Connect LLMs to MongoDB Databases

MongoDB MCP Server is an MCP server that lets an LLM interact with MongoDB databases through a standardized interface, inspecting collection schemas and executing MongoDB operations, queries, aggregations, and, when not restricted, writes, directly against a live database.

Use it when you want an LLM to explore a MongoDB database's structure and run queries or aggregation pipelines against it, with optional write access for inserts, updates, and index creation. It infers collection schemas automatically from document samples rather than requiring a predefined schema, and it can convert string IDs to MongoDB ObjectIds automatically, never, or on-demand depending on configuration. For safer exploratory use, connect with --read-only, or MCP_MONGODB_READONLY=true, to block write operations entirely and query using a secondary read preference, rather than trusting the LLM with write access by default.

Schema inference automatically detects a collection's structure from sampled documents, so there's no need to hand-maintain a schema definition. Query and aggregation support covers full MongoDB query syntax and aggregation pipelines, with optional explain plans for understanding query execution. Smart ObjectId handling offers configurable auto, none, or force modes for converting string values to ObjectIds. Write operations, insert, update, and index creation, are available unless read-only mode is active, which blocks them outright. Collection name completion helps an LLM auto-complete collection names during interaction.

Run it directly with npx, pointing at your MongoDB connection URI:

npx -y mcp-mongo-server mongodb://localhost:27017/database

Add --read-only to restrict it to read operations:

npx -y mcp-mongo-server mongodb://muhammed:kilic@localhost:27017/database --read-only

Configuration can also go through environment variables: MCP_MONGODB_URI for the connection string, and MCP_MONGODB_READONLY set to "true" for read-only mode. The project's own documentation covers integration with Claude Desktop, Windsurf, Cursor, and Docker, plus a full list of available tools, separately from this overview.

Developers who want an LLM to inspect and query a MongoDB database's structure and data directly, with the option to lock it to read-only access for safer exploratory use. It is released under the MIT License, distributed as the mcp-mongo-server npm package, and its own documentation includes dedicated guides for integration, the full tool list, and local development setup.