AI database schema diagram generator.
The physical view: tables, columns, keys and indexes, for when you need what is actually stored rather than the conceptual model.
Schema diagram or entity diagram
They are frequently confused and answer different questions. An entity diagram describes the domain and deliberately hides storage, so join tables become relationships. A schema diagram describes what is physically there, including join tables, indexes and column types, and is what you want when reviewing a migration or reasoning about a slow query. Both are useful; using one where the other was wanted is why some database diagrams feel unhelpful.
How Lucid Train draws one
Describe what you want, or point it at a repository. The agent emits a semantic graph of nodes and edges with no coordinates, and the ELK layout engine computes positions and orthogonal routing. That separation is the reason the output cannot come back with boxes overlapping or arrows crossing through cards, which is the characteristic failure when a language model is asked to place things on a canvas itself. It also means editing is editing the graph: change a component and the layout re-solves rather than drifting out of alignment.
Indexes belong on it
A schema diagram without indexes leaves out most of what determines whether the database performs. Showing which columns are indexed, and which indexes are composite and in what order, turns the diagram into something you can use during a query review rather than only during design.
Reading migrations rather than a dump
Most application repositories contain migrations rather than a checked-in schema, so the current shape has to be reconstructed by applying them in order. That works and takes longer on a long history, which is the argument for keeping a generated schema dump in the repository regardless.
Local, offline, your models
It runs as a desktop application. Against a local Ollama model the whole thing works offline with no API key and no telemetry, which is the practical difference from every browser-based diagram tool: your architecture never leaves the machine.
Schema elements drawn
| Element | Shown as |
|---|---|
| Table | A component with its columns |
| Column with type | An attribute, type included |
| Primary key | Marked on the identifying column |
| Foreign key | An edge with direction |
| Unique constraint | Noted, and used to determine cardinality |
| Index | A note listing the columns in order |
| Composite key | The full column list, since order matters |
| Check constraint | A note on the column |
| View | Drawn separately from tables |
Try it
Questions
Related
- AI Architecture Diagram GeneratorDescribe the system, or point it at the repository and let it find out for itself.
- AI System Design Diagram GeneratorFor a design doc, a review, or the whiteboard round where you have forty minutes and need the shape to be right.
- AI Sequence Diagram GeneratorFor when the question is not what the components are but in what order they talk, and what happens when step four fails.
- AI ER Diagram GeneratorPoint it at the schema you already have. The relationships are declared, so the diagram is a rendering rather than an interpretation.