UML, relaid.
Umlay
Write Prisma-style DSL. Render ten diagram kinds. Emit production code.
Everything runs in the browser — no server, no sign-up, no data leaves your device.
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.
Ten view kinds from one model
ER, Class, Sequence, State, Component, Package, Activity, Deployment, WBS, Gantt — single source of truth.
Code generation
Emit Prisma, SQL, TypeScript, tRPC, OpenAPI from the same IR. No copy-paste drift.
AI review loop
Intent annotations and review comments feed straight into your BYOK LLM prompt.
Privacy first
The whole editor runs in the browser. Your DSL, diagrams, and LLM calls never touch our server.
Start modeling
No sign-up. No server. Everything runs in your browser.
Open the editor