MoonBit C Binding Guide

Step-by-step workflow for binding any C library to MoonBit using native FFI.

When To Use

Use this skill when:

• Adding extern "c" fn declarations for a C library
• Writing C stub files (moonbit.h, MOONBIT_FFI_EXPORT)
• Configuring moon.pkg for native builds (native-stub, link.native)
• Choosing #borrow vs ownership transfer for FFI parameters
• Wrapping C handles with external objects and finalizers
• Implementing callback trampolines (closures or FuncRef)
• Converting strings between MoonBit (UTF-16) and C (UTF-8)
• Running AddressSanitizer to catch memory bugs in bindings

Plan Mode Instructions