Architecture

One JSON contract → one shared UI → multiple frameworks.

Laravel (Eloquent)  ─┐
Python (SQLAlchemy,  ├─▶  laranex-schema 2.0 JSON  ─▶  shared viewer · MCP tools · compare · check
 Django, …)          │      (laranex-schema-viewer-ui: contract, validator, shared algorithms, viewer)
Node.js (this) ──────┘

Every Laranex Schema Viewer writes the same laranex-schema document and shows it with the same viewer. The npm package laranex-schema-viewer-ui provides both: the contract (JSON Schema, validator, canonical JSON, revisions, graph builder, ids, the shared comparison, request-expansion and gate algorithms, and conformance fixtures) and the prebuilt viewer, whose manifest declares the contract major it reads. This package depends on one exact version of it and never duplicates the contract or vendors the viewer.

Layers

Layer	Modules	Reads	Never
Snapshot	src/snapshot.ts	One document, at most 32 MiB; 2.x leniently	Writes anything but strictly validated, canonical 2.0, atomically
Configuration	src/config.ts	The "node-schema-viewer" key of package.json (static JSON)	Loads JavaScript configuration or database URLs
Viewer server	src/server.ts	The viewer files the manifest lists (SHA-256 verified) and the document per request	Serves files the manifest does not list
MCP	src/query.ts, src/mcp.ts	The document, pinned at startup	Writes, computes comparisons, connects to databases
Comparison and gate	src/compare.ts, src/check.ts	The document and package.json	Reimplements the shared algorithms; connects to databases
Producer model	src/schema/	—	Lets extractors write document fields directly
Database introspection	src/introspection/	Database catalogs, in verified read-only sessions	Imports application code; runs DDL, DML or row queries
Isolation	src/isolation/	Your schema modules, in a separate worker (build --source declared)	Falls back to a weaker isolation level

The producer layering

Extractors fill a normalized internal schema model (src/schema/model.ts) that is independent of the document's field names: the catalog readers now, the ORM adapters later. One serializer (src/schema/serialize.ts) is the only module that knows the document. It writes canonical 2.0, builds the links with the contract's shared graph builder, gives diagnostics their rule-based ids, validates strictly, and merges documents of several connections.

Parity with the family

The MCP responses are python-schema-viewer's, by value and by exact text, checked against its recordings; compare and check output is checked byte for byte against python-schema-viewer's on shared documents; database introspection is checked against python-schema-viewer's own documents for the same synthetic databases. See MCP, CLI and database introspection.