supertokens 0.1.5

Fast BPE tokenizer with C++ backend

🚀 supertokens

A high-performance tokenizer for Python — powered by a C++ extension built with nanobind and Meson.

✨ Features

• ⚡ Fast — core tokenization in C++, zero-copy bindings via nanobind
• 🔤 BPE tokenization — Byte-Pair Encoding implementation with full Unicode support via utfcpp
• 🗺️ Robin-map backend — hash map operations use tsl::robin_map for cache-friendly performance
• 🐍 Clean Python API — expressive, Pythonic interface over the C++ core
• 🏗️ Meson build system — reproducible builds, easy subproject management

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📦 Installation

From PyPI

pip install supertokens

From source

Prerequisites:

• Python ≥ 3.10
• C++17 compiler (g++, clang++, or MSVC 2019+)
• Meson ≥ 1.1 and Ninja

git clone https://github.com/yourorg/supertokens.git
cd supertokens
pip install .

Or with editable/dev install:

pip install --no-build-isolation -e .

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🔧 Building Manually (Meson)

# Configure
meson setup build --wipe

# Compile
meson compile -C build

# Run tests
meson test -C build

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🚀 Quick Start

from supertokens import BPE

# Load a pre-trained tokenizer
tokenizer = BPE.from_file("tokenizer.sha")

# Encode text
ids = tokenizer.encode("Hello, world!")
print(ids)  # [15496, 11, 995, 0]

# Decode tokens
text = tokenizer.decode(ids)
print(text)  # "Hello, world!"

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📖 API Reference

supertokens.model

Lower-level access to the underlying model data structures. See python/supertokens/model.py for details.

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🗂️ Project Structure

supertokens/
├── python/supertokens/       # Python package
│   ├── __init__.py
│   ├── BPE.py                # High-level BPE tokenizer
│   └── model.py              # Model data types
│
├── src/                      # C++ extension source
│   ├── bindings.cxx          # nanobind Python bindings
│   ├── tokenizer/
│   │   ├── bpe.cxx / .hxx    # BPE algorithm
│   │   └── datatypes.hxx     # Shared types
│   ├── utils/                # String & BPE utilities
│   └── libs/
│       ├── expected.hxx      # std::expected polyfill
│       └── utfcpp/           # UTF-8 string handling
│
├── subprojects/              # Meson subprojects (vendored)
│   ├── nanobind-2.12.0/      # Python ↔ C++ bindings
│   └── robin-map-1.4.0/      # Fast hash map
│
├── meson.build               # Top-level build definition
└── pyproject.toml            # Python package metadata

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🔩 Dependencies

Dependency	Version	Role
nanobind	2.12.0	C++ ↔ Python bindings
tsl::robin-map	1.4.0	High-performance hash map
utfcpp	bundled	UTF-8 string processing
expected.hxx	bundled	Error handling polyfill

All C++ dependencies are vendored under subprojects/ and managed by Meson — no manual installation required.

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Code style

• C++: follow the existing .cxx/.hxx style; C++17 standard
• Python: Black + Ruff

black python/
ruff check python/

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📋 Changelog

See CHANGELOG.md for release history.

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🤝 Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/my-feature)
3. Commit your changes
4. Open a Pull Request

For major changes, open an issue first to discuss the approach.

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📄 License

This project is licensed under the MIT License. See LICENSE for details.

Third-party licenses:

• nanobind: BSD 3-Clause (subprojects/nanobind-2.12.0/LICENSE)
• tsl::robin-map: MIT (subprojects/robin-map-1.4.0/LICENSE)