Enrich Server Card with icons and supported protocol versions

Populate the optional forward fields the v1 Server Card schema already
defines so the card is complete for discovery:

- icons: the GitHub mark in light and dark themes, reusing the embedded
  Octicons as self-contained data URIs so the card has no external image
  dependency. The icon order is fixed to keep the serialized card — and
  thus its ETag — deterministic.
- supportedProtocolVersions on the streamable-http remote, defaulted from
  DefaultProtocolVersions (mirroring the bundled go-sdk's supported
  versions, which are unexported) and overridable via Config.

The canonical card name io.github.github/github-mcp-server is unchanged,
preserving the downstream AI Catalog identity derived from it.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SamMorrowDrums

pkg/http/servercard/card.go

@@ -13,7 +13,11 @@
 //   - https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2127
 package servercard
 
-import "net/http"
+import (
+	"net/http"
+
+	"github.com/github/github-mcp-server/pkg/octicons"
+)
 
 const (
 	// SchemaURL is the v1 Server Card JSON Schema URI that emitted cards
@@ -31,8 +35,26 @@ const (
 	// DefaultRemoteURL is the streamable-HTTP endpoint of the hosted GitHub MCP
 	// Server on github.com. The remote repository overrides this per environment.
 	DefaultRemoteURL = "https://api.githubcopilot.com/mcp/"
+
+	// iconName is the Octicon used as the server's icon (the GitHub mark).
+	iconName = "mark-github"
+
+	// iconSize is the pixel dimension of the embedded Octicon PNGs (square).
+	iconSize = "24x24"
 )
 
+// DefaultProtocolVersions lists the MCP protocol versions advertised on the
+// card's remote when Config.ProtocolVersions is not set. It mirrors the
+// versions supported by the bundled go-sdk (see modelcontextprotocol/go-sdk
+// mcp.supportedProtocolVersions, which is unexported) and is ordered newest
+// first. Keep it in sync when the go-sdk dependency in go.mod is upgraded.
+var DefaultProtocolVersions = []string{
+	"2025-11-25",
+	"2025-06-18",
+	"2025-03-26",
+	"2024-11-05",
+}
+
 // Identity fields reused from the MCP Registry document (server.json) so the
 // Server Card and the registry entry describe the same server.
 const (
@@ -161,6 +183,10 @@ type Config struct {
 	// It is consumed by the Handler when serving a card; NewServerCard ignores
 	// it, since the card constructor is not request-aware.
 	RemoteURLFunc func(*http.Request) string
+
+	// ProtocolVersions overrides the MCP protocol versions advertised on the
+	// card's remote. When empty, DefaultProtocolVersions is used.
+	ProtocolVersions []string
 }
 
 // NewServerCard builds the GitHub MCP Server's Server Card from cfg.
@@ -175,13 +201,19 @@ func NewServerCard(cfg Config) *ServerCard {
 		remoteURL = DefaultRemoteURL
 	}
 
+	protocolVersions := cfg.ProtocolVersions
+	if protocolVersions == nil {
+		protocolVersions = DefaultProtocolVersions
+	}
+
 	return &ServerCard{
 		Schema:      SchemaURL,
 		Name:        serverName,
 		Version:     version,
 		Description: serverDescription,
 		Title:       serverTitle,
 		WebsiteURL:  repositoryURL,
+		Icons:       githubIcons(),
 		Repository: &Repository{
 			URL:    repositoryURL,
 			Source: repositorySource,
@@ -201,7 +233,36 @@ func NewServerCard(cfg Config) *ServerCard {
 						Name: "Authorization",
 					},
 				},
+				SupportedProtocolVersions: protocolVersions,
 			},
 		},
 	}
 }
+
+// githubIcons returns the light- and dark-theme GitHub mark icons as
+// self-contained data URIs, reusing the embedded Octicons so the card has no
+// external image dependency. The order is fixed so the serialized card — and
+// therefore its ETag — is deterministic. It returns nil if the icons are
+// unavailable.
+func githubIcons() []Icon {
+	themes := []struct {
+		octicon octicons.Theme
+		card    string
+	}{
+		{octicons.ThemeLight, "light"},
+		{octicons.ThemeDark, "dark"},
+	}
+
+	var icons []Icon
+	for _, t := range themes {
+		if src := octicons.DataURI(iconName, t.octicon); src != "" {
+			icons = append(icons, Icon{
+				Src:      src,
+				MimeType: "image/png",
+				Sizes:    []string{iconSize},
+				Theme:    t.card,
+			})
+		}
+	}
+	return icons
+}

pkg/http/servercard/card_test.go

@@ -53,28 +53,39 @@ func TestNewServerCard(t *testing.T) {
 	resolved := resolvedCardSchema(t)
 
