simple_snowflake_mcp CLAUDE.md

simple_snowflake_mcp CLAUDE.md is an instructions file for Claude Code from YannBrrd/simple_snowflake_mcp. It costs 1,491 tokens per session, scanned A, original, MIT.

A project guide for simple-snowflake-mcp, a Python MCP server that lets clients such as Claude Desktop or VS Code access Snowflake through a corporate proxy. It documents commands, tests, architecture, and configuration.

In plain words
What is it for?
Use it when developing, testing, linting, type-checking, packaging, or reviewing security changes in the Snowflake MCP server.
Why use it?
It gives coding agents the repository rules needed to run checks and change the server without requiring a live Snowflake account for tests.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions 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 instructions/yannbrrd/simple_snowflake_mcp/claude-md
Clone the repo
git clone --depth 1 https://github.com/YannBrrd/simple_snowflake_mcp

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 simple_snowflake_mcp CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/yannbrrd/simple_snowflake_mcp/claude-md.svg)](https://agentmods.dev/instructions/yannbrrd/simple_snowflake_mcp/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/yannbrrd/simple_snowflake_mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/yannbrrd/simple_snowflake_mcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,491 This file is loaded in full into every session.
When invoked 1,491 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.01491 $0.01491
Opus 5 $0.00745 $0.00745
Sonnet 5 $0.00298 $0.00298
Haiku 4.5 $0.00149 $0.00149

Measured 5d ago against content hash edea268d1e90, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

simple_snowflake_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 · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 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

A single-process MCP (Model Context Protocol) server that exposes Snowflake to MCP clients (Claude Desktop, VS Code) over stdio. Designed to run behind a corporate proxy. Python ≥3.10, packaged with uv/hatchling, published to PyPI as simple-snowflake-mcp.

Commands

uv sync --all-extras        # Install all deps incl. dev (creates venv)
uv run simple-snowflake-mcp # Run the server (stdio)
uv run pytest               # Run tests
uv run pytest tests/test_snowflake.py::test_list_snowflake_warehouses  # Single test
uv run ruff check .         # Lint
uv run ruff format .        # Format
uv run mypy src             # Type check
uv build                    # Build distribution

Tests are async (asyncio_mode = "auto") and mock snowflake.connector.connect — they run in CI with no credentials and never touch a live account. tests/test_security.py holds the security regression tests (one per audit finding); tests/test_snowflake.py holds tool-dispatch smoke tests.

CI: .github/workflows/ci.yml runs ruff + pytest on push/PR; .github/workflows/workflow.yml builds and publishes to PyPI on v* tags.

Architecture

Essentially everything lives in src/simple_snowflake_mcp/server.py (~900 lines). __init__.py just calls asyncio.run(server.main()).

The server is built on the mcp library's Server object (module-global server). MCP capabilities are registered via decorators, all defined in server.py:

  • @server.list_tools() / @server.call_tool() — the tools
  • @server.list_resources() / @server.read_resource() / @server.subscribe_resource() / @server.unsubscribe_resource() — Snowflake resources + subscription notifications
  • @server.list_prompts() / @server.get_prompt() — prompts

handle_call_tool is a single large if/elif dispatch on tool name. All Snowflake access funnels through one chokepoint, _safe_snowflake_execute(query, description, *, is_user_sql=False, row_limit=None) — this is deliberate and security-critical. It applies the read-only guard, executes via a reused connection (_get_connection/_reset_connection) under a threading.Lock, bounds rows via fetchmany, and returns {"success", "data", "error"} with client-safe (generic) error text while logging full detail. The two user SQL tools both route through _run_user_query, which calls the chokepoint with is_user_sql=True. Internal server queries (resources/prompts) call it with the default is_user_sql=False.

Read the full file on GitHub · 58 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. 5d ago First seen · 58 lines · 1,491 tokens per session scan A edea268d1e90

Subscribe to this mod's changes

simple_snowflake_mcp CLAUDE.md is an instructions file published in the GitHub repository YannBrrd/simple_snowflake_mcp (8 stars, last pushed 1mo ago), licensed MIT. It adds 1,491 tokens to every session, about $0.0075 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.

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