H3
H3 is a minimal h(ttp) framework built for high performance and portability.
👉 Online Playground
Features
✔️ Portable: Works perfectly in Serverless, Workers, and Node.js
✔️ Minimal: Small and tree-shakable
✔️ Modern: Native promise support
✔️ Extendable: Ships with a set of composable utilities but can be extended
✔️ Router: Super fast route matching using unjs/radix3
✔️ Compatible: Compatibility layer with node/connect/express middleware
Install
npm install h3
yarn add h3
pnpm add h3
Using Nightly Releases
If you are directly using h3
as a dependency:
{
"dependencies": {
"h3": "npm:h3-nightly@latest"
}
}
If you are using a framework (Nuxt or Nitro) that is using h3
:
pnpm and yarn:
{
"resolutions": {
"h3": "npm:h3-nightly@latest"
}
}
npm:
{
"overrides": {
"h3": "npm:h3-nightly@latest"
}
}
Note: Make sure to recreate lockfile and node_modules
after reinstall to avoid hoisting issues.
Usage
import { createServer } from "node:http";
import { createApp, eventHandler, toNodeListener } from "h3";
const app = createApp();
app.use(
"/",
eventHandler(() => "Hello world!"),
);
createServer(toNodeListener(app)).listen(process.env.PORT || 3000);
Example using listhen for an elegant listener:
import { createApp, eventHandler, toNodeListener } from "h3";
import { listen } from "listhen";
const app = createApp();
app.use(
"/",
eventHandler(() => "Hello world!"),
);
listen(toNodeListener(app));
Router
The app
instance created by h3
uses a middleware stack (see how it works) with the ability to match route prefix and apply matched middleware.
To opt-in using a more advanced and convenient routing system, we can create a router instance and register it to app instance.
import { createApp, eventHandler, createRouter } from "h3";
const app = createApp();
const router = createRouter()
.get(
"/",
eventHandler(() => "Hello World!"),
)
.get(
"/hello/:name",
eventHandler((event) => `Hello ${event.context.params.name}!`),
);
app.use(router);
Tip: We can register the same route more than once with different methods.
Routes are internally stored in a Radix Tree and matched using unjs/radix3.
For using nested routers, see this example
More app usage examples
app.use(
"/api",
eventHandler((event) => ({ url: event.node.req.url })),
);
app.use(
"/odd",
eventHandler(() => "Is odd!"),
{ match: (url) => url.substr(1) % 2 },
);
app.use(eventHandler(() => "<h1>Hello world!</h1>"));
app
.use(
"/1",
eventHandler(() => "<h1>Hello world!</h1>"),
)
.use(
"/2",
eventHandler(() => "<h1>Goodbye!</h1>"),
);
app.use(
"/api",
eventHandler((event) =>
proxyRequest(event, "https://example.com", {
cookieDomainRewrite: {
"example.com": "example.com",
"example.com": "somecompany.co.uk",
"*": "",
},
cookiePathRewrite: {
"/": "/api",
},
}),
),
);
app.use(
fromNodeMiddleware((req, res, next) => {
req.setHeader("x-foo", "bar");
next();
}),
);
app.use("/big", () => import("./big-handler"), { lazy: true });
Utilities
H3 has a concept of composable utilities that accept event
(from eventHandler((event) => {})
) as their first argument. This has several performance benefits over injecting them to event
or app
instances in global middleware commonly used in Node.js frameworks, such as Express. This concept means only required code is evaluated and bundled, and the rest of the utilities can be tree-shaken when not used.
👉 You can check list of exported built-in utils from JSDocs Documentation.
Body
readRawBody(event, encoding?)
readBody(event)
readValidatedBody(event, validate)
readMultipartFormData(event)
Request
getQuery(event)
getValidatedBody(event, validate)
getRouterParams(event)
getMethod(event, default?)
isMethod(event, expected, allowHead?)
assertMethod(event, expected, allowHead?)
getRequestHeaders(event, headers)
(alias: getHeaders
)getRequestHeader(event, name)
(alias: getHeader
)getRequestURL(event)
getRequestHost(event)
getRequestProtocol(event)
getRequestPath(event)
getRequestIP(event, { xForwardedFor: boolean })
Response
send(event, data, type?)
sendNoContent(event, code = 204)
setResponseStatus(event, status)
getResponseStatus(event)
getResponseStatusText(event)
getResponseHeaders(event)
getResponseHeader(event, name)
setResponseHeaders(event, headers)
(alias: setHeaders
)setResponseHeader(event, name, value)
(alias: setHeader
)appendResponseHeaders(event, headers)
(alias: appendHeaders
)appendResponseHeader(event, name, value)
(alias: appendHeader
)defaultContentType(event, type)
sendRedirect(event, location, code=302)
isStream(data)
sendStream(event, data)
writeEarlyHints(event, links, callback)
Sanitize
sanitizeStatusMessage(statusMessage)
sanitizeStatusCode(statusCode, default = 200)
Error
sendError(event, error, debug?)
createError({ statusCode, statusMessage, data? })
Route
Proxy
sendProxy(event, { target, ...options })
proxyRequest(event, { target, ...options })
fetchWithEvent(event, req, init, { fetch? }?)
getProxyRequestHeaders(event)
Cookie
parseCookies(event)
getCookie(event, name)
setCookie(event, name, value, opts?)
deleteCookie(event, name, opts?)
splitCookiesString(cookiesString)
Session
useSession(event, config = { password, maxAge?, name?, cookie?, seal?, crypto? })
getSession(event, config)
updateSession(event, config, update)
sealSession(event, config)
unsealSession(event, config, sealed)
clearSession(event, config)
Cache
handleCacheHeaders(event, opts)
Cors
handleCors(options)
(see h3-cors for more detail about options)isPreflightRequest(event)
isCorsOriginAllowed(event)
appendCorsHeaders(event, options)
(see h3-cors for more detail about options)appendCorsPreflightHeaders(event, options)
(see h3-cors for more detail about options)
You can use more H3 event utilities made by the community.
Please check their READMEs for more details.
PRs are welcome to add your packages.
- h3-typebox
validateBody(event, schema)
validateQuery(event, schema)
- h3-zod
useValidatedBody(event, schema)
useValidatedQuery(event, schema)
- h3-valibot
useValidateBody(event, schema)
useValidateParams(event, schema)
License
MIT