database-designer

database-designer is a skill for Claude Code, Codex from Morningstar202604/awesome-skillkit. It costs 54 tokens per session (3,008 once invoked), scanned A, a copy of database-designer, Apache-2.0.

A database design aid for modeling and reviewing how data is stored and related. It covers SQL and NoSQL choices, schema structure, constraints, indexes, migrations, and ERD diagrams; an ERD is a visual map of tables and their relationships.

In plain words
What is it for?
Use it to design schemas, check normalization, generate Mermaid ERDs from database definitions, plan migrations and seed data, model multi-tenancy or row-level security, and review query performance.
Why use it?
It helps catch weak relationships, inconsistent structure, missing indexes, and migration risks before they become application problems.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to design schemas, check normalization, generate Mermaid ERDs from database definitions, plan migrations and seed data, model multi-tenancy or row-level security, and review query performance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/morningstar202604/awesome-skillkit/database-designer
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.

Any agent
npx skills add Morningstar202604/awesome-skillkit --skill database-designer
Clone the repo
git clone --depth 1 https://github.com/Morningstar202604/awesome-skillkit

Made for: Claude Code, Codex.

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/morningstar202604/awesome-skillkit/database-designer.svg)](https://agentmods.dev/skills/morningstar202604/awesome-skillkit/database-designer)
Your own site
<a href="https://agentmods.dev/skills/morningstar202604/awesome-skillkit/database-designer"><img src="https://agentmods.dev/badge/skills/morningstar202604/awesome-skillkit/database-designer.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,008 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 97% copy Near-identical to another mod 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 5.1 $0.00054 $0.03008
Opus 5 $0.00027 $0.01504
Sonnet 5 $0.00011 $0.00602
Haiku 4.5 $0.00005 $0.00301

Measured 8d ago against content hash c20ada273be3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 8d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (index_optimizer.py, migration_generator.py, schema_analyzer.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

This is a copy

97% identical to database-designer — 13 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/programming/database/database-designer/SKILL.md · 322 lines

How it starts

The opening of the file, as written. The whole thing — 322 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Designer - POWERFUL Tier Skill

Overview

A comprehensive database design skill that provides expert-level analysis, optimization, and migration capabilities for modern database systems. This skill combines theoretical principles with practical tools to help architects and developers create scalable, performant, and maintainable database schemas.

Core Competencies

Schema Design & Analysis

  • Normalization Analysis: Automated detection of normalization levels (1NF through BCNF)
  • Denormalization Strategy: Smart recommendations for performance optimization
  • Data Type Optimization: Identification of inappropriate types and size issues
  • Constraint Analysis: Missing foreign keys, unique constraints, and null checks
  • Naming Convention Validation: Consistent table and column naming patterns
  • ERD Generation: Automatic Mermaid diagram creation from DDL

Index Optimization

  • Index Gap Analysis: Identification of missing indexes on foreign keys and query patterns
  • Composite Index Strategy: Optimal column ordering for multi-column indexes
  • Index Redundancy Detection: Elimination of overlapping and unused indexes
  • Performance Impact Modeling: Selectivity estimation and query cost analysis
  • Index Type Selection: B-tree, hash, partial, covering, and specialized indexes

Migration Management

  • Zero-Downtime Migrations: Expand-contract pattern implementation
  • Schema Evolution: Safe column additions, deletions, and type changes
  • Data Migration Scripts: Automated data transformation and validation
  • Rollback Strategy: Complete reversal capabilities with validation
  • Execution Planning: Ordered migration steps with dependency resolution

Tool Workflow (run these — do not analyze schemas by hand)

All paths relative to this skill folder; sample inputs in assets/.

1. Analyze the schema

python3 schema_analyzer.py --input schema.sql --generate-erd --output-format json -o analysis.json

Read the full file on GitHub · 322 lines

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. 8d ago First seen · 322 lines · 54 tokens per session scan A c20ada273be3

Subscribe to this mod's changes

database-designer is a skill published in the GitHub repository Morningstar202604/awesome-skillkit (1 stars, last pushed 3d ago), licensed Apache-2.0. It adds 54 tokens to every session and 3,008 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to database-designer, differing in 13 lines, and is treated as a copy.

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