Liam — Auto-Generate Beautiful ER Diagrams from Your Database

Introduction

Liam is an open-source tool that automatically generates interactive, visually appealing ER diagrams from your database schema or ORM definitions. It connects to PostgreSQL, MySQL, SQLite and reads Prisma, Rails, or raw SQL schemas, then renders a clean, navigable diagram in the browser.

What Liam Does

• Generates ER diagrams from live database connections or schema files
• Supports PostgreSQL, MySQL, SQLite, and schema definition formats
• Renders interactive diagrams with zoom, pan, and table detail views
• Reads Prisma schemas, Rails migrations, and tbls YAML format
• Exports diagrams as images or embeddable web components

Architecture Overview

Liam consists of a CLI that parses database schemas into an internal model and a React-based web application that renders the ER diagram using React Flow. The parser layer supports multiple input formats (SQL DDL, Prisma, Rails schema.rb) through adapters. The rendering engine uses WebAssembly for layout computation, producing clean, non-overlapping diagrams automatically.

Self-Hosting & Configuration

• Install the CLI globally or use npx for one-off generation
• Point at a database connection string or local schema file
• Customize table colors, grouping, and layout in the web UI
• Deploy the generated diagram as a static site for team access
• Integrate into CI to keep documentation diagrams up to date

Key Features

• Automatic layout algorithm prevents overlapping tables
• Interactive web UI with click-to-explore table relationships
• Multi-format input: PostgreSQL, MySQL, Prisma, Rails, SQL files
• Clean visual design that produces documentation-quality diagrams
• Open source with an active development community

Comparison with Similar Tools

• ChartDB — browser-based editor but requires manual schema input
• dbdiagram.io — proprietary SaaS with DSL-based schema definition
• DBeaver ER — part of a full database tool, less focused on visual quality
• SchemaSpy — generates HTML reports but dated visual style
• pgModeler — powerful PostgreSQL modeler but steep learning curve

FAQ

Q: Which databases does Liam support? A: PostgreSQL, MySQL, and SQLite via direct connection. It also reads Prisma, Rails, and SQL DDL schema files.

Q: Can I embed the diagram in my documentation? A: Yes. Liam can generate a standalone HTML page with the interactive diagram that you can host alongside your docs.

Q: Does Liam update diagrams when my schema changes? A: Re-run the CLI against your updated schema or database. In CI, you can automate this to keep diagrams in sync.

Q: Is Liam free for commercial use? A: Yes. Liam is open source and free for both personal and commercial use.

Sources

• https://github.com/liam-hq/liam
• https://liambx.com