DataLens: a Java database MCP server
DataLens
A Java MCP server for querying Postgres, MySQL and SQLite in plain language, unrelated to the Yandex DataLens service
High risk
We rate an entry high when the tool writes to external systems, handles money, production databases or secrets, or runs arbitrary commands. The CLI installs it only with your consent.
Why this level
- The server runs queries against a live database, though QueryGuard is meant to block dangerous operations
Install
Manual install
./mvnw spring-boot:runBuilding and running the Spring Boot app from the repository root.
This is third-party code. Review the repository files before installing.
What it does
The Spring and Java server gives an agent access to Postgres, MySQL and SQLite databases through separate JDBC adapters. It has tools for connecting, running queries, explain plans, exporting results, stats and browsing the schema. It separately implements protection against dangerous queries via QueryGuard and QuerySanitizer, plus an AuditLogger audit trail. The project is covered by unit and integration tests. The name DataLens here coincidentally matches the Yandex service's name; these are unrelated, separate products.
Who it is for. For teams where non-technical staff want answers from a working database through an agent instead of asking a developer for SQL.
Good fit when
- You want to give an agent safe access to Postgres, MySQL or SQLite with protection against dangerous queries
- You need an audit trail and explain plans for queries the agent runs
Not a fit when
- You are looking for the Yandex DataLens BI dashboard service: that is a different product, not covered here
- You need databases other than Postgres, MySQL and SQLite
Example request
Show which customers have no orders in the last 90 days, based on the Postgres databaseLimitations
The project is maintained by one author, with no stars or known community. It has no connection to the Russian Yandex DataLens service despite the name overlap. It needs your own database reachable over JDBC; there are no ready cloud BI integrations.
How to disable. Stop the Spring Boot application and remove the server from your MCP client config.
MCP
- Transport
- stdio
- Authentication
- not required
Security check
- The server runs queries against a live database, though QueryGuard is meant to block dangerous operations
README in short
The English README frames the problem: non-technical staff cannot write SQL themselves and wait on a developer. DataLens is described as an MCP server that connects Claude directly to a database, so the team just talks to the assistant, which then queries the database itself.
FAQ
Is this the Yandex DataLens service?
No, this is a separate Java project by an unrelated author; the name overlap is coincidental and it has no connection to Yandex.
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