a lot of experimentation to get it working, but I wouldn't say it is impossible.


The fun part... add some CFML to the cfml/app/folder.

Package it up

To package it up with all the jar depenedencies you will need to use download and install Gradle.

Once you have it installed from the root of the template folder run the following command in Terminal or Command Prompt:

gradle build

At this point you will now have a CFML serverless application all packaged up in a zip file 🎉

The zip file is located in build/distributions/fuseless-template.zip it can be uploaded to Lambda or tested locally using sam local


There are two ways you can test your code - many people test directly on AWS Lambda because it is the only way to replicate the environment. You may find it more convenient to test locally however, for this you can use the AWS Sam CLI

First you will need to install sam, follow these instructions.

Once sam is installed and working you can simply run the following command from your Terminal or Command Prompt:

sam local start-api

This will start a local AWS API Gateway instance on port 3000 (by default). When you make a HTTP request it will spin up an emulated Java AWS Lambda docker container on each invocation. So you take a Cold Start initialization hit on every request in this mode.

Cold Starts & Performance

No matter what language a lambda function is written in, one of the things you will have to deal with is the cold start performance. I have found that the Cold Start time averages around 2 seconds, which is not too bad. Once the lambda is warm, it can serve many additional requests at very high performance (I've seen CFML execution times in the single digit miliseconds with FuseLess!).

Ways to minimize the Cold Start Performance hit:

Frequently Asked Questions

How fast is it?

Running a simple Hello World CFML can execute on lambda as fast as 3ms.

How big is the function code?

A minimal deployment is currently around 20mb! We are working to make this even smaller.

How much RAM is required?

It can work with as little as 256mb of ram but ColdStart times will be very high. Here are some possible Cold Start Request Times for different amounts of RAM

RAM Avg Cold Start Time Avg Warm Request Time
256 MB 6 sec 20 ms
512 MB 2-3 sec 15 ms
1024 MB 1.5 sec 10 ms
2048 MB 0.8 sec 8 ms

Do all CFML tags/function work?

Currently FuseLess bundles Lucee Light, which does not include any extensions so tags such as cfdocument, cfsearch, etc will not work unless you add the extension.

How do I add Lucee Extensions?

We are looking into ways to make this easy, contact Foundeo for assistance.

What other limitations are there?

Lambda has several limits or constraints which are well documented. For example 15 minutes is the maximum execution time, you can only write to the /tmp directory (tip: use ram:// instead), 50mb zipped package size.


FuseLess was built by Foundeo Inc. for questions, comments, support? Contact Foundeo Inc.