mcp-tools

MCP Tools Example

Connect to MCP (Model Context Protocol) tool servers via the PromptKit SDK.

What You'll Learn

• Simple MCP server registration with WithMCP()
• Builder pattern with NewMCPServer() for timeouts and tool filters
• Tool filtering to expose only specific tools from a server

Prerequisites

• Go 1.21+
• OpenAI API key
• Node.js / npx (for the MCP server)
• @modelcontextprotocol/server-everything npm package

Running the Example

export OPENAI_API_KEY=your-key
go run .

Code Overview

Pattern 1: Simple Registration

conv, err := sdk.Open("./mcp-tools.pack.json", "assistant",
    sdk.WithMCP("everything", "npx", "@modelcontextprotocol/server-everything"),
)

Pattern 2: Builder with Tool Filter

server := sdk.NewMCPServer("everything", "npx", "@modelcontextprotocol/server-everything").
    WithTimeout(10000).
    WithToolFilter(&mcp.ToolFilter{
        Allowlist: []string{"echo", "get-sum"},
    })

conv, err := sdk.Open("./mcp-tools.pack.json", "assistant",
    sdk.WithMCPServer(server),
)

Builder Options

Tool Naming

MCP tools are namespaced as mcp__<server>__<tool>:

• mcp__everything__echo
• mcp__everything__get-sum

Key Concepts

1. Auto-Discovery - Tools are discovered from the MCP server at startup
2. Tool Filtering - Expose only the tools you need via allowlist/blocklist
3. Timeouts - Per-request timeouts protect against slow servers
4. No Pack Changes - MCP tools don't need to be defined in the pack file

Next Steps

• A2A Agent Example - Remote agent integration with auth
• HTTP Transforms Example - Argument transforms and response processing
• Tools Example - Basic tool handling