n8n-io/n8n · error · NodeOperationError

Database name must be provided either in credentials or in…

Error message

Database name must be provided either in credentials or in node parameters

What it means

MongoDB chat-memory node builds its connection either from a connection string or from discrete fields; after resolution, no database name is available — neither the node's databaseName parameter nor the credential's database field is set, and the chat history collection cannot be chosen.

Solutions

1. Set the database name in the node parameters
2. Or fill in the database field on the MongoDB credential

When it happens

Trigger: Thrown at packages/@n8n/nodes-langchain/nodes/memory/MemoryMongoDbChat/MemoryMongoDbChat.node.ts:126 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/aec27c9e00faf771. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/nodes-langchain/nodes/memory/MemoryMongoDbChat/MemoryMongoDbChat.node.ts:126

		} else {
			// Build connection string from individual fields
			const host = credentials.host;
			const port = credentials.port;
			const user = credentials.user ? encodeURIComponent(credentials.user) : '';
			const password = credentials.password ? encodeURIComponent(credentials.password) : '';
			const authString = user && password ? `${user}:${password}@` : '';
			const tls = credentials.tls;

			connectionString = `mongodb://${authString}${host}:${port}/?appname=n8n`;
			if (tls) {
				connectionString += '&ssl=true';
			}

			dbName = databaseName || credentials.database;
		}

		if (!dbName) {
			throw new NodeOperationError(
				this.getNode(),
				'Database name must be provided either in credentials or in node parameters',
			);
		}

		const client = new MongoClient(connectionString, {
			minPoolSize: 0,
			maxPoolSize: 1,
			maxIdleTimeMS: 30000,
		});

		try {
			await client.connect();

			const db = client.db(dbName);
			const collection = db.collection(collectionName);

			const mongoDBChatHistory = new MongoDBChatMessageHistory({

View on GitHub (pinned to 5ac6606e81)