UML, relaid.

Umlay

Write Prisma-style DSL. Render ER diagrams instantly with port-level FK arrows.Theme with CSS. Built for the Node / Cloud / AI era.

auth-system.umlay
namespace auth

model User @aggregate_root {
  id    UUID!   @id
  email string! @unique
  name  string!
}

model Session @entity {
  id     UUID! @id
  userId UUID! @ref(User.id, onDelete: CASCADE)
  token  string! @unique
  status SessionStatus = ACTIVE
}

view er @er_diagram { include: auth.* }

Why Umlay?

Prisma-style DSL

Familiar syntax. Draft mode for sketching, Strict mode for review. Instant feedback.

ER Diagrams with Port Arrows

FK lines connect at the column level — not just table-to-table. What Mermaid cannot do.

Multiple Views, One Model

ER, Class, Sequence diagrams from a single source of truth. No copy-paste drift.

CSS Themable Output

SVG with --uml-* variables and semantic classes. Bring your own theme or use presets.

Lint-First Design

Missing multiplicity? Broken @ref? Detected inline. Catch design gaps before code review.

Future-Ready Syntax

Cloud primitives (Lambda, Queue, Topic), React components, protocols — parsed today, rendered tomorrow.

Coming in Phase 2+

-AI reverse import (Prisma/TS/SQL -> DSL)
-AI code generation (DSL -> TypeScript / Prisma / DDL)
-Class diagram rendering
-Sequence diagram rendering
-AI design risk reviewer
-README dynamic badge (live SVG)

Start Modeling

No sign-up. No server. Everything runs in your browser.

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