rust-router

name	rust-router
description	Route Rust work to the smallest useful skill. Use for Rust coding, design, compile errors, API questions, crate layout, async, performance, unsafe, or domain-specific Rust work.
globs	["**/Cargo.toml","**/*.rs"]

Rust Router

Load this first for non-trivial Rust work, then load only the smallest useful follow-on skill.

Working stance

• Start from the concrete problem: error, boundary, hot path, or unsafe edge.
• Prefer one language skill plus at most one domain or architecture skill.
• Use the general leta skill for code navigation, references, implementations, and refactors.
• If the answer starts turning into a tutorial, stop and cut back to the decision that matters.
• When a local fix needs clones, locks, trait-object escape hatches, or unsafe code, re-check the design before keeping the patch.

Route by question

• Polonius adoption, NLL workarounds, defensive clones caused by the borrow checker, or borrow-centric API evolution: nll-to-polonius
• Ownership, borrowing, aliasing, or interior mutability: rust-memory-and-state
• Trait bounds, generics, API shape, newtypes, or typestate: rust-types-and-apis
• Error shape, panic boundary, or library-versus-binary handling: rust-errors
• Unit-test helper shape, fixtures, table tests, serialized tests, or rich assertions: rust-unit-testing
• Tasks, Send/Sync, blocking, channels, or cancellation: rust-async-and-concurrency
• Allocation pressure, layout, or benchmark discipline: rust-performance-and-layout
• unsafe, foreign function interface (FFI), layout guarantees, or soundness: rust-unsafe-and-ffi
• Crate boundaries, features, public surface, or layering: arch-crate-design
• Dependency hygiene, cargo-vet, cargo-deny, SemVer guardrails: arch-supply-chain
• Recording a hard-to-reverse architectural decision (Y-Statement): arch-decision-records
• Verification tool selection (Miri, proptest, cargo-mutants, loom, shuttle, turmoil, Kani, Verus): rust-verification; deep dives in proptest, kani, and verus
• HTTP services, middleware, or request state: domain-web-services
• CLIs, workers, daemons, or long-running jobs: domain-cli-and-daemons
• no_std, firmware, devices, or edge nodes: domain-embedded-and-iot

Pairing rules

• Polonius migrations usually pair nll-to-polonius with rust-types-and-apis only when public API compatibility constrains the migration.
• Web services usually pair domain-web-services with rust-async-and-concurrency or rust-errors.
• CLIs and daemons usually pair domain-cli-and-daemons with rust-errors.
• Embedded and IoT usually pair domain-embedded-and-iot with rust-memory-and-state or rust-unsafe-and-ffi.
• If two language skills both seem necessary, load the one that explains the failure and keep the other in reserve.

Escalate when

• borrow-checker fixes keep adding clones or Arc<Mutex<_>> without clarity,
• a public API needs dyn Any, erased errors, or unstable generic sprawl,
• async code requires shared mutable state and cancellation semantics at once,
• performance claims appear before measurements,
• unsafe code exists without a crisp invariant list.

Read routing-matrix.md only when the route is still unclear.