Quantum4J — deterministic quantum SDK (OpenQASM + JVM)

Quantum4J is a minimal, deterministic quantum SDK designed for real-world software engineering. JVM-native, OpenQASM-aligned, and architected for enterprise deployment and quantum workload orchestration. A minimal surface that keeps engineers focused on circuits, backends, and integrations instead of boilerplate. Reproducible statevectors and counts for CI pipelines and contract tests. Import/export circuits through QasmImporter and QasmExporter for toolchain interoperability. Composable pass pipeline for optimization, device routing, and observability-friendly ASCII renders. Beans, registries, and REST patterns that drop into microservices without extra glue. Quantum4J brings deterministic simulation, strict QASM IO, and Spring-ready services with a clean layered design. All examples live in com.quantum4j.examples and in the GitHub examples folder. Copy, run, and adapt for CI/CD. Entangle two qubits, export to QASM, and sample counts. Run the end-to-end teleportation example from com.quantum4j.examples.teleportation. Expose circuits through REST for CI/CD smoke tests. Installation, quick start, QASM import/export, backends (Statevector + IonQ), Spring Boot integration, and transpiler pipeline—plus links to Javadoc and GitHub examples. Add com.quantum4j:quantum4j:1.3.2 via Maven or Gradle. Java 17+. Configure PassManager to optimize, schedule, and map circuits before execution. Switch RunOptions backend to IonQ when credentials/connectors are configured. Use QasmExporter/QasmImporter for strict OpenQASM interop. Wrap QuantumCircuit execution behind REST endpoints for CI-friendly services. All runnable samples live in com.quantum4j.examples and the GitHub examples folder. Depth in simulation, interoperable hardware connectors, and operational tooling for real delivery pipelines. Quantum4J focuses on production reliability: deterministic simulation today, hardware connectors and orchestration tomorrow. Deterministic by default so tests and CI stay stable. Strict OpenQASM interop to plug into broader tooling. Service-friendly patterns for Spring and JVM stacks. Hardware-ready abstraction to onboard connectors as they arrive. Pull Quantum4J from Maven Central, wire it into your services, and reference the generated JavaDocs hosted online.