Add filtering functionality to server list endpoint

docs/reference/api/official-registry-api.md

@@ -33,6 +33,19 @@ See [Publisher Commands](../cli/commands.md) for authentication setup.
 
 The official registry enforces additional [package validation requirements](../server-json/official-registry-requirements.md) when publishing.
 
+### Server List Filtering
+
+The official registry extends the `GET /v0/servers` endpoint with additional query parameters for improved discovery and synchronization:
+
+- `updated_since` - Filter servers updated after RFC3339 timestamp (e.g., `2025-08-07T13:15:04.280Z`)
+- `search` - Case-insensitive substring search on server names (e.g., `filesystem`)  
+    - This is intentionally simple. For more advanced searching and filtering, use a subregistry.
+- `version` - Filter by version (currently supports `latest` for latest versions only)
+
+These extensions enable efficient incremental synchronization for downstream registries and improved server discovery. Parameters can be combined and work with standard cursor-based pagination.
+
+Example: `GET /v0/servers?search=filesystem&updated_since=2025-08-01T00:00:00Z&version=latest`
+
 ### Additional endpoints
 
 #### Auth endpoints

internal/api/handlers/v0/servers.go

@@ -3,9 +3,11 @@ package v0
 import (
 	"context"
 	"net/http"
+	"time"
 
 	"github.com/danielgtaylor/huma/v2"
 	"github.com/google/uuid"
+	"github.com/modelcontextprotocol/registry/internal/database"
 	"github.com/modelcontextprotocol/registry/internal/service"
 	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
 )
@@ -19,8 +21,11 @@ type Metadata struct {
 
 // ListServersInput represents the input for listing servers
 type ListServersInput struct {
-	Cursor string `query:"cursor" doc:"Pagination cursor (UUID)" format:"uuid" required:"false"`
-	Limit  int    `query:"limit" doc:"Number of items per page" default:"30" minimum:"1" maximum:"100"`
+	Cursor       string `query:"cursor" doc:"Pagination cursor (UUID)" format:"uuid" required:"false" example:"550e8400-e29b-41d4-a716-446655440000"`
+	Limit        int    `query:"limit" doc:"Number of items per page" default:"30" minimum:"1" maximum:"100" example:"50"`
+	UpdatedSince string `query:"updated_since" doc:"Filter servers updated since timestamp (RFC3339 datetime)" required:"false" example:"2025-08-07T13:15:04.280Z"`
+	Search       string `query:"search" doc:"Search servers by name (substring match)" required:"false" example:"filesystem"`
+	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
@@ -53,8 +58,38 @@ func RegisterServersEndpoints(api huma.API, registry service.RegistryService) {
 			}
 		}
 
-		// Get paginated results
-		servers, nextCursor, err := registry.List(input.Cursor, input.Limit)
+		// Build filter from input parameters
+		filter := &database.ServerFilter{}
+
+		// Parse updated_since parameter
+		if input.UpdatedSince != "" {
+			// Parse RFC3339 format
+			if updatedTime, err := time.Parse(time.RFC3339, input.UpdatedSince); err == nil {
+				filter.UpdatedSince = &updatedTime
+			} else {
+				return nil, huma.Error400BadRequest("Invalid updated_since format: expected RFC3339 timestamp (e.g., 2025-08-07T13:15:04.280Z)")
+			}
+		}
+
+		// Handle search parameter
+		if input.Search != "" {
+			filter.SubstringName = &input.Search
+		}
+
+		// Handle version parameter
+		if input.Version != "" {
+			if input.Version == "latest" {
+				// Special case: filter for latest versions
+				isLatest := true
+				filter.IsLatest = &isLatest
+			} else {
+				// Future: exact version matching
+				filter.Version = &input.Version
+			}
+		}
+
+		// Get paginated results with filtering
+		servers, nextCursor, err := registry.List(filter, input.Cursor, input.Limit)
 		if err != nil {
 			return nil, huma.Error500InternalServerError("Failed to get registry list", err)
 		}

