pion · Sean-Der · Jan 13, 2026 · Dec 21, 2025
diff --git a/examples/warp/index.html b/examples/warp/index.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<html>
+  <!--
+		SPDX-FileCopyrightText: 2025 The Pion community <https://pion.ly>
+		SPDX-License-Identifier: MIT
+	-->
+<head>
+  <meta charset="utf-8">
+  <title>WARP: Faster WebRTC with SNAP and SPED</title>
+</head>
+<body>
+  <h2>📡 WebRTC DataChannel Test</h2>
+  <div>
+    <label><input type="checkbox" id="dtlsRole" />Act as DTLS client</label>
+    <button id="startBtn" onclick="start()">Start</button>
+  </div>
+  <input id="msg" placeholder="Message">
+  <button id="sendBtn" disabled onclick="sendMsg()">Send</button>
+  <pre id="log"></pre>
+
+  <script>
+    const pc = new RTCPeerConnection();
+    const channel = pc.createDataChannel("chat");
+
+    pc.onconnectionstatechange = async () => {
+        log(`🔄 Connection state: ${pc.connectionState}`);
+        if (pc.connectionState === 'connected') {
+            const stats = await pc.getStats();
+            const transport = [...stats.values()].find(o => o.type === 'transport');
+            if (transport) {
+                log(`DTLS role: ${transport.dtlsRole}`);
+                const pair = stats.get(transport.selectedCandidatePairId);
+                if (pair) {
+                    log(`RTT: ${pair.totalRoundTripTime / pair.responsesReceived}`);
+                }
+            }
+        }
+    }
+    pc.oniceconnectionstatechange = () => log(`🧊 ICE state: ${pc.iceConnectionState}`);
+    pc.onsignalingstatechange = () => log(`📞 Signaling state: ${pc.signalingState}`);
+
+    channel.onopen = () => {
+      log("✅ DataChannel opened");
+      document.getElementById("sendBtn").disabled = false;
+    }
+    channel.onmessage = e => log(`📩 Server: ${e.data}`);
+
+    pc.onicecandidate = event => {
+      if(event.candidate){
+        fetch("/candidate", {
+          method: "POST",
+          headers: {"Content-Type": "application/json"},
+          body: JSON.stringify(event.candidate),
+        });
+      }
+    };
+    pc.ondatachannel = event => {
+        log("Server opened a channel", event.channel.name)
+        event.channel.onmessage = (ev) => {
+          log(`Server sent: ${ev.data}`)
+        }
+    };
+
+    async function start(){
+      document.getElementById("startBtn").disabled = true;
+      document.getElementById("dtlsRole").disabled = true;
+      try {
+        await pc.setLocalDescription();
+        const offer = pc.localDescription;
+        if (offer.sdp.indexOf("\na=sctp-init:") !== -1) {
+          log("✅ sctp-init found in offer, SNAP is supported");
+        }
+
+        const sdp = document.getElementById("dtlsRole").checked
+          ? offer.sdp.replace("actpass", "active")
+          : offer.sdp;
+        // TODO: parameters to disable SPED/SNAP?
+        const res = await fetch("/offer", {
+          method: "POST",
+          headers: {"Content-Type": "application/json"},
+          body: JSON.stringify({type: "offer", sdp}),
+        })
+
+        if (!res.ok) {
+          throw new Error(`HTTP ${res.status}: ${res.statusText}`);
+        }
+
+        const answer = await res.json();
+        if (answer.sdp.indexOf("\na=sctp-init:") !== -1) {
+          log("✅ sctp-init found in answer, SNAP is supported");
+        }
+        await pc.setRemoteDescription(answer);
+
+      } catch (err) {
+        log(`❌ Connection failed: ${err.message}`);
+        console.error("Connection error:", err);
+      }
+    }
+
+    function sendMsg(){
+      const msg = document.getElementById("msg").value;
+
+      if (msg.trim()) {
+        channel.send(msg);
+        log(`You: ${msg}`);
+        document.getElementById("msg").value = "";
+      }
+    }
+
+    function log(msg){
+      document.getElementById("log").textContent+=msg+"\n";
+    }
+
+
+  </script>
+</body>
+</html>
diff --git a/examples/warp/main.go b/examples/warp/main.go
@@ -0,0 +1,160 @@
+// SPDX-FileCopyrightText: 2025 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+//go:build !js
+// +build !js
+
+// WARP (SNAP+SPED) testbed.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/pion/webrtc/v4"
