Kiro Web supports two ways to extend the agent with additional tools and context: Powers and MCP servers.
Powers are a set of integrations included with Kiro Web that add specialized tools and context to the agent. You can configure which Powers are enabled for your sessions. To manage Powers, go to Settings, select the Agent tab, and click Manage powers under Sandbox.
MCP servers give you full control over custom tool integrations using the Model Context Protocol. You configure MCP servers manually and they are loaded into the sandbox at the start of each task.
To add an MCP server:
MCP servers are loaded when the sandbox starts and remain available throughout task execution.
{ "mcpServers": { "aws-knowledge-mcp-server": { "command": "uvx", "args": [ "fastmcp", "run", "https://knowledge-mcp.global.api.aws" ], "env": {} } } }
Only local MCP servers are currently supported. Remote MCP servers are not available at this time.
You can reference environment variables and secrets in your MCP configuration to securely pass credentials and configuration values to MCP servers.
Use the ${key_name} syntax to reference the key names of your environment variables and secrets in the server configuration:
{ "mcpServers": { "server-name": { "command": "executable", "args": ["arg1", "arg2"], "env": { "ENV_VAR_KEY": "${my_env_var_key}", "SECRET_KEY": "${my_secret_key}" } } } }
Both environment variables and secrets use the same syntax. The values are resolved when the sandbox starts.
Powers and MCP