database-designer

database-designer is a skill for Claude Code, Codex from shining319/claude-code-single-person-workflow. It costs 112 tokens per session (3,577 once invoked), scanned A, original, MIT.

A database design skill that turns system requirements into schemas: structured definitions of tables, fields, indexes, and their relationships. It can also produce documentation, SQL scripts, and files for visual ER-diagram tools.

In plain words
What is it for?
Use it to design MySQL, PostgreSQL, or SQL Server databases for systems such as shops, blogs, customer-management tools, or business software.
Why use it?
It reduces the work of deciding how application data should be organized and recorded before implementation.

Skill for Claude CodeCodex

Part of the database-designer plugin — 1 skill, 1 command shipped together

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.

agentmods
npx agentmods add skills/shining319/claude-code-single-person-workflow/database-designer
Any agent
npx skills add shining319/claude-code-single-person-workflow --skill database-designer
Clone the repo
git clone --depth 1 https://github.com/shining319/claude-code-single-person-workflow

Made for: Claude Code, Codex.

Or install database-designer, the plugin that ships this one along with the rest of its 1 skill, 1 command.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for database-designer

README.md
[![agentmods](https://agentmods.dev/badge/skills/shining319/claude-code-single-person-workflow/database-designer.svg)](https://agentmods.dev/skills/shining319/claude-code-single-person-workflow/database-designer)
Your own site
<a href="https://agentmods.dev/skills/shining319/claude-code-single-person-workflow/database-designer"><img src="https://agentmods.dev/badge/skills/shining319/claude-code-single-person-workflow/database-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,577 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00112 $0.03577
Opus 5 $0.00056 $0.01788
Sonnet 5 $0.00022 $0.00715
Haiku 4.5 $0.00011 $0.00358

Measured 5d ago against content hash d729c6ff6f99, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

database-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 5d 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.

plugins/database-designer/skills/database-designer/SKILL.md · 457 lines

How it starts

The opening of the file, as written. The whole thing — 457 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Designer

Design complete, production-ready database schemas based on user requirements. Generate comprehensive documentation, SQL scripts, and visual ER diagram files compatible with DrawDB.

Core Design Principles

Before starting any design, always read references/design-principles.md to understand:

  • No physical foreign keys (logical relationships only)
  • Realistic field sizes based on actual usage
  • Minimal, strategic index design
  • Mandatory comments on all tables and fields
  • Default system fields (id, timestamps, soft delete)
  • snake_case naming conventions

Workflow

Step 1: Understand Requirements

Gather information about the database design:

  1. Database type: MySQL 8.0 (default), PostgreSQL, SQL Server, etc.
  2. Business domain: E-commerce, blog, CRM, ERP, etc.
  3. Core entities: What are the main tables needed?
  4. Key features: What functionality should the database support?
  5. Special requirements: Any specific constraints or preferences?

If the user provides minimal information, intelligently infer missing details based on common business scenarios and best practices documented in references/design-examples.md.

Key inference scenarios:

  • User says "design a user table" → Infer: username, password, email, phone, status
  • User says "e-commerce system" → Infer: user, product, order, order_detail tables
  • User says "blog system" → Infer: user, article, comment, tag, article_tag tables

Step 2: Load Reference Documentation

Based on the design requirements, load appropriate references:

  • Always load: references/design-principles.md for core design rules
  • For format generation: references/drawdb-formats.md for JSON/DBML specifications
  • For examples: references/design-examples.md for similar system designs

Step 3: Design Database Schema

Create complete table structures following these guidelines:

Table Design Checklist

For each table:

  • ✅ Add default system fields (unless user specifies otherwise):
    • id BIGINT AUTO_INCREMENT PRIMARY KEY
    • created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    • updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
    • is_deleted TINYINT(1) DEFAULT 0

Read the full file on GitHub · 457 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 457 lines · 112 tokens per session scan A d729c6ff6f99

Subscribe to this mod's changes

database-designer is a skill published in the GitHub repository shining319/claude-code-single-person-workflow (21 stars, last pushed 7mo ago), licensed MIT. It adds 112 tokens to every session and 3,577 once invoked, about $0.0006 per session on Opus 5. 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.

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