Quick start

This walk-through views, queries and checks a saved laranex-schema 2.0 document. Write one with build from Drizzle schema modules or a live database, use one that another Laranex producer wrote, or read one with the introspection API.

1. Install and configure

npm install --save-dev node-schema-viewer
npx node-schema-viewer init

init adds "node-schema-viewer": { "output": "schema-viewer.json" } to your package.json, keeping everything else as it was. output is the default document of every command.

2. Get a document

Put a laranex-schema 2.0 document at schema-viewer.json, for example one written by Python Schema Viewer or Laravel Schema Viewer:

laranex-schema-viewer build --output schema-viewer.json      # python-schema-viewer

A 1.x document is refused with one clear error; rebuild it with a producer that writes 2.0.

3. Open the viewer

npx node-schema-viewer serve        # http://127.0.0.1:8765

The server binds to loopback by default, serves only the viewer files its manifest lists, and re-reads and validates the document on every request, so a rebuilt document shows up on reload. See CLI.

serve has no authentication: keep it on loopback for yourself. To add the viewer to your application as a protected development page, see Embedding in your application.

4. Connect an agent

{
  "mcpServers": {
    "laranex_schema": {
      "type": "stdio",
      "command": "/absolute/path/to/node_modules/.bin/node-schema-viewer",
      "args": ["mcp", "--snapshot", "/absolute/path/to/schema-viewer.json"]
    }
  }
}

Save this as .mcp.json for Claude Code; Codex and other clients are in MCP. Use absolute paths.

5. Compare and gate drift

When the document holds database metadata (from a build --source database of another producer, or the introspection API), compare its scopes and fail CI on drift:

npx node-schema-viewer compare 'app:tenant_template=app:*'    # differences between tenant schemas
npx node-schema-viewer check --output gate-report.json         # exit 0 passed, 1 drift, 2 incomplete or invalid

See schema comparison and the drift gate, with a GitHub Actions example.

Read a database instead

The read-only introspection API reads PostgreSQL, MySQL, MariaDB and SQLite catalogs into a strictly validated 2.0 document, which writeDocument saves atomically:

import { introspect, writeDocument } from 'node-schema-viewer';

const document = await introspect({ url: process.env.APP_DATABASE_URL!, connection: 'app' });
writeDocument(document, 'schema-viewer.json');

Give it a read-only role; see database introspection and security.