list_channels
Retrieve a list of Slack channels that the bot can access, with an optional limit on the number of channels returned.
Instructions
List available Slack channels the bot has access to
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Maximum number of channels to list (default: 50) |
Implementation Reference
- index.js:437-461 (handler)Handler function that executes the 'list_channels' tool logic. Calls slack.conversations.list() with a limit (default 50, max 200), maps results to {id, name, is_private, is_member, topic}, and returns JSON-formatted channels.
case "list_channels": { const limit = Math.min(args?.limit || 50, 200); const result = await slack.conversations.list({ types: "public_channel,private_channel", limit: limit, }); const channels = (result.channels || []).map((ch) => ({ id: ch.id, name: ch.name, is_private: ch.is_private, is_member: ch.is_member, topic: ch.topic?.value?.substring(0, 100), })); return { content: [ { type: "text", text: JSON.stringify({ channels }, null, 2), }, ], }; } - index.js:124-138 (schema)Schema/definition for the 'list_channels' tool. Includes optional 'limit' parameter (number, default 50) in the inputSchema.
{ name: "list_channels", description: "List available Slack channels the bot has access to", inputSchema: { type: "object", properties: { limit: { type: "number", description: "Maximum number of channels to list (default: 50)", default: 50, }, }, required: [], }, }, - index.js:46-141 (registration)Tool registration via server.setRequestHandler(ListToolsRequestSchema). The 'list_channels' tool is registered alongside other tools (check_build_status, get_channel_messages, search_messages, send_message).
server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: [ { name: "check_build_status", description: "Get the latest Xcode Cloud build status from Slack notifications. Returns recent build messages including status, workflow name, duration, and timestamp.", inputSchema: { type: "object", properties: { limit: { type: "number", description: "Number of recent build messages to retrieve (default: 5, max: 20)", default: 5, }, workflow: { type: "string", description: "Filter by workflow name (e.g., 'Cuti-E-Admin', 'Nutri-E'). Case-insensitive partial match.", }, }, required: [], }, }, { name: "get_channel_messages", description: "Read recent messages from a specific Slack channel", inputSchema: { type: "object", properties: { channel_id: { type: "string", description: "Slack channel ID (e.g., C01234567). If not provided, uses the build channel.", }, limit: { type: "number", description: "Number of messages to retrieve (default: 10, max: 100)", default: 10, }, }, required: [], }, }, { name: "search_messages", description: "Search for messages in Slack containing specific text", inputSchema: { type: "object", properties: { query: { type: "string", description: "Search query (e.g., 'build failed', 'Cuti-E-Admin')", }, limit: { type: "number", description: "Maximum number of results (default: 10)", default: 10, }, }, required: ["query"], }, }, { name: "send_message", description: "Send a message to a Slack channel", inputSchema: { type: "object", properties: { channel_id: { type: "string", description: "Slack channel ID. If not provided, uses the build channel.", }, text: { type: "string", description: "Message text to send", }, }, required: ["text"], }, }, { name: "list_channels", description: "List available Slack channels the bot has access to", inputSchema: { type: "object", properties: { limit: { type: "number", description: "Maximum number of channels to list (default: 50)", default: 50, }, }, required: [], }, }, ], }; }); - index.js:143-485 (registration)Handler registration via server.setRequestHandler(CallToolRequestSchema). The switch-case on line 148 dispatches to the 'list_channels' case on line 437.
// Handle tool calls server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: args } = request.params; try { switch (name) { case "check_build_status": { if (!buildChannelId) { return { content: [ { type: "text", text: "Error: SLACK_BUILD_CHANNEL_ID not configured. Please set it in your MCP config.", }, ], }; } const workflowFilter = args?.workflow?.toLowerCase(); // Fetch more messages if filtering, to ensure we get enough matches const fetchLimit = workflowFilter ? Math.min((args?.limit || 5) * 4, 100) : Math.min(args?.limit || 5, 20); const result = await slack.conversations.history({ channel: buildChannelId, limit: fetchLimit, }); if (!result.messages || result.messages.length === 0) { return { content: [ { type: "text", text: "No build messages found in the channel.", }, ], }; } // Helper function to extract duration from text const extractDuration = (text, attachments) => { // Common patterns for duration in Xcode Cloud messages const patterns = [ /duration[:\s]+(\d+)\s*(?:min(?:ute)?s?)?(?:\s*(\d+)\s*(?:sec(?:ond)?s?)?)?/i, /took\s+(\d+)\s*(?:min(?:ute)?s?)?(?:\s*(\d+)\s*(?:sec(?:ond)?s?)?)?/i, /completed\s+in\s+(\d+)\s*(?:min(?:ute)?s?)?(?:\s*(\d+)\s*(?:sec(?:ond)?s?)?)?/i, /(\d+)\s*(?:min(?:ute)?s?)\s*(?:(\d+)\s*(?:sec(?:ond)?s?)?)?/i, /(\d+):(\d+)\s*(?:min)?