Pincer Engine Documentation

Welcome to the Pincer Engine docs. Start from the top and work your way down — everything is numbered in reading order.

Built for Grabbit

I originally developed the Pincer engine to power my native macOS Download Manager, Grabbit. If you are looking for a beautiful, polished GUI that leverages the full power of this engine, check it out at grabbit.fyi!

Getting Started

1. How It Works — A jargon-free look at what Pincer does under the hood.
2. User Guide — Start downloading files in minutes.
3. CLI Reference — Every flag and option, with examples.

JSON-RPC API

How to control Pincer programmatically over WebSocket.

1. Connecting — WebSocket URL, port, and token authentication.
2. Managing Downloads — Adding, pausing, removing, and queuing tasks.
3. Checking Status — Querying progress, file lists, and global stats.
4. Configuration — Engine defaults, task options, and system keys.
5. Advanced Features — URL resolution, format conversion, Metalink, FTP/SFTP, and more.
6. Events — Real-time WebSocket notifications.
7. System Controls — Version info, shutdown, session saves, and batch calls.

Guides

Deep-dive walkthroughs for specific use cases.

1. Session & Resume — How auto-save and download resumption work.
2. Swift Integration — Embedding Pincer in a macOS Swift/SwiftUI app.
3. API Comparison — Pincer’s methods mapped against standard download engines.

Contributing

Everything you need to contribute code to Pincer.

1. Getting Started — Setup, code style, and PR workflow.
2. Architecture — System design, modules, and concurrency model.
3. Testing — Test suite architecture and how to run tests.
4. Build & Release — Compiling from source and cutting releases.
5. Roadmap — Dependency migration strategy and optimization paths.
6. Feature Status — What’s done, what’s next.

License

Pincer Engine is free and open-source software licensed under the GNU General Public License v3.0 (GPLv3).