Schemity is a cross-platform ERD tool for designing relational database schemas visually and turning that design into real SQL migrations.
Database design usually splits into two disconnected halves. Diagrams live in a drawing tool and drift out of date the moment someone writes a migration, while the migrations that hold the real schema stay invisible and hard to reason about. Schemity keeps one diagram that is both the design and the source of the migration.
Key features:
- Draw the schema by drag an entity header onto another entity to create a foreign key, with 1:N, 1:1 and N:N via an auto-generated junction table. Unique constraints, check constraints and indexes are part of the picture, not afterthoughts buried in migration files.
- Reverse-engineer an existing database into a diagram, evolve it, then generate the exact SQL diff and apply it. PostgreSQL, MySQL, SQL Server and SQLite, over direct or SSH connections, or work in design-only mode with no database at all.
- Import from SQL and DBML. Export to SVG, PNG, DBML, Mermaid, and a data dictionary in HTML, Markdown or Excel.
- Local-first and git-native. Workspaces are folders in your home directory and diagrams are plain JSON, so you commit them next to the code they describe and review them in pull requests.
- Context maps for splitting a large schema into bounded contexts, plus entity templates, multiple tabs, vim-style keyboard navigation and unlimited undo/redo.
Who it is for: backend and full-stack developers, data engineers and architects who own a relational schema and the migrations that change it, particularly teams practicing domain-driven design.
Getting started: a native desktop app for macOS, Windows and Linux (.deb). It is very lightweight that built on Rust and the system WebView, with no Electron and no JVM, and it runs fully offline. Download it from schemity.com, install, then either start a diagram in design-only mode or add a connection to pull in an existing schema. Schemity Lite runs the design side in any modern browser at lite.schemity.com with nothing to install, and diagrams move between Lite and the desktop app as JSON. Free for education, free trial for commercial use.
What makes it different: most tools pick a side. Diagram editors draw pictures but never touch the database, and migration tools change the database but show you nothing. Schemity does both from a single artifact, offline and with no cloud account. It also treats relations and constraints as first-class objects rather than decoration: full routing control with custom waypoints, connection lines that inherit entity colors, and markers that keep multi-column unique constraints visible at a glance.
The builder has not written a Talk during the contest yet.