# quantumlib/Cirq

Python framework for creating, editing, and running Noisy Intermediate-Scale Quantum (NISQ) circuits.

Repository: https://github.com/quantumlib/Cirq
Canonical: https://ross.abutalabs.com/products/cirq
Homepage: https://quantumai.google/cirq
Language: Python
License: Apache-2.0
License Family: permissive
Topics: nisq, quantum-algorithms, quantum-computing, cirq, algorithms, api, google-quantum, python, quantum, quantum-circuit, quantum-circuit-simulator, quantum-development-kit, quantum-information, quantum-programming, quantum-simulation, sdk, simulation, quantum-computer-simulator, quantum-programming-language, google
Last push: 2026-08-25T20:31:05+00:00

## Health v2 (maintenance only)
Score: 88/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 66, longevity 100
- inputs: {"age_days": 3184, "days_push": 8, "days_rel": 64, "gap_med": 103, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5053, forks 1262 (observed 2026-08-28T04:09:09.117320+00:00)

## What it is
Cirq is a Python framework from Google Quantum AI for writing, manipulating, optimizing, and simulating quantum circuits, with a focus on NISQ (noisy intermediate-scale quantum) hardware. It includes built-in simulators, noise and device modeling, circuit compilation, and integration with the high-performance qsim simulator.

## Use cases
- build and simulate quantum circuits in python
- simulate noisy NISQ quantum circuits
- compile and optimize quantum circuits for real hardware
- model quantum device hardware constraints and noise
- run quantum algorithms on simulators before executing on quantum computers
- learn quantum computing with a python sdk

## When to choose
- you need fine-grained control over qubit placement and hardware-aware circuit design
- you target Google quantum hardware or want hardware-level noise modeling
- you need high-performance circuit simulation via qsim integration

## When to avoid
- you want a higher-level abstraction-focused framework like Qiskit's ecosystem breadth
- you need fault-tolerant quantum error correction tooling rather than NISQ circuits
- your project is not Python-based

## Facets
- artifact type: framework
- maturity: stable
- function: simulation, sdk, machine-learning
- domain: quantum-computing, simulation, programming-languages
- platform: python, windows, cross-platform
- tags: quantum-circuits, nisq, quantum-simulation, quantum-programming, google-quantum-ai, qsim, algorithms, linux, macos

## Member repositories
- quantumlib/Cirq (main) score 88

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:09.117320+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:17:20.640677+00:00, confidence not recorded.
  - readme: https://github.com/quantumlib/Cirq (fetched 2026-08-28T04:09:09.117320+00:00, sha 81c27d1ca7ef)
  - homepage: https://quantumai.google/cirq (fetched 2026-08-29T08:57:48.407184+00:00, sha b886c740d077)
  - site_page: https://quantumai.google/cirq/start/install (fetched 2026-08-29T08:57:48.409899+00:00, sha 4ab0701b989e)
- Data as of 2026-08-30T08:39:29.467469+00:00.