Nickel is a web framework for the Rust programming language designed to handle HTTP requests and responses. It functions as a server-side toolkit that provides integrated routing, middleware, and JSON deserialization.
The framework utilizes a middleware-based request pipeline to insert custom logic and state management into the request-response cycle. It also includes a server-side template engine for generating dynamic HTML pages by merging data with markup templates.
The project covers high-level capabilities for REST API development, web application routing, and global error handling to intercept uncaught exceptions. It further supports type-safe state injection and the deserialization of JSON payloads into structured data.