Get started

mbx reuses compiler work across Rust workspaces, checkouts, and CI runs. Cargo still resolves dependencies and decides what needs building. mbx restores matching compilations and runs the compiler for everything else.

You need an existing Rust toolchain and a Cargo project. No cache server or configuration file is required.

Install

With mise:

mise use --global --tool-option mr_boxington=true rust mr-boxington

This requires mise 2026.9.2 or newer. Drop --global for project-scoped wrapping. See Installation for older mise versions.

Or install from crates.io:

cargo install mbx --locked

Linux, macOS, and Windows binaries are also available. See Installation for verified downloads and platform requirements.

Run a build

From your Rust workspace:

mbx doctor
mbx build

Pass Cargo arguments as usual:

mbx test --workspace --all-features
mbx clippy --workspace --all-targets -- -D warnings
mbx +stable check --workspace

Cargo aliases, installed subcommands, and toolchain selection are preserved. Use the same toolchain, features, and profile across builds to reuse the same cached work.

Keep using plain Cargo

The mise command above enables wrapping without running mbx setup. Use mise exec -- cargo build, mise run tasks, or plain cargo with mise activation or shims on PATH.

For standalone installations, run:

mbx setup
mbx setup --status

See Cargo and editor setup to verify Cargo's path, share project configuration, configure rust-analyzer, and use mbx from desktop applications.

The first build

A new local store has no compilations to restore. The first build fills it; later builds and equivalent worktrees can reuse that work. If Cargo already has up-to-date outputs in target/, it skips those compilations entirely. That is normal and will not appear as mbx cache hits.

For a checkout without an existing target/, mbx creates a managed target and leaves a target symlink in the workspace. An existing directory is replaced only after you accept the interactive prompt. See Managed target directories for placement and cleanup.

The first build also prints the cache location and disk budgets chosen for your machine. Automatic collection runs after builds, at most once an hour.

Read the result

An illustrative summary looks like this:

mbx[cache]: 139 hits, 8 misses, 4 not looked up, 147 prefetched, 7 bypassed; 312.4 MiB downloaded, 0 B uploaded, 280.1 MiB stored locally

Result	What happened
Hit	mbx restored a matching compilation
Miss	mbx looked up a key, then compiled and stored a new result
Not looked up	mbx needed a first compilation to learn the inputs
Bypassed	The invocation ran without shared caching

Cache results explains all counters and how to measure reuse. Use mbx explain --last to inspect the last recorded build or mbx tui to watch builds live.

Inspect the store

mbx cache stats     # size and contents
mbx gc --dry-run    # preview cleanup

A cache can always be rebuilt. Use the management guide to understand what each cleanup command removes.

Next steps

I want to…	Read
Set up an editor or watch loop	Local development
Cache a GitHub Actions job	GitHub Action
Run independent builds together	Parallel builds
Tune disk, output, or build policy	Configuration
Understand an unexpected result	Troubleshooting

Looking for a section that moved?

Verify plain Cargo now lives in the setup guide.

Supported platforms now lives in Installation.

Installation methods and Windows notes have moved there too.

Choose a linker has its own guide.

Parallel builds covers separate targets and shared budgets.

Installation checks and Reporting a problem now live in Troubleshooting.