Grouter

Grouter is an open-source HTTP routing library for the Go programming language. It provides a framework for mapping incoming requests to handlers, supporting common patterns used in web services, APIs, and microservices.

Core features commonly found in grouter implementations include dynamic route parameters, allowing paths like /users/:id, and method-based routing to distinguish GET, POST, and other actions. It also offers middleware support for cross-cutting concerns such as logging, authentication, and error handling, as well as route grouping to share common prefixes or middleware across multiple endpoints. Named routes and URL generation are often provided to simplify link construction and reverse lookups within applications.

Architecturally, grouter libraries are designed to integrate with Go’s standard net/http package. They typically expose a router object that implements http.Handler, enabling straightforward composition with other middleware and handlers. Many implementations use a tree- or trie-like structure to efficiently match paths and extract parameters, which helps minimize routing overhead in high-concurrency environments. The design emphasizes low allocations, predictable performance, and a small surface area for ease of use and maintenance.

Usage patterns usually involve creating a router instance, registering routes with associated handlers, and applying middleware in a layered fashion. Grouter is frequently compared to other Go routers such as gorilla/mux, chi, and httprouter, offering a balance between speed, ergonomics, and feature set.

See also: Go web frameworks and routing libraries, HTTP middleware patterns, REST API design.