plasmite 0.3.0

Persistent JSON message queues for Python - native bindings for local and remote IPC

Plasmite Python Bindings (v0)

These bindings wrap the libplasmite C ABI via ctypes.

Installation

Wheels are designed to bundle native assets under plasmite/_native/:

• libplasmite.(dylib|so) for ctypes loading
• plasmite CLI binary (invoked via Python console script entrypoint)

Using uv (recommended)

uv tool install plasmite

For project dependencies in a uv-managed workspace:

uv add plasmite

Runtime load order is:

1. PLASMITE_LIB_DIR override (development escape hatch)
2. Bundled plasmite/_native/libplasmite.(dylib|so) absolute path
3. System linker fallback (plasmite / libplasmite)

For development/testing from this repo, see Install & Test below.

Build Requirements

• Python 3.10+
• libplasmite built from this repo (cargo build -p plasmite) for local development

Install & Test

From the repo root:

cargo build -p plasmite

Canonical repo-root command:

just bindings-python-test

Equivalent manual commands (from bindings/python):

uv venv
source .venv/bin/activate
PLASMITE_LIB_DIR="$(pwd)/../../target/debug" uv pip install -e .
PLASMITE_LIB_DIR="$(pwd)/../../target/debug" PLASMITE_BIN="$(pwd)/../../target/debug/plasmite" python3 -m unittest discover -s tests

Build a wheel with bundled native assets from a specific SDK directory:

PLASMITE_SDK_DIR=/path/to/sdk python -m build

Usage

from plasmite import Client, Durability

with Client("./data") as client:
    with client.create_pool("docs", 64 * 1024 * 1024) as pool:
        message = pool.append_json(
            b'{"kind":"note","text":"hi"}',
            ["note"],
            Durability.FAST,
        )
        print(message.decode("utf-8"))

        frame = pool.get_lite3(1)
        print(len(frame.payload))

        for item in pool.tail(tags=["note"], max_messages=1, timeout_ms=100):
            print(item.decode("utf-8"))

Pool.tail(..., tags=[...]) uses exact tag matching and composes with other filters using AND semantics.

Error behavior

• Invalid local arguments raise ValueError / TypeError.
• ABI/runtime failures raise PlasmiteError with kind, path, seq, and offset when present.