Plugin#

A plugin is a way to decouple logic into smaller parts, defining reusable components across the server.

Defining a plugin is as simple as defining a new Elysia instance:

import { Elysia } from "elysia";

const plugin = new Elysia().state("plugin-version", 1).get("/from-plugin", () => "Hi");

const app = new Elysia()
  .use(plugin)
  .get("/version", ({ store }) => store["plugin-version"])
  .listen(8080);

Plugins can be registered by using use method.

Registering a plugin will combine types between the plugin and current instance, and the scope of hooks and schema get merged as well.

Separate file#

Using the plugin pattern, you can define and decouple your logic into a separate file.

// plugin.ts
export const plugin = new Elysia().get("/from-plugin", () => "Hi");

// main.ts
import { plugin } from "./plugin";

const app = new Elysia().use(plugin).listen(8080);

Functional callback#

You can also define a function callback to inline the plugin.

// plugin.ts
export const plugin = (app: Elysia) => app.get("/from-plugin", () => "Hi");

// main.ts
import { plugin } from "./plugin";

const app = new Elysia().use(plugin).listen(8080);

Functional callback will allow a user to access main instance values like routes, schema, store, etc.

Config#

You can customize a plugin by creating a function to return callback which accepts Elysia.

import { Elysia } from "elysia";

const plugin = <const Prefix>({ prefix = "/v1" }: { prefix: Prefix }) => new Elysia({ prefix }).get(`/hi`, () => "Hi");

const app = new Elysia()
  .use(
    plugin({
      prefix: "/v2",
    })
  )
  .listen(8080);

Config type will be inferred into use, generating auto completion and type strict as intend.

Plugin deduplication#

By default, Elysia will register any plugin and handle type definitions which when using multiple times will results in a multiple duplication of setting value or routes.

This can be fixed by providing name and optional seeds to help Elysia identify instance duplication:

import { Elysia } from "elysia";

const plugin = config =>
  new Elysia({
    name: "my-plugin",
    seed: config,
  }).get(`${config.prefix}/hi`, () => "Hi");

const app = new Elysia()
  .use(
    plugin({
      prefix: "/v2",
    })
  )
  .listen(8080);

Official plugins#

You can find pre-built plugins for Elysia at plugins.