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Extensions Introduction

This page contains a step-by-step guide for creating and using your first Kwil extension. It will walk through the following steps:

  1. Creating a valid Kwil Extension
  2. Creating a Docker Image for the Extension
  3. Using Docker Compose to run the extension with Kwil

You will need to install Docker and log in to complete this guide.

Creating a valid Kwil Extension

Kwil currently supports libraries for building extensions in both TypeScript/JavaScript and Golang.

We will use either of these libraries to create a gRPC server that can be used as a Kwil extension.

To build an extension server in TypeScript/JavaScript, we will be referencing the example found here.

Initalize Repository

Create a new repository and install the kwil-extensions package:

npm init -y
npm install kwil-extensions
npm install -D ts-node

Implementing the Extension

To create a valid extension server:

  1. Create a file called index.js or index.ts
  2. Paste the example code from the JavaScript Extension Example into the file, or write your own extension.

To test that it is working properly, run:

ts-node index.ts

Creating a Docker Image

To create a Docker image for your extension, you will need to create a Dockerfile in the root of your repository. This process will be slightly different depending on whether you are using TypeScript/JavaScript or Golang.

In the root directory of your application, create a file called Dockerfile and paste the following:

# First stage: build the application
FROM node:14

# Set working directory

# Copy package.json and package-lock.json
COPY package*.json ./

# Install dependencies
RUN npm install

# Copy the source from the current directory to the working directory inside the container
COPY . .

# Build the application
RUN npm run build

# Expose port
EXPOSE 50051

# Command to run the application
CMD ["node", "dist/index.js"]

Now that you have a Dockerfile, you can build the image by running:

docker build -t my-extension-name .

Running the Extension with Kwil using Docker Compose

Now that you have built your extension as a Docker image, you can run it with Kwil using Docker Compose.

To do this, we will be using the Kwil extension deployment template:

git clone

Once you have cloned the repository, open the docker-compose.yaml. Under services:extensions-1:name, replace "<your_image_here>" with the name of your Docker image:

version: '3'
image: <your_image_here>
- 50055:50051
restart: on-failure

Now, simply use the Makefile to download Kwil and run both Kwil and your extension. This will make the database accessible on http://localhost:8080.

make download-and-run

To access the KwilProvider https://localhost:8080 in browser from the Kuneiform IDE, you may need to disable some browser security protections.

For Brave Browser, disable the shields for by clicking the lion icon in the top right corner of the browser.

And that's it! You have successfully shipped your first Kwil extension alongside a Kwil database!

Video Tutorial (TypeScript)

Check out the video below for a step-by-step guide to creating your first Kwil Extension with TypeScript.

Next Steps

To get started using the extension within Kuneiform, check out the Kuneiform Guide for extensions. Or, if you're curious to learn how to build more complex extensions, check out the guide to the structure of extensions here.