internal/api/handlers/v0/servers_test.go

@@ -127,6 +127,122 @@ func TestServersListEndpoint(t *testing.T) {
 			expectedStatus:  http.StatusOK,
 			expectedServers: []apiv0.ServerJSON{},
 		},
+		{
+			name:        "successful search by name substring",
+			queryParams: "?search=test-server",
+			setupRegistryService: func(registry service.RegistryService) {
+				server1 := apiv0.ServerJSON{
+					Name:        "com.example/test-server-matching",
+					Description: "Matching test server",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/test-matching",
+						Source: "github",
+						ID:     "example/test-matching",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				server2 := apiv0.ServerJSON{
+					Name:        "com.example/other-server",
+					Description: "Non-matching server",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/other",
+						Source: "github",
+						ID:     "example/other",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				_, _ = registry.Publish(server1)
+				_, _ = registry.Publish(server2)
+			},
+			expectedStatus:  http.StatusOK,
+			expectedServers: nil, // Will verify in test that only matching server is returned
+		},
+		{
+			name:        "successful updated_since filter with RFC3339",
+			queryParams: "?updated_since=2020-01-01T00:00:00Z",
+			setupRegistryService: func(registry service.RegistryService) {
+				server := apiv0.ServerJSON{
+					Name:        "com.example/recent-server",
+					Description: "Recently updated server",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/recent",
+						Source: "github",
+						ID:     "example/recent",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				_, _ = registry.Publish(server)
+			},
+			expectedStatus:  http.StatusOK,
+			expectedServers: nil, // Will verify server is returned since it was updated after 2020
+		},
+		{
+			name:        "successful version=latest filter",
+			queryParams: "?version=latest",
+			setupRegistryService: func(registry service.RegistryService) {
+				server1 := apiv0.ServerJSON{
+					Name:        "com.example/versioned-server",
+					Description: "First version",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/versioned",
+						Source: "github",
+						ID:     "example/versioned",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				server2 := apiv0.ServerJSON{
+					Name:        "com.example/versioned-server",
+					Description: "Second version (latest)",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/versioned",
+						Source: "github",
+						ID:     "example/versioned",
+					},
+					VersionDetail: model.VersionDetail{Version: "2.0.0"},
+				}
+				_, _ = registry.Publish(server1)
+				_, _ = registry.Publish(server2) // This will be marked as latest
+			},
+			expectedStatus:  http.StatusOK,
+			expectedServers: nil, // Will verify only latest server is returned
+		},
+		{
+			name:        "combined search and updated_since filter",
+			queryParams: "?search=combined&updated_since=2020-01-01T00:00:00Z",
+			setupRegistryService: func(registry service.RegistryService) {
+				server1 := apiv0.ServerJSON{
+					Name:        "com.example/combined-test",
+					Description: "Server with combined filtering",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/combined",
+						Source: "github",
+						ID:     "example/combined",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				server2 := apiv0.ServerJSON{
+					Name:        "com.example/other-server",
+					Description: "Server that doesn't match search",
+					Repository: model.Repository{
+						URL:    "https://github.com/example/nomatch",
+						Source: "github",
+						ID:     "example/nomatch",
+					},
+					VersionDetail: model.VersionDetail{Version: "1.0.0"},
+				}
+				_, _ = registry.Publish(server1)
+				_, _ = registry.Publish(server2)
+			},
+			expectedStatus:  http.StatusOK,
+			expectedServers: nil, // Will verify only matching server is returned
+		},
+		{
+			name:                 "invalid updated_since format",
+			queryParams:          "?updated_since=invalid-timestamp",
+			setupRegistryService: func(_ service.RegistryService) {},
+			expectedStatus:       http.StatusBadRequest,
+			expectedError:        "Invalid updated_since format: expected RFC3339",
+		},
 	}
 
 	for _, tc := range testCases {
@@ -170,7 +286,25 @@ func TestServersListEndpoint(t *testing.T) {
 					assert.Equal(t, tc.expectedServers, resp.Servers)
 				} else {
 					// For tests with dynamic data, check structure and count
-					assert.NotEmpty(t, resp.Servers, "Expected at least one server")
+					// Special handling for filter test cases
+					switch tc.name {
+					case "successful search by name substring":
+						assert.Len(t, resp.Servers, 1, "Expected exactly one matching server")
+						assert.Contains(t, resp.Servers[0].Name, "test-server", "Server name should contain search term")
+					case "successful updated_since filter with RFC3339":
+						assert.Len(t, resp.Servers, 1, "Expected one server updated after 2020")
+						assert.Contains(t, resp.Servers[0].Name, "recent-server")
+					case "successful version=latest filter":
+						assert.Len(t, resp.Servers, 1, "Expected one latest server")
+						assert.Contains(t, resp.Servers[0].Description, "latest")
+					case "combined search and updated_since filter":
+						assert.Len(t, resp.Servers, 1, "Expected one server matching both filters")
+						assert.Contains(t, resp.Servers[0].Name, "combined", "Server name should contain search term")
+					default:
+						assert.NotEmpty(t, resp.Servers, "Expected at least one server")
+					}
+
+					// General structure validation
 					for _, server := range resp.Servers {
 						assert.NotEmpty(t, server.Name)
 						assert.NotEmpty(t, server.Description)

internal/database/database.go

@@ -3,6 +3,7 @@ package database
 import (
 	"context"
 	"errors"
+	"time"
 
 	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
 )
@@ -19,8 +20,12 @@ var (
 
 // ServerFilter defines filtering options for server queries
 type ServerFilter struct {
-	Name      *string // for finding versions of same server
-	RemoteURL *string // for duplicate URL detection
+	Name          *string    // for finding versions of same server
+	RemoteURL     *string    // for duplicate URL detection
+	UpdatedSince  *time.Time // for incremental sync filtering
+	SubstringName *string    // for substring search on name
+	Version       *string    // for exact version matching
+	IsLatest      *bool      // for filtering latest versions only
 }
 
 // Database defines the interface for database operations

internal/database/memory.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"sort"
+	"strings"
 	"sync"
 
 	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
@@ -164,6 +165,7 @@ func (db *MemoryDB) filterAndSort(allEntries []*apiv0.ServerJSON, filter *Server
 }
 
