07f6c490c6In practice, the streamable client transport was having trouble connecting to various backends, because they are nonconformant in various ways. While it would be nice if all servers conformed to the spec, in practice there are certain spec violations that are recoverable, and we can and should recover them. Specifically: - tolerate 404 instead of 405 for the hanging GET (#393) - tolerate (=ignore) spurious response body for notifications and responses, since we know none are expected Additionally, fix a bug that we weren't parsing Content-Type correctly. Fixes #521
86 lines
2.4 KiB
Go
86 lines
2.4 KiB
Go
// Copyright 2025 The Go MCP SDK Authors. All rights reserved.
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// Use of this source code is governed by an MIT-style
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// license that can be found in the LICENSE file.
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// The listfeatures command lists all features of a stdio MCP server.
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//
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// Usage: listfeatures <command> [<args>]
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//
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// For example:
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//
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// listfeatures go run github.com/modelcontextprotocol/go-sdk/examples/server/hello
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//
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// or
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//
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// listfeatures npx @modelcontextprotocol/server-everything
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package main
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import (
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"context"
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"flag"
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"fmt"
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"iter"
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"log"
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"os"
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"os/exec"
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"github.com/modelcontextprotocol/go-sdk/mcp"
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)
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var (
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endpoint = flag.String("http", "", "if set, connect to this streamable endpoint rather than running a stdio server")
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)
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func main() {
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flag.Parse()
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args := flag.Args()
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if len(args) == 0 && *endpoint == "" {
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fmt.Fprintln(os.Stderr, "Usage: listfeatures <command> [<args>]")
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fmt.Fprintln(os.Stderr, "Usage: listfeatures --http=\"https://example.com/server/mcp\"")
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fmt.Fprintln(os.Stderr, "List all features for a stdio MCP server")
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fmt.Fprintln(os.Stderr)
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fmt.Fprintln(os.Stderr, "Example:\n\tlistfeatures npx @modelcontextprotocol/server-everything")
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os.Exit(2)
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}
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var (
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ctx = context.Background()
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transport mcp.Transport
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)
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if *endpoint != "" {
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transport = &mcp.StreamableClientTransport{
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Endpoint: *endpoint,
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}
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} else {
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cmd := exec.Command(args[0], args[1:]...)
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transport = &mcp.CommandTransport{Command: cmd}
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}
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client := mcp.NewClient(&mcp.Implementation{Name: "mcp-client", Version: "v1.0.0"}, nil)
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cs, err := client.Connect(ctx, transport, nil)
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if err != nil {
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log.Fatal(err)
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}
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defer cs.Close()
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if cs.InitializeResult().Capabilities.Tools != nil {
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printSection("tools", cs.Tools(ctx, nil), func(t *mcp.Tool) string { return t.Name })
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}
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if cs.InitializeResult().Capabilities.Resources != nil {
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printSection("resources", cs.Resources(ctx, nil), func(r *mcp.Resource) string { return r.Name })
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printSection("resource templates", cs.ResourceTemplates(ctx, nil), func(r *mcp.ResourceTemplate) string { return r.Name })
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}
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if cs.InitializeResult().Capabilities.Prompts != nil {
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printSection("prompts", cs.Prompts(ctx, nil), func(p *mcp.Prompt) string { return p.Name })
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}
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}
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func printSection[T any](name string, features iter.Seq2[T, error], featName func(T) string) {
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fmt.Printf("%s:\n", name)
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for feat, err := range features {
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if err != nil {
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log.Fatal(err)
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}
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fmt.Printf("\t%s\n", featName(feat))
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}
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fmt.Println()
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}
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