Discourse MCP

import type { RegisterFn } from "../types.js"; import { z } from "zod"; export const registerGetChatMessages: RegisterFn = (server, ctx) => { const schema = z.object({ channel_id: z.number().int().positive().describe("The chat channel ID"), page_size: z.number().int().min(1).max(500).optional().describe("Number of messages to return (default: 50, max: 500)"), target_message_id: z.number().int().positive().optional().describe("Message ID to query around or paginate from"), direction: z.enum(["past", "future"]).optional().describe("Pagination direction: 'past' for older messages (DESC), 'future' for newer messages (ASC)"), target_date: z.string().optional().describe("ISO 8601 date string (e.g., '2024-01-15' or '2024-01-15T10:30:00Z') to query messages around that date"), fetch_from_last_read: z.boolean().optional().describe("If true, start from the user's last read message"), include_target_message_id: z.boolean().optional().describe("Whether to include the target message in results (default: true)"), }).strict(); server.registerTool( "discourse_get_chat_messages", { title: "Get Chat Messages", description: "Get messages from a chat channel with flexible pagination and date-based filtering. Supports: (1) paginating with direction='past'/'future' from a target_message_id, (2) querying messages around a specific target_date, (3) getting messages around a target_message_id, or (4) fetching from last read position.", inputSchema: schema.shape, }, async ({ channel_id, page_size = 50, target_message_id, direction, target_date, fetch_from_last_read, include_target_message_id }, _extra: any) => { try { const { base, client } = ctx.siteState.ensureSelectedSite(); // Build query parameters const params = new URLSearchParams(); params.append("page_size", String(page_size)); if (target_message_id !== undefined) { params.append("target_message_id", String(target_message_id)); } if (direction) { params.append("direction", direction); } if (target_date) { params.append("target_date", target_date); } if (fetch_from_last_read !== undefined) { params.append("fetch_from_last_read", String(fetch_from_last_read)); } if (include_target_message_id !== undefined) { params.append("include_target_message_id", String(include_target_message_id)); } const url = `/chat/api/channels/${channel_id}/messages?${params.toString()}`; const data = (await client.get(url)) as any; const messages: any[] = data?.messages || []; const meta = data?.meta || {}; if (messages.length === 0) { return { content: [{ type: "text", text: "No messages found in this channel." }] }; } const limit = Number.isFinite(ctx.maxReadLength) ? ctx.maxReadLength : 50000; const lines: string[] = []; // Header lines.push(`# Chat Messages (Channel ${channel_id})`); lines.push(`Showing ${messages.length} messages`); if (target_date) { lines.push(`Around date: ${target_date}`); } if (meta.target_message_id) { lines.push(`Target message ID: ${meta.target_message_id}`); } lines.push(""); // Pagination info // Note: The API only sets flags for the direction you queried: // - direction='future': only can_load_more_future is meaningful // - direction='past': only can_load_more_past is meaningful // - no direction: defaults to latest messages, so can_load_more_past is meaningful const canLoadMorePast = meta.can_load_more_past ?? false; const canLoadMoreFuture = meta.can_load_more_future ?? false; const hints: string[] = []; // When querying in a specific direction, assume the opposite direction is available // unless we're at the absolute start/end of the channel if (direction === "future") { // Going forward in time (to newer messages) if (canLoadMoreFuture) { const newestId = messages[messages.length - 1]?.id; hints.push(`more messages available (use direction='future' with target_message_id=${newestId})`); } else { hints.push(`no more messages (reached end of channel)`); } // We came from somewhere, so there are likely older messages if (target_message_id) { hints.push(`to go back, use direction='past' with target_message_id=${messages[0]?.id}`); } } else if (direction === "past") { // Going backward in time (to older messages) if (canLoadMorePast) { const oldestId = messages[0]?.id; hints.push(`more messages available (use direction='past' with target_message_id=${oldestId})`); } else { hints.push(`no more messages (reached start of channel)`); } // We came from somewhere, so there are likely newer messages if (target_message_id) { hints.push(`to go forward, use direction='future' with target_message_id=${messages[messages.length - 1]?.id}`); } } else { // No direction specified = fetching latest messages if (canLoadMorePast) { const oldestId = messages[0]?.id; hints.push(`older messages available (use direction='past' with target_message_id=${oldestId})`); } else { hints.push(`no older messages (this is the entire channel history)`); } // At the latest, so no newer messages hints.push(`no newer messages (at end of channel)`); } if (hints.length > 0) { lines.push(`_Pagination: ${hints.join("; ")}_`); lines.push(""); } // Messages for (const msg of messages) { const username = msg.user?.username || "unknown"; const createdAt = msg.created_at || "unknown time"; const messageText = (msg.message || msg.cooked || "").toString().slice(0, limit); const edited = msg.edited ? " (edited)" : ""; const threadId = msg.thread_id ? ` [thread:${msg.thread_id}]` : ""; const inReplyTo = msg.in_reply_to ? ` [reply to #${msg.in_reply_to.id}]` : ""; lines.push(`## Message #${msg.id}${edited}`); lines.push(`**@${username}** at ${createdAt}${threadId}${inReplyTo}`); lines.push(""); lines.push(messageText); lines.push(""); // Reactions if (msg.reactions && msg.reactions.length > 0) { const reactionStr = msg.reactions .map((r: any) => `${r.emoji} ${r.count}`) .join(", "); lines.push(`_Reactions: ${reactionStr}_`); lines.push(""); } // Uploads/attachments if (msg.uploads && msg.uploads.length > 0) { lines.push("_Attachments:_"); for (const upload of msg.uploads) { lines.push(`- ${upload.original_filename || upload.url}`); } lines.push(""); } // Mentioned users if (msg.mentioned_users && msg.mentioned_users.length > 0) { const mentions = msg.mentioned_users.map((u: any) => `@${u.username}`).join(", "); lines.push(`_Mentions: ${mentions}_`); lines.push(""); } lines.push("---"); lines.push(""); } return { content: [{ type: "text", text: lines.join("\n") }] }; } catch (e: any) { return { content: [{ type: "text", text: `Failed to get chat messages: ${e?.message || String(e)}` }], isError: true }; } } ); };