55 lines
2.6 KiB
Markdown
55 lines
2.6 KiB
Markdown
# Support for MCP client features
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%toc
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## Roots
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MCP allows clients to specify a set of filesystem
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["roots"](https://modelcontextprotocol.io/specification/2025-06-18/client/roots).
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The SDK supports this as follows:
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**Client-side**: The SDK client always has the `roots.listChanged` capability.
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To add roots to a client, use the
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[`Client.AddRoots`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#Client.AddRoots)
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and
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[`Client.RemoveRoots`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#Client.RemoveRoots)
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methods. If any servers are already [connected](protocol.md#lifecycle) to the
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client, a call to `AddRoot` or `RemoveRoots` will result in a
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`notifications/roots/list_changed` notification to each connected server.
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**Server-side**: To query roots from the server, use the
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[`ServerSession.ListRoots`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerSession.ListRoots)
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method. To receive notifications about root changes, set
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[`ServerOptions.RootsListChangedHandler`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerOptions.RootsListChangedHandler).
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%include ../../mcp/client_example_test.go roots -
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## Sampling
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[Sampling](https://modelcontextprotocol.io/specification/2025-06-18/client/sampling)
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is a way for servers to leverage the client's AI capabilities. It is
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implemented in the SDK as follows:
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**Client-side**: To add the `sampling` capability to a client, set
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[`ClientOptions.CreateMessageHandler`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientOptions.CreateMessageHandler).
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This function is invoked whenever the server requests sampling.
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**Server-side**: To use sampling from the server, call
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[`ServerSession.CreateMessage`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerSession.CreateMessage).
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%include ../../mcp/client_example_test.go sampling -
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## Elicitation
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[Elicitation](https://modelcontextprotocol.io/specification/2025-06-18/client/elicitation)
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allows servers to request user inputs. It is implemented in the SDK as follows:
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**Client-side**: To add the `elicitation` capability to a client, set
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[`ClientOptions.ElicitationHandler`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ClientOptions.ElicitationHandler).
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The elicitation handler must return a result that matches the requested schema;
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otherwise, elicitation returns an error.
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**Server-side**: To use elicitation from the server, call
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[`ServerSession.Elicit`](https://pkg.go.dev/github.com/modelcontextprotocol/go-sdk/mcp#ServerSession.Elicit).
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%include ../../mcp/client_example_test.go elicitation -
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