Adding MCP to Postman

What is MCP in Postman?

The Model Context Protocol (MCP) in Postman enables you to test, build, and interact with MCP servers directly within the Postman AI Agent Builder. This integration allows you to evaluate MCP servers, test their functionality, and integrate them with your API workflows.

With MCP in Postman, you can:

  • Test and validate MCP servers before deployment

  • Evaluate community MCP servers from the Postman MCP Catalog

  • Build and debug custom MCP implementations

  • Integrate MCP tools with existing API testing workflows

  • Access verified API providers through MCP

Prerequisites

Before using MCP with Postman, ensure you have:

  • Postman installed (latest version)

  • Access to Postman AI Agent Builder

  • Your NLX API key and application URL

  • Basic understanding of MCP protocol concepts

Creating MCP Requests

Step 1: Access MCP in Postman

  1. Open Postman

  2. Navigate to your workspace

  3. Click New → MCP

  4. Select your preferred communication method

Step 2: Configure STDIO Connection

For testing the NLX MCP server locally:

  1. Choose Communication Method: Select STDIO

  2. Copy/Paste your setup snippet

    npx -y @nlxai/mcp-nodejs-server

  3. Set Environment Variables:

    • NLX_API_KEY: Your NLX API key

    • NLX_APP_URL: Your NLX application URL

Step 3: Load and Test Server Methods

  1. Click Load Server Methods

  2. Review available MCP tools and resources

  3. Select a method to test

  4. Configure method parameters

  5. Set authorization if required

  6. Click Run to execute the request

Example: Testing NLX MCP Server

{
  "communication": "stdio",
  "command": "npx",
  "args": ["-y", "@nlxai/mcp-nodejs-server"],
  "env": {
    "NLX_API_KEY": "nlx_api_1234567890abcdef",
    "NLX_APP_URL": "https://your-app.nlx.ai"
  }
}

Working with MCP Requests

Testing MCP Tools

Once connected to the NLX MCP server, you can test available tools:

  1. List Available Tools: Query the server for available MCP tools

  2. Test Tool Execution: Execute individual tools with sample parameters

  3. Validate Responses: Verify tool outputs and error handling

  4. Performance Testing: Measure response times and reliability

Testing MCP Resources

Access server resources:

  1. Browse Resources: List available resources from the MCP server

  2. Fetch Resource Data: Retrieve specific resource content

  3. Test Resource Updates: Verify resource modification capabilities

  4. Access Control Testing: Test resource permissions and security

Testing MCP Prompts

Interact with server prompts:

  1. List Prompts: Discover available prompt templates

  2. Execute Prompts: Run prompts with various parameters

  3. Template Testing: Validate prompt template functionality

  4. Context Integration: Test how prompts integrate with external context

Troubleshooting

Common Issues

STDIO connection fails:

  • Verify Node.js and npm are installed

  • Check that the MCP server package is accessible

  • Ensure environment variables are correctly set

MCP methods not loading:

  • Confirm the server is running and responsive

  • Check server logs for initialization errors

  • Verify MCP protocol compliance

Debug Configuration

Enable detailed logging for troubleshooting:

{
  "communication": "stdio",
  "command": "npx",
  "args": ["-y", "@nlxai/mcp-nodejs-server"],
  "env": {
    "NLX_API_KEY": "your-api-key",
    "NLX_APP_URL": "your-app-url",
    "DEBUG": "mcp:*",
    "LOG_LEVEL": "debug"
  }
}

Support Resources

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