Release Notes - v0.1.0¶

Release Date: 2026-01-10

Overview¶

This is the initial release of mcpkit, a library-first runtime for building MCP (Model Context Protocol) servers in Go. It wraps the official MCP Go SDK to provide a unified API where tools, prompts, and resources can be invoked either directly as library calls or exposed over standard MCP transports.

Installation¶

go get github.com/plexusone/mcpkit@v0.1.0

Requires Go 1.23+ and MCP Go SDK v1.2.0+.

Key Features¶

Dual Execution Modes¶

Define capabilities once, use them two ways:

Library Mode: Direct in-process function calls without JSON-RPC overhead
Server Mode: Standard MCP transports (stdio, HTTP, SSE)

rt := mcpkit.New(&mcp.Implementation{Name: "my-server", Version: "v1.0.0"}, nil)

// Register once
mcpkit.AddTool(rt, &mcp.Tool{Name: "add"}, addHandler)

// Library mode
result, err := rt.CallTool(ctx, "add", args)

// Server mode
rt.ServeStdio(ctx)

Full MCP SDK Compatibility¶

Uses mcp.Tool, mcp.Prompt, mcp.Resource types directly
Same handler signatures as the MCP SDK
Automatic JSON schema inference via generic AddTool[In, Out]()
All MCP transports supported

Comprehensive Feature Support¶

Feature	Library Mode	Server Mode
Tools	Yes	Yes
Prompts	Yes	Yes
Static Resources	Yes	Yes
Resource Templates	No	Yes

API Highlights¶

Runtime Creation¶

rt := mcpkit.New(impl *mcp.Implementation, opts *mcpkit.Options)

Tool Registration¶

// Generic with schema inference
mcpkit.AddTool(rt, tool, handler)

// Low-level
rt.AddToolHandler(tool, handler)

Library Mode Invocation¶

rt.CallTool(ctx, name, args)
rt.GetPrompt(ctx, name, args)
rt.ReadResource(ctx, uri)

Transport Adapters¶

rt.ServeStdio(ctx)
rt.StreamableHTTPHandler(opts)
rt.SSEHandler(opts)
rt.InMemorySession(ctx)  // for testing

Escape Hatch¶

rt.MCPServer()  // access underlying mcp.Server for advanced use

Use Cases¶

Unit testing MCP tools without mocking transports
Embedding agent capabilities directly in applications
Building local pipelines with MCP tools
Serverless runtimes where subprocess overhead is unacceptable
Gradual migration from library calls to full MCP server

Breaking Changes¶

None (initial release).

Known Limitations¶

Resource templates (dynamic URI patterns) work in server mode only; library mode supports exact URI matches
Advanced MCP features (subscriptions, progress notifications) accessible via MCPServer() escape hatch