Waku

A minimal React Server Components app powered by Waku (by Daishi Kato). The template ships both halves of the RSC boundary in ReScript: a Server Component (Greet.res, no JS shipped) and a Client Component (Counter.res, made client-side via a thin TSX "use client" wrapper).

Generated layout

src/
├── pages/
│   └── index.tsx
├── components/
│   ├── Greet.res
│   ├── Counter.res
│   └── CounterClient.tsx
└── __tests__/
    └── Greet.test.mjs
tsconfig.json
rescript.json
package.json

Key files

• src/pages/index.tsx — Server Component (Waku’s default for src/pages/). Imports the ReScript Greet directly and the CounterClient Client wrapper.

• src/components/Greet.res — Server Component body. Renders to HTML on the server; ships zero JS for itself.

• src/components/Counter.res — Client Component body, written in ReScript with useState.

• src/components/CounterClient.tsx — Thin TSX wrapper that owns the "use client" directive and re-exports the ReScript make function. ReScript cannot emit "use client" itself, so this small file is the canonical workaround.

npm scripts

Command	Description
dev	Start waku dev with rescript -w.
build	Compile ReScript and run waku build.
start	Run the production server.
test	Run Vitest.

Day-two pointers

• Add Server Components — drop another .res file under src/components/ and import it from any page or other Server Component. No client wrapper required.

• Add Client Components — write the body in ReScript, then add a <Name>Client.tsx wrapper that begins with "use client" and re-exports make. Keep the wrapper as small as possible.

• Server Functions — when stable in your version of Waku, expose any function from a server file and call it from a Client Component; Waku rewires the call into an RPC at build time.