axum-syntax-extractors

What problem does it solve?

This Skill prevents common Axum handler failures by guiding you to choose the correct extractor types and place them in the required order so requests deserialize and reject consistently instead of failing with opaque Handler trait errors.

Core Features & Use Cases

• Correct extractor selection: Use FromRequestParts for path/query/headers/state/extension and FromRequest for the single body extractor (Json, Form, Bytes, String, or Request).
• Deterministic ordering rules: Ensures all FromRequestParts arguments come before exactly one body extractor, which must be last.
• Axum 0.7 vs 0.8 correctness: Covers the route-capture syntax differences that affect Path deserialization while keeping extractor usage consistent.
• Safe optional and explicit failure handling: Explains Axum 0.8 Option<Extractor> absent-vs-invalid semantics and when to use Result<Extractor, Rejection> to inspect rejection details.
• Practical deserialization patterns: Covers Path<T> shapes (primitive, tuple, struct, map) and how query and JSON behave, including Content-Type requirements.

Quick Start

Ask the AI to rewrite your handler signature to use Path, Query, State, Extension, and a single last body extractor (Json/Form) according to Axum 0.7/0.8 rules, and to diagnose any “Handler is not satisfied” error.