elysia-line

Official LINE Messaging API webhook plugin for Elysia — clean, typed, zero-config.

This plugin for ElysiaJS simplifies the process of creating LINE bots by providing a clean, typed, and zero-config integration with the official LINE bot SDK.

Features

• Zero-config: Just provide your channel secret and access token.
• Type-safe: Fully typed event handling for all webhook events.
• Easy to use: A simple and intuitive API for handling events and sending messages.
• Official SDK: Built on top of the official @line/bot-sdk.

Installation

bun add elysia-line

Usage

import { Elysia } from "elysia";
import { line } from "elysia-line";

const app = new Elysia()
  .use(
    line({
      channelSecret: process.env.LINE_CHANNEL_SECRET!,
      channelAccessToken: process.env.LINE_CHANNEL_ACCESS_TOKEN!,
    })
  )
  .post("/webhook", async ({ line, set }) => {
    if (!line) {
      return "Not a LINE webhook";
    }

    line.on("message:text", (event) => {
      line.reply(event.replyToken, {
        type: "text",
        text: `You said: ${event.message.text}`,
      });
    });

    await line.handle();
    return "OK";
  })

  .listen(3000);

console.log(`Elysia is running at http://localhost:3000`);

API

line(options: LineOptions)

The main plugin function.

• options.channelSecret: Your LINE channel secret.
• options.channelAccessToken: Your LINE channel access token.
• options.verbose (optional): Set to true to enable detailed, colorful logging for debugging. Defaults to false.

line.on(eventType, handler)

Registers an event handler for a specific event type. The event object in the handler is fully typed based on the eventType.

Supported event types:

• message:text
• message:image
• message:video
• message:audio
• message:file
• message:location
• message:sticker
• follow
• unfollow
• join
• leave
• postback
• beacon
• * (wildcard for all events)

line.reply(replyToken, messages)

Replies to a message.

line.push(to, messages)

Pushes a message to a user, group, or room.

line.getEvents()

Returns the raw webhook events.

line.getClient()

Returns the underlying MessagingApiClient from the @line/bot-sdk for advanced usage.

Exports

This package exports the following main components:

• line: The main Elysia plugin.
• LineHelper: The helper class for handling events and sending messages. You can access it via context.line.
• LineLogger: The internal logger class.
• All relevant types from the @line/bot-sdk, such as WebhookEvent, MessageEvent, etc.

Project Structure

The project is organized into the following directories:

• src/: The main source code directory.
  • core/: Contains the core logic, like the LineHelper class.
  • logger/: Contains the LineLogger class for logging.
  • plugin/: Contains the main Elysia plugin logic.
  • types/: Contains all type definitions for the plugin.
  • index.ts: The main entry point, which exports all public APIs.
• dist/: The compiled JavaScript output.
• test/: Example and test applications.

Development

This project uses Bun for package management and running scripts.

To install dependencies:

bun install

To build the project (compiles TypeScript from src/ to JavaScript in dist/):

bun run build

To run the example application located in test/app.ts:

bun run test/app.ts