nodejs-core

Node.js Core is a deep-internals expertise skill for contributing to and debugging Node.js core itself. It solves the problem that working in nodejs/node requires knowledge spanning C++ addons, the V8 engine, libuv, the build system, and the project's contribution conventions - knowledge that is scattered and hard to apply consistently. The skill packages this into a SKILL.md index plus a large set of focused rule files that the assistant reads on demand.

Its rule library covers V8 (garbage collection, hidden classes and inline caching, TurboFan JIT and deopt patterns), libuv (event-loop phases, thread pool and UV_THREADPOOL_SIZE, async I/O), native addons (N-API/node-addon-api, native memory and leak prevention), core-module internals (streams, net, fs, crypto, child_process, worker threads), and JavaScript internals like primordials for preventing prototype pollution in lib/internal. It also documents the build-and-test cycle, mandatory pre-commit lint and core-validate-commit gate, ./configure flags for debug/ASan/Ninja builds, commit-message and PR-description style with DCO sign-off, PR reviewing, documentation editing, and native debugging and profiling with gdb/lldb, --prof, --trace-opt/--trace-deopt, and heap snapshots.

It targets Node.js core contributors, native-addon authors, and engineers diagnosing native crashes, segfaults, memory leaks, V8 deoptimizations, node-gyp/binding.gyp build failures, and event-loop issues. Typical use cases include drafting or reviewing a nodejs/node commit or PR, understanding core architecture, and debugging or optimizing at the engine level. The code shown in rule files (for example child_process spawn/fork/IPC and file-descriptor passing) is illustrative internals documentation for education, not an executable tool.