# Oclif — Open CLI Framework for Building TypeScript Command-Line Tools

> A framework by Salesforce for building extensible CLI applications in TypeScript with plugins, auto-generated help, and argument parsing.

## Install

Save as a script file and run:

# Oclif — Open CLI Framework for Building TypeScript Command-Line Tools

## Quick Use
```bash
npx oclif generate my-cli
cd my-cli
npm install
./bin/dev.js hello world
```

## Introduction
Oclif (Open CLI Framework) is a TypeScript-first framework for building command-line tools. Created by Salesforce and used to power the Heroku CLI and Salesforce CLI, it provides a structured way to define commands, flags, arguments, and plugins for CLIs of any size.

## What Oclif Does
- Scaffolds new CLI projects with a single command using the generator
- Provides a class-based command structure with typed flags and arguments
- Auto-generates help text, man pages, and README documentation from command metadata
- Supports a plugin system that lets users extend your CLI with third-party packages
- Handles command discovery, lifecycle hooks, and error reporting out of the box

## Architecture Overview
Oclif organizes a CLI as a collection of command classes, each defining its flags, arguments, and run method. At startup, the framework discovers commands from the file system or installed plugin packages and builds a command tree. Flag and argument parsing uses a strict, typed approach that validates input before the command runs. Plugins are npm packages that expose additional commands and hooks, loaded dynamically at runtime.

## Self-Hosting & Configuration
- Generate a new project: `npx oclif generate my-cli`
- Define commands as TypeScript classes in the `src/commands/` directory
- Configure the CLI name, version, and plugins in `package.json` under the `oclif` key
- Distribute via npm or build standalone installers for macOS, Windows, and Linux
- Add plugins by listing them in the `oclif.plugins` array or let users install them dynamically

## Key Features
- TypeScript-first with full type inference for flags, arguments, and configuration
- Plugin architecture powering large-scale CLIs like Heroku CLI and Salesforce CLI
- Auto-generated help output formatted for terminal with color and layout
- Built-in testing utilities for unit and integration testing commands
- Standalone packaging to create single-binary installers without requiring Node.js

## Comparison with Similar Tools
- **Commander.js** — lightweight flag parser; Oclif adds plugins, scaffolding, and auto-generated docs
- **Yargs** — flexible argument parsing; Oclif provides more structure with classes and lifecycle hooks
- **Cobra (Go)** — similar command framework for Go; Oclif is the TypeScript equivalent
- **Clipanion** — Yarn's CLI engine; Oclif has a larger ecosystem and standalone packaging

## FAQ
**Q: Can I use Oclif with plain JavaScript?**
A: Yes, though TypeScript is recommended. The generator scaffolds TypeScript by default.

**Q: How do plugins work?**
A: Plugins are npm packages that export Oclif commands. Users install them with `my-cli plugins install plugin-name`.

**Q: Can I build standalone executables?**
A: Yes. Oclif includes a `pack` command that creates tarballs and platform-specific installers.

**Q: What CLIs are built with Oclif?**
A: Heroku CLI, Salesforce CLI (sf), Shopify CLI, and Twilio CLI are all built on Oclif.

## Sources
- https://github.com/oclif/oclif
- https://oclif.io

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Source: https://tokrepo.com/en/workflows/asset-4b049ef8
Author: Script Depot