Select fabric carrier by endpoint

agents/rap-node-agent/cmd/rap-node-agent/main.go

@@ -4447,7 +4447,7 @@ func fabricSessionGatewayTransportForAssignment(ctx context.Context, identity st
 	if meshState.VPNFabricTransport == nil {
 		meshState.VPNFabricTransport = mesh.NewWebSocketFabricTransport(meshState.VPNFabricSessionPeers)
 	}
-	session, err := meshState.VPNFabricTransport.Connect(dialCtx, mesh.FabricTransportTarget{
+	target := mesh.FabricTransportTarget{
 		PeerID:         nextHop,
 		Endpoint:       endpoint,
 		Token:          fabricSessionGatewayToken(identity, assignment, nextHop),
@@ -4455,7 +4455,13 @@ func fabricSessionGatewayTransportForAssignment(ctx context.Context, identity st
 		OutboundBuffer: 256,
 		InboundBuffer:  256,
 		ErrorBuffer:    16,
-	})
+	}
+	carrier, target, err := mesh.FabricTransportForTarget(target, meshState.VPNFabricTransport, nil)
+	if err != nil {
+		log.Printf("vpn fabric session transport skipped: vpn_connection_id=%s next_hop=%s reason=transport_select_failed error=%v", assignment.VPNConnectionID, nextHop, err)
+		return nil
+	}
+	session, err := carrier.Connect(dialCtx, target)
 	if err != nil {
 		log.Printf("vpn fabric session transport skipped: vpn_connection_id=%s next_hop=%s reason=session_open_failed error=%v", assignment.VPNConnectionID, nextHop, err)
 		return nil

agents/rap-node-agent/internal/mesh/fabric_quic_transport.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -37,6 +38,7 @@ func (t *QUICFabricTransport) Connect(ctx context.Context, target FabricTranspor
 	if target.Endpoint == "" {
 		return nil, fmt.Errorf("quic fabric endpoint is required")
 	}
+	target.Endpoint = strings.TrimPrefix(strings.TrimSpace(target.Endpoint), "quic://")
 	tlsConfig := target.TLSConfig
 	if tlsConfig == nil {
 		tlsConfig = &tls.Config{NextProtos: []string{fabricQUICNextProto}}
@@ -76,7 +78,7 @@ func (t *QUICFabricTransport) Connect(ctx context.Context, target FabricTranspor
 		maxPayload: maxPayload,
 		timeout:    target.Timeout,
 	}
-	go session.readLoop(ctx)
+	go session.readLoop(context.Background())
 	return session, nil
 }
 

agents/rap-node-agent/internal/mesh/fabric_session_manager.go

@@ -66,7 +66,7 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 	if err != nil {
 		return nil, err
 	}
-	pump := session.StartPump(ctx, target.Pump)
+	pump := session.StartPump(context.Background(), target.Pump)
 
 	m.mu.Lock()
 	if existing := m.sessions[key]; existing != nil {

agents/rap-node-agent/internal/mesh/fabric_transport.go

@@ -3,7 +3,9 @@ package mesh
 import (
 	"context"
 	"crypto/tls"
+	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/example/remote-access-platform/agents/rap-node-agent/internal/fabricproto"
@@ -25,6 +27,7 @@ type FabricTransport interface {
 type FabricTransportTarget struct {
 	PeerID         string
 	Endpoint       string
+	Transport      string
 	Token          string
 	Header         http.Header
 	TLSConfig      *tls.Config
@@ -35,6 +38,29 @@ type FabricTransportTarget struct {
 	ErrorBuffer    int
 }
 
+func FabricTransportForTarget(target FabricTransportTarget, websocket *WebSocketFabricTransport, quicTransport *QUICFabricTransport) (FabricTransport, FabricTransportTarget, error) {
+	transportLabel := strings.ToLower(strings.TrimSpace(target.Transport))
+	endpoint := strings.TrimSpace(target.Endpoint)
+	if strings.HasPrefix(strings.ToLower(endpoint), "quic://") {
+		transportLabel = "quic"
+		target.Endpoint = strings.TrimPrefix(endpoint, "quic://")
+	}
+	switch transportLabel {
+	case "quic", "direct_quic", "udp_quic", "quic_udp":
+		if quicTransport == nil {
+			quicTransport = NewQUICFabricTransport(nil)
+		}
+		return quicTransport, target, nil
+	case "", "websocket", "ws", "wss", "direct_http", "direct_https", "direct_tcp_tls":
+		if websocket == nil {
+			websocket = NewWebSocketFabricTransport(nil)
+		}
+		return websocket, target, nil
+	default:
+		return nil, target, fmt.Errorf("unsupported fabric transport %q", target.Transport)
+	}
+}
+
 type WebSocketFabricTransport struct {
 	Manager *FabricSessionPeerManager
 }

agents/rap-node-agent/internal/mesh/fabric_transport_test.go

@@ -107,3 +107,33 @@ func TestWebSocketFabricTransportReopensClosedSession(t *testing.T) {
 		t.Fatalf("opened = %d, want 2", opened)
 	}
 }
+
+func TestFabricTransportForTargetSelectsQUICByScheme(t *testing.T) {
+	transport, target, err := FabricTransportForTarget(FabricTransportTarget{
+		Endpoint: "quic://127.0.0.1:4433",
+	}, nil, nil)
+	if err != nil {
+		t.Fatalf("select transport: %v", err)
+	}
+	if _, ok := transport.(*QUICFabricTransport); !ok {
+		t.Fatalf("transport = %T, want QUIC", transport)
+	}
+	if target.Endpoint != "127.0.0.1:4433" {
+		t.Fatalf("endpoint = %q", target.Endpoint)
+	}
+}
+
+func TestFabricTransportForTargetSelectsWebSocketByDefault(t *testing.T) {
+	transport, target, err := FabricTransportForTarget(FabricTransportTarget{
+		Endpoint: "https://node.example",
+	}, nil, nil)
+	if err != nil {
+		t.Fatalf("select transport: %v", err)
+	}
+	if _, ok := transport.(*WebSocketFabricTransport); !ok {
+		t.Fatalf("transport = %T, want websocket", transport)
+	}
+	if target.Endpoint != "https://node.example" {
+		t.Fatalf("endpoint = %q", target.Endpoint)
+	}
+}

docs/architecture/DISTRIBUTED_FABRIC_NODE_PROTOCOL_PLAN.md

@@ -297,6 +297,8 @@ future QUIC/UDP transport can be added without changing VPN/RDP/HTTP services.
 `QUICFabricTransport` now implements the same interface and carries the same
 binary `fabricproto` frames over a QUIC stream, with local smoke coverage for
 `PING`/`PONG` and DATA/ACK.
+Carrier selection understands QUIC transport labels and `quic://host:port`
+endpoints while preserving WebSocket as the default fallback.
 
 Deliverables: