Negroni — Idiomatic HTTP Middleware Library for Go

Introduction

Negroni is a small, non-intrusive middleware library for Go that embraces the standard net/http interfaces. Rather than replacing the standard library, it wraps it with a composable middleware stack so developers can layer logging, recovery, and custom handlers without learning a new API.

What Negroni Does

• Composes middleware functions into a sequential processing pipeline
• Wraps any net/http handler or ServeMux without requiring a custom router
• Ships with Classic() defaults: request logger, panic recovery, and static file server
• Allows per-route middleware via integration with third-party routers like Gorilla Mux
• Provides a Handler interface compatible with standard http.Handler for easy adoption

Architecture Overview

Negroni maintains an ordered slice of middleware handlers. Each middleware receives a ResponseWriter, Request, and a next function. Calling next passes control to the subsequent middleware or the final handler. This design is intentionally simple: no reflection, no dependency injection, and no hidden magic — just function composition around net/http types.

Self-Hosting & Configuration

• Requires Go 1.17 or later
• Install with go get github.com/urfave/negroni
• Create an instance with negroni.New() or negroni.Classic() for defaults
• Add custom middleware with n.Use() or n.UseFunc() for simple functions
• Bind to a port with n.Run(":8080") or attach to your own http.Server

Key Features

• Zero-magic design that follows Go idioms and net/http conventions
• Classic() preset bundles production-ready logging and recovery
• Works with any router (Gorilla Mux, Chi, httprouter, or the standard ServeMux)
• Middleware ordering is explicit and predictable
• Tiny codebase under 300 lines makes auditing and understanding straightforward

Comparison with Similar Tools

• Gin — full router with middleware; Negroni is middleware-only and router-agnostic
• Chi — composable router with inline middleware; Negroni separates middleware from routing
• Alice — similar middleware chaining; Negroni adds Classic() defaults and Run()
• Echo — batteries-included framework; Negroni is deliberately minimal
• Martini — by the same author but uses reflection; Negroni avoids reflection entirely

FAQ

Q: Does Negroni include a router? A: No. Negroni handles middleware composition only. Pair it with Gorilla Mux, Chi, or the standard ServeMux for routing.

Q: What is the Classic() preset? A: Classic() creates a Negroni instance pre-loaded with Logger, Recovery, and Static middleware — suitable for most web applications out of the box.

Q: Can I use Negroni with Go modules? A: Yes. The github.com/urfave/negroni path is fully compatible with Go modules.

Q: How does Negroni compare to writing raw middleware with net/http? A: Negroni provides the same pattern but adds a structured stack, default handlers, and the convenience of Run(). It does not replace net/http — it wraps it.

Sources

• https://github.com/urfave/negroni
• https://github.com/urfave/negroni#readme