API Reference

This page lists all public exports from Fresh’s entry points.

Info
You can also explore Fresh’s full API documentation on JSR: @fresh/core

`fresh`

The main entry point for server-side code.

import { App, createDefine, HttpError, page, staticFiles } from "fresh";

Export	Kind	Description
`App`	Class	The main application class. See App.
`staticFiles`	Function	Middleware for serving static files. See Static Files.
`createDefine`	Function	Create type-safe `define.*` helpers. See Define Helpers.
`page`	Function	Return data from a handler to a page component. See Data Fetching.
`HttpError`	Class	Throw HTTP errors with status codes. See Error Handling.
`cors`	Function	CORS middleware. See cors.
`csrf`	Function	CSRF protection middleware. See csrf.
`csp`	Function	Content Security Policy middleware. See csp.
`trailingSlashes`	Function	Trailing slash enforcement middleware. See trailingSlashes.

Types:

Export	Kind	Description
`Context` / `FreshContext`	Interface	The request context passed to all middlewares and handlers.
`PageProps`	Type	Props received by page components (`data`, `url`, `params`, `state`, etc.).
`Middleware` / `MiddlewareFn`	Type	Middleware function type.
`HandlerFn`	Type	Single handler function type.
`HandlerByMethod`	Type	Object with per-method handler functions.
`RouteHandler`	Type	Union of `HandlerFn` and `HandlerByMethod`.
`PageResponse`	Type	Return type of `page()`.
`RouteConfig`	Interface	Route configuration (`routeOverride`, `skipInheritedLayouts`, etc.).
`LayoutConfig`	Interface	Layout configuration (`skipInheritedLayouts`, `skipAppWrapper`).
`Define`	Interface	Type of the object returned by `createDefine()`.
`FreshConfig` / `ResolvedFreshConfig`	Interface	App configuration types.
`ListenOptions`	Interface	Options for `app.listen()`.
`Island`	Type	Island component type.
`Method`	Type	HTTP method union type.
`RouteData`	Type	Data type returned by route handlers via `page()`.
`Lazy` / `MaybeLazy`	Type	Utility types for lazily-loaded routes and middleware.
`CORSOptions`	Interface	Options for `cors()`.
`CsrfOptions`	Interface	Options for `csrf()`.
`CSPOptions`	Interface	Options for `csp()`.

Shared runtime utilities for both server and client code. Safe to import in islands.

import {
  asset,
  assetSrcSet,
  Head,
  HttpError,
  IS_BROWSER,
  Partial,
} from "fresh/runtime";

Export	Kind	Description
`IS_BROWSER`	Constant	`true` in the browser, `false` on the server. Use to guard browser-only code.
`asset`	Function	Add cache-busting query params to asset URLs. See Static Files.
`assetSrcSet`	Function	Apply `asset()` to all URLs in a `srcset` string.
`Partial`	Component	Mark a region for partial updates. See Partials.
`Head`	Component	Add elements to the document `<head>`. See element.
`HttpError`	Class	HTTP error class (re-exported from `fresh`).

Development and build tools. Only used in dev.ts (legacy) or build scripts.

import { Builder } from "fresh/dev";

Export	Kind	Description
`Builder`	Class	Pre-Vite build system (legacy). See Builder.

Types:

Export	Kind	Description
`BuildOptions`	Interface	Options for `new Builder()`.
`ResolvedBuildConfig`	Interface	Resolved build configuration.
`OnTransformArgs` / `OnTransformOptions` / `TransformFn`	Type	Build plugin hook types.