Getting started with RedwoodJS

​

Setup

​

Use the Defer RedwoodJS CLI Plugin

For projects based on RedwoodJS >= 6.3.0, run the following command

  yarn rw setup package @defer/redwood

For projects based on RedwoodJS < 6.3.0, please refer to the Custom stack getting started guide.

​

Create a first background function

A background function is a function equivalent to a background job.

All background functions must live in the defer/ folder shown above.

Choose how to create your first background function:

// the defer() helper will be used to define a background function
import { defer } from "src/jobs/clients/defer";
import { logger } from "src/lib/logger";

const sleep = (seconds: number) =>
  new Promise<void>((resolve) => {
    setTimeout(() => {
      resolve();
    }, seconds);
  });

// a background function must be async
const helloWorld = async (name: string) => {
  await sleep(10);
  logger.info(`Hello ${name}!`);
};

// the function must be wrapped with defer() and exported as default
export default defer(helloWorld, {
  // retry: 5,
  // concurrency: 10,
  // maxDuration: 5 * 60 // in seconds
});

yarn rw @defer function <nameOfTheFunction>

yarn rw @defer function syncContacts

// the `defer()` helper will be used to define a background function
import { defer } from "src/jobs/clients/defer";
// the `defer()` helper will be used to define a background function
import syncContacts from "/src/services/syncContacts"

// the imported function must be wrapped with `defer()` and re-exported as default
// be certain your service is `async`
export default defer(syncContacts)

Our background function is ready to be used; let’s see how to call it from your application.

​

Call your background function

Whenever you choose to use the helloWorld() function or create your own, the following example showcasing how to call helloWorld() from a RedwoodJS serverless function demonstrates how easily you can trigger a background function execution.

First, generate a RedwoodJS serverless function:

  yarn rw generate function helloWorld

import type { APIGatewayEvent, Context } from "aws-lambda";

import helloWorld from "src/jobs/defer/helloWorld";
import { logger } from "src/lib/logger";

export const handler = async (event: APIGatewayEvent, _context: Context) => {
  logger.info(`${event.httpMethod} ${event.path}: runHelloWorld function`);

  await helloWorld(event.queryStringParameters["name"] || "World");

  return {
    statusCode: 200,
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      ok: true,
    }),
  };
};

To test in local development, first start your RedwoodJS development server:

  yarn rw dev

Then, open your browser and visit the http://localhost:8910/.redwood/functions/helloWorld?name=Charly function endpoint.

Your development log should show the following:

api | 09:09:56 🌲 incoming request GET xxx /helloWorld?name=Charly
api | 09:09:56 🌲 GET /helloWorld: runHelloWorld function
api | 09:09:56 🌲 request completed 1ms
api | 09:10:01 🌲 Hello Charly!

and the response:

{ "ok": true }

Once your RedwoodJS function is defined, please commit and push it to your branch.

Now that your RedwoodJS contains a background function and a serverless function that calls it, let’s ensure that your Defer token and Build Settings are correctly configured.

​

Setup your Node.js / Bun version

Node.js is the default runtime, and version 18.x will be used if you don't specify your own.

To change your runtime and its version, edit the engines field of your package.json:

{
  ...
  "engines": {
    "node": "18.x"
  }
  ...
}

​

Configure

​

Create your Defer application

First, sign in to the Defer Console, then, go to the “Setup application page.”

1. Selecting a repository

Install Defer on your GitHub account or organization on so Defer can list your repositories:

Ensure to install Defer on your GitHub account

Then, select the GitHub repository of your application:

2. Environment variables (ex: Database access)

The background functions that run in Defer might need to access some externally configured services or databases. For this reason, we recommend using the same environment variables configuration for your target API environment and Defer application.

Got a .env file?

Copy the file’s content into your clipboard and paste it into the first field of the “Add” line. ✨

3. Prisma generate command

It’s important to configure your Pre-Builds Settings to generate the Prisma client before each build.

In Settings, go to Advanced options and then add the following Pre-build command to generate the Prisma client:

yarn rw prisma generate

Ensure to add the Prisma generate as pre-build command

Once your application is correctly configured, click the “Create” button.

You should land on the application’s page with a build running; you can go to the Defer Console to check its status.

Your first successful build on the Defer Console

You can now get a Defer Token by navigating to the Settings page:

Copy your Defer token for the next step

​

Configure your API deployment

Your API deployment should expose your Defer Token as an environment variable in order to get your background function deferred when called.

Set your Defer Token on Vercel

1. Go to your Vercel Dashboard
2. From your project, go to settings
3. Then, to "Environment Variables"
4. Finally, add a new environment variable with Key as DEFER_TOKEN:

Set your Defer Token on Heroku

1. Go to your Heroku Dashboard
2. Select your app, and go to settings
3. Scroll to "Config Vars" and click on "Reveal Config Vars"
4. Finally, add a new environment variable with DEFER_TOKEN as "key":

Set your Defer Token on Render

1. Go to your Render Dashboard
2. Select a service
3. Then, go to "Environment" and click on Add Environment Variable
4. Finally, add a new environment variable with DEFER_TOKEN as "key":

Set your Defer Token on Fly.io

Update your fly.toml configuration filename as follow:

filename="fly.toml" {3} copy

[env]
MY_ENV = "debug"
DEFER_TOKEN = "<your defer token>"

Set your Defer Token on other hosting providers

Update your environment variables by adding the following:

• key: "DEFER_TOKEN"
• value: your Defer Token

​

Deploy

Now, with your API deployment containing your Defer Token and your project’s builds ready on Defer, open your browser and test the RedwoodJS function endpoint.

In the scenario of the helloWorld() background function, visit the /.redwood/functions/helloWorld endpoint of your deployed application.

You should see that your API answered quickly, and by going to your Defer Console, you should see that your background function has 1 execution running - or finished:

By clicking on see executions, you will access the executions list:

​

Next steps