npm install chene
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At a high level chêne is built on the same concept of middleware chain as express with two big differences.

1. The next function takes an input and returns an output. The input and output are typed. Which means middleware can enrich or transform both the input and outputs of route handler in a fully typed fashion.
2. Middleware can be chained at the route level and not just the app level.

Given the heavy focus on proper types, chêne integrates with zod to ensure data coming in has the expected type. Proper validation should be the default, not something that needs to be manually added on top of user logic.

import { body, response, router, z } from "chene"
import { serve } from "chene/node"

const signupData = z.object({
  email: z.string().email(),
  password: z.string().min(8),
})

const app = router()
app.post(
  "/signup",
  // the json body middleware is registered at the route level and uses a Zod schema for validation
  (ctx) => ctx.use(body.json(signupData)),
  // the json body middleware enriches the route handler input with the parsed and validated body
  async ({ body }) => {
    // ...
    return response.json({ success: true })
  },
)

serve(app, { port: 8080 })
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Zod validation is also available for form data with body.form and form URL query parameters with url.query.

The router also internally uses middleware chains to enrich route handler input with route parameters.

app.get("/hello/:name", ({ path }) => response.text(`Hello ${path.name} !`))
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The handler input also always includes a request key containing a standard Request object and the output is expected to be a standard Response object.

CommonJS is not supported, only ESM. This needs to be reflected in you package.json by setting the type field to module.

{
  // ...
  "type": "module",
}
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When using TypeScript, the module and moduleResolution compiler options should be set to node16 to respect said field.

{
  // ...
  "compilerOptions": {
    // ...
    "module": "node16",
    "moduleResolution": "node16",
  },
}
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Lastly, there's builtin JSX support, just set the right compiler options in your tsconfig.json.

{
  // ...
  "compilerOptions": {
    // ...
    "jsx": "react-jsx",
    "jsxImportSource": "chene",
  },
}
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With those settings set it's possible to pass JSX nodes to the response.html function !

app.get("/hello/:name", ({ path }) =>
  response.html(<p className="hello">Hello {path.name} !</p>),
)
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And that's pretty much all you need to know to get started !