claudia-data

claudia-data is a skill for Claude Code from reganomalley/claudia. It costs 96 tokens per session (961 once invoked), scanned A, original, MIT.

Data modeling guidance for designing database tables, relationships, migrations, indexes, data pipelines, and data history. Data modeling means deciding how information is structured and connected so software can use it reliably.

In plain words
What is it for?
Use it to design schemas, choose when to normalize or duplicate data, plan migrations and indexes, model relationships, and decide when an audit history or event log is appropriate.
Why use it?
It helps prevent difficult queries, unsafe database changes, poor performance, and data-integrity problems as an application grows.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the claudia plugin — 10 skills, 12 commands, 5 hooks shipped together

Good fit Use it to design schemas, choose when to normalize or duplicate data, plan migrations and indexes, model relationships, and decide when an audit history or event log is appropriate.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/reganomalley/claudia/claudia-data
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 reganomalley/claudia --skill claudia-data
Clone the repo
git clone --depth 1 https://github.com/reganomalley/claudia

Made for: Claude Code.

Or install claudia, the plugin that ships this one along with the rest of its 10 skills, 12 commands, 5 hooks.

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 claudia-data

README.md
[![agentmods](https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-data/github.svg)](https://agentmods.dev/skills/reganomalley/claudia/claudia-data)
Your own site
<a href="https://agentmods.dev/skills/reganomalley/claudia/claudia-data"><img src="https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-data/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for claudia-data

Your own site · 80×15
<a href="https://agentmods.dev/skills/reganomalley/claudia/claudia-data"><img src="https://agentmods.dev/badge/skills/reganomalley/claudia/claudia-data.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 961 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 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 5.1 $0.00096 $0.00961
Opus 5 $0.00048 $0.00481
Sonnet 5 $0.00019 $0.00192
Haiku 4.5 $0.00010 $0.00096

Measured 10d ago against content hash 1589827116a8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

claudia-data 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 10d 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.

skills/claudia-data/SKILL.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claudia Data Modeling Domain

Overview

Good data modeling prevents most "scaling" problems before they start. Get the schema right and everything downstream gets easier -- queries are simpler, migrations are safer, performance is predictable, and your future self won't want to rewrite the whole thing.

Schema Design Decision Tree

How should I model my data?
├── Start normalized (3NF)
│   ├── Relationships are clear → foreign keys + join tables
│   ├── Schema is stable → strict types + constraints
│   └── Data integrity matters → NOT NULL, CHECK, UNIQUE
├── Denormalize only for measured read performance
│   ├── Dashboard query is slow → materialized view or computed column
│   ├── N+1 joins killing latency → embed or cache the joined data
│   └── Read:write ratio > 100:1 → read replica or denormalized table
└── Consider event sourcing only for audit-heavy domains
    ├── Need full history of every change → event log + projections
    ├── Regulatory/compliance requirements → append-only audit trail
    └── Complex business rules with undo → event replay

Common Patterns

Pattern When to Use Example
Soft deletes Need to recover data, regulatory retention deleted_at timestamp column, filter in queries
Audit trails Compliance, debugging, blame tracking Separate _audit table with old/new values + actor
Multi-tenancy SaaS with isolated customer data tenant_id column on every table + RLS policies
Polymorphic associations Different types share a relationship STI, CTI, or delegated types (see references)
EAV (avoid) Almost never -- use JSONB instead entity_id, attribute, value tables are a trap
JSON columns Semi-structured data within a relational model Preferences, metadata, form responses
Temporal data Track how values change over time valid_from/valid_to columns (SCD Type 2)
Junction tables Many-to-many relationships post_tags table linking posts and tags

Read the full file on GitHub · 84 lines

Files

What ships with it

2 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. 10d ago First seen · 84 lines · 96 tokens per session scan A 1589827116a8

Subscribe to this mod's changes

claudia-data is a skill published in the GitHub repository reganomalley/claudia (4 stars, last pushed 6mo ago), licensed MIT. It adds 96 tokens to every session and 961 once invoked, about $0.0005 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 2026-08-31.

Related

Other skills, from other repositories

create-pr

Creates a GitHub PR with a Linear-ticket-prefixed title and a decision-led, narrative description for prisma-next. Use when the user wants to create a pull request, open a PR, or submit changes for review.

prisma/orm · 47 tokens

schema-exploration

Lists tables, describes columns and data types, identifies foreign key relationships, and maps entity relationships in a database. Use when the user asks about database schema, table structure, column types, what tables exist, ERD, foreign keys, or how entities relate.

langchain-ai/deepagents · 57 tokens

ha-data-stores

Map of Hope Agent's local data stores and safe read-only query workflow. Use when the user asks where Hope Agent stores data, wants to inspect sessions/messages/memory/logs/background jobs/knowledge indexes/settings, asks the model to query local app data, or debugging requires checking persisted state. Trigger…

shiwenwen/hope-agent · 115 tokens

supabase

Supabase / PostgREST Row-Level-Security playbook — pull the anon (or leaked servicerole) key out of the frontend JS, map tables from the auto-generated OpenAPI spec, test anonymous RLS READ disclosures (PII/secret leaks), and anonymous RLS WRITE abuse (insert/update/delete — e.g. forging…

PentesterFlow/agent · 120 tokens

nornicdb-cypher-queries

Pick fast, predictable Cypher query shapes in NornicDB — point lookups, batch retrieval, pagination, search, traversal, batched UNWIND/MERGE writes, cleanup, multi-tenant isolation. Use when writing or reviewing Cypher whose latency or throughput matters; maps user intent to the executor's hot-path query templates.

orneryd/NornicDB · 79 tokens

dsql

Build with Aurora DSQL — manage schemas, execute queries, handle migrations, diagnose query plans, diagnose cluster performance, load data, and develop applications with a serverless, distributed SQL database. Covers IAM auth, multi-tenant patterns, MySQL-to-DSQL and PostgreSQL-to-DSQL schema conversion, foreign key…

awslabs/agent-plugins · 229 tokens