---
description: Idiomatic Rust API design (official Rust API Guidelines)
globs: ["**/*.rs"]
alwaysApply: true
---

- RFC 430 casing: `UpperCamelCase` types/traits/variants, `snake_case` fns/modules/macros, `SCREAMING_SNAKE_CASE` consts; acronyms are one word (`Uuid`).
- Getters drop `get_` (`fn name(&self)`); reserve `get` for the obvious single accessor.
- Conversions by cost: `as_*` free, `to_*` expensive, `into_*` consuming. Use `From`/`TryFrom`/`AsRef`/`AsMut`; never hand-write `Into`/`TryInto`.
- Iterators: `iter` / `iter_mut` / `into_iter` returning `Iter` / `IterMut` / `IntoIter`.
- Derive common traits eagerly: `Debug`, `Clone`, `Copy`, `PartialEq`/`Eq`, `PartialOrd`/`Ord`, `Hash`, `Default`; add `Display` for human output.
- Collections implement `FromIterator` + `Extend`; gate Serde behind a `serde` feature; keep types `Send + Sync` where possible.
- Error types implement `std::error::Error` + `Send + Sync + 'static`. `Drop` never panics or blocks — use `close()`/`flush()` -> `Result`.
- Newtypes for static distinctions; enums/structs over bare `bool`/`Option` args; `bitflags` for flag sets; builders for complex construction.
- Validate arguments; keep struct fields private; seal non-downstream traits; mark extensible enums/structs `#[non_exhaustive]`; don't duplicate derived bounds on the struct.
- Document `# Errors` / `# Panics` / `# Safety`; rustdoc examples use `?`, not `unwrap()`.
- Feature names have no placeholders (`std`, not `use-std`); crate names avoid `-rs`/`-rust`.