Install • Demo • Commands • Stacks • How it works
rex detects your project's stack and runs the right command. No config file. No README reading. No memorizing.
git clone https://github.com/someone/unknown-project
cd unknown-project
rex testThat's it. Works for Go, Node, Python, Rust, Java, Ruby, PHP, Zig, Elixir, Docker, Make, and Just projects.
https://github.com/rexrun-dev/rex/releases/download/v0.2.0/demo.mp4
Text version
$ cd some-go-project/
$ rex
🦖 some-go-project
stack go
commands
rex test → go test ./...
rex run → go run ./cmd/server
rex build → go build ./...
rex deps → go mod download
rex fmt → gofmt -w .
rex lint → go vet ./...
rex clean → go clean -cache
$ rex test
→ go test ./...
ok github.com/example/app 1.2s
$ cd some-node-project/
$ rex
🦖 some-node-project
stack node + pnpm
commands
rex test → pnpm test
rex run → pnpm run dev
rex build → pnpm run build
rex deps → pnpm install
rex clean → rm -rf node_modules dist .next .nuxt build out
# Homebrew (macOS/Linux)
brew tap rexrun-dev/tap && brew install rex
# Go
go install rexrun.dev/rex/cmd/rex@latestOr download a binary from Releases.
| Command | What it does |
|---|---|
rex |
Show project overview |
rex test |
Run tests |
rex run |
Start the app / dev server |
rex build |
Build the project |
rex deps |
Install dependencies |
rex clean |
Remove build artifacts |
rex fresh |
clean → deps → build (the "I pulled and it broke" fix) |
rex fmt |
Format code |
rex lint |
Lint code |
rex watch [verb] |
Watch files and re-run on change (default: test) |
rex ci |
Generate GitHub Actions CI workflow for your stack |
rex docker |
Generate multi-stage Dockerfile for your stack |
rex compose |
Generate docker-compose.yml for your stack |
rex stats |
Show project report (files, lines, size) |
rex badge |
Generate README badge markdown |
rex clone <url> |
Clone + detect + install deps (URL to ready in one command) |
rex init |
Generate rex.toml from detected commands (commit for your team) |
rex completion |
Generate shell completions (bash/zsh/fish) |
rex doctor |
Diagnose environment issues |
rex --list # show all detected commands
rex --dry-run test # show what would run without executing
rex test -- -v -run TestFoo # pass extra args to underlying command| Stack | Package managers | Detection |
|---|---|---|
| Go | go modules | go.mod |
| Node | npm, pnpm, yarn, bun | package.json + lockfile |
| Python | pip, uv, poetry, pipenv | pyproject.toml, requirements.txt, setup.py |
| Rust | cargo | Cargo.toml |
| PHP | composer | composer.json (detects Laravel via artisan) |
| Ruby | bundler | Gemfile (detects Rails via app/ + config/) |
| Java | maven, gradle | pom.xml, build.gradle (uses wrapper if present) |
| Zig | zig | build.zig |
| Elixir | mix | mix.exs (detects Phoenix via assets/) |
| Docker | docker compose | docker-compose.yml, compose.yml |
| Make | — | Makefile |
| Just | — | Justfile |
Rex reads existing task runners first. If your project has a Makefile, Justfile, or Taskfile, those take priority.
Rex auto-detects monorepos (packages/, apps/, services/ etc.) and shows all sub-projects:
$ rex
🦖 my-monorepo (monorepo)
workspace 3 sub-projects detected
packages/api → node + pnpm
packages/web → node + pnpm
services/auth → go
hint: cd into a sub-project, then use rex test
- Detect — Rex looks at your project root for known files (
go.mod,package.json,Cargo.toml, etc.) - Resolve — It maps standard verbs (test, run, build...) to the correct command for your stack
- Execute — It runs the command with full stdio passthrough and correct exit codes
No config needed. No lock-in. No magic.
1. Justfile / Makefile (task runner overrides)
2. package.json scripts / Cargo.toml / go.mod (ecosystem)
3. Language heuristics (fallback)
If a Makefile defines a test target, rex test runs make test — even in a Go project. Rex respects what's already there.
- Zero config — works out of the box, in any repo
- Transparent — always shows what it will run (the
→line) - Fast — single binary, <50ms startup, no network calls
- Composable — correct exit codes, works in CI pipelines
- Non-invasive — creates no files, modifies nothing
- Watch mode —
rex watchre-runs on file change .envloading — auto-loads.envbefore commands
For repos that want to pin commands explicitly:
[commands]
test = "go test -race -count=1 ./..."
run = "air"
build = "goreleaser build --snapshot"Generate one automatically:
rex init
# ✓ created rex.toml (go project)
# hint: edit commands to customize, then commit for your teamRex uses this first when present. Your team always gets the right command.
# GitHub Actions
- run: rex test
# That's it. Works for any stack.git clone https://github.com/rexrun-dev/rex
cd rex
rex test # yes, rex tests itself 🦖Apache 2.0
