heir-py 2026.3.30.dev0

The HEIR compiler

HEIR: Homomorphic Encryption Intermediate Representation

An MLIR-based toolchain for homomorphic encryption compilers. Read the docs at the HEIR website.

For more information on MLIR, see the MLIR homepage.

Quickstart (Python)

Pip install the heir_py package

pip install heir_py

Then run an example:

from heir import compile
from heir.mlir import I64, Secret

@compile()  # defaults to scheme="bgv", OpenFHE backend, and debug=False
def func(x: Secret[I64], y: Secret[I64]):
    sum = x + y
    diff = x - y
    mul = x * y
    expression = sum * diff + mul
    deadcode = expression * mul
    return expression

func.setup()
enc_x = func.encrypt_x(7)
enc_y = func.encrypt_y(8)
result_enc = func.eval(enc_x, enc_y)
result = func.decrypt_result(result_enc)

print(
  f"Expected result for `func`: {func.original(7,8)}, FHE result:"
  f" {result}"
)

This will compile the function above using the BGV scheme to machine code via the OpenFHE backend. Then calling the function will encrypt the inputs, run the function, and return the decrypted result. The function call foo(7, 8) runs the entire encrypt-run-decrypt flow for ease of testing.

Quickstart (heir-opt, heir-translate)

The python package heir_py ships with the heir-opt and heir-translate. If you install via virtualenv, the binaries will be in your venv/bin.

venv/bin/heir-opt --help

Supported backends and schemes

Backend Library	BGV	BFV	CKKS	CGGI
OpenFHE	✅	✅	✅	❌
Lattigo	✅	✅	✅	❌
tfhe-rs	❌	❌	❌	✅
Jaxite	❌	❌	❌	✅

Note some backends do not support all schemes.

Contributing

There are many ways to contribute to HEIR:

• Come to our monthly meetings to discuss active work on HEIR and future project directions. The meetings are recorded and posted to our blog and YouTube channel.
• Come to our weekly office hours for informal discussions and debugging help.
• Ask questions or discuss feature ideas in the #heir channel on the FHE.org discord.
• Work on an issue marked "good first issue" or browse issues labeled by topic.
• Help us understand new FHE research: either
  • Read a paper tagged under research synthesis and summarize the novel techniques that could be ported to HEIR.
  • File new issues under research synthesis to alert us of papers that should be investigated and incorporated into HEIR.

Citations

The HEIR project can be cited in in academic work through following entry:

@misc{ali2025heir,
      title={HEIR: A Universal Compiler for Homomorphic Encryption},
      author={Asra Ali and Jaeho Choi and Bryant Gipson and Shruthi Gorantala
              and Jeremy Kun and Wouter Legiest and Lawrence Lim and Alexander
              Viand and Meron Zerihun Demissie and Hongren Zheng},
      year={2025},
      eprint={2508.11095},
      archivePrefix={arXiv},
      primaryClass={cs.CR},
      url={https://arxiv.org/abs/2508.11095},
}

Support disclaimer

This is not an officially supported Google product.