facebook/astryx
Stack:
TypeScript
React
MCP
Open source React design system built over eight years inside Meta (13,000+ internal apps): 90+ components, StyleX as the styling engine, and a CLI with a JSON manifest built to be read by coding agents too.
Why it's interesting
The JSON manifest and MCP server turn the CLI into a machine-readable contract: an agent no longer has to guess component props, it reads them from one structured payload.