mongo-list-collections

Retrieve all collection names from a specified MongoDB database to view available data structures and manage database organization.

Instructions

List all collections in a MongoDB database

Input Schema

TableJSON Schema

Name	Required	Description	Default
`database`	Yes	Database name

Implementation Reference

src/index.ts:299-317 (handler)

The handler function that ensures connection to the MongoDB database, lists all collections using db.listCollections(), maps to names, and returns a formatted text response with the list of collection names.

async ({ database: dbName }) => {
  try {
    const db = await ensureConnection(dbName);
    
    const collections = await db.listCollections().toArray();
    const collectionNames = collections.map(col => col.name);
    
    return {
      content: [
        {
          type: "text",
          text: `Collections in database '${dbName}':\n${collectionNames.join('\n')}`,
        },
      ],
    };
  } catch (error) {
    throw new Error(`Failed to list collections: ${error instanceof Error ? error.message : 'Unknown error'}`);
  }
}

src/index.ts:296-298 (schema)
Zod schema defining the input parameter 'database' as a required string.
```
{
  database: z.string().describe("Database name"),
},
```

src/index.ts:293-318 (registration)

Registration of the 'mongo-list-collections' tool with server.tool(), including name, description, schema, and handler.

server.tool(
  "mongo-list-collections",
  "List all collections in a MongoDB database",
  {
    database: z.string().describe("Database name"),
  },
  async ({ database: dbName }) => {
    try {
      const db = await ensureConnection(dbName);
      
      const collections = await db.listCollections().toArray();
      const collectionNames = collections.map(col => col.name);
      
      return {
        content: [
          {
            type: "text",
            text: `Collections in database '${dbName}':\n${collectionNames.join('\n')}`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`Failed to list collections: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }
);

src/index.ts:88-100 (helper)

Helper function used by the tool to establish and cache MongoDB connection and database instance.

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)!;
}

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