ERD Editor

Design database schemas visually: in your browser, in your IDE, or by asking your coding agent

English | 한국어 | 中文 | 日本語

Open erd-editor.io in your browser, nothing to install, or get it for VS Code, JetBrains IDEs, Obsidian and Google Drive.

One editor and one .erd.json file wherever you work: on the web, in Google Drive, VS Code, JetBrains IDEs and Obsidian, inside your own app, and in your coding agent's hands.

Features

• Design — tables, columns, memos and table groups, four relationship cardinalities, ON DELETE and ON UPDATE, alternate keys, Auto Layout
• Import — SQL DDL, GraphQL SDL, DBML and AML, replacing the diagram or adding to it
• Export — DDL for eight databases, code in 22 languages and ORMs, PNG and SVG
• Navigate — command palette (Ctrl/Cmd+K), an Explorer tree with find and replace, Graph and Flow views
• History — undo and redo, time travel through the session, a diff viewer against another file
• 25 languages and a System, Light or Dark theme with your own gray and accent colors
• Collaboration — live sessions on erd-editor.io, and coding agents that edit beside you

Databases: Databricks, MariaDB, MSSQL, MySQL, Oracle, PostgreSQL, Snowflake, SQLite

Code: TypeScript, GraphQL, C#, Java, JPA, Kotlin, Scala, Go, SQLAlchemy, TypeORM, Sequelize, Drizzle, DBML, AML, Mermaid, PHP, Doctrine, Rust, SeaORM, Swift, Zod, JSON Schema

Every feature step by step: the Editing Guide.

Coding agents

Ask Claude Code, Codex or any MCP client to change the schema, and watch it happen on the canvas.

@dineug/erd-editor-mcp gives the agent one tool per editing operation. When VS Code, Obsidian or a JetBrains IDE holds the diagram, the agent joins it as one more collaborator, and its undo reverts only its own edits; with no editor, it edits the file on disk. An editor with its connection off, or an untrusted workspace or project, lets the agent read but refuses its edits. It needs Node.js 22.12 or later. Add it with one command, in your project folder:

# Claude Code
claude mcp add --transport stdio erd-editor -- npx -y @dineug/erd-editor-mcp
# Codex
codex mcp add erd-editor -- npx -y @dineug/erd-editor-mcp

Other clients and the tool list: its README.

Where to use it

	Install
Web app	erd-editor.io	Installable PWA that works offline, with real-time collaboration
Google Drive	Google Workspace Marketplace	Drive's Open with and New menus, saving back to the same file
VS Code	Marketplace	Opens .erd.json files
IntelliJ	JetBrains Marketplace	Opens .erd.json files in IntelliJ-based IDEs
Obsidian	Community plugins	Opens .erd and .erd.json files in a vault, desktop only
Your app	npm install @dineug/erd-editor	The <erd-editor> custom element, no framework needed
Coding agents	@dineug/erd-editor-mcp	MCP server for Claude Code, Codex and other clients

In an IDE, create an empty .erd.json file and open it. In Obsidian, run ERD Editor: Create new diagram; in Google Drive, choose New → More → ERD Editor.

Real-time collaboration

Every ERD Editor shares its edits as a stream of actions, which keeps several views of one diagram in sync, such as browser tabs or split editors, and lets a coding agent join as one more collaborator.

On erd-editor.io, choose Start session from the collaboration button in the sidebar and share the link: everyone who opens it edits with you. The link is the only key, so share it only with people you would let edit. The session lives in the host's browser and ends when the host closes their last tab, so a guest who wants the diagram exports it first.

Peers connect over WebRTC, with the diagram and every edit encrypted by AES-GCM. The signaling relay never sees plaintext, and the room key lives in the URL fragment, which browsers leave out of every request.

