rewrite-rs

setup-rust-ci

Write a GitHub Actions workflow for a Rust repo — format, clippy at the configured level, tests, and an MSRV job, derived from the posture the repo already recorded.

setup-rust-pre-commit

Set up fast pre-commit hooks for a Rust repo — format and lint the staged changes only, with CI left as the real gate.

rust-skills-map

The router for this skill set — which Rust skill covers which decision, how they relate, and which one to reach for from where you are.

setup-rust-skills

Configure a Rust repo for this skill set — lint and format configuration, and a recorded project posture (edition, MSRV, async runtime, no_std, unsafe policy) at docs/agents/rust.md.

Design an FFI boundary meant to last — a thin translation layer with the logic in core crates, no panic across the boundary, explicit ownership on every pointer, repr(transparent) newtypes, and unsafe extern in edition 2024. Use when designing or reviewing a Rust FFI surface, when exposing a Rust library to another language, when a DLL or shared library keeps state, or when the user asks how to shape an extern function.

rust-macros

Write a macro only when a function, a trait, or a generic cannot do the job — then by-example before proc-macro, with hygiene, a `_private` helper module, and spanned compile errors instead of panics. Use when writing or reviewing macro_rules! or a proc macro, when a derive or attribute macro is being added, when macro hygiene or `$crate` comes up, or when the user asks whether something should be a macro.

Data & Documents Listed

rust-serde

Serde as the boundary where untrusted input becomes a domain type — rename_all, default, skip_serializing_if, flatten, the four enum representations, deny_unknown_fields, and try_from validation. Use when deriving Serialize or Deserialize, when choosing an enum wire representation, when a JSON or YAML shape does not match the Rust type, or when the user asks how to validate deserialized data.

rust-supply-chain

Audit a Rust dependency tree — advisories, licences, banned and duplicate crates, and unmaintained dependencies — and turn each finding into a decision. Use when checking whether dependencies are safe to ship, when cargo audit or cargo deny reports something, when adding a dependency to a project with a licence policy, when a build pulls in two versions of the same crate, or when the user asks about supply chain risk in Rust.

port-from-c

Port C into Rust — recovering the ownership, lifetime, nullability, and length that C never recorded, mapping pointers to references and slices, tag-plus-union to enums, return codes and errno to Result, and linking Rust into the existing build with bindgen and cbindgen. Use when porting, rewriting, or migrating C, a C library, firmware, or a C application into Rust, when replacing C modules one at a time behind the existing build, or when the user asks how a C construct such as malloc, a char pointer, a union, or a preprocessor macro translates to Rust.

port-from-cpp

Port C++ into Rust — RAII and smart pointers onto ownership, templates onto generics and traits, exceptions onto Result, the STL onto Rust collections, and the traps (move semantics, implicit conversions, undefined behaviour, iterator invalidation). Use when porting, rewriting, or migrating C++, a C++ library, or a C++ application into Rust, when replacing a C++ module with Rust behind the existing build, or when the user asks how a C++ construct such as unique_ptr, shared_ptr, a template, or an STL container translates to Rust.

port-from-go

Port Go into Rust — goroutines and channels onto tasks and async, interfaces onto traits, error values onto Result, and the value-semantics traps (zero values, integer wraparound, slice aliasing, nil). Use when porting, rewriting, or migrating Go, Golang, a Go service, or a Go CLI into Rust, when replacing a Go component with a Rust one behind the same interface, or when the user asks how a Go construct translates to Rust.

port-from-java

Port Java into Rust — class hierarchies onto enums and composition, exceptions onto Result, collections and streams onto Rust equivalents, and the traps (UTF-16 strings, silent integer wraparound, null, equals/hashCode contracts). Use when porting, rewriting, or migrating Java, a JVM service, a Spring or Jakarta application, or a Java library into Rust, when replacing a JVM component with a Rust one behind the same interface, or when the user asks how a Java construct translates to Rust.

port-from-python

Port Python into Rust — construct mapping, the semantic traps (integer width, floor division, str versus bytes, exceptions to Result), and the seam, which is a process boundary for a standalone replacement and PyO3 when Python keeps calling the code. Use when porting, rewriting, or migrating Python, CPython, Django, Flask, FastAPI, NumPy, or a Python CLI into Rust, when replacing a Python tool with a Rust binary or a hot Python module with a native extension, or when the user asks how a Python construct translates to Rust.

port-from-typescript

Port TypeScript or JavaScript into Rust — construct mapping against runtime semantics, the traps (every number is an f64, two kinds of absent, structural typing, regex feature gaps), and the napi-rs and wasm-bindgen boundaries. Use when porting, rewriting, or migrating TypeScript, JavaScript, Node, Deno, Bun, Express, or a JS CLI or library into Rust, when replacing a hot JS module with a native addon or WebAssembly, or when the user asks how a TypeScript or JavaScript construct translates to Rust.

