Node.js Express Bot Protection Integration

Express

BotBye! integration for Node.js Express applications.

Install

npm i @botbye/express

yarn add @botbye/express

Requires express >= 4 as a peer dependency.

Configuration

Call init once at application startup, before any routes are defined:

import { init } from "@botbye/express";

init({
  // Use your project server-key
  serverKey: "00000000-0000-0000-0000-000000000000",
});

init options

Option	Type	Required	Description
serverKey	string	Yes	Server key from your BotBye project
url	string	No	Override BotBye API endpoint (default: https://verify.botbye.com)
logger.level	"error" "warn" "info" "debug" "log"	No	Log level (default: "info")
logger.logger	TLogger	No	Custom logger instance implementing { error, warn, info, debug, log }
timeouts.evaluate	number	No	Timeout in milliseconds for each evaluate call

Usage

Call evaluate in route handlers where bot protection is needed.

It accepts an event object describing what you know about the request and the context around it, and returns a promise that resolves to a decision.

import { evaluate } from "@botbye/express";

app.post("/api/submit", async (req, res) => {
  const result = await evaluate({
    type: "validate",
    request: {
      request: req,
      // "x-botbye-token" is an example — pass the token from wherever you store it
      token: req.headers["x-botbye-token"],
    },
  });

  if (result.decision === "BLOCK") {
    return res.status(403).json({ error: "Forbidden" });
  }

  // proceed normally
});

There are three event types — validate, risk, and full — each suited for a different layer of your application.

validate — edge-level bot check

Use at the edge — API gateway, route handler, middleware — when you just want to know: was this request made by a bot? No user or domain context needed.

Event fields:

{
  type: "validate";

  request:
    // Option A: pass the Express request object directly — SDK extracts everything automatically
    | { request: express.Request; token?: string | null }
    // Option B: construct request info manually
    | { ip: string; headers: Record<string, string>; requestMethod?: string | null; requestUri?: string | null; token?: string | null };

  customFields?: Record<string, string>;

}

The SDK extracts IP, headers, method, and URI from the Express request automatically. You can also pass request info manually — see Option B above. The token is a one-time token generated by the BotBye client-side SDK that contains information about the user's device. Pass whatever the client sent; if no token is received, the decision will be "BLOCK".

import { evaluate } from "@botbye/express";

app.post("/api/submit", async (req, res) => {
  const result = await evaluate({
    type: "validate",
    request: {
      request: req,
      // "x-botbye-token" is an example — pass the token from wherever you store it
      token: req.headers["x-botbye-token"],
    },
  });

  if (result.decision === "BLOCK") {
    return res.status(403).json({ error: "Forbidden" });
  }

  // proceed normally
});

risk — domain-level risk scoring

Use inside services that already know the user: auth, payments, account management, etc. The purpose shifts from "is this a bot?" to "is something suspicious happening for this user?" — credential stuffing, account takeover, account sharing, logins from a new geo.

Event fields:

{
  type: "risk";

  request:
    // Only ip is needed at this level
    | { ip: string; headers?: Record<string, string>; requestMethod?: string | null; requestUri?: string | null; token?: string | null }
    // Express request object also accepted if convenient
    | { request: express.Request };

  event: {
    type: string;   // e.g. "login", "password_change", "checkout"
    status: "ATTEMPTED" | "SUCCESSFUL" | "FAILED" | "UNKNOWN";
  };

  user: {
    accountId: string;
    username?: string | null;
    email?: string | null;
    phone?: string | null;
  };

  customFields?: Record<string, string>;
  botbyeResult?: string; // if a validate call was made earlier, pass its result.botbyeResult here to link the requests; omit if there was no prior validate

}

event and user are the key fields here — they define what action is being performed and who is performing it, which is what drives the risk score. ip is equally important: BotBye tracks which IPs access the account to detect patterns like account sharing, credential stuffing, and suspicious geo logins. Pass it directly as { ip }, or pass the Express request object if that's more convenient.

import { evaluate } from "@botbye/express";

// Inside an auth service, after a login attempt
async function onLoginAttempt({ ip, userId, email, loginSucceeded }) {
  const result = await evaluate({
    type: "risk",
    request: {
      ip,
      headers: {},
    },
    event: {
      type: "login",
      status: loginSucceeded ? "SUCCESSFUL" : "FAILED",
    },
    user: {
      accountId: userId,
      email,
    },
  });

  if (result.decision === "BLOCK") {
    // Lock account, trigger MFA, send alert, etc.
  }
}

Linking validate and risk events

When the same request is evaluated at two layers — for example, once at the edge (type: "validate") and then again inside a domain service (type: "risk") — BotBye can link both events and display them as a single event in the dashboard.

Step 1 — edge layer (gateway, middleware, or route handler): run validate and capture botbye_result:

const edgeResult = await evaluate({
  type: "validate",
  request: {
    request: req,
    // "x-botbye-token" is an example — pass the token from wherever you store it
    token: req.headers["x-botbye-token"],
  },
});
const edgeBotbyeResult = edgeResult.botbye_result;
// Pass edgeBotbyeResult downstream — a request header, function argument, shared context, etc.

