MonoSmith — a simple monorepo tool

MonoSmith

MonoSmith runs a monorepo in Node, Go, Python, Rust, .NET, Ruby, PHP, C++, Dart, the JVM and Bicep from one command, smith. It scaffolds projects, runs their tasks in dependency order from a cache, generates the CI pipeline from what is in the repository, and releases from conventional commits.

smith is a single static binary written in Go. Each language is a plugin that runs out-of-process over a small JSON-RPC protocol; the built-in ones ship inside the binary, and a plugin for another language can be written in any language without touching smith.

smith new acme && cd acme
smith add app web --lang node        # deployed, never published
smith add lib core --lang go         # imported internally, never published
smith add package sdk --lang python  # published on release
smith add app api --stack react      # a stack: the plugins a project is built with

smith build                          # every project, in dependency order, cached
smith test --affected                # only what changed since main
smith graph                          # how projects depend on each other (--format tui to browse)
smith release --dry-run              # what the next release would publish
smith doctor                         # is the workspace healthy?
smith                                # the interactive shell, in a terminal

Install

curl -fsSL https://raw.githubusercontent.com/monosmith-app/monosmith/main/install.sh | sh     # Linux, macOS, Git Bash
irm https://raw.githubusercontent.com/monosmith-app/monosmith/main/install.ps1 | iex           # Windows PowerShell

Or with the package manager of your language; each installs the same smith binary:

npm install --global monosmith
pipx install monosmith                  # or: uv tool install monosmith, pip install monosmith
dotnet tool install --global monosmith  # .NET 10 SDK
gem install monosmith
dart pub global activate monosmith

Or download a zip from the releases. From the release after PR #243, each release also carries a .deb and an .rpm. Linux, macOS and Windows on x64 and arm64 are supported. Installing covers each channel, upgrading, checking a download, and the unsigned-binary prompts a browser download gets.

MonoSmith continues mnci, which was built on Nx; smith convert converts Nx workspaces and those made by mnci.

What it does


Three kinds	`app` (deployed), `lib` (internal), `package` (published). The kind decides what release does with a project.
Eleven languages	Node (JavaScript and TypeScript), Python, Go, Rust, .NET (C#, F#), Ruby, PHP, C and C++ (CMake), Dart and Flutter, the JVM (Java with Maven, Kotlin with Gradle, Android) and Bicep, each through a built-in plugin.
Stacks	A project records the plugins it is built with: React, Vue, Svelte, Angular, an Astro docs site or a VS Code extension next to a plain Node library, in the same workspace.
No configuration to write	Projects, tasks and dependencies come from the manifests (`package.json`, `go.mod`, `Cargo.toml`, `*.csproj`, …) and from what the sources import. `smith.toml` names the workspace; everything else has a default.
Cache	A task whose inputs did not change replays its output and log from a content-addressed cache, locally or from a shared remote (HTTP, S3, Azure Blob).
Affected	`--affected` runs only the projects a change can break, and runs everything when it cannot be sure.
CI generated	GitHub Actions, Azure Pipelines and GitLab CI, derived from the plugins in use, calling `smith ci <phase>` — the same commands you run locally.
Release	feat → minor, fix → patch, breaking → major. Packages release in dependency order to their registries (npm, PyPI, crates.io, NuGet, RubyGems, pub.dev, a Maven repository, Go module tags); an app releases per-platform binaries to GitHub Releases and, if you ask, to npm, PyPI, NuGet and RubyGems. A failed release resumes when re-run.
Conventions	`vertical-slices` checks that code is laid out by what it does, in each language's own naming style. `docker` builds and pushes an image for every app with a `Dockerfile`.
Convert	`smith convert` turns an Nx workspace, or one made by the old Nx-based mnci, into a smith workspace, keeping its projects and release tags. It reports anything it cannot map.
Editors and assistants	Stable `--json` contracts for editors, a JSON Schema for `smith.toml`, and `smith mcp` for AI assistants.

Documentation

Everything is in docs/, in four sections:

Guides: installing, getting started, converting from Nx, editors
Reference: configuration (smith.toml), tasks, cache and affected, CI pipelines, releasing, stacks, recipes, conventions, plugins and the protocol
Design: architecture, decisions, research
Contributing: working on MonoSmith

Status

The golden path — a new workspace, projects in every built-in language, build, test, run, CI and release — is tested end to end on Windows, macOS and Linux, and MonoSmith builds and releases itself. Plans and bugs are tracked in issues, and their progress on the MonoSmith board.

License

MIT