erdn-langEntity-Relationship Diagrams as Code

Write plain-text .erdn schemas, render clean SVG diagrams, and export SQL DDL for multiple databases.

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Text-Based

Store .erdn files alongside your source code and track changes in version control — no more opaque binary diagram files.

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Generate SQL DDL from your .erdn schema for MySQL, PostgreSQL, SQL Server, Oracle, and SQLite.

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Catch semantic errors — unknown tables, duplicate keys, conflicting modifiers — before you render.

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# comments on tables, columns, and links are rendered as subtitle rows directly in the diagram.

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AI-ready — connect Claude, Cursor, or any MCP-compatible assistant to convert SQL and generate diagrams directly from your editor.