MPLang: Multi-Party Programming Language

MPLang (Multi-Party Language) is a single-controller programming library for multi-party and multi-device workloads. It follows the SPMD (Single Program, Multiple Data) model, where one Python program orchestrates multiple parties and devices (e.g., P0/P1/SPU) with explicit security domains. Programs are compilable and auditable, and can run in local simulation or on secure-computation backends.

Highlights

• Single-controller SPMD: one program, multiple parties in lockstep
• Explicit devices and security domains: clear annotations for P0/P1/SPU
• Function-level compilation (@mplang.function): narrow instruction surface, reduce RCE risk, enable graph optimizations and audit
• Pluggable frontends and backends: not tied to specific FE/BE technologies
  • Frontends (FE): JAX, Ibis, and other computation frameworks
  • Backends (BE): StableHLO IR, Substrait IR, SPU PPHlo IR, and other intermediate representations
  • Execution: in-memory simulation, gRPC-based executors, or your custom engines

Quick start

Writing multi-party secure computation programs is easy:

Note: The snippet below is illustrative and not directly runnable; for a complete runnable example of the device API, see tutorials/3_device.py.

import mplang.device as mpd

def millionaire():
    # Alice's value on P0
    x = mpd.device("P0")(randint)(0, 1000000)
    # Bob's value on P1
    y = mpd.device("P1")(randint)(0, 1000000)
    # Compare values on SPU
    z = mpd.device("SPU")(lambda a, b: a < b)(x, y)
    return z

Add one decorator to get the "compiled version":

@mplang.function
def millionaire():
    x = mpd.device("P0")(randint)(0, 1000000)
    y = mpd.device("P1")(randint)(0, 1000000)
    z = mpd.device("SPU")(lambda a, b: a < b)(x, y)
    return z

# Run it
sim = mplang.Simulator(2)
result = mplang.eval(sim, millionaire)
print("result:", mplang.fetch(sim, result))

Installation and setup

• Install uv (if not installed):

  Linux/macOS:

  curl -LsSf https://astral.sh/uv/install.sh | sh

  Or with pipx:

  pipx install uv

• Install from source:

  uv pip install .

• Editable install for development:

  uv pip install -e .

• Run tutorials (complete examples and explanations):

  uv run tutorials/0_basic.py

See more examples in tutorials/ (e.g., 1_condition.py, 2_whileloop.py).

Beyond the basics

• SPMD for all-party execution: describe once, execute on all parties
• mplang.compile(...): inspect compiler IR for understanding and optimization
• SMPC primitives: smpc.seal, smpc.reveal, smpc.srun to express secure operators

Contributing and development

We welcome PRs and issues. Common dev commands:

uv sync --group dev
uv run pytest
uv run ruff check . --fix && uv run ruff format .
uv run mypy mplang/

License

Apache-2.0. See LICENSE for details.