refactor: consolidate server list response types (#387)

## Summary
- Consolidate ServerListResponse and Metadata types into pkg/api/v0
- Remove duplication between handler and API types
- Change metadata from optional pointer to required value
- Remove unused Total field from Metadata

internal/api/handlers/v0/servers.go

@@ -12,13 +12,6 @@ import (
 	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
 )
 
-// Metadata contains pagination metadata
-type Metadata struct {
-	NextCursor string `json:"next_cursor,omitempty"`
-	Count      int    `json:"count,omitempty"`
-	Total      int    `json:"total,omitempty"`
-}
-
 // ListServersInput represents the input for listing servers
 type ListServersInput struct {
 	Cursor       string `query:"cursor" doc:"Pagination cursor (UUID)" format:"uuid" required:"false" example:"550e8400-e29b-41d4-a716-446655440000"`
@@ -28,12 +21,6 @@ type ListServersInput struct {
 	Version      string `query:"version" doc:"Filter by version ('latest' for latest version, or an exact version like '1.2.3')" required:"false" example:"latest"`
 }
 
-// ListServersBody represents the paginated server list response body
-type ListServersBody struct {
-	Servers  []apiv0.ServerJSON `json:"servers" doc:"List of MCP servers with extensions"`
-	Metadata *Metadata          `json:"metadata,omitempty" doc:"Pagination metadata"`
-}
-
 // ServerDetailInput represents the input for getting server details
 type ServerDetailInput struct {
 	ID string `path:"id" doc:"Server ID (UUID)" format:"uuid"`
@@ -49,7 +36,7 @@ func RegisterServersEndpoints(api huma.API, registry service.RegistryService) {
 		Summary:     "List MCP servers",
 		Description: "Get a paginated list of MCP servers from the registry",
 		Tags:        []string{"servers"},
-	}, func(_ context.Context, input *ListServersInput) (*Response[ListServersBody], error) {
+	}, func(_ context.Context, input *ListServersInput) (*Response[apiv0.ServerListResponse], error) {
 		// Validate cursor if provided
 		if input.Cursor != "" {
 			_, err := uuid.Parse(input.Cursor)
@@ -94,21 +81,14 @@ func RegisterServersEndpoints(api huma.API, registry service.RegistryService) {
 			return nil, huma.Error500InternalServerError("Failed to get registry list", err)
 		}
 
-		// Build response body
-		body := ListServersBody{
-			Servers: servers,
-		}
-
-		// Add metadata if there's a next cursor
-		if nextCursor != "" {
-			body.Metadata = &Metadata{
-				NextCursor: nextCursor,
-				Count:      len(servers),
-			}
-		}
-
-		return &Response[ListServersBody]{
-			Body: body,
+		return &Response[apiv0.ServerListResponse]{
+			Body: apiv0.ServerListResponse{
+				Servers: servers,
+				Metadata: apiv0.Metadata{
+					NextCursor: nextCursor,
+					Count:      len(servers),
+				},
+			},
 		}, nil
 	})
 

internal/api/handlers/v0/servers_test.go

@@ -26,7 +26,7 @@ func TestServersListEndpoint(t *testing.T) {
 		setupRegistryService func(service.RegistryService)
 		expectedStatus       int
 		expectedServers      []apiv0.ServerJSON
-		expectedMeta         *v0.Metadata
+		expectedMeta         *apiv0.Metadata
 		expectedError        string
 	}{
 		{
@@ -268,10 +268,7 @@ func TestServersListEndpoint(t *testing.T) {
 				assert.Equal(t, "application/json", w.Header().Get("Content-Type"))
 
 				// Parse response body
-				var resp struct {
-					Servers  []apiv0.ServerJSON `json:"servers"`
-					Metadata *v0.Metadata       `json:"metadata,omitempty"`
-				}
+				var resp apiv0.ServerListResponse
 				err := json.NewDecoder(w.Body).Decode(&resp)
 				assert.NoError(t, err)
 
@@ -297,7 +294,7 @@ func TestServersListEndpoint(t *testing.T) {
 					default:
 						assert.NotEmpty(t, resp.Servers, "Expected at least one server")
 					}
-					
+
 					// General structure validation
 					for _, server := range resp.Servers {
 						assert.NotEmpty(t, server.Name)
@@ -311,11 +308,9 @@ func TestServersListEndpoint(t *testing.T) {
 				// Check metadata if expected
 				if tc.expectedMeta != nil {
 					assert.NotNil(t, resp.Metadata, "Expected metadata to be present")
-					if resp.Metadata != nil {
-						assert.Equal(t, tc.expectedMeta.Count, resp.Metadata.Count)
-						if tc.expectedMeta.NextCursor != "" {
-							assert.NotEmpty(t, resp.Metadata.NextCursor)
-						}
+					assert.Equal(t, tc.expectedMeta.Count, resp.Metadata.Count)
+					if tc.expectedMeta.NextCursor != "" {
+						assert.NotEmpty(t, resp.Metadata.NextCursor)
 					}
 				}
 			} else if tc.expectedError != "" {
@@ -336,7 +331,7 @@ func TestServersDetailEndpoint(t *testing.T) {
 	testServer, err := registryService.Publish(apiv0.ServerJSON{
 		Name:        "com.example/test-server",
 		Description: "A test server",
-		Version: "1.0.0",
+		Version:     "1.0.0",
 	})
 	assert.NoError(t, err)
 
@@ -466,9 +461,7 @@ func TestServersEndpointsIntegration(t *testing.T) {
 		assert.Equal(t, "application/json", resp.Header.Get("Content-Type"))
 
 		// Parse response body
-		var listResp struct {
-			Servers []apiv0.ServerJSON `json:"servers"`
-		}
+		var listResp apiv0.ServerListResponse
 		err = json.NewDecoder(resp.Body).Decode(&listResp)
 		assert.NoError(t, err)
 

pkg/api/v0/types.go

@@ -17,7 +17,7 @@ type RegistryExtensions struct {
 // ServerListResponse represents the paginated server list response
 type ServerListResponse struct {
 	Servers  []ServerJSON `json:"servers"`
-	Metadata *Metadata    `json:"metadata,omitempty"`
+	Metadata Metadata     `json:"metadata"`
 }
 
 // ServerMeta represents the structured metadata with known extension fields
@@ -42,6 +42,5 @@ type ServerJSON struct {
 // Metadata represents pagination metadata
 type Metadata struct {
 	NextCursor string `json:"next_cursor,omitempty"`
-	Count      int    `json:"count,omitempty"`
-	Total      int    `json:"total,omitempty"`
+	Count      int    `json:"count"`
 }