/i, // MM:SS format ]; const allText = text + ' ' + (attachments?.map(a => `${a.title || ''} ${a.text || ''}`).join(' ') || ''); for (const pattern of patterns) { const match = allText.match(pattern); if (match) { const mins = parseInt(match[1]) || 0; const secs = parseInt(match[2]) || 0; const totalSeconds = mins * 60 + secs; return { minutes: mins, seconds: secs, totalSeconds, formatted: mins > 0 ? `${mins}m ${secs}s` : `${secs}s`, }; } } return null; }; // Helper function to extract workflow name const extractWorkflow = (text, attachments) => { // Look for workflow name in text or attachments const allText = text + ' ' + (attachments?.map(a => `${a.title || ''} ${a.text || ''}`).join(' ') || ''); // Common patterns: "Workflow: Name", title of attachment often contains workflow const patterns = [ /workflow[:\s]+([^\n\r,]+)/i, /^([A-Z][a-zA-Z0-9-]+(?:\s+[A-Z][a-zA-Z0-9-]+)*)\s+(?:build|workflow)/i, ]; for (const pattern of patterns) { const match = allText.match(pattern); if (match) { return match[1].trim(); } } // Check attachment titles - often contains workflow name if (attachments && attachments.length > 0) { const title = attachments[0].title; if (title && title.length > 0 && title.length < 50) { return title; } } return null; }; // Parse build messages - Xcode Cloud messages have specific format let buildMessages = result.messages.map((msg) => { const timestamp = new Date(parseFloat(msg.ts) * 1000).toISOString(); // Try to extract build status from message let status = "unknown"; const text = msg.text || ""; if (text.toLowerCase().includes("succeeded") || text.toLowerCase().includes("success")) { status = "succeeded"; } else if (text.toLowerCase().includes("failed") || text.toLowerCase().includes("failure")) { status = "failed"; } else if (text.toLowerCase().includes("started") || text.toLowerCase().includes("running")) { status = "running"; } else if (text.toLowerCase().includes("cancelled") || text.toLowerCase().includes("canceled")) { status = "cancelled"; } const workflow = extractWorkflow(text, msg.attachments); const duration = extractDuration(text, msg.attachments); return { timestamp, status, workflow, duration, text: text.substring(0, 500), // Truncate long messages attachments: msg.attachments?.map(a => ({ title: a.title, text: a.text?.substring(0, 200), color: a.color, })), }; }); // Apply workflow filter if specified if (workflowFilter) { buildMessages = buildMessages.filter((msg) => { const workflow = msg.workflow?.toLowerCase() || ''; const text = msg.text?.toLowerCase() || ''; const attachmentText = msg.attachments?.map(a => `${a.title || ''} ${a.text || ''}`).join(' ').toLowerCase() || ''; return workflow.includes(workflowFilter) || text.includes(workflowFilter) || attachmentText.includes(workflowFilter); }); } // Apply limit after filtering const limit = Math.min(args?.limit || 5, 20); buildMessages = buildMessages.slice(0, limit); return { content: [ { type: "text", text: JSON.stringify({ builds: buildMessages, filter: workflowFilter ? { workflow: args.workflow } : null, count: buildMessages.length, }, null, 2), }, ], }; } case "get_channel_messages": { const channelId = args?.channel_id || buildChannelId; if (!channelId) { return { content: [ { type: "text", text: "Error: No channel_id provided and SLACK_BUILD_CHANNEL_ID not configured.", }, ], }; } const limit = Math.min(args?.limit || 10, 100); const result = await slack.conversations.history({ channel: channelId, limit: limit, }); const messages = (result.messages || []).map((msg) => ({ timestamp: new Date(parseFloat(msg.ts) * 1000).toISOString(), user: msg.user, text: msg.text?.substring(0, 500), bot_id: msg.bot_id, })); return { content: [ { type: "text", text: JSON.stringify({ messages }, null, 2), }, ], }; } case "search_messages": { const query = args?.query; if (!query) { return { content: [ { type: "text", text: "Error: query parameter is required", }, ], }; } const limit = Math.min(args?.limit || 10, 100); try { const result = await slack.search.messages({ query: query, count: limit, sort: "timestamp", sort_dir: "desc", }); const matches = (result.messages?.matches || []).map((match) => ({ timestamp: new Date(parseFloat(match.ts) * 1000).toISOString(), channel: match.channel?.name, text: match.text?.substring(0, 500), user: match.user, })); return { content: [ { type: "text", text: JSON.stringify({ results: matches, total: result.messages?.total || 0 }, null, 2), }, ], }; } catch (error) { // Search requires additional OAuth scopes if (error.data?.error === "missing_scope") { return { content: [ { type: "text", text: "Error: Bot token missing 'search:read' scope. Add it in your Slack App settings.", }, ], }; } throw error; } } case "send_message": { const channelId = args?.channel_id || buildChannelId; const text = args?.text; if (!channelId) { return { content: [ { type: "text", text: "Error: No channel_id provided and SLACK_BUILD_CHANNEL_ID not configured.", }, ], }; } if (!text) { return { content: [ { type: "text", text: "Error: text parameter is required", }, ], }; } const result = await slack.chat.postMessage({ channel: channelId, text: text, }); return { content: [ { type: "text", text: JSON.stringify({ success: result.ok, timestamp: result.ts, channel: result.channel, }, null, 2), }, ], }; } case "list_channels": { const limit = Math.min(args?.limit || 50, 200); const result = await slack.conversations.list({ types: "public_channel,private_channel", limit: limit, }); const channels = (result.channels || []).map((ch) => ({ id: ch.id, name: ch.name, is_private: ch.is_private, is_member: ch.is_member, topic: ch.topic?.value?.substring(0, 100), })); return { content: [ { type: "text", text: JSON.stringify({ channels }, null, 2), }, ], }; } default: return { content: [ { type: "text", text: `Unknown tool: ${name}`, }, ], isError: true, }; } } catch (error) { return { content: [ { type: "text", text: `Slack API error: ${error.message}`, }, ], isError: true, }; } });