🤖 Add SchemaLens to Claude Desktop in 60 seconds

Free, open-source MCP server. No account. No API key. Your schemas never leave your machine.

🔍 Semantic Schema Diff

Ask Claude Desktop to compare two schemas and get a structured summary of added, removed, and modified tables, columns, indexes, and constraints.

🛡️ Breaking Change Detection

Spot risky changes before they ship: dropped columns, type changes, NOT NULL additions, dropped foreign keys, and more.

📝 Migration SQL Generation

Generate forward and rollback migration scripts in PostgreSQL, MySQL, SQLite, SQL Server, or Oracle dialects.

🔒 Runs Locally

The MCP server uses the same local engine as the SchemaLens web app. No schemas are uploaded to external servers.

Clone the SchemaLens repo

Claude Desktop will run mcp-server.js directly from your local copy. Open a terminal and clone the repo.

git clone https://github.com/aimadetools/race-kimi.git
cd race-kimi

Add to Claude Desktop's MCP config

Open ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or the equivalent config path on your OS. Add the schemalens server under mcpServers.

          
// ~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "schemalens": {
      "command": "node",
      "args": ["/path/to/race-kimi/mcp-server.js"]
    }
  }
}
        

Restart Claude Desktop and start chatting

Close and reopen Claude Desktop so it picks up the new MCP server, then try these prompts:

Diff: "Compare these two PostgreSQL schemas and tell me what changed. [paste schema A] [paste schema B]"

Migration: "Generate the MySQL migration to go from schema A to schema B."

Breaking changes: "Are there any breaking changes between these two schemas?"

🧰 Available tools

schemalens_diff_schemas Compare two SQL schemas and return a semantic diff summary with risk score.
schemalens_generate_migration Generate forward and rollback migration SQL for the detected changes.
schemalens_detect_breaking_changes List breaking changes with severity levels (high, medium, low).

Privacy-first by design: The MCP server loads lib/engine.js from the repo and runs every diff on your local machine. No network calls, no telemetry, no schema uploads.

Ready to automate schema reviews?

Add SchemaLens to your CI/CD pipeline for free and catch breaking changes in every pull request.

SchemaLens GitHub Action → All CI/CD integrations → Team plan →

SchemaLens MCP Server for Claude Desktop Free