Zen Router

Zen Router is an HTTP API router designed for use with modern JavaScript runtimes such as Cloudflare Workers, Node.js, Bun, and Deno. Developed by Liveblocks, it is built to handle high volumes of requests and emphasizes an opinionated approach to API routing, with a focus on type safety, built-in validation, and structured authorization. The router is compatible with any environment supporting the Web Request and Response APIs, offering flexibility for deployment across a range of serverless and traditional platforms.

A defining characteristic of Zen Router is its type-safe handling of route parameters, query strings, and request bodies. Route handlers receive fully typed objects for these elements, which supports reliable request processing. Body validation is integrated and can be performed using any standard schema-compatible library, allowing developers to enforce data integrity. The router enforces mandatory authorization by default, requiring authentication logic for routes unless explicitly opted out for public endpoints. This approach ensures consistent security practices across APIs.

Zen Router also provides features for composing routers, enabling developers to isolate different parts of an API based on authentication strategy through the use of ZenRelay. Additional built-in capabilities include support for Cross-Origin Resource Sharing (CORS), customizable error handling with the ability to abort requests and define custom error shapes, and response helpers for returning JSON, HTML, or text streams. For observability, it integrates with OpenTelemetry, automatically adding span attributes for matched routes.

Installation is available via npm, pnpm, bun, or yarn. The router is intended for developers building APIs in JavaScript environments who require a type-safe, validated, and authorization-focused routing solution.