AbuseGraph + Firebase Auth

Block risky Firebase signups and logins with beforeUserCreated and beforeUserSignedIn blocking functions.

Quick path

Set ABUSEGRAPH_* secrets on Cloud Functions.
Deploy beforeUserCreated (signup) and beforeUserSignedIn (login) blocking functions.
Optionally collect browser signals client-side and pass via Callable Function.

Keys

Key	Env	Use
Secret	`ABUSEGRAPH_SECRET_KEY` (`sk_test_…` / `sk_live_…`)	Server `/api/v1/check`
Publishable	`NEXT_PUBLIC_ABUSEGRAPH_PUBLISHABLE_KEY` (`pk_test_…`)	Browser SDK
Site	`ABUSEGRAPH_SITE`	DNS-verified domain

Free includes 1,000 live API checks / month after DNS verify. Test keys never bill.

Env

ABUSEGRAPH_SITE=yourdomain.com
ABUSEGRAPH_CHECK_URL=https://abusegraph.com/api/v1/check
ABUSEGRAPH_SECRET_KEY=sk_test_…

Use sk_live_… in production after DNS verify.

Server check

Cloud Functions use fetch — POST to https://abusegraph.com/api/v1/check. Events: signup | login | password_reset | email_change. Optional sessionId.

Load the browser SDK from the AbuseGraph CDN before your signup/login code. The publishable key is safe to expose; send the resulting body to your own backend, which makes the authoritative check with its server-held secret key.

<script src="https://abusegraph.com/sdk/abusegraph.min.js"></script>
<script>
  const sdk = AbuseGraph.init({ publicKey: "pk_test_…" });

  async function collectForAuth(email, event = "signup") {
    const collected = await sdk.collect();
    const evaluated = await sdk.evaluate(collected, { email });
    return sdk.toCheckBody(collected, {
      email,
      event,
      verdictToken: evaluated.verdictToken?.token,
    });
  }
</script>

POST the returned JSON to your own endpoint. Never treat the browser result as the authoritative decision or put an sk_ key in browser code.

Firebase blocking functions

Use ESM imports. Throw HttpsError on block.

import { beforeUserCreated } from "firebase-functions/v2/identity"
import { HttpsError } from "firebase-functions/v2/https"

export const abusegraphBeforeCreate = beforeUserCreated(async (event) => {
  const email = event.data.email
  if (!email) return

  const site = process.env.ABUSEGRAPH_SITE!
  const res = await fetch(
    process.env.ABUSEGRAPH_CHECK_URL ??
      "https://abusegraph.com/api/v1/check",
    {
      method: "POST",
      headers: {
        "content-type": "application/json",
        "x-api-key": process.env.ABUSEGRAPH_SECRET_KEY!,
        "x-abusegraph-site": site,
      },
      body: JSON.stringify({
        email,
        userId: event.data.uid,
        event: "signup",
        ip: event.ipAddress,
        site,
      }),
    },
  )

  if (res.status === 402) {
    throw new HttpsError("resource-exhausted", "credits_exhausted")
  }

  const result = await res.json()
  if (result.verdict === "block") {
    throw new HttpsError("permission-denied", "Signup blocked")
  }
})

import { beforeUserSignedIn } from "firebase-functions/v2/identity"
import { HttpsError } from "firebase-functions/v2/https"

export const abusegraphBeforeSignIn = beforeUserSignedIn(async (event) => {
  const email = event.data.email
  if (!email) return

  const site = process.env.ABUSEGRAPH_SITE!
  const res = await fetch(
    "https://abusegraph.com/api/v1/check",
    {
      method: "POST",
      headers: {
        "content-type": "application/json",
        "x-api-key": process.env.ABUSEGRAPH_SECRET_KEY!,
        "x-abusegraph-site": site,
      },
      body: JSON.stringify({
        email,
        userId: event.data.uid,
        event: "login",
        ip: event.ipAddress,
        site,
      }),
    },
  )

  const result = await res.json()
  if (result.verdict === "block") {
    throw new HttpsError("permission-denied", "Sign-in blocked")
  }
})

Lifecycle events

login — beforeUserSignedIn with event: "login".
password_reset — call check from a Callable Function on reset with event: "password_reset".
email_change — call before applying the email update with event: "email_change".

Platform

Lists, rules, and linked accounts apply on every check — configure in the console. Optional session: POST /api/v1/session. Native apps: iOS, Android, React Native.

Verify

Create a test user with sk_test_…. Blocked signups should throw before the user is created; check Activity for the row.