openclaw - 💡(How to fix) Fix [Feature] Discord: fetch a single message by channelId + messageId (or URL) [1 pull requests]

Summary

Add an action: "fetch" (or get) to the Discord message tool that retrieves one specific message by channelId + messageId, or by parsing a Discord message URL (https://discord.com/channels/{guildId}/{channelId}/{messageId}).

Motivation

Today the agent can only:

• read — list recent N messages from a channel
• search — keyword search across a guild

There is no way to fetch a specific message by ID. This is a frequent need:

• A user pastes a Discord message link in chat ("見て、これ") — the agent currently has to reply "リンク踏んでも中身見えない、コピペして" which is bad UX.
• Cross-thread / cross-channel referencing (quoting a decision from another channel).
• Following up on a reply_to_id that is older than the agent's read window.

Related: #59895 added read for session-boot history, but doesn't cover pinpoint fetch. #17207 covers the inbound side (exposing the triggering messageId).

Proposed API

{
  "action": "fetch",
  "channel": "discord",
  "channelId": "1503919293882957906",
  "messageId": "1503919454814208141"
}

Or by URL (convenience):

{
  "action": "fetch",
  "channel": "discord",
  "url": "https://discord.com/channels/1285.../1503.../1503..."
}

Returns the message object (content, author, attachments, embeds, timestamp, reference, etc.).

Validated with curl

The underlying Discord REST endpoint works fine with the existing bot token + Read Message History perm:

GET https://discord.com/api/v10/channels/{channelId}/messages/{messageId}
Authorization: Bot <token>

Returns full message payload. So this is purely a tool-surface gap, not a permissions/protocol problem.

Constraints / Notes

• Honor existing channels.discord.actions.* gating.
• Bot must be in the guild and have read access to the channel.
• DMs: only the bot's own DMs are fetchable (same as Discord API behavior — document, don't block).
• Should probably reuse the same return shape as read so consumers don't fork code paths.

Out of scope

• Bulk fetch by ID list (could be a follow-up).
• Cross-guild fetch where bot is not a member (impossible at the API layer).