Repository rules for the db-conn-mcp project, covering design choices, code quality, database safety, and consistency between instruction files. An MCP project uses the Model Context Protocol to expose tools or data to AI assistants.

Use them when changing db-conn-mcp code, checking formatting and linting with Ruff, preserving read-only database behavior, or keeping CLAUDE.md, .cursorrules, and the canonical rules file synchronized.

They give coding agents clear boundaries for modifying the project, including avoiding unnecessary architecture and keeping database access rules in the database dialect. They also identify which documentation is canonical.

How Idle-Sync/db-conn-mcp configures Cursor

Reuse

Borrowing it

Nothing to install: this file belongs to Idle-Sync/db-conn-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/Idle-Sync/db-conn-mcp/main/.cursorrules

Clone the repo

git clone --depth 1 https://github.com/Idle-Sync/db-conn-mcp

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.

README.md

[![agentmods](https://agentmods.dev/badge/rules/idle-sync/db-conn-mcp/cursorrules/github.svg)](https://agentmods.dev/rules/idle-sync/db-conn-mcp/cursorrules)

Your own site

<a href="https://agentmods.dev/rules/idle-sync/db-conn-mcp/cursorrules"><img src="https://agentmods.dev/badge/rules/idle-sync/db-conn-mcp/cursorrules/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.

Your own site · 80×15

<a href="https://agentmods.dev/rules/idle-sync/db-conn-mcp/cursorrules"><img src="https://agentmods.dev/badge/rules/idle-sync/db-conn-mcp/cursorrules.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,662 This file is loaded in full into every session.

When invoked 1,662 The same file — it is already loaded in full.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01662	$0.01662
Opus 5.5	$0.00665	$0.00665
Sonnet 5.5	$0.00332	$0.00332
Haiku 4.5	$0.00166	$0.00166

Measured 2mo ago against content hash 12edbe38d3bb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cursorrules 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 2mo 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.

.cursorrules · 64 lines

How it starts

The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AI Agent Rules (CLAUDE.md / .cursorrules)

Welcome, AI Agent (Claude, Agy, Cursor, or otherwise)! When assisting the user with the db-conn-mcp project, please strictly adhere to the following rules to maintain the project's core philosophy.

Note: docs/AGENT_RULES.md is canonical. CLAUDE.md and .cursorrules at the repo root are exact copies — when you change a rule, update all three so they stay byte-identical.

1. Simplicity First (No Over-engineering)

DO NOT introduce complex architectures, custom OAuth servers, or JWT minting.
DO NOT use complex AST parsers to validate read vs. write queries.
DO rely on native database features. Read-only enforcement lives inside each dialect (for Postgres v1: set the session read-only with SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY;).

2. Code Quality & Standards (Production Grade)

Ruff: Use ruff as the strict standard for all linting and formatting. Ensure all code passes ruff check and ruff format.
SOLID & KISS: Code must be highly modular but radically simple. Follow SOLID principles to keep concerns separated (e.g., config parsing vs. database connection vs. MCP transport), but never at the expense of KISS (Keep It Simple, Stupid).
DevX & AgentX: The codebase must be highly readable and easy to modify for both human developers and AI agents. Keep files reasonably small, avoid deep nesting, and use explicit typing (typing module) everywhere.
Documentation: Well-documented from day one. Every class, module, and non-trivial function must have a clear Python docstring.

3. Configuration via JSON

The single source of truth for database connections is connections.json.
The schema is a top-level object { "connections": [ ... ] }; each connection has name, dsn, mode ("read" or "write"), an optional yolo (boolean, default false), and an optional fallback_ports (list of ints, probed in order when the primary port refuses — see README).
Feel free to programmatically read, update, or create connections.json for the user if they ask you to add a database.

Read the full file on GitHub · 64 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.

2mo ago First seen · 64 lines · 1,662 tokens per session scan A 12edbe38d3bb

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository Idle-Sync/db-conn-mcp (2 stars, last pushed yesterday), licensed MIT. It adds 1,662 tokens to every session, about $0.0066 per session on Opus 5.5. 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.

Building agents Databases

cursorrules next to 6 cursor rules from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
cursorrulesIdle-Sync/db-conn-mcp	Cursor rule	2	yesterday	MIT	A	1,662	Cursor
as-contract-cast-smellprisma/orm	Cursor rule	48k	yesterday	Apache-2.0	A	943	Cursor
no-backward-compatibilityprisma/orm	Cursor rule	48k	yesterday	Apache-2.0	A	0	Cursor
postgresqlsanjeed5/awesome-cursor-rules-mdc	Cursor rule	3.6k	5mo ago	CC0-1.0	A	2,337	Cursor
ehs-ims-conventionsSafetyMP/Autonomous-EHS-Management	Cursor rule	9	6d ago	Apache-2.0	A	722	Cursor
sync-timedb-archive-janitor-contractTACC/HPCPerfStats	Cursor rule	60	today	LGPL-2.1	A	0	Cursor
schemaGktuOktay/ai-skills	Cursor rule	2	2mo ago	MIT	A	0	Cursor

db-conn-mcp: Cursor rule for Cursor