database

database is a cursor rule for Cursor from first-fluke/fullstack-starter. It costs 0 tokens per session (629 once invoked), scanned A, original, MIT.

A set of rules for designing database schemas, including tables or records, relationships, indexes, validation, transactions, and consistency. It applies to SQL, NoSQL, and vector databases.

In plain words
What is it for?
It helps choose a database model, structure schemas, define integrity rules, plan indexes and transactions, document consistency tradeoffs, and maintain schema decisions.
Why use it?
It helps prevent duplicated or unreliable data and makes important choices about access, transactions, concurrency, and scale explicit.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit It helps choose a database model, structure schemas, define integrity rules, plan indexes and transactions, document consistency tradeoffs, and maintain schema decisions.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/first-fluke/fullstack-starter/database
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.

Clone the repo
git clone --depth 1 https://github.com/first-fluke/fullstack-starter

Made for: Cursor.

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

README.md
[![agentmods](https://agentmods.dev/badge/rules/first-fluke/fullstack-starter/database/github.svg)](https://agentmods.dev/rules/first-fluke/fullstack-starter/database)
Your own site
<a href="https://agentmods.dev/rules/first-fluke/fullstack-starter/database"><img src="https://agentmods.dev/badge/rules/first-fluke/fullstack-starter/database/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 database

Your own site · 80×15
<a href="https://agentmods.dev/rules/first-fluke/fullstack-starter/database"><img src="https://agentmods.dev/badge/rules/first-fluke/fullstack-starter/database.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 629 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 $0.00000 $0.00629
Opus 5.5 $0.00000 $0.00252
Sonnet 5.5 $0.00000 $0.00126
Haiku 4.5 $0.00000 $0.00063

Measured today against content hash 29292e6cbc32, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • database — 86% identical, 8 lines differ
.cursor/rules/database.mdc · 30 lines

How it starts

The opening of the file, as written. The whole thing — 30 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Database Standards

Core Rules

  1. Choose model first, engine second: workload, access pattern, consistency, and scale drive DB selection.
  2. For relational workloads, enforce at least 3NF by default. Break 3NF only with explicit performance justification.
  3. For distributed/non-relational workloads, model around aggregates and access paths; document BASE and consistency tradeoffs.
  4. Document ACID expectations for relational transactions. For distributed tradeoffs, document consistency compromises explicitly.
  5. For schema architecture work, document the relevant schema layers: external schema, conceptual schema, internal schema.
  6. Treat integrity as first-class: entity, domain, referential, and business-rule integrity must be explicit.
  7. Concurrency is never implicit: define transaction boundaries, locking strategy, and isolation level per critical flow.
  8. For new or changed data models, specify: naming, definition, format, allowed values, and validation rules.
  9. Update the affected schema decisions and data definitions; add capacity estimates when the task changes capacity requirements.
  10. Proactively flag anti-patterns and insecure shortcuts instead of silently implementing them.
  11. Vector DBs are retrieval infrastructure, not source-of-truth databases. Store embeddings and metadata there; keep canonical documents elsewhere.
  12. Never treat vector search as a drop-in for lexical search. Default to hybrid retrieval when exact match or explainability matters.
  13. Embeddings are schema-like assets: version model, dimension, chunking, and preprocessing. Plan re-embedding migrations explicitly.
  14. Schema or data changes on live tables follow expand-contract: additive expand, dual-write + batched backfill, verified read switch, delayed contract. Use lock-aware DDL with timeouts; ship destructive steps in a separate deploy after a soak window.
  15. Tune queries from measurement and execution plans, never guesswork: measure, explain, nominate the dominant cost node, optimize, re-measure p95.
  16. Strongly recommend explicit application ownership of business policies, workflows, and external side effects in both new and existing triggers, stored procedures/functions, views, DB jobs, and ORM hooks. For affected existing logic, give a concrete alternative and transition priority; existing convention alone does not justify retention. Use .agents/skills/oma-db/resources/anti-patterns.md §5 for review and technical retention criteria. This is a strong recommendation, not a blanket feature ban or authorization for an unrelated rewrite.
  17. Preserve DB integrity constraints, atomic updates, transactions/isolation/locking, RLS and privileges, DB audit, justified dependent cascades, and efficient set-based operations. For an accepted transition, follow .agents/skills/oma-db/resources/migration-playbook.md to cover every writer, prevent duplicate side effects, and define rollback.

Read the full file on GitHub · 30 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. today Changed · +2 lines 29292e6cbc32
  2. 1mo ago Changed fa6b15f39c0e
  3. 1mo ago First seen · 28 lines · 0 tokens per session scan A c5880768939d

Subscribe to this mod's changes

database is a cursor rule published in the GitHub repository first-fluke/fullstack-starter (224 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 629 tokens. 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.