Lets you call C and C++ libraries directly from Bun using the bun:ffi module. You get dlopen for loading shared libraries, FFI type definitions for mapping JavaScript to native types, and helpers for working with pointers and strings. The skill covers function definitions, struct handling, callbacks, and memory management. Most useful when you need to integrate existing native libraries without writing Node.js addons or when performance matters enough to justify the pointer juggling. The SQLite example is solid if you want to see a real use case. Just remember FFI calls are synchronous and block the main thread, so move heavy work to Web Workers.
npx skills add https://github.com/secondsky/claude-skills --skill bun-ffi