Step 2 — domain service (auth, payment, account management): pass it as botbyeResult in the risk call:

const riskResult = await evaluate({
  type: "risk",
  request: { ip },
  event: {
    type: "login",
    status: loginSucceeded ? "SUCCESSFUL" : "FAILED",
  },
  user: {
    accountId: userId,
    email,
  },
  botbyeResult: edgeBotbyeResult,
});

botbye_result is optional in the response — if it is absent, omit botbyeResult and the events will be recorded independently.

full — edge check and domain scoring in one call

Use when you have all context at once: raw request, token, user, and event. A login endpoint is a typical example — it receives the HTTP request and immediately knows the user and outcome.

Event fields:

{
  type: "full";

  request:
    | { request: express.Request; token?: string | null }
    | { ip: string; headers: Record<string, string>; requestMethod?: string | null; requestUri?: string | null; token?: string | null };

  event: {
    type: string;
    status: "ATTEMPTED" | "SUCCESSFUL" | "FAILED" | "UNKNOWN";
  };

  user: {
    accountId: string;
    username?: string | null;
    email?: string | null;
    phone?: string | null;
  };

  customFields?: Record<string, string>;

}

Equivalent to running validate and risk in a single call.

import { evaluate } from "@botbye/express";

app.post("/auth/login", async (req, res) => {
  const { email, password } = req.body;
  const user = await findUser(email);
  const loginSucceeded = user && (await checkPassword(user, password));

  const result = await evaluate({
    type: "full",
    request: {
      request: req,
      token: req.headers["x-botbye-token"], // example header — pass the token from wherever you store it
    },
    event: {
      type: "login",
      status: loginSucceeded ? "SUCCESSFUL" : "FAILED",
    },
    user: {
      accountId: user?.id ?? "unknown",
      email,
    },
  });

  if (result.decision === "BLOCK") {
    return res.status(403).json({ error: "Forbidden" });
  }

  // proceed normally
});

Response

evaluate always returns a Promise<TEvaluationResult>:

type TEvaluationResult =
  | {
      decision: "ALLOW" | "BLOCK" | "CHALLENGE";
      request_id: string;
      risk_score: number;
      scores: Record<string, number>;
      signals: string[];
      botbye_result?: string;
    }
  | {
      decision: "ALLOW";
      botbye_result?: string;
      error: { message: string };
    };

Check result.decision to decide how to handle the request:

"ALLOW" — request appears legitimate, proceed normally
"BLOCK" — bot or suspicious activity detected, block the request
"CHALLENGE" — uncertain, consider issuing a CAPTCHA, MFA, or additional verification step

When the response contains an error field, BotBye could not evaluate the request (e.g. invalid server key). In that case decision defaults to "ALLOW" so that a misconfiguration does not block real users — but you should monitor and fix the underlying error.

Examples of BotBye API responses

Blocked (bot detected):

{
  "request_id": "f77b2abd-c5d7-44f0-be4f-174b04876583",
  "decision": "BLOCK",
  "risk_score": 0.95,
  "scores": { "bot": 0.95 },
  "signals": ["AutomationTool"]
}

Allowed:

{
  "request_id": "f77b2abd-c5d7-44f0-be4f-174b04876583",
  "decision": "ALLOW",
  "risk_score": 0.05,
  "scores": { "bot": 0.05, "ato": 0.02 },
  "signals": []
}

Challenge:

{
  "request_id": "f77b2abd-c5d7-44f0-be4f-174b04876583",
  "decision": "CHALLENGE",
  "risk_score": 0.65,
  "scores": { "bot": 0.65 },
  "signals": ["SuspiciousFingerprint"],
  "challenge": { "type": "captcha", "token": "..." }
}

Invalid server-key:

{
  "decision": "ALLOW",
  "error": { "message": "[BotBye] Bad Request: Invalid Server Key" }
}

Middleware usage

You can wrap evaluate into reusable Express middleware to protect multiple routes:

import { evaluate } from "@botbye/express";

async function botProtection(req, res, next) {
  const result = await evaluate({
    type: "validate",
    request: {
      request: req,
      token: req.headers["x-botbye-token"], // example header — pass the token from wherever you store it
    },
  });

  if (result.decision === "BLOCK") {
    return res.status(403).json({ error: "Forbidden" });
  }

  next();
}

app.post("/protected", botProtection, (req, res) => {
  res.json({ ok: true });
});

Advanced: multiple instances

Use factory to create independent SDK instances (useful when protecting multiple projects from one service):

import { factory } from "@botbye/express";

const sdk = factory();

sdk.init({
  // Use your project server-key
  serverKey: "00000000-0000-0000-0000-000000000000",
});

const result = await sdk.evaluate({
  type: "validate",
  request: { request: req, token },
});

Dev utilities

import { dev } from "@botbye/express";

// Change log verbosity at runtime
dev.setLoggerLevel("debug"); // "error" | "warn" | "info" | "debug" | "log"