OCaml Project Setup Standards

When to Use This Skill

Invoke this skill when:

Initializing a new OCaml project - Setting up dune-project, LICENSE, README, CI, etc.
Preparing for opam release - Ensuring all metadata is correct for publication
Setting up CI/CD - Configuring GitHub Actions, Tangled, or GitLab CI
Discussing project structure - Best practices for directory layout

Do not use for:

Regular code edits or bug fixes
Simple function additions
Refactoring existing code

User Configuration

Read configuration from ~/.claude/ocaml-config.json:

{
  "author": {
    "name": "Author Name",
    "email": "author@example.com"
  },
  "license": "ISC",
  "copyright_year_start": 2025,
  "ci_platform": "github",
  "git_hosting": {
    "type": "github",
    "org": "username"
  },
  "opam_overlay": {
    "enabled": false,
    "path": null,
    "name": null
  },
  "ocaml_version": "5.2.0"
}

If config file doesn't exist, prompt user for values and offer to save.

License Header

Every OCaml source file should start with a license header. Use the configured license.

ISC License:

(*---------------------------------------------------------------------------
  Copyright (c) {{YEAR}} {{AUTHOR_NAME}} <{{AUTHOR_EMAIL}}>. All rights reserved.
  SPDX-License-Identifier: ISC
 ---------------------------------------------------------------------------*)

MIT License:

(*---------------------------------------------------------------------------
  Copyright (c) {{YEAR}} {{AUTHOR_NAME}} <{{AUTHOR_EMAIL}}>

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.
  SPDX-License-Identifier: MIT
 ---------------------------------------------------------------------------*)

Build System (Dune)

Use Dune for builds with automatic opam file generation.

dune-project

See templates/dune-project.template for the full template.

Key points:

Always set (generate_opam_files true)
Use (maintenance_intent "(latest)") for actively maintained projects
Do not add a (version ...) field - added at release time
For Tangled projects, use appropriate URL schema

Root dune file

See templates/dune-root.template.

Include (data_only_dirs third_party) to ignore fetched dependency sources.

Version Control

.gitignore

See templates/gitignore for the standard template.

Always include:

_build/
third_party/
*.install
Editor and OS files

Code Formatting

Use OCamlFormat with default styling.

See templates/ocamlformat - current version 0.28.1.

Continuous Integration

Templates available for:

GitHub Actions: templates/ci-github.yml
Tangled: templates/ci-tangled.yml
GitLab CI: templates/ci-gitlab.yml

Select based on user's ci_platform configuration.

Documentation

README.md

See templates/README.template.md for structure.

Include:

Project title and brief description
Key features
Installation instructions
Usage examples
License

File Checklist for New Projects

Essential files:

Test files:

test/dune
test/test_*.ml

Template Variables

When using templates, replace:

{{PROJECT_NAME}} - snake_case project name
{{PROJECT_NAME_KEBAB}} - kebab-case project name
{{AUTHOR_NAME}} - from config
{{AUTHOR_EMAIL}} - from config
{{YEAR}} - current year
{{LICENSE}} - license identifier (ISC, MIT, etc.)
{{OCAML_VERSION}} - minimum OCaml version
{{GIT_URL}} - full git URL
{{GIT_HOSTING_TYPE}} - github, tangled, or gitlab

ocaml-project-setup