port-to-rust

Run a port into Rust without losing behaviour — define the parity contract, sequence the phases, migrate incrementally behind a stable boundary, and prove parity differentially. Use when moving, porting, rewriting, or migrating an existing codebase into Rust from any language, when deciding how to sequence or scope a rewrite, when a port needs to prove it matches its source, or when a partially-ported system needs both implementations running side by side.

async-rust

Write correct async Rust — runtime choice, Send and Sync bounds, cancellation safety, blocking work inside async contexts, and shared state across tasks. Use when writing or reviewing async code, when a future is held across an await point, when the user hits a Send bound error on a spawned task, when a runtime stalls or deadlocks, or when the user asks about tokio, select!, or spawn_blocking.

idiomatic-rust

Write Rust that reads like Rust — iterator pipelines over index loops, From/Into over ad-hoc converters, derives over hand-written impls, newtypes over bare primitives. Use when writing new Rust, when reviewing Rust that reads like a translation from another language, or when the user asks how to make Rust code more idiomatic or less repetitive.

ownership-not-clone

Use ownership and borrowing instead of reaching for clone, Rc, RefCell, or Arc<Mutex<_>> to silence the borrow checker. Every clone must be explainable. Use when code clones to make an error go away, when a borrow-checker fight is being resolved by copying data, when reviewing Rust dense with .clone() or Rc<RefCell<_>>, or when the user asks whether a clone is necessary.

API & Backend Listed

rust-api-design

Design a Rust public API — trait design, generics versus dyn, sealed traits, what is exported, and which changes break semver. Use when designing or reviewing a crate public surface, when choosing between a generic parameter and a trait object, when adding a trait method or enum variant to a released crate, or when the user asks whether a change is a breaking change.

rust-concurrency

Pick the concurrency model from the workload shape — rayon for data parallelism, scoped threads for borrowed stack data, channels for handoff, shared state last — and use the weakest correct atomic ordering. Use when writing or reviewing threaded Rust, when Mutex, RwLock, atomics, or manual Send/Sync appear, when a deadlock or data race is suspected, or when the user asks how to parallelize Rust code.

rust-docs

Doc comments as API contract — a one-line first sentence, module-level docs, Examples, Errors, Panics and Safety sections, doctests that actually run, and intra-doc links. Use when writing or reviewing rustdoc comments, when a public item is undocumented, when doctests are marked ignore or fail, when magic values appear undocumented, or when the user asks how to document a Rust crate.

rust-errors

Design Rust error types and panic policy — Result over unwrap, thiserror for libraries, anyhow for binaries, context that survives the call stack. Use when code calls unwrap or expect outside tests, when designing or refactoring an error enum, when choosing between thiserror and anyhow, or when the user asks how errors should be handled or propagated.

rust-observability

Logs are structured events with named fields, not formatted strings — tracing over log over println!, spans for async context, error chains logged once, and never a secret in a field. Use when adding or reviewing logging, tracing, or metrics in Rust, when println! or string-interpolated log messages appear, when a library installs a subscriber, or when the user asks how to instrument Rust code.

rust-performance

Profile before optimizing, cut allocation out of hot paths, and treat LTO, codegen-units, PGO and target-cpu as the last five percent. Use when Rust code is too slow, when a benchmark regresses, when reviewing code that allocates or formats inside a loop, when release-profile or codegen flags come up, or when the user asks how to make Rust faster.

type-driven-design

Make illegal states unrepresentable — enums instead of boolean and string flags, newtypes instead of bare primitives, parsed types instead of validated ones, typestate for protocol order. Use when a struct has fields that are only valid in some combinations, when validation is re-checked at many call sites, when boolean flags multiply, or when the user asks how to model a domain in Rust.

unsafe-rust

Justify, document, and verify unsafe Rust — safety invariants on every unsafe block, sound safe wrappers, undefined behaviour hazards, and verification with Miri. Use when writing or reviewing unsafe code, when working across an FFI boundary, when raw pointers or transmute appear, when a safe API wraps an unsafe primitive, or when the user asks whether an unsafe block is justified.

rust-code-review

Review Rust changes on two axes at once — standards (idioms, ownership, errors, API surface, unsafe) and spec (does the change do what was asked) — with a Rust smell baseline layered on the repo lint configuration. Use when reviewing a Rust diff, pull request, or branch, when asked whether a change is ready to merge, or when a review needs to cover more than what clippy already reports.

Testing & QA Listed

rust-testing

Design Rust tests that catch real regressions — unit, integration, doc, property, snapshot, and golden tests, and differential tests that prove a port matches its source. Use when writing or reviewing Rust tests, when a change lands without tests, when deciding what form a test should take, when a port needs parity evidence, or when the user asks about proptest, insta, rstest, or test coverage.