Open Arsenal

QGuardian Registry is an open-source infrastructure layer that standardizes how quantum hardware capabilities are described, discovered, and matched to quantum circuits. In the growing landscape of Quantum Computing, hardware varies significantly across providers, with differences in native gate sets, qubit connectivity, fidelity, and calibration. QGuardian Registry addresses this fragmentation by creating a machine-readable, global index of quantum devices, enabling software systems to automatically determine which hardware is compatible with a given circuit.

At its core, QGuardian Registry maintains structured hardware capability profiles for each quantum device. These profiles include key attributes such as native gate sets, qubit count, topology, coherence times, and fidelity metrics. By standardizing this information, the registry allows runtimes to evaluate compatibility instantly, eliminating the need for developers to manually compare documentation or rewrite circuits for different platforms. This is especially important when working across multiple providers such as IBM, IonQ, and Rigetti Computing, where hardware architectures can differ dramatically.

A major feature of QGuardian Registry is its ability to support native gate set matching and transpilation cost estimation. By understanding which gates a device supports natively, the registry can help runtimes select hardware that minimizes circuit transformation, reducing execution errors and improving overall fidelity. In addition, it enables hardware ranking and compatibility scoring, allowing systems to prioritize devices based on how well they match a circuit’s requirements, including performance and reliability considerations.

QGuardian Registry also supports real-time updates and dynamic hardware discovery, ensuring that changes in calibration, performance, or availability are reflected in the system. This creates a living index of quantum hardware that evolves alongside the technology itself. When integrated with QGuardian — Fidelity First, the registry becomes a critical component of a larger ecosystem, enabling circuits to be routed to the right hardware before execution and ensuring that quantum workloads are both portable and reliable across platforms.

This specification is released under the GNU Affero General Public License v3.0 or later (AGPL-3.0+) and may be used freely with required attribution under Section 7. A Specification Branding License is available for attribution-free deployments, with fees based on usage, scope, and deployment size.