Astra DB MCP Server

Instructions

Implementation Reference

• tools/ListRecords.ts:18-49 (handler)

  Core handler function that executes the ListRecords tool: fetches records from the specified collection using db.collection().find(), applies limit, sanitizes output, handles errors.

  export async function ListRecords(params: {
    collectionName: string;
    limit?: number;
  }) {
    const { collectionName, limit = 10 } = params;
  
    const collection = db.collection(collectionName);
    
    try {
      // Try to use the limit method if available
      const cursor = collection.find({});
      
      // Handle the case when toArray is not available
      if (!cursor || typeof cursor.toArray !== 'function') {
        console.warn(`cursor.toArray is not available for collection '${collectionName}'`);
        return sanitizeRecordData([]);
      }
      
      if (typeof cursor.limit === 'function') {
        const records = await cursor.limit(limit).toArray();
        return sanitizeRecordData(records);
      } else {
        // Fallback if limit is not available
        const allRecords = await cursor.toArray();
        const limitedRecords = allRecords.slice(0, limit);
        return sanitizeRecordData(limitedRecords);
      }
    } catch (error) {
      console.error(`Error listing records from collection '${collectionName}':`, error);
      return sanitizeRecordData([]);
    }
  }

• tools.ts:117-135 (schema)

  Input schema definition for the ListRecords tool, specifying parameters collectionName (required) and optional limit.

  {
    name: "ListRecords",
    description: "List records from a collection in the database",
    inputSchema: {
      type: "object",
      properties: {
        collectionName: {
          type: "string",
          description: "Name of the collection to list records from",
        },
        limit: {
          type: "number",
          description: "Maximum number of records to return",
          default: 10,
        },
      },
      required: ["collectionName"],
    },
  },

• index.ts:140-154 (registration)

  Registration and dispatch logic in the MCP server's CallToolRequestSchema handler: imports ListRecords, calls it with arguments, sanitizes, and returns JSON response.

  case "ListRecords":
    const records = await ListRecords({
      collectionName: args.collectionName as string,
      limit: args.limit as number | undefined,
    });
    // Sanitize records to prevent prompt injection
    const sanitizedRecords = sanitizeRecordData(records);
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(sanitizedRecords, null, 2),
        },
      ],
    };