design-database

design-database is a command for Claude Code from kumaran-is/claude-code-onboarding. It costs 16 tokens per session (198 once invoked), scanned A, original, MIT.

A database design command that turns a set of application requirements into a data structure, relationship diagram, database change scripts, and indexes. An ERD is a diagram showing tables and their relationships; migrations are files that apply database changes over time.

In plain words
What is it for?
Use it to design entities and relationships, create a Mermaid ERD, write Flyway migration SQL, and optionally describe Firestore collections and security rules.
Why use it?
It helps prevent unclear table relationships, missing indexes, and database changes that are difficult to apply consistently.

Command 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.

agentmods
npx agentmods add commands/kumaran-is/claude-code-onboarding/design-database
Clone the repo
git clone --depth 1 https://github.com/kumaran-is/claude-code-onboarding

Made for: Claude Code.

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 design-database

README.md
[![agentmods](https://agentmods.dev/badge/commands/kumaran-is/claude-code-onboarding/design-database.svg)](https://agentmods.dev/commands/kumaran-is/claude-code-onboarding/design-database)
Your own site
<a href="https://agentmods.dev/commands/kumaran-is/claude-code-onboarding/design-database"><img src="https://agentmods.dev/badge/commands/kumaran-is/claude-code-onboarding/design-database.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 198 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00016 $0.00198
Opus 5 $0.00008 $0.00099
Sonnet 5 $0.00003 $0.00040
Haiku 4.5 $0.00002 $0.00020

Measured today against content hash 00908c8dd87e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

design-database 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 today.

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.

.claude/commands/design-database.md · 26 lines

What it actually says

Design Database Schema

Design a complete database schema for the following domain:

Domain / Requirements: $ARGUMENTS

Steps

  1. Identify the core entities and their relationships
  2. Draw an ERD in Mermaid syntax
  3. Write Flyway migration SQL files (V1__*.sql, V2__*.sql, etc.)
  4. Include proper indexes for expected query patterns
  5. Add updated_at trigger function
  6. If Firestore is relevant, provide the collection/document structure
  7. Provide Firestore security rules if applicable
  8. Summarize the design decisions

Use the database-schema-designer skill for conventions and templates. Save output files to a docs/database/ directory.

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. today First seen · 26 lines · 16 tokens per session scan A 00908c8dd87e

Subscribe to this mod's changes

design-database is a command published in the GitHub repository kumaran-is/claude-code-onboarding (35 stars, last pushed 2mo ago), licensed MIT. It adds 16 tokens to every session and 198 once invoked, about $0.0001 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 2026-09-03.