title: "Wrap Any APIs as MCP Server: Test in Claude and Postman"
source: https://www.threeportkeys.com/wrap-any-apis-as-mcp-server-test-in-claude-and-postman/
author:
  - "[[Authority Pro]]"
published: 2025-06-20
created: 2025-10-13
description:
tags:
  - Computer/Code

Wrap Any APIs as MCP Server Test in Claude and Postman

n8n Now Runs My ENTIRE Homelab

Additional menu

Three Portkeys

Collection of skills, ideas and reflections

Wrap Any APIs as MCP Server: Test in Claude and Postman

posted on June 20, 2025

How-To Build Your First MCP Server with PyCharm

In this video, I’m going to show you how to wrap any APIs into a MCP Server, and then test it with Claude Desktop and Postman.
Github: https://github.com/portkeys/nasa-mcp

🎯 What You’ll Learn

By the end of this guide, you’ll know how to:

Use FastMCP for rapid MCP server development
Configure Claude Desktop to use custom MCP servers
Test Python MCP servers with both Claude and Postman
Leverage PyCharm’s AI Assistant for enhanced development

🚀 What We’re Building

We’ll create an MCP server that wraps two powerful NASA APIs:

Astronomy Picture of the Day (APOD) – Get stunning space imagery with detailed descriptions
NASA Image and Video Library – Search through NASA’s vast collection of space media

Four-step Plan

Step 1: Project Setup with UV Package Manager

First, let’s set up our project with UV, a modern Python package manager that’s faster and more reliable than pip.

Installing Dependencies

# uv add requests python-dotenv mcp

Environment Configuration

Create a .env file in your project root:

1	`NASA_API_KEY=your_nasa_api_key_here`

This approach keeps sensitive API keys out of your source code and makes your project more secure and portable.

Step 2: API Development & Testing

Now we’ll create our NASA API functions.

Create a new file nasa_api/nasa.py:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 import os from dotenv ``import load_dotenv import requests from typing ``import Optional, ``Dict load_dotenv() NASA_API_KEY ``= os.getenv(``"NASA_API_KEY"``) ``or "DEMO_KEY" def make_api_request(url: ``str``, params: ``dict``, timeout: ``int = 10``) ``-``> Optional[``Dict``]: """ Make an HTTP GET request to the specified URL with given parameters. Args: url (str): The URL to make the request to params (dict): Dictionary of parameters to include in the request timeout (int, optional): Request timeout in seconds. Defaults to 10. Returns: Optional[Dict]: JSON response as a dictionary if successful, None if failed Raises: Prints error message to console if request fails """ try``: response ``= requests.get(url, params``=``params, timeout``=``timeout) # Check if the response status code indicates success response.raise_for_status() # Try to parse JSON response return response.json() except requests.exceptions.Timeout: print``(f``"Request timeout after {timeout} seconds for URL: {url}"``) return None except requests.exceptions.ConnectionError: print``(f``"Connection error occurred for URL: {url}"``) return None except requests.exceptions.HTTPError as e: print``(f``"HTTP error {response.status_code} for URL: {url} - {e}"``) return None except requests.exceptions.RequestException as e: print``(f``"Request error for URL: {url} - {e}"``) return None except ValueError as e: print``(f``"JSON decode error for URL: {url} - Invalid JSON response: {e}"``) return None except Exception as e: print``(f``"Unexpected error for URL: {url} - {e}"``) return None def get_nasa_apod(date: Optional[``str``] ``= None``): """ Retrieve NASA's Astronomy Picture of the Day (APOD). Args: api_key (str, optional): NASA API key. Defaults to NASA_API_KEY from environment. date (Optional[str], optional): Date in YYYY-MM-DD format for specific APOD. If None, returns today's APOD. Defaults to None. Returns: Optional[Dict]: Dictionary containing APOD data including title, explanation, image URL, and other metadata. Returns None if request fails. Example: apod = get_nasa_apod(date="2023-01-01") print(apod["title"]) """ # Build API URL and parameters base_url ``= "[https://api.nasa.gov/planetary/apod](https://api.nasa.gov/planetary/apod)" params ``= { "api_key"``: NASA_API_KEY, } if date: # params[``"date"``] ``= date return make_api_request(base_url, params, timeout``=``10``) def search_nasa_images(query: ``str``, size: ``int = 3``) ``-``> Optional[``Dict``]: """ Search NASA's Image and Video Library for images matching the query. Args: query (str): Search term to look for in NASA's image library size (int, optional): Number of results to return (page size). Defaults to 3. Returns: Optional[Dict]: Dictionary containing search results with image metadata, URLs, and descriptions. Returns None if request fails. Example: results = search_nasa_images("Mars rover", size=5) for item in results["collection"]["items"]: print(item["data"][0]["title"]) """ # NASA Image and Video Library API endpoint base_url ``= "[https://images-api.nasa.gov/search](https://images-api.nasa.gov/search)" # Build parameters params ``= { "q"``: query, "media_type"``: ``"image"``, "page"``: ``1``, "page_size"``: size } return make_api_request(base_url, params, timeout``=``15``)

