AbuseGraph + Express

Express middleware calls the HTTPS API before issuing a signup or login session.

Quick path

Set ABUSEGRAPH_SECRET_KEY and ABUSEGRAPH_SITE in env.
Copy a test key from the console; no package installation is required for the HTTPS API path.
Add middleware on register/login routes that calls scoreAuth before issuing a session.

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_…
ABUSEGRAPH_SECRET_KEY_TEST=sk_test_…
NEXT_PUBLIC_ABUSEGRAPH_PUBLISHABLE_KEY=pk_test_…

Use sk_live_… in production after DNS verify.

Server check

Call the HTTPS API from your server. Keep ABUSEGRAPH_SECRET_KEY in server-only environment configuration. Events: signup | login | password_reset | email_change; sessionId is optional.

const API = "https://abusegraph.com/api/v1/check";

export async function scoreAuth(input: Record<string, unknown>) {
  const site = process.env.ABUSEGRAPH_SITE!;
  const response = await fetch(API, {
    method: "POST",
    headers: {
      "content-type": "application/json",
      "x-api-key": process.env.ABUSEGRAPH_SECRET_KEY!,
      "x-abusegraph-site": site,
    },
    body: JSON.stringify({
      ...input,
      event: typeof input.event === "string" ? input.event : "signup",
      site,
    }),
  });
  if (!response.ok) throw new Error(`AbuseGraph check failed: ${response.status}`);
  return response.json();
}

Run this before creating an account or issuing a session. Handle block and challenge according to your policy; 402 means the live monthly allowance is exhausted.

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.

Express middleware

import type { Request, Response, NextFunction } from "express"

export function abusegraphGuard(event: "signup" | "login") {
  return async (req: Request, res: Response, next: NextFunction) => {
    const email = req.body?.email
    if (!email) return next()

    const { password, ...browserFields } = req.body

    const result = await scoreAuth({
      ...browserFields,
      email,
      event,
      ip: req.ip,
    })

    if (result.verdict === "block") {
      return res.status(403).json({ error: "blocked", ...result })
    }
    if (result.verdict === "challenge") {
      // require step-up before session create
    }

    res.locals.abusegraph = result
    next()
  }
}

app.post("/register", abusegraphGuard("signup"), createUserHandler)
app.post("/login", abusegraphGuard("login"), loginHandler)

Lifecycle events

login — abusegraphGuard("login") before session create.
password_reset — middleware or route handler with event: "password_reset".
email_change — call check 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

POST to /register with sk_test_…, confirm Activity shows the check, and blocked emails get 403.