Atlas / MCP servers / microsoft / Weather Server

Weather ServerSAFE

mcp/microsoft/weather-server-3
Verdict
SAFE
Grade
B
Trust score
89 /100
Exposed tools
1 1r · 0w · 0d
Transport
stdio
License
MIT
Stars
97
01

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

A simple Model Context Protocol (MCP) server that provides real-time weather data to AI agents like GitHub Copilot.

Quick Start

Clone the repository:

git clone https://github.com/microsoft/lets-learn-mcp-javascript.git
cd mcp-weather-server

1. Install Dependencies

npm install

2. Run the Server

Test with MCP Inspector:

npx -y @modelcontextprotocol/inspector npx -y tsx main.ts

3. Use with VS Code

  1. Open the mcp.jsonfile in .vscode folder
  2. Click the start server button above line 4
  3. Open Chat mode and select agent and choose a modal that supports MCPs such as Claude Sonnet
  4. Type or speak into the chat and ask it what the weather is like in your city

Features

  • 🌤️ Real-time weather data for any city
  • 🌍 No API key required (uses Open-Meteo)
  • 🤖 Works with GitHub Copilot and other MCP-compatible AI tools
  • ⚡ Easy to test with MCP Inspector

Usage Examples

Ask GitHub Copilot:

  • "What's the weather like in Tokyo?"
  • "How's the weather in London today?"
  • "Give me the current weather for Paris"

How It Works

The server provides a get-weather tool that:

  1. Converts city names to coordinates using geocoding
  2. Fetches current weather data from Open-Meteo API
  3. Returns structured data that AI agents can format beautifully

Code Structure

// Creates MCP server with weather tool
const server = new McpServer({
name: "Weather Server",
version: "1.0.0"
});

// Defines the get-weather tool
server.tool('get-weather', 'Tool to get the weather of a city', ...);

// Connects via stdio transport
const transport = new StdioServerTransport();
server.connect(transport);

Dependencies

  • @modelcontextprotocol/sdk - MCP server framework
  • zod - Schema validation
  • tsx - TypeScript execution (for development)

API Used

  • Open-Meteo - Free weather API with no authentication required
Read from source at commit 42688b402550OBSERVED · 2026-10-07
02

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.

claude-code
claude mcp add mcp-server-weather -- npx -y [email protected]
claude-desktop
{
  "mcpServers": {
    "mcp-server-weather": {
      "command": "npx",
      "args": [
        "-y",
        "[email protected]"
      ]
    }
  }
}
03

Exposed tools (1)

1 read · 0 write · 0 destructive.

ToolRiskDescription
get-weatherreadTool to get the weather of a city
04

Trust audit

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codePASS
L2Instruction surface (what it tells the agent)PASS
L3Class-specific surfacePASS
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
none-observed
Network
declared (2 observation(s))
Shell
none-observed
Dependencies
not all pinned
Secrets in source
none-found

Findings (3)

LOWNetwork egress · net.raw_ip · CWE-200, CWE-319
part2-building-mcp-server.md:121
- A localhost URL (like http://127.0.0.1:6274)
LOWSupply chain · supply.unpinned · CWE-829, CWE-1357
package.json
@modelcontextprotocol/sdk, zod
Why it matters. 2 dependency range(s) float
Fix. pin exact versions or ship a lockfile
INFOInventory / provenance · inv.oversize · CWE-1104
Lets Learn MCP.pdf
Lets Learn MCP.pdf
Why it matters. 3895373 bytes not read

Gates applied: no_behavioural_pass.

Audited 2026-10-07 · audit v0.4.1 · source sha 42688b402550full audit observations/trust-audit/mcp-server/microsoft__weather-server-3.json · Report an issue / request a re-scan
05

Audit history

Every audit this server has had. A grade with a past is a grade somebody is still checking.

DateSourceVerdictGradeScoreChange
2026-10-0742688b402550SAFEB89first audit
06

Questions

What tools does Weather Server expose?

1 in total: 1 read-only, 0 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.

Is Weather Server safe to connect to an agent?

The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.

What credentials does Weather Server need?

No credential environment variables were found in its source, so it appears to need none.

How does Weather Server run?

It speaks stdio, so it runs as a local process your client starts. It is published on npm as mcp-server-weather at 1.0.0.

How current is this page?

The grade is for one exact copy of the source (42688b402550), read on 2026-10-07. The repository is watched and re-audited when it changes.

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