Borrowing it
Nothing to install: this file belongs to cmer81/open-meteo-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.
curl -O https://raw.githubusercontent.com/cmer81/open-meteo-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/cmer81/open-meteo-mcpWrote 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.
[](https://agentmods.dev/instructions/cmer81/open-meteo-mcp/claude-md)<a href="https://agentmods.dev/instructions/cmer81/open-meteo-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/cmer81/open-meteo-mcp/claude-md/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.
<a href="https://agentmods.dev/instructions/cmer81/open-meteo-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/cmer81/open-meteo-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.01998 | $0.01998 |
| Opus 5 | $0.00999 | $0.00999 |
| Sonnet 5 | $0.00400 | $0.00400 |
| Haiku 4.5 | $0.00200 | $0.00200 |
Grade A, and why
open-meteo-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 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.
How it starts
The opening of the file, as written. The whole thing — 147 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.
Repository Overview
This is an Open-Meteo MCP (Model Context Protocol) server that provides comprehensive access to weather APIs for Large Language Models. It connects LLMs to Open-Meteo's weather forecasting, historical data, air quality, marine conditions, and climate projection services.
Architecture
Core Components
src/index.ts- Main MCP server implementation using@modelcontextprotocol/sdksrc/client.ts- HTTP client with multiple API endpoints (forecast, archive, air quality, marine, etc.)src/tools.ts- Tool metadata (name, title, description, annotations); input schemas come fromtypes.tssrc/types.ts- Zod validation schemas for all API parameters and responsessrc/truncation.ts- Caps oversized responses and serializes them for the clientsrc/security.ts- Auth, origin validation, rate limiting, trusted-proxy IP extraction (HTTP transport only)
API Client Architecture
The OpenMeteoClient class manages separate Axios instances for different Open-Meteo services:
- Main forecast API (
api.open-meteo.com) - Air quality API (
air-quality-api.open-meteo.com) - Marine weather API (
marine-api.open-meteo.com) - Archive/historical API (
archive-api.open-meteo.com) - Seasonal forecast API (
seasonal-api.open-meteo.com) - Ensemble forecast API (
ensemble-api.open-meteo.com) - Geocoding API (
geocoding-api.open-meteo.com) - Flood API (
flood-api.open-meteo.com)
Each service can be configured via environment variables with sensible defaults.
Transport Modes
The server supports two transport modes (configured via TRANSPORT env var):
- stdio (default) - Standard input/output for direct MCP client integration (Claude Desktop, etc.). Never write logs to stdout here — it would corrupt the protocol stream;
log()writes to stderr. - Streamable HTTP (
TRANSPORT=http) - Express-based HTTP server with session management, listening onPORT(default: 3000) at/mcpendpoint, bound toHOST(default:127.0.0.1, loopback only)
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.
- 10d ago First seen · 147 lines · 1,998 tokens per session scan A c603aee43ce0
open-meteo-mcp CLAUDE.md is an instructions file published in the GitHub repository cmer81/open-meteo-mcp (68 stars, last pushed 1mo ago), licensed MIT. It adds 1,998 tokens to every session, about $0.0100 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 2026-08-30.
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