Adding New JSI Functionality

When adding new functionality (methods) to the JSI Runtime interface, you must modify a specific set of files across multiple layers. This skill describes each file, the patterns to follow, and important conventions.

Architecture Overview

JSI (JavaScript Interface) is an abstraction layer that allows C++ code to interact with JavaScript runtimes. The architecture consists of:

1. JSI Core (xplat/jsi/jsi/) — The abstract interface definitions
2. Hermes Implementation (xplat/static_h/API/hermes/) — Hermes-specific implementation
3. SynthTrace (xplat/static_h/API/hermes/) — Recording and replay infrastructure for debugging

Checklist of Files to Modify

JSI Core Files