update-mcp

Manage MCP Server Templates

MCP (Model Context Protocol) server configurations define external tool servers available to AI tools. They use JSON format (not markdown), similar to hooks.

Finding Existing MCP Configs

List files in <%= mcpTemplatePath() %>/ to discover existing MCP templates (.json files). Read them to understand what servers are already configured.

Note: Servers from multiple files are merged by server name during generation, and the first declaration of a name wins (templatesDir before additionalTemplateDirs, in order). You can organize servers by concern (e.g. github.json, databases.json).

Deciding What to Do

• Create new file: for an entirely new server or group of related servers
• Update existing file: modify server config, add servers to an existing file
• Merge strategy: since servers merge by name, you can split them across files for better organization
• Delete: remove an MCP config file when the server is no longer needed

Creating a New MCP Config

1. Create a .json file in <%= mcpTemplatePath() %>/ with a descriptive name (e.g. github.json)
2. Use the standard MCP JSON structure

JSON Structure

{
  "mcpServers": {
    "server-name": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@some/mcp-server"],
      "env": {
        "API_KEY": "${API_KEY}"
      }
    }
  }
}

Server Fields

See the MCP Servers → Server Fields section in <%= instructionPath('uac-template-guide') %> for the complete reference, including all 13 Codex-specific fields (cwd, envVars, enabledTools, disabledTools, bearerTokenEnvVar, envHttpHeaders, startupTimeoutSec, startupTimeoutMs, toolTimeoutSec, enabled, required, oauthResource, scopes, experimentalEnvironment).

Key cross-target fields: