# MCP Go SDK

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module, once it exists. -->

[![PkgGoDev](https://pkg.go.dev/badge/golang.org/x/tools)](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk)

This repository contains an unreleased implementation of the official Go
software development kit (SDK) for the Model Context Protocol (MCP).

**WARNING**: The SDK should be considered unreleased, and is currently unstable
and subject to breaking changes. Please test it out and file bug reports or API
proposals, but don't use it in real projects. See the issue tracker for known
issues and missing features. We aim to release a stable version of the SDK in
August, 2025.

## Package documentation

The SDK consists of two importable packages:

- The
  [`github.com/modelcontextprotocol/go-sdk/mcp`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp)
  package defines the primary APIs for constructing and using MCP clients and
  servers.
- The
  [`github.com/modelcontextprotocol/go-sdk/jsonschema`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/jsonschema)
  package provides an implementation of [JSON
  Schema](https://json-schema.org/), used for MCP tool input and output schema.

## Example

In this example, an MCP client communicates with an MCP server running in a
sidecar process:

%include client/client.go -

Here's an example of the corresponding server component, which communicates
with its client over stdin/stdout:

%include server/server.go -

The `examples/` directory contains more example clients and servers.

## Design

The design doc for this SDK is at [design.md](./design/design.md), which was
initially reviewed at
[modelcontextprotocol/discussions/364](https://github.com/orgs/modelcontextprotocol/discussions/364).

Further design discussion should occur in GitHub issues. See CONTRIBUTING.md
for details.

## Acknowledgements

Several existing Go MCP SDKs inspired the development and design of this
official SDK, notably [mcp-go](https://github.com/mark3labs/mcp-go), authored
by Ed Zynda. We are grateful to Ed as well as the other contributors to mcp-go,
and to authors and contributors of other SDKs such as
[mcp-golang](https://github.com/metoro-io/mcp-golang) and
[go-mcp](https://github.com/ThinkInAIXYZ/go-mcp). Thanks to their work, there
is a thriving ecosystem of Go MCP clients and servers.

## License

This project is licensed under the MIT License - see the [LICENSE](./LICENSE)
file for details.