Axum is a web framework for Rust built on top of Tokio and Hyper. One of its

standout features is a simple and predictable error handling model — once

you understand the pattern, writing safe, expressive web servers becomes

surprisingly natural.

This guide walks you from the very basics to real-world patterns you'll use in

production.

The Core Idea: Errors Must Become Responses

In Axum, every error must eventually become an HTTP response . There is no

unhandled-exception mechanism. If something goes wrong, you decide what the

client sees — a 404, a 500, a JSON error body, or anything else.

The key trait is IntoResponse . Anything that implements it can be returned

from a handler, including error types.

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