What is database-mcp CLAUDE.md?

Repository instructions for a read-only MCP server that lets AI assistants query SQL Server and PostgreSQL databases. It describes the TypeScript and Node.js project structure, commands, and database-driver layers.

Use them when developing or maintaining the server, including compiling it, running tests, starting it locally, and working on configuration, connection management, or database-specific drivers.

They give a coding agent the project context needed to build, test, run, and modify the server without guessing how its database connections and tools are organized.

database-mcp CLAUDE.md — Instructions file for coding agents by hadi21k: Repository instructions for a read-only MCP server that lets…

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 instructions/hadi21k/database-mcp/claude-md

Clone the repo

git clone --depth 1 https://github.com/hadi21k/database-mcp

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/instructions/hadi21k/database-mcp/claude-md.svg)](https://agentmods.dev/instructions/hadi21k/database-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/hadi21k/database-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/hadi21k/database-mcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>

Per session 1,618 This file is loaded in full into every session.

When invoked 1,618 The same file — it is already loaded in full.

Security scan A 0 findings. Scan, not verified.

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	$0.01618	$0.01618
Opus 5	$0.00809	$0.00809
Sonnet 5	$0.00324	$0.00324
Haiku 4.5	$0.00162	$0.00162

Measured 5d ago against content hash 25eca91b8962, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

database-mcp CLAUDE.md 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 5d 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.

CLAUDE.md · 145 lines

How it starts

The opening of the file, as written. The whole thing — 145 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

Database MCP Server — a Model Context Protocol server that gives AI assistants read-only access to SQL Server and PostgreSQL databases. Built with TypeScript, Node.js 18+, ESM modules, and the @modelcontextprotocol/sdk.

Commands

npm run build            # Compile TypeScript → build/
npm run dev              # Watch mode compilation
npm start                # Run server (node build/index.js)
npm test                 # Run all tests (Vitest)
npm run test:unit        # Unit tests only
npm run test:integration # Integration tests only
npm run test:watch       # Tests in watch mode
npm run test:coverage    # Coverage report (V8 provider)

Architecture

Layers

index.ts (entry)
  → ConfigLoader (env/file/CLI config)
  → SqlServerMcpServer (server.ts)
      → ConnectionManager (pool-per-profile, lazy init, multi-database)
      → IDatabaseDriver (driver abstraction per profile)
          → SqlServerDriver (mssql package)
          → PostgresDriver (postgres/porsager package)
      → ToolRegistry → 11 tools (BaseTool subclasses)
      → ResourceRegistry → 3 resources (BaseResource subclasses)
  → StdioServerTransport (MCP stdio transport)

Driver Abstraction

The IDatabaseDriver interface (src/database/interfaces/database-driver.ts) abstracts all database-specific operations. Each database type implements this interface:

SqlServerDriver (src/database/drivers/sqlserver.driver.ts) — uses mssql ConnectionPool, sys.* views for metadata, TOP for row limiting
PostgresDriver (src/database/drivers/postgres.driver.ts) — uses postgres (porsager) tagged template queries, pg_catalog/information_schema for metadata, LIMIT for row limiting

Tools and resources interact only with IDatabaseDriver, never with database-specific APIs.

Key Directories

src/config/ — Config loading (ConfigLoader) and types (ConnectionProfile, DatabaseType, connection string parsing)
src/core/ — Abstract base classes (BaseTool, BaseResource) and registries
src/database/ — ConnectionManager (pool management, driver creation)
src/database/interfaces/ — IDatabaseDriver interface and result type interfaces
src/database/drivers/ — Database-specific driver implementations and factory
src/tools/ — MCP tool implementations:
- Universal: list-schemas, list-tables, describe-table, get-relationships, get-indexes, run-select-query, explain-query, estimate-cost
- PostgreSQL-only: list-materialized-views, list-extensions, list-enums
src/resources/ — MCP resource implementations (table-schema, database-info, connection-profiles) using db:/// URI scheme
src/utils/ — Dialect-aware query validation (validation.ts) and error sanitization (error-handler.ts)
tests/unit/ — Vitest unit tests

Read the full file on GitHub · 145 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.

5d ago First seen · 145 lines · 1,618 tokens per session scan A 25eca91b8962

Subscribe to this mod's changes

database-mcp CLAUDE.md is an instructions file published in the GitHub repository hadi21k/database-mcp (3 stars, last pushed 1mo ago), licensed MIT. It adds 1,618 tokens to every session, about $0.0081 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.

Databases PostgreSQL

database-mcp CLAUDE.md

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

CLAUDE.md

Project Overview

Commands

Architecture

Layers

Driver Abstraction

Key Directories

What this file has done since we first saw it

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