erd-designer

A tool for creating and editing ERD Designer files, which describe database tables and how they connect. It can also export the design as database-definition SQL.

In plain words
What is it for?
Use it to add or change tables, columns, and relationships in .erd files, then export the result as DDL, the SQL commands used to create database structures.
Why use it?
It lets an agent update a database design without requiring the ERD application or an MCP server. This reduces manual editing of table, column, and relationship definitions.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add kajitiluna/erd-designer
agentmods
npx agentmods add plugins/kajitiluna/erd-designer/agent-plugin
Clone the repo
git clone --depth 1 https://github.com/kajitiluna/erd-designer

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

erd-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agent-plugin/.claude-plugin/plugin.json · 25 lines

What it actually says

{
    "name": "erd-designer",
    "description": "Design and edit ERD Designer (.erd) files with an agent. Provides a bundled CLI and a skill so agents can add tables, columns and relations, and export DDL without the MCP server.",
    "version": "0.260811.154059",
    "author": {
        "name": "kajitiluna"
    },
    "homepage": "https://github.com/kajitiluna/erd-designer",
    "repository": "https://github.com/kajitiluna/erd-designer",
    "license": "Apache-2.0",
    "keywords": [
        "erd",
        "er-diagram",
        "database",
        "database-design",
        "schema-design",
        "ddl",
        "sql",
        "diagram",
        "mcp",
        "claude-code",
        "agent-skills"
    ]
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 25 lines scan A 387535837ee7

Subscribe to this mod's changes

erd-designer is a plugin published in the GitHub repository kajitiluna/erd-designer (18 stars, last pushed 9d ago), licensed Apache-2.0. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.