RailsERD.com is now Open Source

RailsERD is a small Rails app that turns your schema.rb into an interactive Entity‑Relationship Diagram (ERD). Paste your schema on the left and get a zoomable, pannable graph on the right with smart routing, highlighting, search, and compact views for wide tables.

• Zoom, pan and drag tables to arrange your diagram
• Click a table to highlight its connected tables
• Use the “Highlight Depth” control to show hops
• Search to bring a model into focus
• Press "Compact 3+" to collapse tables with > 3 columns

• Rails + Stimulus
• D3 for SVG rendering and interactions
• Esbuild bundling; Tailwind for styling

Open http://localhost:3000. The ERD lives at / and /erd.

• Client: erd_controller.js orchestrates rendering with helpers:
  • geometry.js: sizing and paths
  • table_renderer.js: draws tables
  • link_renderer.js: draws links and updates on movement
  • layout_manager.js: layout, routing, and path updates
  • highlight_manager.js: selection, depth, and dimming
• Server: SchemaToGraph parses schema.rb and returns { nodes, links }.

MIT