The python binding API for NeuG

Architecture

The Python binding (neug_py_bind*.so) dynamically links against the core shared library libneug.{dylib,so} produced by the root CMake build. Both bindings and core are built in the same root build tree (<repo>/build/); the Python flow consumes those artifacts rather than re-running a separate CMake configure.

<repo>/build/                          # single root build tree
├── src/libneug.{dylib,so}             # core (shared)
└── tools/python_bind/
    └── neug_py_bind.<abi>.so          # binding, RPATH → core

Future bindings (Node, Rust, …) follow the same pattern: their .so lives under build/tools/<binding>/ and link against the same libneug.

Development

Setup

cd tools/python_bind
make requirements    # one-time: install Python deps
make dev             # incremental rebuild of neug_py_bind; auto-bootstraps
                     # the root build on first run or if it wasn't configured
                     # with -DBUILD_PYTHON=ON

make dev-full is also available if you want to force a full reconfigure (equivalent to cmake -S <repo> -B <repo>/build -DBUILD_PYTHON=ON && cmake --build ...).

Dev loop

# After editing C++ binding sources or core
make dev          # incremental rebuild of neug_py_bind only (seconds)

# After editing only Python sources (neug/*.py): no rebuild needed,
# editable import works because the loader auto-finds the .so in
# <repo>/build/tools/python_bind/.

python3 -m pytest -s tests/test_db_query.py

The neug/__init__.py loader resolves neug_py_bind*.so in this order:

1. The neug/ package directory itself (wheel-installed layout).
2. $NEUG_BUILD_DIR/tools/python_bind/ (default <repo>/build/...).
3. Legacy tools/python_bind/build/lib.<plat>-cpython-* (back-compat fallback).

So you can point at an out-of-tree build via NEUG_BUILD_DIR=/path/to/build.

Building the Wheel

make wheel        # produces dist/neug-*.whl

make wheel reuses the root build (creating it on the fly via the setup.py fallback if absent). The wheel bundles both neug_py_bind*.so and libneug.{dylib,so} into the neug package; they find each other at runtime via @loader_path (macOS) / $ORIGIN (Linux) RPATH. Wheel builds always force NEUG_PACKAGE_BUILD=ON and NEUG_NATIVE_ARCH=OFF. For local source builds via setup.py build_ext, override with NEUG_PACKAGE_BUILD=OFF NEUG_NATIVE_ARCH=ON make build.

Python service API

Database.serve() starts the database in service mode and can configure the service thread count:

from neug import Database

db = Database("/path/to/database", mode="rw")
endpoint = db.serve(
    host="0.0.0.0",
    port=10000,
    blocking=False,
    thread_num=0,
    auto_compaction=True,
)

thread_num=0 is the default and auto-selects from the database max_thread_num. If set explicitly, it must be less than or equal to that value. With the default database thread setting, max_thread_num is resolved from hardware concurrency and falls back to 1 if the runtime cannot detect it. Service threads run TP queries concurrently, but each query uses one execution context and one thread.

Embedded (AP) queries are currently single-threaded; using max_thread_num for intra-query parallelism is future work. This is separate from client-side Session(..., num_threads=...), which configures the client's HTTP connection pool.

auto_compaction controls whether a background auto-compaction thread runs while serving (default True).

Multi-version wheels via cibuildwheel

python3 -m pip install cibuildwheel
cd <repo>
cibuildwheel ./tools/python_bind --output-dir wheelhouse

Cibuildwheel runs in fresh manylinux/macOS containers; setup.py detects no pre-existing root build and falls back to running cmake configure in <repo>/build/ inside the container, then builds only the neug_py_bind target. No changes to pyproject.toml are needed.

Clean

make clean        # clears dist/, *.egg-info, and any stray .so left in neug/
                  # (does NOT touch <repo>/build — keep that for incremental builds)

# Or from the repo root, also nuke <repo>/build:
make -C ../.. dist-clean

Neug CLI

The Neug CLI tool provides an interactive shell for querying and managing NeuG database. It supports both local and remote database connections, Cypher query execution, and result formatting.

Installation

neug-cli is included in neug package.

pip install neug

After installation, you can verify that neug-cli is installed correctly by running:

neug-cli --version

This should display:

neug-cli, version 0.2.0

Usage

Overview

The neug-cli tool allows you to interact with the Neug database in both local and remote modes. To view the basic usage, run:

neug-cli --help

This displays:

Usage: neug-cli [OPTIONS] COMMAND [ARGS]...

  Neug CLI Tool.

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.

Commands:
  connect  Connect to a remote database.
  open     Open a local database.

Start the Shell by Opening a Local Database

To open a local Neug database, specify the database path when starting the CLI. By default, the database is opened in read-write mode, and changes are persisted to disk when the shell exits. If the specified directory does not exist, it will be created automatically.

To open the database in read-only mode, use the --readonly or -r option.

neug-cli open <path-to-db> -m [read-only|read-write]

• --mode, -m: Specify mode of database.

Start the Shell by Connecting to a Remote Database

To connect to a remote Neug server, specify the server URI when starting the CLI. You can optionally provide a username, password, and query timeout. Note that remote connection support is under development.

neug-cli connect <host:port> [--timeout <seconds>]

• --timeout: Connection timeout in seconds (default: 300).

Interactive Shell Commands

Once you start the shell, you can execute Cypher queries and use various interactive commands:

• Enter Cypher queries directly to execute them.
• Use :help to display this help message.
• Use :quit or press Ctrl+C to leave the shell.
• Use :max_rows <number> to set the maximum number of rows to display for query results.
• Use :ui <endpoint> to start a web ui service.
• Multi-line commands are supported. Use ';' at the end to execute.
• Command history is supported; use the up/down arrow keys to navigate previous commands.

Example

neug-cli open /tmp/modern_graph

This will open embedded Neug database at /tmp/modern_graph in rw mode by default, and start the shell. Then you can execute Cypher queries directly:

Welcome to the Neug shell. Type :help for usage hints.

neug > MATCH (n:person) RETURN n;
+-------------------------------------------------------+
| n                                                     |
+=======================================================+
| {_ID: 0, _LABEL: person, id: 1, name: marko, age: 29} |
+-------------------------------------------------------+
| {_ID: 1, _LABEL: person, id: 2, name: vadas, age: 27} |
+-------------------------------------------------------+
| {_ID: 2, _LABEL: person, id: 4, name: josh, age: 32}  |
+-------------------------------------------------------+
| {_ID: 3, _LABEL: person, id: 6, name: peter, age: 35} |
+-------------------------------------------------------+