Edge Functions — Push Notifications

Introduction

lerix.notifications is a typed client for the push notifications REST API. A common setup is a Supabase Database Webhook that calls an edge function, which pushes to the users affected by the change.

Sending needs a private key with the send push notifications permission, created in the Project Settings of the project your app uses. It is not the SDK key. Keep it in a function secret, never in client code.

Configure

supabase secrets set LERIX_PUSH_KEY=...

const lerix = Lerix.init({
  apiKey: Deno.env.get('LERIX_KEY')!,
  projectId: Deno.env.get('LERIX_PROJECT_ID')!,
  app: { id: 'order-status-push' },
  notifications: { apiKey: Deno.env.get('LERIX_PUSH_KEY')! },
});

notifications.projectId defaults to the SDK’s projectId. Set it when your functions report to one project and your mobile app lives in another.

Example: push when an order ships

Create a Database Webhook on UPDATE of orders that calls this function:

supabase/functions/order-status-push/index.ts

Deno.serve(lerix.wrap(async (req) => {
  const { record, old_record } = await req.json();
  if (record.status === old_record.status || record.status !== 'shipped') {
    return new Response('ignored');
  }

  await lerix.notifications.send({
    title: 'Your order is on its way',
    body: `Order #${record.number} has shipped.`,
    externalUserIds: [record.user_id],
    metadata: { orderId: record.id },
  });
  return new Response('sent');
}));

externalUserIds are your own user ids, as passed to setUser() in the client SDKs. One send reaches every device the user is signed in on, on every platform. See Users & Identity.

Send

Field	Description
`title`, `body`	Required
`externalUserIds`	Up to 1000 of your user ids; can’t be combined with the other targets
`deviceTokens`	Lerix device ids
`sendByTopic` + `topic`	Broadcast to a topic’s subscribers
`sound`, `imageUrl`, `metadata`	Optional content
`sentAt`	ISO string or `Date` to schedule for later

The result has the notificationId. For externalUserIds sends it also has matchedUsers, matchedDevices and unknownUserIds (users with no device yet, which is not an error).

Update, unsend, cancel, deliveries

await lerix.notifications.update(id, { title: 'Delivered', body: 'Enjoy!' });
await lerix.notifications.unsend(id);      // remove from devices, keep history
await lerix.notifications.cancel(id);      // stop a scheduled one
const rows = await lerix.notifications.deliveries(id); // per-recipient status

API errors throw LerixApiException with the backend’s code and status.

Identity verification

When the project requires identity verification, each setUser() call needs an identityHash computed on your server. An edge function is a good place for it:

import { identityHash } from 'npm:@lerix-dev/lerix-edge';

const hash = await identityHash(Deno.env.get('LERIX_IDENTITY_SECRET')!, user.id);
return Response.json({ identityHash: hash });

It is the lowercase hex HMAC-SHA256 of the user id, the same value the NestJS, Python and .NET SDKs compute. It is async here because Web Crypto is.

Getting started

Frameworks

Modules

Developers

Edge Functions — Push Notifications

Introduction

Configure

Example: push when an order ships

Send

Update, unsend, cancel, deliveries

Identity verification

​Introduction

​Configure

​Example: push when an order ships

​Send

​Update, unsend, cancel, deliveries

​Identity verification

Introduction

Configure

Example: push when an order ships

Send

Update, unsend, cancel, deliveries

Identity verification