Node CrowdSec Client

node-crowdsec

This repository will host multiples packages, you can found them with examples below

Technical documentation is available here

Full CrowdSec client : watcher & bouncer clients for the CrowdSec LAPI (alerts, decisions, stream, watcher registration/self-delete...).
High-performance bouncer : decisions are streamed from the LAPI and indexed locally by CIDR (numeric prefix lookup). Checking an IP costs ~µs with a negligible event loop impact, even with hundreds of thousands of decisions.
Live mode (optional) : unknown IPs are checked against the LAPI in the background, closing the freshness gap of the stream poll. A malicious unknown IP passes at most once.
Configurable trust scope : subnetLevel lets you choose how far up the prefix hierarchy to consider as malicious (resident / company / country), so a whole country block is never banned by accident.
Watcher scenarios : bundled scenarios (user-agent, ip-extraction...) to detect and alert on malicious requests, with a pluggable scenario system.

an alpha http middleware that allow to include CrowdSec to protect your http serveur

Here are some optionals scenarios available to use with the middleware

express-bouncer : an example of use of the crowdsec-client to create an express bouncer
express-bouncer-cjs : the same as express-bouncer, but wrote in (common) js only
express-web-parser : a watcher example that will ban user checking the user-agent

This library is a Node.js client to talk with crowdsec rest API . Please note that Node.js >= 24 is required.