mongo-find-documents
Query documents from a MongoDB collection using database name, collection name, and optional filters to retrieve specific data records.
Instructions
Query documents from a MongoDB collection
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| collection | Yes | Collection name | |
| database | Yes | Database name | |
| filter | No | Query filter as JSON object (optional) | |
| limit | No | Maximum number of documents to return (optional) |
Input Schema (JSON Schema)
{
"properties": {
"collection": {
"description": "Collection name",
"type": "string"
},
"database": {
"description": "Database name",
"type": "string"
},
"filter": {
"additionalProperties": {},
"description": "Query filter as JSON object (optional)",
"type": "object"
},
"limit": {
"description": "Maximum number of documents to return (optional)",
"type": "number"
}
},
"required": [
"database",
"collection"
],
"type": "object"
}
Implementation Reference
- src/index.ts:140-165 (handler)The core handler function for the 'mongo-find-documents' tool. It connects to the specified MongoDB database, queries the collection using the provided filter (default empty), applies an optional limit, retrieves the documents, formats the output using a helper, and returns a formatted text response.async ({ database: dbName, collection: collectionName, filter = {}, limit }) => { try { const db = await ensureConnection(dbName); const collection: Collection = db.collection(collectionName); let cursor = collection.find(filter); if (limit) { cursor = cursor.limit(limit); } const documents = await cursor.toArray(); const formattedOutput = formatJsonOutput(documents); return { content: [ { type: "text", text: `Found ${documents.length} document(s):\n\n${formattedOutput}`, }, ], }; } catch (error) { throw new Error(`Failed to find documents: ${error instanceof Error ? error.message : 'Unknown error'}`); } }
- src/index.ts:134-139 (schema)Zod input schema defining the parameters for the tool: required database and collection names, optional filter object and limit number.{ database: z.string().describe("Database name"), collection: z.string().describe("Collection name"), filter: z.record(z.any()).optional().describe("Query filter as JSON object (optional)"), limit: z.number().optional().describe("Maximum number of documents to return (optional)"), },
- src/index.ts:131-166 (registration)The server.tool() call that registers the 'mongo-find-documents' tool with its name, description, input schema, and inline handler function.server.tool( "mongo-find-documents", "Query documents from a MongoDB collection", { database: z.string().describe("Database name"), collection: z.string().describe("Collection name"), filter: z.record(z.any()).optional().describe("Query filter as JSON object (optional)"), limit: z.number().optional().describe("Maximum number of documents to return (optional)"), }, async ({ database: dbName, collection: collectionName, filter = {}, limit }) => { try { const db = await ensureConnection(dbName); const collection: Collection = db.collection(collectionName); let cursor = collection.find(filter); if (limit) { cursor = cursor.limit(limit); } const documents = await cursor.toArray(); const formattedOutput = formatJsonOutput(documents); return { content: [ { type: "text", text: `Found ${documents.length} document(s):\n\n${formattedOutput}`, }, ], }; } catch (error) { throw new Error(`Failed to find documents: ${error instanceof Error ? error.message : 'Unknown error'}`); } } );
- src/index.ts:64-78 (helper)Helper function used by the tool handler to format and truncate large JSON outputs for safe display in responses.function formatJsonOutput(data: unknown): string { const truncatedData = truncateForOutput(data); let outputText = JSON.stringify(truncatedData, null, 2); outputText = outputText.replace( /"\.\.\.(\d+) more items"/g, "...$1 more items" ); outputText = outputText.replace( /"\.\.\.(\d+) more properties": "\.\.\.?"/g, "...$1 more properties" ); return outputText; }
- src/index.ts:88-100 (helper)Helper function to ensure a MongoDB client connection exists and return the database instance, cached per database name. Used in the tool handler.async function ensureConnection(dbName: string): Promise<Db> { if (!mongoClient) { const uri = getMongoUri(); mongoClient = new MongoClient(uri); await mongoClient.connect(); } if (!databases.has(dbName)) { databases.set(dbName, mongoClient.db(dbName)); } return databases.get(dbName)!; }