Cloudflare has made Precursor generally available, giving websites a browser-session bot detector at a time when the company puts automated traffic at roughly 57 percent of web requests, SiliconANGLE reported.

The system runs inside a visitor's browser and streams interaction signals back to Cloudflare's edge, where servers score the session in real time for evidence of automation.

Precursor is designed to replace one-time CAPTCHA-style checks with continuing behavioural scoring.

Precursor Tracks Full Browser Sessions

Precursor follows behaviour across an entire visit rather than testing a user only once on arrival.

A challenge page checks the visitor at the door, while later actions are normally assumed to be legitimate.

Cloudflare Chief Technology Officer Dane Knecht told SiliconANGLE that the company is looking at behaviour over the whole visit instead of only checking an ID at the gate.

The tool is meant to make it harder for automated systems to pass a single check and then continue browsing with a clean status.

Bot Traffic Reaches 57 Percent Of Requests

Cloudflare put bot traffic at roughly 57 percent of web requests, according to SiliconANGLE.

The company's argument, as reported by the outlet, is that automation now outweighs people online and that single-action tests are easier for bots to imitate.

Precursor continues scoring after the initial page load.

The system continues to accumulate session context when an automated agent tries to erase its behavioural signature by reloading a page under per-request challenges.

Browser Script Records Timing And Visibility Signals

Customers can turn on Precursor with one click and without code changes.

Cloudflare injects a small script into pages already passing through its network, then logs mouse movement, scrolling rhythm, typing cadence, clipboard activity and the length of time a page stays visible in the browser tab.

The analysis engine checks for contradictions inside those signals.

Examples included pointer activity while a page is hidden and typing events at a moment when no text field has focus.

Cloudflare said the script records aggregate patterns rather than the typed inputs themselves.

Keyboard activity is stored as rhythm and cadence, while the characters typed are not captured, according to the company.

AI Scraper Controls Sit Behind The Launch

The launch follows earlier Cloudflare bot and crawler products.

Last year, the company began blocking artificial intelligence scrapers by default for new customers and later built tools for publishers to set crawler access terms.

Knecht said login and checkout are already covered by Cloudflare protections billions of times each day, while the activity between those events had remained a black box.

Precursor is generally available now, but the public record still lacks pricing, customer adoption figures and false-positive rates for the session-scoring product.