Architecture

flowchart TB
    subgraph clientA["Client A"]
        bcA["Broadcast Channel"]
        tabA1["Tab (leader)"]
        tabA2["Tab"]
        swA["Shared Worker"]
        idbA[("IndexedDB")]

        bcA <--> tabA1
        bcA <--> tabA2
        tabA1 <--> swA
        tabA2 <--> swA
        swA <--> idbA
    end

    subgraph clientB["Client B (guest)"]
        tabB1["Tab"]
    end

    relay["Signaling Relay (nostr / mqtt)"]

    tabA1 <-->|"WebRTC (AES-GCM)"| tabB1
    tabA1 -. "signaling" .-> relay
    tabB1 -. "signaling" .-> relay

Loading

Embedding

npm install @dineug/erd-editor

import '@dineug/erd-editor';

const editor = document.createElement('erd-editor');
// the editor fills its container, and a custom element is inline by default
Object.assign(editor.style, { display: 'block', width: '100%', height: '100vh' });
document.body.appendChild(editor);

It works from any framework or from none. Attributes and the element API: packages/erd-editor.

Documentation

• Editing Guide — every editor feature
• Element API — <erd-editor> for your own app
• MCP — the MCP server and its tools
• Documentation

Packages

A pnpm workspace. @dineug/erd-editor and @dineug/erd-editor-mcp are published to npm, the three plugins ship through their stores, app is erd-editor.io, and the rest are private libraries those builds take in.

All 18 packages

Folder	npm name	Description
erd-editor	@dineug/erd-editor	The editor core: the <erd-editor> custom element and the headless engine.js and peer.js entries
erd-editor-schema	@dineug/erd-editor-schema	The v2/v3 document schema, parsing, serializers, queries and LWW operators
schema-sql-parser	@dineug/schema-sql-parser	Permissive DDL parser used for SQL import
uuid	@dineug/uuid	UUIDv7 and the Uuid25 encoding, the ids the editor mints
r-html	@dineug/r-html	The tagged-template rendering framework and store the editor is built on
vite-plugin-r-html	@dineug/vite-plugin-r-html	JSX → tagged templates, plus HMR boundaries
app	@dineug/erd-editor-app	The React PWA at erd-editor.io, with the Google Drive editor at /gdrive, whose OAuth relay is the Pages Function in functions/
vscode-extension	vuerd-vscode	The published VS Code extension, with its side of the coding-agent hub
vscode-webview	@dineug/erd-editor-vscode-webview	The bundle inside the VS Code webview
webview-client	@dineug/erd-editor-webview-client	The editor mounted into an IDE webview, host protocol wired, shared by both IDE bundles
webview-bridge	@dineug/erd-editor-webview-bridge	Typed host ↔ webview command protocol
replication-store-worker	@dineug/erd-editor-replication-store-worker	Headless document replica in a Worker, serializing what the IDE webviews and the Obsidian plugin save
intellij-webview	@dineug/erd-editor-intellij-webview	The bundle inside the IntelliJ plugin's editor panel
intellij-plugin	@dineug/erd-editor-intellij-plugin	The published IntelliJ plugin, in Kotlin and Gradle, with its own Kotlin hub for coding agents
obsidian-plugin	@dineug/erd-editor-obsidian-plugin	The Obsidian plugin, released from erd-editor-obsidian-plugin
agent-hub	@dineug/erd-editor-agent-hub	The protocol between an editor window and a coding agent's MCP server: messages, lock files, framing
agent-hub-host	@dineug/erd-editor-agent-hub-host	The editor window's side of that protocol, shared by the VS Code extension and the Obsidian plugin; the IntelliJ plugin ports it to Kotlin
mcp-server	@dineug/erd-editor-mcp	The published MCP server, live in VS Code, Obsidian or a JetBrains IDE, or headless on the file

Development

You need Node 22.22.1+, 24.11+ or 26+ (.nvmrc pins 22.23.2), pnpm 10.34.3 and Git 2.32+; the IntelliJ plugin also needs JDK 17+.

pnpm install
pnpm --filter @dineug/erd-editor exec playwright install --with-deps chromium # for pnpm test
pnpm --filter @dineug/erd-editor-app dev # the web app
pnpm check # format and lint
pnpm test  # every package's type check and specs
pnpm build

The IntelliJ plugin builds with Gradle from packages/intellij-plugin, and the e2e suites run apart from pnpm test. AGENTS.md has the rest: which checks a change runs, coverage, the e2e suites and the commit rules.

Contributing

Issues and pull requests are welcome. Commit messages follow Conventional Commits.

License

MIT © SeungHwan-Lee