Handbook

The contract lives in the repo root: AGENTS.md is the single source, and estate.yml is the registry of record. This page is the tour.

The four compounding rules

1. Everything arrives by script. bun run scripts/new-kit.ts name area scaffolds a package with SPEC, tests, tsconfig, and a registry entry. Nothing depends on remembering steps.
2. Wire truth is written once. Fixtures in conformance/ are consumed by Bun tests and Rust cargo test alike; both languages must pass the same file. Where a kit mirrors a Rust crate (mirrors: in estate.yml), the wire shapes are named after the Rust side.
3. Status is earned. core means a consumer app pins the package at an exact version; scripts/estate-audit.ts fails a package that claims core without the pin. Drifting pins fail the same audit.
4. wasm is optional behind a twin. Rust never touches the DOM; Solid owns rendering. Every wasm crate implements the ABI of a TS reference implementation and passes the same fixtures, so shipping without the wasm binary is always safe.

The verbs

build test lint fmt fmt-check coverage contract ci: Makefile aliases of package.json scripts. CI runs make ci and nothing else; there are no CI-only steps.

Stack

Layer	Choice	Why
Runtime/tooling	Bun	workspaces, test runner, scripts
UI runtime	SolidJS	signals-first, islands-friendly
App framework	Astro	prerendered entity pages, islands only where interactive
Docs	Starlight	estate handbook and kit reference
Pure logic	Rust to wasm	money math, search, CRDTs; never the DOM