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Plugin an existing JS SDK


In this guide, we'll walk you through creating your own JavaScript-based plugin that can be added to the JavaScript Polywrap Client.


Plugins do not retain all of Polywrap's benefits. We recommend re-writing your existing JavaScript SDKs as Wasm wraps if possible.

As always, if you need any help, message us on Discord!


You'll need the following installed before building your plugin:

  • nvm
  • yarn

You'll be using TypeScript to implement your Polywrap plugin.


In the future, TypeScript will be one of many supported languages for implementing plugins. As more Polywrap Clients are released in various languages, implementing plugins in those languages will be supported as well.

Getting started

To get started, use the following command to spin up a project folder for your plugin.

npx polywrap create plugin typescript <project-name>

Where <project-name> is replaced with a custom name of your choosing. For example my-plugin.

Once complete, you'll see a new folder appear, named after the custom name you've chosen. Please navigate into this new directory (using cd for example).


Let's ensure all of your project's dependencies are installed. From inside your project's directory, simply run:

  • nvm install && nvm use
  • yarn

Overview of project files

Your project should look something like this:

polywrap.yaml           # Plugin Manifest
| index.ts # Entry File
│ schema.graphql # Schema


The Plugin Project Manifest describes the layout of a plugin.


Each wrap project has a Wrap Schema. The schema defines the wrap's dependencies, methods, and custom types. In short, it's an interface describing how to use the wrap.


The index.ts file exports the wrap's method's implementations, which contain the plugin's logic. Learn more about the plugin's code architecture by reading Plugin Architecture

Building the plugin

To build your plugin, all you need is the following command:

yarn build # alias for "npx polywrap build"

Example Plugins

See Understanding Plugins for some examples of Plugins used within the default configuration of the Polywrap Client.