 	tests := []struct {
-		name              string
-		cfg               Config
-		expectedVersion   string
-		expectedRemoteURL string
+		name                     string
+		cfg                      Config
+		expectedVersion          string
+		expectedRemoteURL        string
+		expectedProtocolVersions []string
 	}{
 		{
-			name:              "defaults",
-			cfg:               Config{},
-			expectedVersion:   "0.0.0-dev",
-			expectedRemoteURL: DefaultRemoteURL,
+			name:                     "defaults",
+			cfg:                      Config{},
+			expectedVersion:          "0.0.0-dev",
+			expectedRemoteURL:        DefaultRemoteURL,
+			expectedProtocolVersions: DefaultProtocolVersions,
 		},
 		{
-			name:              "explicit version",
-			cfg:               Config{Version: "1.2.3"},
-			expectedVersion:   "1.2.3",
-			expectedRemoteURL: DefaultRemoteURL,
+			name:                     "explicit version",
+			cfg:                      Config{Version: "1.2.3"},
+			expectedVersion:          "1.2.3",
+			expectedRemoteURL:        DefaultRemoteURL,
+			expectedProtocolVersions: DefaultProtocolVersions,
 		},
 		{
-			name:              "per-environment remote URL",
-			cfg:               Config{Version: "1.2.3", RemoteURL: "https://api.example.test/mcp/"},
-			expectedVersion:   "1.2.3",
-			expectedRemoteURL: "https://api.example.test/mcp/",
+			name:                     "per-environment remote URL",
+			cfg:                      Config{Version: "1.2.3", RemoteURL: "https://api.example.test/mcp/"},
+			expectedVersion:          "1.2.3",
+			expectedRemoteURL:        "https://api.example.test/mcp/",
+			expectedProtocolVersions: DefaultProtocolVersions,
+		},
+		{
+			name:                     "explicit protocol versions",
+			cfg:                      Config{ProtocolVersions: []string{"2025-06-18"}},
+			expectedVersion:          "0.0.0-dev",
+			expectedRemoteURL:        DefaultRemoteURL,
+			expectedProtocolVersions: []string{"2025-06-18"},
 		},
 	}
 
@@ -88,6 +99,7 @@ func TestNewServerCard(t *testing.T) {
 			assert.Equal(t, "io.github.github/github-mcp-server", card.Name)
 			assert.Equal(t, "GitHub", card.Title)
 			assert.Equal(t, tc.expectedVersion, card.Version)
+			assert.Equal(t, "https://github.com/github/github-mcp-server", card.WebsiteURL)
 			assert.LessOrEqual(t, len(card.Description), 100, "description must respect the schema maxLength")
 
 			require.NotNil(t, card.Repository)
@@ -101,12 +113,45 @@ func TestNewServerCard(t *testing.T) {
 			require.Len(t, card.Remotes[0].Headers, 1)
 			assert.Equal(t, "Authorization", card.Remotes[0].Headers[0].Name)
 			assert.True(t, card.Remotes[0].Headers[0].IsSecret)
+			assert.Equal(t, tc.expectedProtocolVersions, card.Remotes[0].SupportedProtocolVersions)
 
 			assertSchemaValid(t, resolved, card)
 		})
 	}
 }
 
+// TestServerCardIcons verifies the card advertises the self-contained GitHub
+// mark icons in both themes.
+func TestServerCardIcons(t *testing.T) {
+	t.Parallel()
+
+	card := NewServerCard(Config{})
+
+	require.Len(t, card.Icons, 2)
+	themes := make(map[string]Icon, len(card.Icons))
+	for _, icon := range card.Icons {
+		assert.True(t, strings.HasPrefix(icon.Src, "data:image/png;base64,"), "icon must be a self-contained data URI")
+		assert.Equal(t, "image/png", icon.MimeType)
+		assert.Equal(t, []string{"24x24"}, icon.Sizes)
+		themes[icon.Theme] = icon
+	}
+	assert.Contains(t, themes, "light")
+	assert.Contains(t, themes, "dark")
+}
+
+// TestServerCardIsDeterministic guards the ETag contract: identical Config must
+// always marshal to identical bytes, so unordered sources (e.g. icons) cannot
+// destabilize the response hash.
+func TestServerCardIsDeterministic(t *testing.T) {
+	t.Parallel()
+
+	first, err := json.Marshal(NewServerCard(Config{Version: "1.2.3"}))
+	require.NoError(t, err)
+	second, err := json.Marshal(NewServerCard(Config{Version: "1.2.3"}))
+	require.NoError(t, err)
+	assert.Equal(t, first, second)
+}
+
 // TestServerCardIsRemoteOnly guards the SEP-2127 requirement that a Server Card
 // never enumerates installable packages — those stay in the registry server.json.
 func TestServerCardIsRemoteOnly(t *testing.T) {