feat: Discord Integration

[research-developer]

Overview

Add Discord bot integration for notifications and slash commands.

Interaction Webhooks ✅

Discord uses HTTP interactions (not WebSocket required):

Interaction Types

• 1 - PING (verification)
• 2 - APPLICATION_COMMAND (slash commands)
• 3 - MESSAGE_COMPONENT (buttons, selects)
• 4 - APPLICATION_COMMAND_AUTOCOMPLETE
• 5 - MODAL_SUBMIT

Identification

• Header: X-Signature-Ed25519 (Ed25519 signature)
• Header: X-Signature-Timestamp
• Payload: Contains type, application_id, guild_id

Signature Verification (Ed25519)

from nacl.signing import VerifyKey
verify_key = VerifyKey(bytes.fromhex(public_key))
message = timestamp.encode() + body
verify_key.verify(message, bytes.fromhex(signature))

Interaction Payload

{
  "type": 2,
  "id": "interaction_id",
  "application_id": "app_id",
  "guild_id": "server_id",
  "channel_id": "channel_id",
  "member": {
    "user": { "id": "user_id", "username": "user" }
  },
  "data": {
    "name": "review",
    "options": [{ "name": "url", "value": "https://..." }]
  }
}

Tasks

• Add Discord interaction handler
• Implement slash commands (/review, /describe, /ask)
• Ed25519 signature verification
• Send PR notifications to Discord channels
• Embed-rich PR summaries
• Button interactions for quick actions

Use Cases

1. Notifications: Alert channel when PR opens/updates
2. Commands: /review <pr_url> from Discord
3. Rich Embeds: Formatted PR summaries with status
4. Buttons: Approve/request changes via buttons