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Install

pip install qmlkit

That is the whole install. qmlkit depends on NumPy and nothing else — the NumPy backend is the reference implementation, and every core feature works with no optional package present.

Python 3.10 or newer. 3.9 reached end of life in October 2025, and 3.10 is also the highest version SpinQit supports, so it is the overlap that matters.

Extras

Each extra adds one capability. None of them is required, and import qmlkit never imports any of them — a missing SDK produces an install command, not a traceback.

pip install "qmlkit[torch]"

Unlocks QuantumLayer, VQC, VQRegressor, the structured architectures, and method="backprop".

pip install "qmlkit[qiskit]"

Adds the Qiskit backend and to_qiskit(), so a circuit can be handed to Qiskit's own transpiler and visualisation.

pip install "qmlkit[cirq]"

pip install "qmlkit[spinqit]"

SpinQit ships wheels for Python 3.8–3.10 only and pins numpy<2, so the extra is gated behind an environment marker: on 3.11+ it resolves cleanly to nothing rather than failing. Use a dedicated 3.10 environment for it.

pip install "qmlkit[torch,qiskit,cirq,sklearn,viz]"

sklearn enables QSVC/QSVR (which wrap scikit-learn's precomputed-kernel solver) and viz enables matplotlib plotting helpers.

Check what you have

import qmlkit as qk

print(qk.__version__)
print(qk.available_backends())
print(qk.backend_report())

backend_report() prints one line per backend with an install command for the ones you are missing:

qmlkit backends:
  [ok]      numpy
  [ok]      torch
  [missing] cirq     -> pip install 'qmlkit[cirq]'
  [missing] qiskit   -> pip install 'qmlkit[qiskit]'
  [missing] spinqit  -> pip install 'qmlkit[spinqit]'

Set the default with the QMLKIT_BACKEND environment variable, or in code:

import qmlkit as qk

qk.set_default_backend("numpy")
print(qk.default_backend().name)

From source

git clone https://github.com/Ziadt160/qmlkit
cd qmlkit
pip install -e ".[dev]"
pytest

Verifying an install you did not build

If you want to confirm a release is intact — that nothing is missing from the wheel and no optional dependency is secretly required — the repository ships the check it runs in CI:

python -m venv /tmp/clean && /tmp/clean/bin/pip install qmlkit && /tmp/clean/bin/python scripts/verify_install.py