Serverless functions that are always warm, powered by open source.

LatenSee is a tool that dynamically pings your AWS lambda functions, reducing cold starts to improve your user's experience.

Go to Github

Proudly open source and built on fantastic tools

    • React
    • Node
    • Express
    • AWS Lambda
    • Docker
    • Jest

Keep your serverless functions fast and responsive.

Self-host LatenSee and it will ping your serverless functions and measure cold starts. LatenSee will intelligently ping more often to avoid cold starts.

See all of your function's latency from recent invocations and stats about your app's lambdas.

LatenSee is easy to get running.

Two simple steps and LatenSee is ready to keep your functions warm.

1. Add two lines around your lambda function's declaration. These tell your lambda to break when it recognizes LatenSee.

let cold=true;                                                                                                          
export const handler= async (event) => {
  if(event.body==='LatenSee'){const body={cold};cold=false;return{statusCode:200,body:JSON.stringify(body)};}cold=false;
  /**
   * Retain all other Lambda functionality here
   */
  return { statusCode: 200, body: JSON.stringify('Lambda complete') };
};

2. Build your LatenSee docker image, and deploy anywhere you host your containers.

npm run build
docker build -t latensee-image .

Set up LatenSee today

It’s time to say goodbye to slow first page loads, and degraded user experiences. Take control of your serverless functions.

Go to Github

Crafted with care

Our team wanted to build a product we'd be proud to use without compromising developer experience or functionality.

Frequently asked questions

If you can’t find what you’re looking for, open an issue in our Github.

    • Does any of my data go to a third party server?

      No. All data for running the application stays within your self-hosted app. There is no third party communication in LatenSee.

    • Where can I host LatenSee?

      LatenSee is easily hosted anywhere you can host a docker container. We recommend using the same cluster that your app is deployed in in order to ensure secure connections between your LatenSee app and the functions you are warming.

    • I don't want my Lambda to run or send data back, how can I ensure that LatenSee doesn't receive any other info?

      LatenSee's only addition to your Lambda is a small closure variable (used to detect if the invocation is a cold start) and immediately processes a response - feel free to audit the code snippet!

    • I'd like to suggest a new feature, what can I do?

      Feel free to open an issue on our Github - and of course, feel free to contribute directly yourself!

    • My Lambda doesn't have an API endpoint and is triggered by something else, what should I do?

      We suggest adding an additional API gateway trigger for your Lambda.

    • How can I get in touch with the team?

      Feel free to follow us on LinkedIn or Github, we're always willing to share what we've learned with others!