Defining simple functions

Creating a package that uses SQRL

We recommend developing SQRL functions using TypeScript. Getting set up with TypeScript is out of scope for this tutorial, but as a prerequisite you should be comfortable running TypeScript code on the command line.

First install the sqrl package. We’ll also install the sqrl-cli package which makes it easy to create a command line application to test with.

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npm install --save sqrl sqrl-cli

Once the packages are installed you can create a basic registration function

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import {Instance, Execution, AT } from "sqrl"

function registerFunctions(instance: Instance) => {
    instance.register(async function sayHello(state: Execution, name) {
        return 'Hello, ' + name + '!';
    }, {
        args: [AT.state, AT.any]
    })
}

Finally sqrl-cli exposes a run method that makes testing this out far easier:

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import { run } from "sqrl-cli";
run({ registerFunctions });

Now if you run your TypeScript file, you should get the standard SQRL command line interface with your function included. We use ts-node so that you don’t have to recompile each time.

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$ ts-node src/cli.ts repl
sqrl> sayHello("Josh")
'Hello, Josh!'