{"id":23032,"library":"amazon-braket-default-simulator","title":"Amazon Braket Default Simulator","description":"An open-source quantum circuit simulator that runs locally with the Amazon Braket SDK. It provides a default local simulator to test quantum programs before running on AWS-managed backends. Current version 1.39.0, actively maintained, supports Python >=3.11, and includes features like mid-circuit measurements and classical control flow.","status":"active","version":"1.39.0","language":"python","source_language":"en","source_url":"https://github.com/amazon-braket/amazon-braket-default-simulator-python","tags":["quantum computing","simulator","amazon braket","local simulation"],"install":[{"cmd":"pip install amazon-braket-default-simulator","lang":"bash","label":"Latest stable"}],"dependencies":[{"reason":"Required for creating Braket circuits and devices; the simulator is used through the SDK's LocalSimulator.","package":"amazon-braket-sdk","optional":false}],"imports":[{"note":"The simulator backend is automatically available when you import LocalSimulator from braket.devices; direct import from amazon_braket_default_simulator is not the intended usage.","wrong":"from amazon_braket_default_simulator import LocalSimulator","symbol":"LocalSimulator","correct":"from braket.devices import LocalSimulator"}],"quickstart":{"code":"from braket.devices import LocalSimulator\nfrom braket.circuits import Circuit\n\n# Create a local simulator device\ndevice = LocalSimulator()\n\n# Build a Bell state circuit\ncircuit = Circuit().h(0).cnot(0, 1)\n\n# Run the circuit\nresult = device.run(circuit, shots=1000).result()\n\n# Get measurement counts\ncounts = result.measurement_counts\nprint(counts)","lang":"python","description":"Set up and run a quantum circuit on the local default simulator."},"warnings":[{"fix":"Use `from braket.devices import LocalSimulator` and ensure `amazon-braket-default-simulator` is installed as a dependency.","message":"Do NOT manually import from `amazon_braket_default_simulator` directly. The package is a backend plugin; use `from braket.devices import LocalSimulator` to access the simulator. Direct imports may break or give unexpected results.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Explicitly create the simulator with a backend: `LocalSimulator('braket_dm')` for density matrix or `LocalSimulator('braket_sv')` for state vector.","message":"The `LocalSimulator` default backend may change. In older versions, it defaulted to a state vector simulator; newer versions may use density matrix. Always specify the backend if you rely on a specific simulation method.","severity":"deprecated","affected_versions":"<1.0.0 (historical) or unspecified"}],"env_vars":null,"last_verified":"2026-05-01T00:00:00.000Z","next_check":"2026-07-30T00:00:00.000Z","problems":[{"fix":"Run `pip install amazon-braket-default-simulator` and use `from braket.devices import LocalSimulator` instead.","cause":"The package is not installed, or it is installed but not imported correctly (users often try to import it directly).","error":"ModuleNotFoundError: No module named 'amazon_braket_default_simulator'"},{"fix":"Update both packages: `pip install --upgrade amazon-braket-sdk amazon-braket-default-simulator` and ensure imports are correct.","cause":"Using an older version of Braket SDK where `LocalSimulator` was not fully supported or imported from an incorrect module.","error":"AttributeError: 'LocalSimulator' object has no attribute 'run'"}],"ecosystem":"pypi","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}