Guides / Signups & Auth
How to Track Firebase Auth User Registrations
3 min read·Signups & Auth
Use Firebase Cloud Functions
Firebase Auth triggers let you run code when a user is created. This is the cleanest way to log signups.
ts
// functions/src/index.ts
import * as functions from "firebase-functions";
import { logit } from "./lib/logit";
export const onUserCreated = functions.auth.user().onCreate(async (user) => {
const provider = user.providerData[0]?.providerId ?? "unknown";
await logit.now("signups", {
event: "New Firebase Auth user",
description: user.email ?? user.phoneNumber ?? user.uid,
icon: "👤",
notify: true,
tags: { provider: provider.replace(".com", "") },
metadata: {
uid: user.uid,
email: user.email,
provider,
displayName: user.displayName,
createdAt: user.metadata.creationTime,
},
});
});
logit helper (Node.js compatible)
ts
// functions/src/lib/logit.ts
import { init } from "logit";
export const logit = init({
token: process.env.LOGIT_API_KEY ?? functions.config().logit?.api_key ?? "",
});
Set the API key
bash
# Using Firebase CLI
firebase functions:config:set logit.api_key="lk_live_xxxxxxxxxxxxxxxx"
# Or in .env.local
LOGIT_API_KEY=lk_live_xxxxxxxxxxxxxxxx
Track deletions too
ts
export const onUserDeleted = functions.auth.user().onDelete(async (user) => {
await logit.now("churn", {
event: "Firebase user deleted",
description: user.email ?? user.uid,
icon: "👋",
notify: false,
metadata: { uid: user.uid, email: user.email },
});
});
Note: Cloud Functions trigger asynchronously — there may be a few seconds delay between signup and the LogIt notification. For instant alerts, call LogIt directly in your app's sign-up handler instead.
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