Specification-First, Agent-Driven Development of a Quantum Simulation SDK: The AGENTS.md Methodology Behind @hviana/js-quantum

js-quantum is a complete, self-contained quantum computing SDK written in TypeScript. It enables developers and researchers to build, simulate, transpile, and serialize quantum circuits using a clean, declarative API, without relying on native extensions, WebAssembly, or external linear algebra libraries. At its core, the library provides a real state-vector simulator implemented from scratch, including complex arithmetic, matrix operations, gate composition, and Born-rule measurement sampling. This makes it suitable both for educational use and for rigorous experimentation with quantum circuit behavior in a fully portable JavaScript/TypeScript environment. The SDK also includes an OpenQASM 3.1 transpiler and cloud backend adapters for IBM Quantum and qBraid, allowing the same circuit-building workflow to be used for both local simulation and external quantum execution pipelines. In addition, js-quantum provides an experimental high-level API for quantum algorithm development, making it possible to express higher-level quantum programming workflows beyond low-level gate-by-gate circuit construction. This experimental layer is designed to support the development, organization, and testing of quantum algorithms in a more expressive and scalable way. Key features Pure TypeScript implementation based only on Web Standards Real state-vector quantum simulation Circuit construction through a fluent, declarative API Experimental high-level API for quantum algorithm development OpenQASM 3.1 transpilation and serialization support Cloud backend adapters for IBM Quantum and qBraid No native dependencies No WebAssembly No external math or linear algebra libraries Cross-runtime compatibility with Deno, Node.js, Bun, Browsers, and Cloudflare Workers Typical use cases Quantum computing education and demonstrations Quantum algorithm prototyping and experimentation Browser-based quantum tools and interactive simulators Portable TypeScript/JavaScript quantum software development OpenQASM-based circuit generation and interoperability workflows License This project is distributed under the MIT License.