add-mcp-server

Add an MCP Server

Add an MCP server configuration to pi-mcp-adapter. Determine scope and server type, write the config, and verify the connection.

Step 1: Determine Scope

Ask the user if not obvious from context:

Scope	Config File	When to Use
Global	~/.pi/agent/mcp.json	Server used across all projects
Project	.pi/mcp.json (project root)	Server specific to one project

Project-local configs override global ones. Both files use the same format.

Step 2: Determine Server Type

MCP servers connect via stdio (local process) or HTTP (remote URL).

Stdio server — runs a local command:

{
  "mcpServers": {
    "server-name": {
      "command": "npx",
      "args": ["-y", "package-name@latest"],
      "env": { "KEY": "value" }
    }
  }
}

HTTP server — connects to a URL:

{
  "mcpServers": {
    "server-name": {
      "url": "http://localhost:8080/mcp",
      "headers": { "Authorization": "Bearer token" }
    }
  }
}

Step 3: Gather Configuration

Collect only what's needed. All fields except command/url are optional.

Field	Type	Description
command	string	Executable to run (stdio)
args	string[]	Command arguments (stdio)
env	object	Environment variables (stdio)
cwd	string	Working directory (stdio)
url	string	Server URL (HTTP)
headers	object	HTTP headers (HTTP)
auth	"oauth" or "bearer"	Auth method (HTTP)
bearerToken	string	Static bearer token
bearerTokenEnv	string	Env var name for bearer token
lifecycle	"lazy" / "eager" / "keep-alive"	Connection strategy (default: lazy)
idleTimeout	number	Minutes before idle disconnect
debug	boolean	Show server stderr

Lifecycle modes:

• lazy (default) — connects on first tool call, disconnects after idle timeout
• eager — connects at session start, no auto-disconnect
• keep-alive — connects at start, auto-reconnects if dropped

Step 4: Write the Config

1. Read the target config file if it exists
2. Merge the new server into the existing mcpServers object
3. Write the updated JSON

If the file doesn't exist, create it with the full structure:

{
  "mcpServers": {
    "server-name": { ... }
  }
}

Warn if a server with the same name already exists and confirm before overwriting.

Step 5: Verify

1. Run /reload to pick up the new config
2. Use mcp({ connect: "server-name" }) to test the connection
3. Use mcp({ server: "server-name" }) to list available tools
4. Report success or troubleshoot connection errors