---

name: new-project description: Scaffold a new Lean 4 project in the workspace. Use when creating a new project, library, or application.

New Project Scaffolding

Create a new Lean 4 project with the correct structure for this workspace.

Quick Start

1. Determine project category and name
2. Create directory structure
3. Generate lakefile.lean with GitHub-style dependencies
4. Create README.md and CLAUDE.md
5. Set up test structure with Crucible

Project Categories

Directory Structure

Copy<category>/<project>/
├── lakefile.lean
├── README.md
├── CLAUDE.md
├── <Project>/
│   └── Basic.lean
├── <Project>.lean
└── Tests/
    └── Main.lean

Template: lakefile.lean

Copyimport Lake
open Lake DSL

package «projectName» where
  leanOptions := #[
    ⟨`autoImplicit, false⟩
  ]

@[default_target]
lean_lib «ProjectName» where
  roots := #[`ProjectName]

require crucible from git "https://github.com/nathanial/crucible" @ "v0.0.1"

lean_exe tests where
  root := `Tests.Main

@[test_driver]
script test do
  let result ← IO.Process.run {
    cmd := ".lake/build/bin/tests"
    args := #[]
  }
  IO.println result
  return 0

Template: Main Library (.lean)

Copyimport ProjectName.Basic

Template: Basic.lean

Copynamespace ProjectName

-- Your code here

end ProjectName

Template: Tests/Main.lean

Copyimport Crucible
import ProjectName

open Crucible

def main : IO Unit := Crucible.runTests "ProjectName" do
  describe "Basic" do
    it "works" do
      assert true

Template: CLAUDE.md

Copy# <Project Name>

Brief description.

## Build

\`\`\`bash
lake build && lake test
\`\`\`

## Usage

\`\`\`lean
import ProjectName
\`\`\`

Naming Conventions

• Directory: lowercase with hyphens (e.g., my-project)
• Package: lowercase with hyphens in lakefile
• Library/namespace: PascalCase (e.g., MyProject)
• GitHub repo: matches directory name (except chronos → chronos-lean)

After Creation

1. lake build to verify structure
2. lake test to run initial tests
3. git init && git add -A && git commit -m "Initial commit"
4. Create GitHub repo and push
5. Add to workspace CLAUDE.md project list