Checkpoint Docs
Detect

Detect

AI agent detection methods — Pixel, Beacon, Middleware, and Gateway

What is Detect?

Checkpoint Detect provides passive AI agent detection for your web applications. Unlike Enforce, Detect methods identify and classify traffic without blocking or redirecting visitors. Use Detect to build analytics, understand your traffic composition, and gather intelligence before deciding on an enforcement strategy.

Every detection returns:

  • A classification of the visitor: human, ai_agent, bot, or incomplete_data
  • A confidence score from 0 to 100
  • Metadata — for agent/bot traffic, the detected agent's name (detectedAgent.name), plus verificationMethod and riskLevel (human results carry no detectedAgent)

Detection Methods

Checkpoint offers four detection methods. This table covers only what each method detects and how; to decide which integration fits your stack, see Choose Your Integration.

MethodWhere It RunsWhat It SeesLatency
PixelBrowser (script tag)JS-executing browsers, page-load signalsAsync, non-blocking
BeaconBrowser (npm SDK)JS-executing browsers, richer browser/performance signalsAsync, non-blocking
MiddlewareYour server (Node.js)Every request reaching your server~5–10ms
GatewayCloudflare edge (DNS)Every request to your domain~1–5ms

Middleware and Gateway detect and enforce, using the same policy engine, so they're documented once — under Enforce — instead of being split across two sections. Running either detection-only is simply a matter of leaving it in observe mode; see Enforce vs. observe.

What Each Method Can See

Each method's visibility into a request is fixed by where it runs — that's the detection-relevant difference. (For which method fits your stack, see Choose Your Integration.)

Pixel and Beacon — client-side signals only

Both run in the browser and only see what a JS-executing client can observe: page-load timing and browser/performance signals (Beacon also lets you send custom events). Neither has access to raw HTTP headers or TLS-layer data, and both are invisible to traffic that never executes JavaScript.

Pixel guide → · Beacon guide →

Middleware — server-side headers, no TLS fingerprint

Middleware runs in your Node.js process, after TLS termination. It sees every header on every request that reaches your server (User-Agent, Accept, Language, cookies) plus request-pattern signals, but not the TLS fingerprint — that's captured only at the edge, before the request reaches server-side code. See Detection Signals.

See Middleware setup.

Gateway — headers plus a TLS fingerprint

The Gateway runs at Cloudflare's edge, ahead of your origin. Alongside the same header and request-pattern analysis available to Middleware, it's the only method that captures a TLS fingerprint (cipher suites + extensions) — see Edge Detection. That fingerprint is currently logged for observability only; it is not yet consumed by the classifier.

See Gateway setup.

Detection Classes

Every detection is assigned one of four classes:

ClassValueDescription
HumanhumanRegular browser traffic from a human visitor
AI Agentai_agentAI assistants like ChatGPT, Claude, Perplexity, Gemini
BotbotWeb crawlers, scrapers, and automated tools (Googlebot, Bingbot)
Incomplete Dataincomplete_dataInsufficient signals to make a confident determination

This page is the canonical reference for what these classes mean and how confidence is scored. For how the engine produces them — signals, scoring internals, edge vs. server mechanics — see Detection in Enforce Mode.

Confidence Scores

Confidence scores range from 0 to 100 and indicate how certain Checkpoint is about a detection:

RangeLevelMeaning
91–100Very highStrong, corroborated signals.
71–90HighSolid evidence from multiple indicators.
31–70MediumModerate evidence; some indicators present but not conclusive.
0–30LowWeak signals; may be based on a single indicator.

Confidence reflects how certain Checkpoint is in the assigned classification — not a measure of "agent evidence." A human classification still carries a confidence (a clean browser request scores low, around 10). A score of exactly 0 indicates an error or incomplete_data, not a confident human result.

Combining Detection Methods

You can use multiple detection methods simultaneously. For example:

  • Pixel on your marketing site for traffic analytics
  • Beacon in your authenticated application for detailed event tracking
  • Middleware on your API routes for server-side detection with enforcement

Each method sends data to the same Checkpoint project, giving you a unified view in the dashboard.

Next Steps