 // matchesFilter checks if an entry matches the provided filter
+//nolint:cyclop // Filter matching logic is inherently complex but clear
 func (db *MemoryDB) matchesFilter(entry *apiv0.ServerJSON, filter *ServerFilter) bool {
 	if filter == nil {
 		return true
@@ -188,6 +190,44 @@ func (db *MemoryDB) matchesFilter(entry *apiv0.ServerJSON, filter *ServerFilter)
 		}
 	}
 
+	// Check updatedSince filter
+	if filter.UpdatedSince != nil {
+		if entry.Meta == nil || entry.Meta.Official == nil {
+			return false
+		}
+		if entry.Meta.Official.UpdatedAt.Before(*filter.UpdatedSince) ||
+			entry.Meta.Official.UpdatedAt.Equal(*filter.UpdatedSince) {
+			return false
+		}
+	}
+
+	// Check name search filter (substring match)
+	if filter.SubstringName != nil {
+		// Case-insensitive substring search
+		searchLower := strings.ToLower(*filter.SubstringName)
+		nameLower := strings.ToLower(entry.Name)
+		if !strings.Contains(nameLower, searchLower) {
+			return false
+		}
+	}
+
+	// Check exact version filter
+	if filter.Version != nil {
+		if entry.VersionDetail.Version != *filter.Version {
+			return false
+		}
+	}
+
+	// Check is_latest filter
+	if filter.IsLatest != nil {
+		if entry.Meta == nil || entry.Meta.Official == nil {
+			return false
+		}
+		if entry.Meta.Official.IsLatest != *filter.IsLatest {
+			return false
+		}
+	}
+
 	return true
 }
 

internal/database/postgres.go

@@ -40,6 +40,7 @@ func NewPostgreSQL(ctx context.Context, connectionURI string) (*PostgreSQL, erro
 	}, nil
 }
 
+//nolint:cyclop // Database filtering logic is inherently complex but clear
 func (db *PostgreSQL) List(
 	ctx context.Context,
 	filter *ServerFilter,
@@ -71,6 +72,26 @@ func (db *PostgreSQL) List(
 			args = append(args, *filter.RemoteURL)
 			argIndex++
 		}
+		if filter.UpdatedSince != nil {
+			whereConditions = append(whereConditions, fmt.Sprintf("(value->'_meta'->'io.modelcontextprotocol.registry/official'->>'updated_at')::timestamp > $%d", argIndex))
+			args = append(args, *filter.UpdatedSince)
+			argIndex++
+		}
+		if filter.SubstringName != nil {
+			whereConditions = append(whereConditions, fmt.Sprintf("value->>'name' ILIKE $%d", argIndex))
+			args = append(args, "%"+*filter.SubstringName+"%")
+			argIndex++
+		}
+		if filter.Version != nil {
+			whereConditions = append(whereConditions, fmt.Sprintf("(value->'version_detail'->>'version') = $%d", argIndex))
+			args = append(args, *filter.Version)
+			argIndex++
+		}
+		if filter.IsLatest != nil {
+			whereConditions = append(whereConditions, fmt.Sprintf("(value->'_meta'->'io.modelcontextprotocol.registry/official'->>'is_latest')::boolean = $%d", argIndex))
+			args = append(args, *filter.IsLatest)
+			argIndex++
+		}
 	}
 
 	// Add cursor pagination using registry metadata ID

internal/service/registry_service.go

@@ -29,8 +29,8 @@ func NewRegistryService(db database.Database, cfg *config.Config) RegistryServic
 	}
 }
 
-// List returns registry entries with cursor-based pagination in flattened format
-func (s *registryServiceImpl) List(cursor string, limit int) ([]apiv0.ServerJSON, string, error) {
+// List returns registry entries with cursor-based pagination and optional filtering
+func (s *registryServiceImpl) List(filter *database.ServerFilter, cursor string, limit int) ([]apiv0.ServerJSON, string, error) {
 	// Create a timeout context for the database operation
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
@@ -40,8 +40,8 @@ func (s *registryServiceImpl) List(cursor string, limit int) ([]apiv0.ServerJSON
 		limit = 30
 	}
 
-	// Use the database's ListServers method with pagination
-	serverRecords, nextCursor, err := s.db.List(ctx, nil, cursor, limit)
+	// Use the database's ListServers method with pagination and filtering
+	serverRecords, nextCursor, err := s.db.List(ctx, filter, cursor, limit)
 	if err != nil {
 		return nil, "", err
 	}

internal/service/service.go

@@ -1,13 +1,14 @@
 package service
 
 import (
+	"github.com/modelcontextprotocol/registry/internal/database"
 	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
 )
 
 // RegistryService defines the interface for registry operations
 type RegistryService interface {
-	// Retrieve all servers
-	List(cursor string, limit int) ([]apiv0.ServerJSON, string, error)
+	// Retrieve all servers with optional filtering
+	List(filter *database.ServerFilter, cursor string, limit int) ([]apiv0.ServerJSON, string, error)
 	// Retrieve a single server by registry metadata ID
 	GetByID(id string) (*apiv0.ServerJSON, error)
 	// Publish a server