MCP Servers

MCP (Model Context Protocol) servers extend Kiro with additional tools. Configure them in .kiro/settings/mcp.json in your workspace:

Kiro CLI: MCP can also be configured globally (~/.kiro/settings/mcp.json) or per-agent in ~/.kiro/agents/{name}.json. See MCP Overview and AWS MCP Integration for the terminal workflow.

mkdir -p .kiro/settings
cat > .kiro/settings/mcp.json << 'EOF'
{
  "mcpServers": {
    "aws": {
      "command": "uvx",
      "args": ["awslabs.aws-documentation-mcp-server@latest"],
      "env": {
        "FASTMCP_LOG_LEVEL": "ERROR"
      }
    }
  }
}
EOF

This example configures the AWS Documentation MCP server, which gives Kiro access to AWS documentation for more accurate infrastructure guidance.

Configuration Levels

MCP servers can be configured at two levels:

Level	Path	Scope
Workspace	.kiro/settings/mcp.json	Applies only to the current project
User	~/.kiro/settings/mcp.json	Applies globally across all workspaces

If both files exist, workspace settings take precedence. Use workspace-level for project-specific servers and user-level for servers you use everywhere.

Configuration Properties

Each server entry supports these properties:

Property	Description
command	Command to run the server (e.g., uvx, npx, node)
args	Arguments to pass to the command
env	Environment variables for the server process (supports ${VAR} expansion)
disabled	Set to true to temporarily disable without removing config
autoApprove	Tool names to auto-approve without prompting (use "*" for all)
disabledTools	Tool names to omit from the agent

Available MCP Servers

Server	Use case	Command
AWS Documentation	AWS service docs and best practices	uvx awslabs.aws-documentation-mcp-server@latest
AWS CDK	CDK construct guidance	uvx awslabs.cdk-mcp-server@latest
Terraform	Terraform provider docs	Community MCP servers available

Prerequisite for uvx: The uvx command comes from the uv Python package manager. If you did not install it during the WSL2 packages step, install it now:

curl -LsSf https://astral.sh/uv/install.sh | sh
source ~/.bashrc
uvx --version

uv is not included in the essential packages installed earlier because it’s only needed if you use MCP servers that rely on uvx.

Verify MCP Configuration

After saving .kiro/settings/mcp.json:

• Changes apply automatically when you save the file — servers reconnect without restarting Kiro
• Open the Kiro panel to check server status (running, connected, or error)
• If a server fails to start, check:
  • The command is available in your WSL PATH
  • Required environment variables are set
  • Network access is available (some servers fetch remote resources)
  • JSON syntax is valid (no missing commas or brackets)