What is open-meteo-mcp CLAUDE.md?

A repository instruction file for Claude Code, an AI coding assistant, working on an Open-Meteo weather-service connector. It explains the project structure, main components, and how the API client is organized.

Use it when modifying the repository's weather connector, including forecast, historical weather, air quality, marine, seasonal, and climate-related API code.

It gives the coding assistant the repository context needed to make changes consistently. It describes the different weather services and where their code lives.

How windsornguyen/open-meteo-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to windsornguyen/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.

Copy the file

curl -O https://raw.githubusercontent.com/windsornguyen/open-meteo-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/windsornguyen/open-meteo-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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/windsornguyen/open-meteo-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/windsornguyen/open-meteo-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/windsornguyen/open-meteo-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/windsornguyen/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/windsornguyen/open-meteo-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/windsornguyen/open-meteo-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 942 This file is loaded in full into every session.

When invoked 942 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	$0.00942	$0.00942
Opus 5.5	$0.00377	$0.00377
Sonnet 5.5	$0.00188	$0.00188
Haiku 4.5	$0.00094	$0.00094

Measured 2mo ago against content hash 8c49613bd84d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

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 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.

CLAUDE.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 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/sdk
src/client.ts - HTTP client with multiple API endpoints (forecast, archive, air quality, marine, etc.)
src/tools.ts - MCP tool definitions with comprehensive JSON schemas
src/types.ts - Zod validation schemas for all API parameters and responses

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)

Each service can be configured via environment variables with sensible defaults.

Tool System

Tools are organized by weather service type:

Core weather tools: weather_forecast, weather_archive, air_quality, marine_weather, elevation
Specialized model tools: dwd_icon_forecast, gfs_forecast, meteofrance_forecast, ecmwf_forecast, jma_forecast, metno_forecast, gem_forecast
Advanced forecasting: flood_forecast, seasonal_forecast, climate_projection, ensemble_forecast

Each tool has comprehensive JSON schema validation with proper enum constraints for weather variables and units.

Development Commands

# Development with auto-reload
npm run dev

# Build TypeScript to dist/
npm run build

# Start production server 
npm start

# Run tests
npm test

# Type checking
npm run typecheck

# Linting
npm run lint

Read the full file on GitHub · 104 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 · 104 lines · 942 tokens per session scan A 8c49613bd84d

Subscribe to this mod's changes

open-meteo-mcp CLAUDE.md is an instructions file published in the GitHub repository windsornguyen/open-meteo-mcp (0 stars, last pushed 1y ago), licensed MIT. It adds 942 tokens to every session, about $0.0038 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.

open-meteo-mcp CLAUDE.md next to 6 instructions from other repositories
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open-meteo-mcp: Instructions file for Claude Code