f211cc8e4a
CallToolParams.Arguments is any. Clients can send whatever they want. Tool authors who create their own ToolHandler (bypassing NewTool) will receive the arguments as a map[string]any which has been validated against the input schema. Tool authors who call NewTool can choose the type that the arguments unmarshal into. There is no double-unmarshaling and no downcasting. There is no way for tool authors to avoid the unmarshal, and no way to avoid the validation unless the omit an input schema, which is probably bad for LLMs. If tool authors want this optimization, we can provide it later. Change-Id: Ieb201e56c7fb8a23bb1a93b27e946630ec9e79ad Reviewed-on: https://go-review.googlesource.com/c/tools/+/679595 TryBot-Bypass: Jonathan Amsterdam <jba@google.com> Auto-Submit: Jonathan Amsterdam <jba@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
127 lines
3.5 KiB
Markdown
127 lines
3.5 KiB
Markdown
<!-- Autogenerated by weave; DO NOT EDIT -->
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# MCP SDK prototype
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[](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp)
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# Contents
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1. [Installation](#installation)
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1. [Quickstart](#quickstart)
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1. [Design](#design)
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1. [Testing](#testing)
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1. [Code of Conduct](#code-of-conduct)
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1. [License](#license)
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The mcp package provides a software development kit (SDK) for writing clients
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and servers of the [model context
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protocol](https://modelcontextprotocol.io/introduction). It is unstable, and
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will change in breaking ways in the future. As of writing, it is a prototype to
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explore the design space of client/server transport and binding.
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# Installation
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The mcp package is currently internal and cannot be imported using `go get`.
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# Quickstart
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Here's an example that creates a client that talks to an MCP server running
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as a sidecar process:
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```go
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package main
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import (
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"context"
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"log"
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"os/exec"
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"github.com/modelcontextprotocol/go-sdk/mcp"
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)
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func main() {
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ctx := context.Background()
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// Create a new client, with no features.
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client := mcp.NewClient("mcp-client", "v1.0.0", nil)
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// Connect to a server over stdin/stdout
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transport := mcp.NewCommandTransport(exec.Command("myserver"))
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session, err := client.Connect(ctx, transport)
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if err != nil {
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log.Fatal(err)
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}
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defer session.Close()
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// Call a tool on the server.
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params := &mcp.CallToolParams{
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Name: "greet",
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Arguments: map[string]any{"name": "you"},
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}
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if res, err := session.CallTool(ctx, params); err != nil {
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log.Printf("CallTool failed: %v", err)
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} else {
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if res.IsError {
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log.Print("tool failed")
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}
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for _, c := range res.Content {
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log.Print(c.Text)
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}
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}
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}
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```
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Here is an example of the corresponding server, connected over stdin/stdout:
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```go
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package main
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import (
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"context"
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"github.com/modelcontextprotocol/go-sdk/mcp"
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)
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type HiParams struct {
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Name string `json:"name"`
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}
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func SayHi(ctx context.Context, cc *mcp.ServerSession, params *mcp.CallToolParamsFor[HiParams]) (*mcp.CallToolResultFor[string], error) {
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return &mcp.CallToolResultFor[string]{
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Content: []*mcp.Content{mcp.NewTextContent("Hi " + params.Name)},
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}, nil
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}
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func main() {
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// Create a server with a single tool.
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server := mcp.NewServer("greeter", "v1.0.0", nil)
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server.AddTools(mcp.NewTool("greet", "say hi", SayHi))
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// Run the server over stdin/stdout, until the client disconnects
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_ = server.Run(context.Background(), mcp.NewStdIOTransport())
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}
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```
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# Design
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See [design.md](./design/design.md) for the SDK design. That document is
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canonical: given any divergence between the design doc and this prototype, the
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doc reflects the latest design.
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# Testing
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To test your client or server using stdio transport, you can use an in-memory
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transport. See [example](server_example_test.go).
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To test your client or server using sse transport, you can use the [httptest](https://pkg.go.dev/net/http/httptest)
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package. See [example](sse_example_test.go).
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# Code of Conduct
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This project follows the [Go Community Code of Conduct](https://go.dev/conduct).
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If you encounter a conduct-related issue, please mail conduct@golang.org.
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# License
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Unless otherwise noted, the Go source files are distributed under the BSD-style
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license found in the [LICENSE](../../LICENSE) file.
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Upon a potential move to the
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[modelcontextprotocol](https://github.com/modelcontextprotocol) organization,
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the license will be updated to the MIT License, and the license header will
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reflect the Go MCP SDK Authors.
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