Service catalog: announce foundation, external catalog, consumer-side resolver

Makefile

@@ -9,6 +9,7 @@ build:
 	go build -v -o "$(OUT_DIR)/sam-node" ./cmd/sam-node
 	go build -v -o "$(OUT_DIR)/sam-hub" ./cmd/sam-hub
 	go build -v -o "$(OUT_DIR)/mcp-client" ./cmd/mcp-client
+	go build -v -o "$(OUT_DIR)/sam-catalog" ./cmd/sam-catalog
 
 .PHONY: proto
 proto:

api/sam.proto

@@ -59,6 +59,7 @@ enum ServiceType {
   SERVICE_TYPE_UNSPECIFIED = 0;
   SERVICE_TYPE_MCP = 1;
   SERVICE_TYPE_INFERENCE = 2;
+  SERVICE_TYPE_CATALOG = 3;
 }
 
 message ServiceInfo {
@@ -67,6 +68,16 @@ message ServiceInfo {
   string description = 3;
 }
 
+message ServiceAnnounce {
+  ServiceType type = 1;
+  string name = 2;
+  string peer_id = 3;
+  repeated string addrs = 4;
+  int64 timestamp = 5;
+  int64 ttl_ms = 6;
+  bytes signature = 7;
+}
+
 message CommandBackend {
   repeated string command = 1;
   map<string, string> env = 2;

api/types.go

@@ -26,6 +26,7 @@ const EnrollProtocolID protocol.ID = "/sam/enroll/1.0.0"
 const MCPProtocolID protocol.ID = "/sam/mcp/1.0.0"
 const GossipEvents = "/sam/mesh/events/v1"
 const GossipHubSync = "/sam/hub/sync/v1"
+const GossipServiceAnnounce = "/sam/service/announce/v1"
 const AuthProtocolID protocol.ID = "/sam/auth/1.0.0"
 
 // CatalogTarget is the special target service name used to retrieve tool catalogs from remote nodes.
@@ -101,6 +102,7 @@ func ParseServiceTarget(target string) (svcType, svcName string) {
 const (
 	ServiceTypeStringMCP       = "mcp"
 	ServiceTypeStringInference = "inference"
+	ServiceTypeStringCatalog   = "catalog"
 )
 
 // InferenceServicePrefix is the conventional prefix used for LLM gateway inference services.
@@ -113,6 +115,8 @@ func ParseServiceType(s string) (ServiceType, error) {
 		return ServiceType_SERVICE_TYPE_MCP, nil
 	case ServiceTypeStringInference:
 		return ServiceType_SERVICE_TYPE_INFERENCE, nil
+	case ServiceTypeStringCatalog:
+		return ServiceType_SERVICE_TYPE_CATALOG, nil
 	default:
 		return ServiceType_SERVICE_TYPE_UNSPECIFIED, fmt.Errorf("invalid service type: %s", s)
 	}
@@ -125,6 +129,8 @@ func ServiceTypeToString(t ServiceType) (string, error) {
 		return ServiceTypeStringMCP, nil
 	case ServiceType_SERVICE_TYPE_INFERENCE:
 		return ServiceTypeStringInference, nil
+	case ServiceType_SERVICE_TYPE_CATALOG:
+		return ServiceTypeStringCatalog, nil
 	default:
 		return "", fmt.Errorf("invalid or unspecified service type")
 	}