Developer Setup

Relevant source files

The following files were used as context for generating this wiki page:

• docker-compose.prod.yml
• nodemon.json
• package.json
• tsconfig.json
• build.sh
• src/app.ts
• src/env.ts
• src/deploy.ts
• stt/src/main.rs

This document outlines the technical details of the developer setup for the Discord Live Translator bot. It covers project structure, dependencies, configuration, build processes, and execution scripts. The project is a TypeScript application that leverages Docker for containerizing its services, including the main bot, a speech-to-text (STT) service, a translation service, and a Redis database.

The development environment is designed for hot-reloading using nodemon, while the production setup is managed via docker-compose. Understanding these components is crucial for contributing to the project or self-hosting the bot.

Prerequisites

The project requires Node.js version 20 to be installed in the development environment.

Sources: package.json:8

Core Technologies

The project is built upon a modern stack for both the bot logic and its supporting services.

Technology	Role	Source Files
Node.js	Runtime for the main bot application.	package.json:8
TypeScript	Primary programming language.	tsconfig.json, package.json:47
Discord.js	Library for interacting with the Discord API.	package.json:23
Rust	Language for the high-performance STT service.	stt/Cargo.toml
Docker	Containerization for production and development services.	docker-compose.prod.yml
Redis	In-memory data store, likely for session or settings management.	docker-compose.prod.yml:28-33, package.json:26

Project Scripts

Several scripts are defined in package.json to streamline common development tasks.

Script	Description	Command
build	Compiles the TypeScript source code into JavaScript in the dist directory.	sh build.sh
deploy	Deploys the bot's slash commands globally to Discord.	ts-node src/deploy.ts
start	Runs the compiled JavaScript application from the dist directory.	node -r source-map-support/register dist/app.js
dev	Starts the application in development mode with hot-reloading using nodemon.	nodemon
format	Formats the source code using Prettier.	prettier src/** --write

Sources: package.json:10-15

Configuration

Application configuration is managed through environment variables, which are loaded via dotenv and validated using @t3-oss/env-core with zod.

Sources: src/env.ts:2-4

Environment Variables

The following server-side environment variables are defined:

Variable	Type	Required	Description
BOT_TOKEN	string	Yes	The Discord bot token.
CLIENT_ID	string	No	The Discord application client ID. Used for auto-deploying commands.
GUILD_ID	string	No	The Discord server ID for auto-deploying guild-specific commands.
LOG_PATH	string	No	Optional file path for writing logs.
POSTHOG_API_KEY	string	No	API key for PostHog analytics.
POSTHOG_HOST	string	No	Host for PostHog instance. Defaults to https://app.posthog.com.
REDIS_URL	string	No	Connection URL for the Redis instance.
STT_HOST	string	Yes	URL for the Speech-to-Text (STT) service.
TRANSLATION_HOST	string	Yes	URL for the translation service (e.g., LibreTranslate).
HEARTBEAT_URL	string	No	A URL to send a POST request to as a heartbeat/health check.

Sources: src/env.ts:11-21

Build Process

The build process is orchestrated by the build.sh script and the TypeScript compiler (tsc).

This diagram illustrates the steps executed by the pnpm run build command.

TypeScript Configuration

The tsconfig.json file configures the TypeScript compiler to:

• Inherit base settings from @tsconfig/node20/tsconfig.json.
• Place compiled JavaScript files into the ./dist directory.
• Generate source maps for easier debugging.

{
  "extends": "@tsconfig/node20/tsconfig.json",
  "compilerOptions": {
    "outDir": "./dist",
    "sourceMap": true
  }
}

Sources: tsconfig.json:1-6

Running in Development

For development, the project uses nodemon to monitor file changes and automatically restart the application.

The dev script uses nodemon, which is configured by nodemon.json to watch for changes in .ts, .js, and .json files and execute ts-node src/app.ts on any change.

{
  "ext": "js,ts,json",
  "exec": "ts-node src/app.ts"
}

Sources: nodemon.json:1-4, package.json:14

This sequence diagram shows the hot-reloading process.

Docker Architecture (Production)

The production environment is defined in docker-compose.prod.yml and consists of four main services.

This diagram shows the interaction between the containerized services.

Service Details

• bot: The main Discord bot application. It depends on all other services to function.
  • Image: ghcr.io/wotschofsky/discord-live-translator
  • Connects to stt, libretranslate, and redis using internal Docker networking.
• stt: The Rust-based Speech-to-Text service.
  • Image: ghcr.io/wotschofsky/discord-live-translator/stt
  • Exposes an HTTP server on port 8000 to process audio files.
• libretranslate: An open-source machine translation service.
  • Image: libretranslate/libretranslate:v1.3.11
  • The environment is configured to load only specific languages (de,en,es,fr,it) to conserve resources.
• redis: A Redis server for data persistence.
  • Image: redis:alpine
  • Uses a Docker volume named redis to persist data across container restarts.

Sources: docker-compose.prod.yml

Slash Command Deployment

Slash commands are registered with Discord's API using scripts. There are two methods for deployment:

1. Global Deployment: The pnpm run deploy script executes src/deploy.ts, which registers all commands globally for any server the bot is in. This is suitable for production bots.
   Sources: package.json:12, src/deploy.ts:6, src/interactions.ts:31-43

2. Guild-Specific Deployment: If CLIENT_ID and GUILD_ID environment variables are set, the application will automatically register/update the commands for that specific guild on startup. This is ideal for development and testing as updates are nearly instantaneous.
   Sources: src/app.ts:50-56, src/interactions.ts:19-29