Discord Translation Bot

A Discord bot that translates messages in a Discord server (guild) using country flag reactions, the /translate command, and message commands, powered by .NET and Discord.Net.

It supports the following translation providers, all of which are disabled by default, in this order of priority:

1. Azure Translator (has a free tier)
2. LibreTranslate (free and open-source)

If a provider fails to translate, the bot falls back to the next enabled provider. At least one provider must be enabled or the app will exit.

Features

Country flag reactions

React to a message with a country flag emoji to translate it to that country's language. The bot replies to the message with the translation, then deletes the reply and removes your reaction after 90 seconds. If the translation fails, the bot posts an error reply that is deleted after 15 seconds.

/translate slash command

Translate any text and post the result in the channel. The to and text options are required. If you leave out from, the source language is detected automatically.

Translate (Auto) message command

Right-click a message (or long-press on mobile), then select Apps > Translate (Auto) to translate it to the language set in your Discord settings. Only you can see the translation.

Translate To... message command

Right-click a message (or long-press on mobile), then select Apps > Translate To... and pick a language in the form that opens. Only you see the translation unless you tick Share in channel, which posts it as a reply to the original message.

Limitations

• The /translate and Translate To... commands only use the first enabled translation provider. Their language choices are limited to 25 of that provider's supported languages because of Discord's limit on the number of choices.
• Messages sent by the bot can't be translated.
• Each user can request up to 5 translations every 30 seconds. Flag reactions beyond this limit are ignored.

Requirements

Create a Discord bot

1. Go to the Discord Developer Portal and create a new application with the name you want the bot to have.
2. Go to the "Bot" page in the sidebar and click "Reset Token" to get the bot token. Save it somewhere safe, as you can't view it again. Turn off "Public Bot" if you don't want other people to add the bot to their servers.
3. On the same page, enable "Message Content Intent" under Privileged Gateway Intents.
4. Go to the "OAuth2" page in the sidebar and use the URL generator. Select the bot scope and the Send Messages, Manage Messages, and Read Message History permissions.
5. Open the generated URL in your browser to add the bot to your Discord server.

Optional: Run LibreTranslate

1. See the LibreTranslate repository for how to run it with Docker.
2. To keep the language models between restarts, mount a named volume at /home/libretranslate/.local.

Development

1. Configure the user secrets file for src/DiscordTranslationBot with the required settings. Example below:

{
  "Discord": {
    "BotToken": ""
  },
  "TranslationProviders": {
    "AzureTranslator": {
      "Enabled": true,
      "ApiUrl": "https://api.cognitive.microsofttranslator.com",
      "Region": "",
      "SecretKey": ""
    },
    "LibreTranslate": {
      "Enabled": true,
      "ApiUrl": "http://localhost:5000"
    }
  },
  "Telemetry": {
    "Enabled": true
  },
  "OTEL_EXPORTER_OTLP_ENDPOINT": "http://localhost:5434/ingest/otlp",
  "OTEL_EXPORTER_OTLP_PROTOCOL": "http/protobuf"
}

2. Make sure that you've created a Discord bot and have configured at least one translation provider using the steps above.

Deployment

1. Build a Docker image by running docker build -t discordtranslationbot -f ./src/DiscordTranslationBot/Dockerfile . from the repository root.
2. Run a container with docker run --env-file <file> discordtranslationbot, where the file sets the following environment variables:

Discord__BotToken=
TranslationProviders__AzureTranslator__Enabled=true
TranslationProviders__AzureTranslator__ApiUrl=https://api.cognitive.microsofttranslator.com
TranslationProviders__AzureTranslator__Region=
TranslationProviders__AzureTranslator__SecretKey=
TranslationProviders__LibreTranslate__Enabled=true
TranslationProviders__LibreTranslate__ApiUrl=http://libretranslate:5000

Set TranslationProviders__<ProviderName>__Enabled to true for each provider you want to enable. An enabled provider must have all of its settings configured or the app will exit with an error.

Telemetry

The app logs information, warnings, and errors, and collects metrics and traces for performance and troubleshooting. It doesn't log the contents of messages.

To export logs, metrics, and traces using the OpenTelemetry protocol, enable the following setting:

Telemetry__Enabled=true

Then configure the OpenTelemetry exporter. Example environment variables:

OTEL_EXPORTER_OTLP_ENDPOINT=
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
OTEL_EXPORTER_OTLP_HEADERS=

Refer to the OpenTelemetry documentation for other environment variables.

License

See LICENSE file in this repo.

This app has been developed by Austin S.