+)
+
+func main() {
+	var pc *webrtc.PeerConnection
+
+	setupOfferHandler(&pc)
+	setupCandidateHandler(&pc)
+	setupStaticHandler()
+
+	fmt.Println("google-chrome-unstable --force-fieldtrials=" +
+		"WebRTC-Sctp-Snap/Enabled/WebRTC-IceHandshakeDtls/Enabled/ " +
+		"--disable-features=WebRtcPqcForDtls http://localhost:8080")
+	fmt.Printf("Add `--enable-logging --v=1` and then " +
+		"`grep SCTP_PACKET chrome_debug.log | " +
+		"text2pcap -D -u 1001,2001 -t \"%%H:%%M:%%S.%%f\" - out.pcap` " +
+		"for inspecting the raw packets.\n")
+	fmt.Println("🚀 Signaling server started on http://localhost:8080")
+	//nolint:gosec
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		fmt.Printf("Failed to start server: %v\n", err)
+	}
+}
+
+func setupOfferHandler(pc **webrtc.PeerConnection) {
+	http.HandleFunc("/offer", func(responseWriter http.ResponseWriter, r *http.Request) {
+		var offer webrtc.SessionDescription
+		if err := json.NewDecoder(r.Body).Decode(&offer); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusBadRequest)
+
+			return
+		}
+
+		var err error
+		*pc, err = webrtc.NewPeerConnection(webrtc.Configuration{
+			BundlePolicy: webrtc.BundlePolicyMaxBundle,
+		})
+		if err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+
+		setupICECandidateHandler(*pc)
+		setupDataChannelHandler(*pc)
+
+		if err := processOffer(*pc, offer, responseWriter); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusInternalServerError)
+
+			return
+		}
+	})
+}
+
+func setupICECandidateHandler(pc *webrtc.PeerConnection) {
+	pc.OnICECandidate(func(c *webrtc.ICECandidate) {
+		if c != nil {
+			fmt.Printf("🌐 New ICE candidate: %s\n", c.Address)
+		}
+	})
+}
+
+func setupDataChannelHandler(pc *webrtc.PeerConnection) {
+	pc.OnDataChannel(func(d *webrtc.DataChannel) {
+		d.OnOpen(func() {
+			fmt.Println("✅ DataChannel opened (Server)")
+			if sendErr := d.SendText("Hello from Go server 👋"); sendErr != nil {
+				fmt.Printf("Failed to send text: %v\n", sendErr)
+			}
+		})
+		d.OnMessage(func(msg webrtc.DataChannelMessage) {
+			fmt.Printf("📩 Received: %s\n", string(msg.Data))
+			if sendErr := d.SendText("ECHO " + string(msg.Data)); sendErr != nil {
+				fmt.Printf("Failed to send text: %v\n", sendErr)
+			}
+		})
+	})
+	if serverDc, err := pc.CreateDataChannel("server-opened-channel", nil); err == nil {
+		serverDc.OnOpen(func() {
+			if sendErr := serverDc.SendText("Server opened channel ready"); sendErr != nil {
+				fmt.Printf("Failed to send on server-opened channel: %v\n", sendErr)
+			}
+		})
+	}
+}
+
+func processOffer(
+	pc *webrtc.PeerConnection,
+	offer webrtc.SessionDescription,
+	responseWriter http.ResponseWriter,
+) error {
+	// Set remote description
+	if err := pc.SetRemoteDescription(offer); err != nil {
+		return err
+	}
+
+	// Create answer
+	answer, err := pc.CreateAnswer(nil)
+	if err != nil {
+		return err
+	}
+
+	// Set local description
+	if err := pc.SetLocalDescription(answer); err != nil {
+		return err
+	}
+
+	// Wait for ICE gathering to complete before sending answer
+	gatherComplete := webrtc.GatheringCompletePromise(pc)
+	<-gatherComplete
+
+	finalAnswer := pc.LocalDescription()
+	if finalAnswer == nil {
+		//nolint:err113
+		return fmt.Errorf("local description is nil after ICE gathering")
+	}
+
+	responseWriter.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(responseWriter).Encode(*finalAnswer); err != nil {
+		fmt.Printf("Failed to encode answer: %v\n", err)
+	}
+
+	return nil
+}
+
+func setupCandidateHandler(pc **webrtc.PeerConnection) {
+	http.HandleFunc("/candidate", func(responseWriter http.ResponseWriter, r *http.Request) {
+		var candidate webrtc.ICECandidateInit
+		if err := json.NewDecoder(r.Body).Decode(&candidate); err != nil {
+			http.Error(responseWriter, err.Error(), http.StatusBadRequest)
+
+			return
+		}
+		if *pc != nil {
+			if err := (*pc).AddICECandidate(candidate); err != nil {
+				fmt.Println("Failed to add candidate", err)
+			}
+		}
+	})
+}
+
+func setupStaticHandler() {
+	http.HandleFunc("/", func(responseWriter http.ResponseWriter, r *http.Request) {
+		http.ServeFile(responseWriter, r, "./index.html")
+	})
+}