tsujikiri — 辻斬り

Cut through C++ bindings

tsujikiri parses C++ headers via libclang, filters by namespace and pattern, transforms symbols — rename, remap types, inject code — then renders ready-to-compile bindings through a Jinja2 template. Precise control, zero boilerplate.

Built-in support for LuaBridge3 (Lua bindings), LuaLS (Lua Language Server annotations), pybind11 (Python bindings), and Python type stubs (.pyi). Custom formats are first-class.

How It Works

C++ Header (.hpp)
    │
    ▼  libclang
Intermediate Representation (IR)
    │
    ├─▶  FilterEngine        suppress classes / methods / fields by pattern
    │
    ├─▶  Transform Pipeline  rename, inject, remap types
    │
    ▼  Jinja2 templates
Target Binding Code

Each phase is independently configurable per input file and per output format.

Documentation

Full documentation is available at tsujikiri.readthedocs.io.

Installation

Using pip:

pip install tsujikiri

Using uv:

uv pip install tsujikiri

Requirements: Python ≥ 3.12

Clang Version

By default tsujikiri installs libclang-ng>=19, which resolves to the latest available version (see https://github.com/kunitoki/libclang-ng for more information). To pin a specific Clang release use an extra:

# pip
pip install "tsujikiri[clang19]"
pip install "tsujikiri[clang20]"
pip install "tsujikiri[clang21]"
pip install "tsujikiri[clang22]"

# uv
uv pip install "tsujikiri[clang21]"

Only one clangXX extra may be active at a time — they are mutually exclusive.

Quick Start

1. Write an input config

# myproject.input.yml
source:
  path: myproject.hpp
  parse_args: ["-std=c++17"]
  include_paths: ["/usr/local/include"]

filters:
  namespaces: ["myproject"]
  classes:
    whitelist: ["Vec3", "Matrix4", "Camera"]
  constructors:
    include: true

generation:
  includes: ["<myproject.hpp>"]

2. Generate bindings

# Print to stdout
tsujikiri -i myproject.input.yml --target luabridge3 -

# Write to file
tsujikiri -i myproject.input.yml --target luabridge3 bindings.cpp

# Generate multiple outputs in one pass
tsujikiri -i myproject.input.yml \
  --target luabridge3 bindings.cpp \
  --target pybind11 py_bindings.cpp \
  --target pyi mymodule.pyi

# Dry-run: parse and filter, print summary
tsujikiri -i myproject.input.yml --target luabridge3 - --dry-run

# List available formats
tsujikiri --list-formats

3. Example output (LuaBridge3)

Given a header with a Vec3 class, tsujikiri emits:

#include <myproject.hpp>
#include <LuaBridge/LuaBridge.h>

void register_myproject(lua_State* L)
{
    luabridge::getGlobalNamespace(L)
        .beginClass<myproject::Vec3>("Vec3")
            .addConstructor<void(*)(float, float, float)>()
            .addFunction("length", &myproject::Vec3::length)
            .addFunction("dot", &myproject::Vec3::dot)
            .addProperty("x", &myproject::Vec3::x)
            .addProperty("y", &myproject::Vec3::y)
            .addProperty("z", &myproject::Vec3::z)
        .endClass();
}

Built-in Formats

luabridge3

Generates C++ registration code for LuaBridge3.

tsujikiri -i project.input.yml --target luabridge3 bindings/lua_bindings.cpp

Handles: classes, constructors, instance/static methods, overloaded methods, properties, enums, free functions, inheritance.

luals

Generates Lua Language Server annotation stubs.

tsujikiri -i project.input.yml --target luals types/myproject.lua

Emits ---@class, ---@field, ---@param, ---@return annotations with C++→Lua type mappings.

pybind11

Generates C++ registration code for pybind11.

tsujikiri -i project.input.yml --target pybind11 src/py_bindings.cpp

Handles: classes with multiple inheritance, constructors, instance/static methods, overloaded methods (via py::overload_cast), read-write/read-only properties, enums (via py::enum_), free functions, doc strings.

pyi

Generates Python type stub files (.pyi) for use alongside pybind11 bindings.

tsujikiri -i project.input.yml --target pyi mymodule.pyi

Emits Python-typed stubs with @overload, @staticmethod, class inheritance, enum stubs as class Foo(int), and C++→Python type mappings.

Custom Formats

Create a myformat.output.yml alongside your templates:

format_name: "myformat"
format_version: "1.0"
description: "My custom binding format"

type_mappings:
  "std::string": "String"
  "int32_t": "int"

unsupported_types:
  - "CFStringRef"

template:
  {%- block prologue -%}
  # DO NOT EDIT - Auto-generated Python stubs for {{ module_name }} by tsujikiri
  from __future__ import annotations
  from typing import overload
  {{ code_injections | code_at("beginning") }}
  {%- endblock %}
  # ... finish the template

Point tsujikiri at your format directory:

tsujikiri -i project.input.yml --target myformat out/bindings.cpp -f ./my_formats/

CLI Reference

usage: tsujikiri [-h] [--input FILE] [--target FORMAT FILE] [--formats-dir DIR] [--list-formats] [--dry-run] [--manifest-file FILE]
                 [--check-compat] [--embed-version] [--trace-transforms] [--dump-ir [FILE]] [--validate-config] [--verbose]
                 [--api-version VERSION] [--pretty [FORMAT ...]] [--strict] [--jobs N]

辻斬り — Generic C++ Binding Generator

options:
  -h, --help            show this help message and exit
  --input FILE, -i FILE
                        Input config YAML (e.g. myproject.input.yml)
  --target FORMAT FILE, -t FORMAT FILE
                        Output target: FORMAT is a built-in name (luabridge3) or path to .output.yml; FILE is the output path ('-' for
                        stdout). Repeatable.
  --formats-dir DIR, -f DIR
                        Additional directory to search for .output.yml format files (repeatable)
  --list-formats        Print available built-in output formats and exit
  --dry-run             Parse and filter but do not generate output; print a summary instead
  --manifest-file FILE, -m FILE
                        Write API manifest JSON to FILE; if FILE already exists, compare with new manifest
  --check-compat        Exit 1 if --manifest-file exists and breaking API changes are detected
  --embed-version       Embed the API version hash in the generated code (template must support it)
  --trace-transforms    Print which transform stages ran and on what entities to stderr
  --dump-ir [FILE]      Dump the post-transform IR as JSON to FILE (default: stdout when flag is given without FILE)
  --validate-config     Validate the input config YAML (regex patterns, transform stage names) and exit
  --verbose, -v         Enable verbose output during parsing (currently only applies to Clang diagnostics)
  --api-version VERSION
                        Target API version (semver). Entities with api_since > VERSION or api_until <= VERSION are excluded.
  --pretty [FORMAT ...]
                        Enable pretty printing. With no FORMAT args, enable for all targets. With FORMAT names (e.g. --pretty luabridge3
                        pybind11), enable only for those targets. Overrides the input.yml `pretty` setting.
  --strict              Exit 1 if clang reports any errors during parsing; no output is written
  --jobs N, -j N        Parse sources using N worker processes, or 'auto' for one per CPU. Default: 1 (serial). Output is identical for
                        any N.

Development

# Install task runner and sync dependencies
pip install just uv
just sync

# Run tests
just test

# Run tests with coverage
just coverage

# Build wheel
just build

The test suite covers parsing, filtering, transforms, generation, CLI integration, and end-to-end compilation with LuaBridge3.

Coverage

License

MIT — see LICENSE.