Discord bot implementation using discord.js v14 with slash commands and message content access.

Bot Configuration

Required intents:

• GatewayIntentBits.Guilds – Guild information access
• GatewayIntentBits.GuildMessages – Message history access
• GatewayIntentBits.MessageContent – Message content and attachments

Message content intent:
Required for image URL extraction from Discord messages. Without this intent, bot cannot access attachment URLs or embed content.

Command Registration

Registration scope:
Guild-specific registration via REST API.

Registration endpoint:
Routes.applicationGuildCommands(clientId, guildId)

Registered commands:

• /pin – Search for and pin images to Pinterest
• /prompt – Generate Midjourney prompts
• /sync – Sync Pinterest boards
• /auth – Authenticate with Pinterest
• /settings – Manage Pinterest accounts
• /restart – Restart bot process
• /editprompt – Edit system prompt sections
• /model – Configure OpenAI model

Registration timing:
Commands registered on ClientReady event after bot connects.

Command structure:
Each command exports:

• data – SlashCommandBuilder instance
• execute – Async function handling interaction

Interaction Handling

Interaction types supported:

• Chat input commands (slash commands)
• String select menus (dropdowns)
• Modal submits (text input forms)

Interaction routing:
Main interaction handler in src/index.js routes interactions to command modules based on:

• Command name for slash commands
• Custom ID for select menus and modals

Deferred replies:
All commands use interaction.deferReply() for operations exceeding 3 seconds:

• Pinterest API calls
• OpenAI API calls
• Board synchronization
• Message history searches

Ephemeral messages:
Used for:

• /auth – Authorization URLs (privacy)
• /settings – Account management (privacy)
• /model – Configuration (reduces channel clutter)
• /editprompt – Admin operations (security)
• /restart – Admin operations (security)

Message Fetching

Fetch methods:

• channel.messages.fetch(messageId) – Single message by ID
• channel.messages.fetch({ limit: N }) – Recent messages
• channel.messages.fetch({ before: id, limit: N }) – Paginated backward
• channel.messages.fetch({ after: id, limit: N }) – Paginated forward

Pagination limits:

• Maximum 100 messages per fetch
• Rate limited to prevent API throttling (100ms delay between batches)
• /pin searches up to 1000 messages maximum

Message content access:

• message.content – Text content
• message.attachments – Attachment collection
• message.embeds – Embed array
• message.interaction – Command interaction metadata

Image detection:
Bot checks multiple sources:

1. Direct attachments: message.attachments.first().url
2. Embed images: message.embeds[0].image.url
3. Embed thumbnails: message.embeds[0].thumbnail.url

Error Handling

Global error handlers:

• unhandledRejection – Logs and continues
• uncaughtException – Logs and exits with code 1
• SIGTERM – Graceful shutdown with client.destroy()
• SIGINT – Graceful shutdown with client.destroy()

Command error handling:
Centralized in interaction event handler:

1. Try command execution
2. Catch errors
3. Respond with generic error message
4. Multiple response strategies:
   • Not replied/deferred: Use reply() with ephemeral flag
   • Deferred: Use editReply()
   • Already replied: Use followUp() with ephemeral flag

Component interaction timeouts:
Select menus and modals timeout after 60 seconds:

• /settings account selection
• /model model selection
• No timeout for /editprompt modal

Permission Checks

Permission system:
Commands verify Discord permissions before execution.

Permission levels:

• Manage Server (ManageGuild): /model, /sync
• Administrator (Administrator): /editprompt, /restart

Permission check implementation:

interaction.member.permissions.has(PermissionsBitField.Flags.PermissionName)

Permission denied responses:
Ephemeral messages indicating insufficient permissions.

Login and Reconnection

Login retry logic:

• Maximum 3 retry attempts
• Exponential backoff: 2^retry * 1000ms
• Exit with code 1 if all retries fail

Connection events:

• ClientReady – Initial connection established
• Error – Client error occurred
• Disconnect – Client disconnected
• Reconnecting – Reconnection attempt in progress
• Resume – Connection resumed after disconnect

Restart handling:
Bot reads data/restart_info.json on startup:

• Fetches original restart message
• Updates to "Restart successful."
• Deletes restart info file
• Logs success or errors

Environment Configuration

Required environment variables:

• MJPIN_DISCORD_TOKEN – Bot authentication token
• MJPIN_DISCORD_CLIENT_ID – Application client ID
• MJPIN_DISCORD_GUILD_ID – Target guild for command registration

Token security:
Token logged as ‘[HIDDEN]’ in console output.