148 lines
4.8 KiB
Markdown
148 lines
4.8 KiB
Markdown
<!-- Autogenerated by weave; DO NOT EDIT -->
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# Support for MCP server features
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1. [Prompts](#prompts)
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1. [Resources](#resources)
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1. [Tools](#tools)
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1. [Utilities](#utilities)
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1. [Completion](#completion)
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1. [Logging](#logging)
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1. [Pagination](#pagination)
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## Prompts
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**Server-side**:
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MCP servers can provide LLM prompt templates (called simply _prompts_) to clients.
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Every prompt has a required name which identifies it, and a set of named arguments, which are strings.
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Construct a prompt with a name and descriptions of its arguments.
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Associated with each prompt is a handler that expands the template given values for its arguments.
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Use [`Server.AddPrompt`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#Server.AddPrompt)
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to add a prompt along with its handler.
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If `AddPrompt` is called before a server is connected, the server will have the `prompts` capability.
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If all prompts are to be added after connection, set [`ServerOptions.HasPrompts`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerOptions.HasPrompts)
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to advertise the capability.
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**Client-side**:
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To list the server's prompts, call
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Call [`ClientSession.Prompts`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.Prompts) to get an iterator.
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If needed, you can use the lower-level
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[`ClientSession.ListPrompts`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.ListPrompts) to list the server's prompts.
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Call [`ClientSession.GetPrompt`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.GetPrompt) to retrieve a prompt by name, providing
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arguments for expansion.
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Set [`ClientOptions.PromptListChangedHandler`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientOptions.PromptListChangedHandler) to be notified of changes in the list of prompts.
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```go
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func Example_prompts() {
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ctx := context.Background()
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promptHandler := func(ctx context.Context, req *mcp.GetPromptRequest) (*mcp.GetPromptResult, error) {
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return &mcp.GetPromptResult{
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Description: "Hi prompt",
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Messages: []*mcp.PromptMessage{
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{
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Role: "user",
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Content: &mcp.TextContent{Text: "Say hi to " + req.Params.Arguments["name"]},
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},
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},
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}, nil
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}
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// Create a server with a single prompt.
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s := mcp.NewServer(&mcp.Implementation{Name: "server", Version: "v0.0.1"}, nil)
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prompt := &mcp.Prompt{
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Name: "greet",
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Arguments: []*mcp.PromptArgument{
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{
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Name: "name",
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Description: "the name of the person to greet",
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Required: true,
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},
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},
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}
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s.AddPrompt(prompt, promptHandler)
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// Create a client.
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c := mcp.NewClient(&mcp.Implementation{Name: "client", Version: "v0.0.1"}, nil)
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// Connect the server and client.
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t1, t2 := mcp.NewInMemoryTransports()
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if _, err := s.Connect(ctx, t1, nil); err != nil {
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log.Fatal(err)
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}
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cs, err := c.Connect(ctx, t2, nil)
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if err != nil {
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log.Fatal(err)
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}
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// List the prompts.
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for p, err := range cs.Prompts(ctx, nil) {
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if err != nil {
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log.Fatal(err)
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}
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fmt.Println(p.Name)
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}
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// Get the prompt.
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res, err := cs.GetPrompt(ctx, &mcp.GetPromptParams{
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Name: "greet",
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Arguments: map[string]string{"name": "Pat"},
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})
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if err != nil {
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log.Fatal(err)
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}
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for _, msg := range res.Messages {
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fmt.Println(msg.Role, msg.Content.(*mcp.TextContent).Text)
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}
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// Output:
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// greet
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// user Say hi to Pat
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}
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```
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## Resources
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<!-- TODO -->
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## Tools
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<!-- TODO -->
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## Utilities
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<!-- TODO -->
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### Completion
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<!-- TODO -->
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### Logging
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<!-- TODO -->
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### Pagination
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Server-side feature lists may be
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[paginated](https://modelcontextprotocol.io/specification/2025-06-18/server/utilities/pagination),
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using cursors. The SDK supports this by default.
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**Client-side**: The `ClientSession` provides methods returning
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[iterators](https://go.dev/blog/range-functions) for each feature type.
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These iterators are an `iter.Seq2[Feature, error]`, where the error value
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indicates whether page retrieval failed.
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- [`ClientSession.Prompts`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.Prompts)
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iterates prompts.
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- [`ClientSession.Resource`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.Resource)
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iterates resources.
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- [`ClientSession.ResourceTemplates`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.ResourceTemplates)
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iterates resource templates.
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- [`ClientSession.Tools`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientSession.Tools)
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iterates tools.
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The `ClientSession` also exposes `ListXXX` methods for fine-grained control
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over pagination.
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**Server-side**: pagination is on by default, so in general nothing is required
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server-side. However, you may use
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[`ServerOptions.PageSize`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerOptions.PageSize)
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to customize the page size.
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