Step 3: MCP Server Implementation

This is where the magic happens. We’ll use FastMCP to transform our API functions into MCP tools that Claude can use.

Create nasa_mcp_server.py:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 import json from mcp.server.fastmcp ``import FastMCP from api.nasa ``import get_nasa_apod, search_nasa_images mcp ``= FastMCP() @mcp``.tool(``"get_nasa_apod"``) def get_apod_data(date: ``str = None``): """Get NASA's Astronomy Picture of the Day (APOD). Retrieves the featured astronomy image or video for a specific date, along with its title, explanation, and metadata from NASA's APOD service. Args: date: Optional date in YYYY-MM-DD format. If not provided, returns today's APOD. Must be between 1995-06-16 (first APOD) and today's date. Returns: JSON object containing APOD data including title, explanation, image URL, date, and other metadata, or error message if request fails. """ result ``= get_nasa_apod(date) if result: return json.dumps(result, indent``=``4``) else``: return {``"error"``: ``"Failed to retrieve APOD data"``} @mcp``.tool(``"search_images_data"``) def search_images_data(q: ``str``, size: ``int = 3``): """Search NASA's image and video library. Searches through NASA's extensive collection of images, videos, and audio files using keywords. Returns metadata and links to matching media assets. Args: q: Search query string. Can include keywords like mission names, celestial objects, astronauts, space phenomena, etc. (e.g., "Mars rover", "International Space Station") size: Number of results to return (default: 3). Recommended range: 1-20. Returns: JSON array containing search results with titles, descriptions, image URLs, dates, and other metadata for each matching item, or error message if search fails. """ result ``= search_nasa_images(query``=``q, size``=``size) if result: return json.dumps(result, indent``=``4``) else``: return {``"error"``: ``"Failed to search for images"``} def main(): mcp.run() if __name__ ``=``= "__main__"``: mcp.run()

Testing with MCP Inspector

Install MCP inspector globally

npm install -g @modelcontextprotocol/inspector

Run the inspector

mcp-inspector uv run python nasa_mcp_server.py

The inspector provides a web interface where you can test your MCP tools interactively, making debugging much easier.

Step 4: Test with Claude Desktop and Postman

Claude Desktop

Now we’ll configure Claude Desktop to use our custom MCP server. Edit your claude_desktop_config.json

{
    "mcpServers": {
      "nasa-mcp": {
          "command": "uv",
          "args":[
            "--directory",
            "/Users/wyang/Projects/2025/nasa_mcp/", 
            "run", 
            "nasa_mcp_server.py"]
      }
    }
  }

Important: Replace /path/to/your/project with the actual path to your project directory.

After updating the configuration:

Restart Claude Desktop
Look for the Claude settings and tools indicating MCP servers are connected
Try asking Claude: “Show me today’s NASA Astronomy Picture of the Day”

Testing with Postman

uv --directory /Users/wyang/Projects/2025/nasa_mcp/ run nasa_mcp_server.py

🥳 Whohoo~

Filed Under: GenAI

Reader Interactions

Primary Sidebar

Hey, I’m Wen!

Thanks for visiting Three Portkeys, I hope you enjoy it! Click around, and I look forward to connecting with you!

Wrap Any APIs as MCP Server: Test in Claude and Postman