polyglot-ffi 0.4.2

Automatic FFI bindings generator for polyglot projects

Polyglot FFI

Automatic FFI bindings generator for polyglot projects

Stop writing FFI boilerplate. Start building amazing things.

Full Documentation | Quickstart | API Reference | Type Mapping

What is Polyglot FFI?

Polyglot FFI automatically generates complete Foreign Function Interface (FFI) bindings between programming languages. Write your OCaml interface once, and get type-safe, memory-safe bindings for Python (and soon Rust, Go, etc.) instantly.

The Problem

Building multi-language projects requires writing:

• 50+ lines of OCaml ctypes boilerplate
• 30+ lines of C stubs with tricky memory management
• 20+ lines of Python ctypes configuration
• Plus: Dune configs, debugging, memory leaks...

The Solution

polyglot-ffi generate crypto.mli

Done! All 100+ lines generated automatically.

Why Polyglot FFI?

Zero Boilerplate - One command generates OCaml ctypes declarations, C wrappers, Python modules, build configs, type conversions, and error handling.

Type Safe - Preserves type information with Python type hints, OCaml type constraints, C type declarations, and compile-time checking.

Memory Safe - Proper memory management with CAMLparam/CAMLreturn macros, no memory leaks, and GC-safe conversions.

Quick Start

Initialize a new project:

polyglot-ffi init my-crypto-lib
cd my-crypto-lib

Write your OCaml interface:

(* src/my-crypto-lib.mli *)
val greet : string -> string
val add : int -> int -> int

Generate bindings:

polyglot-ffi generate src/my-crypto-lib.mli

Implement your OCaml functions:

(* src/my-crypto-lib.ml *)
let greet name = "Hello, " ^ name ^ "!"
let add x y = x + y

let () =
  Callback.register "greet" greet;
  Callback.register "add" add

Use from Python:

from generated.my_crypto_lib_py import greet, add

print(greet("World"))  # Hello, World!
print(add(2, 3))       # 5

Complex types supported: Records, variants (Result, Option), lists, tuples, and more. See the Type Mapping docs for details.

Installation

pip install polyglot-ffi

Verify installation:

polyglot-ffi --version

To upgrade:

pip install --upgrade polyglot-ffi

See the full installation guide for virtual environments, shell completion, and troubleshooting.

Features

• Automatic Code Generation - One command generates OCaml ctypes, C wrappers, Python modules, and build configs
• Rich Type Support - Primitives, records, variants (Result, Option), lists, tuples, and nested types
• Type Safety - Full Python type hints and OCaml type preservation
• Memory Safety - Proper GC integration, no memory leaks
• Watch Mode - Auto-regenerate bindings on file changes
• Project Validation - Built-in dependency and configuration checking
• Zero Runtime Overhead - All generation happens at build time

Roadmap

• Rust target support
• Go target support
• Bidirectional bindings (call Python from OCaml)
• Plugin system for custom type mappings

Use Cases

• Cryptography - OCaml for correctness, Python for integration
• Data Processing - OCaml for logic, Python for data science
• Financial Systems - OCaml for algorithms, Python for reporting
• ML Infrastructure - OCaml for pipelines, Python for training

CLI Reference

polyglot-ffi init my-project              # Initialize new project
polyglot-ffi generate src/module.mli      # Generate bindings
polyglot-ffi watch                        # Auto-regenerate on changes
polyglot-ffi check                        # Validate configuration
polyglot-ffi clean                        # Remove generated files
polyglot-ffi --help                       # Get help

Run any command with --help for full options. See the CLI documentation for detailed usage.

Documentation

• Quickstart Guide - Get started in 5 minutes
• Type Mapping - Complete type system reference
• Architecture - How it works under the hood
• Installation Guide - Detailed setup instructions
• Contributing - Join development

Contributing & Community

We welcome contributions! See CONTRIBUTING.md for development setup, testing requirements, and PR process. Look for good-first-issue labels to get started.

Get in touch:

• GitHub: chizy7/polyglot-ffi
• Issues: Report bugs or request features
• Email: [e-mail]
• Twitter: @Chizyization

License

MIT License - See LICENSE for details.

Acknowledgments

Built with inspiration from PyO3, OCaml-Ctypes, and SWIG.