Model Context Protocol (MCP)

Model Context Protocol (MCP) extends Kiro's capabilities by connecting to specialized servers that provide additional tools and context. This guide helps you set up, configure, and use MCP servers with Kiro across all surfaces.

MCP is a protocol that allows Kiro to communicate with external servers to access specialized tools, prompts, and resources. For example, the AWS Documentation MCP server provides tools to search, read, and get recommendations from AWS documentation directly within Kiro.

With MCP, you can:

• Access specialized knowledge bases and documentation
• Integrate with external services and APIs
• Extend Kiro's capabilities with domain-specific tools
• Use server-provided prompt templates and resource templates via the # mention system in chat
• Respond to server elicitation requests when tools need additional input during execution
• Create custom tools for your specific workflows

Before using MCP, make sure you have:

1. The latest version of Kiro installed
2. Any specific prerequisites for the MCP servers you want to use (listed in each server's documentation)

{
  "mcpServers": {
    "fetch": {
      "command": "uvx",
      "args": ["mcp-server-fetch"],
      "disabled": false
    }
  }
}

Some server directories and websites offer one-click install links that use the kiro:// URL scheme. Opening one of these links doesn't change your setup immediately: Kiro shows a confirmation dialog before anything is written to your configuration. The dialog lists the command that will run and its arguments, along with the names of any environment variables or headers - their values stay hidden. Review the details and confirm to add the server, or cancel to leave your configuration unchanged.

You can also define MCP servers directly in an agent's configuration file. The mcpServers field specifies which MCP servers the agent has access to:

{
  "name": "myagent",
  "description": "My special agent",
  "mcpServers": {
    "fetch": {
      "command": "fetch3.1",
      "args": []
    }
  },
  "includeMcpJson": false
}

The includeMcpJson field determines whether to include MCP servers defined in workspace and user-level configuration files. When set to true, the agent has access to all MCP servers defined in user and workspace-level configurations in addition to those defined in the agent's mcpServers field.

If you see "The following tools have been excluded due to validation errors", the tool fails one of these requirements:

• Tool name exceeds 64 characters (including server prefix)
• Tool name contains invalid characters (must match ^[a-zA-Z][a-zA-Z0-9_]*$)
• Tool description is empty

Contact the MCP server maintainer to fix the tool specification.

If you see "The following tools have large descriptions which may impact agent performance", a tool description exceeds 10,000 characters. The tool still works but may slow down responses. Consider asking the server maintainer to shorten the description.

• Official MCP Documentation

• Configuration - Detailed configuration options and file structure
• Server directory - Browse available MCP servers
• Tools - Learn how to use MCP tools effectively
• Best practices - Security best practices for MCP usage