---
url: /validators/mcp.md
description: >-
  Validate .mcp.json configuration files for transport types, URL formats,
  environment variable syntax, and server command validity with claudelint.
---

# MCP Servers Validator

The MCP validator checks `.mcp.json` configuration files for transport types, URLs, environment variables, and server configuration.

## What It Checks

* Transport type validity (stdio, SSE, HTTP, WebSocket)
* URL format validation per transport type
* Environment variable syntax
* Variable expansion patterns
* Command validation for stdio transport

## Rules

This validator includes  rules. See the [MCP rules category](/rules/mcp/mcp-http-empty-url) for the complete list.

## CLI Usage

```bash
claudelint validate-mcp
claudelint validate-mcp --verbose
```

## Plugin Skill

If you have the [claudelint plugin](/integrations/claude-code-plugin) installed, you can run this validator inside Claude Code with `/validate-mcp` or by asking "Validate my MCP config."

## See Also

* [Claude Code MCP Servers](https://code.claude.com/docs/en/mcp) - Official MCP documentation
* [Configuration](/guide/configuration) - Customize rule severity