wt: use cdn relay defaults and native setup before overrides

README.md

@@ -53,7 +53,7 @@ Publish (node -> Cloudflare relay):
 
 ```sh
 cargo run -p ec-node -- wt-publish \
-  --url https://interop-relay.cloudflare.mediaoverquic.com/ \
+  --url https://cdn.moq.dev/anon \
   --name la-nbc \
   --input http://<hdhr-host>/auto/v4.1
 ```
@@ -61,7 +61,7 @@ cargo run -p ec-node -- wt-publish \
 Watch (web):
 
 ```txt
-https://every.channel/watch?url=https%3A%2F%2Finterop-relay.cloudflare.mediaoverquic.com%2F&name=la-nbc
+https://every.channel/watch?url=https%3A%2F%2Fcdn.moq.dev%2Fanon&name=la-nbc
 ```
 
 Coverage:

apps/web/app.js

@@ -3,7 +3,7 @@
 // This uses the upstream hang web component (WebTransport + WebCodecs).
 // It is intentionally dependency-light: no framework, no bundler.
 
-const DEFAULT_RELAY_URL = "https://interop-relay.cloudflare.mediaoverquic.com/";
+const DEFAULT_RELAY_URL = "https://cdn.moq.dev/anon";
 const HANG_WATCH_MODULE_URL = "https://esm.sh/@kixelated/hang@0.7.0/watch/element.js";
 let hangWatchModulePromise = null;
 

crates/ec-node/src/main.rs

@@ -4446,11 +4446,21 @@ async fn wt_publish(args: WtPublishArgs) -> Result<()> {
             .await
             .context("failed WebTransport CONNECT")?;
 
-        // Establish a MoQ session. Cloudflare's relay currently does not always include a selected
-        // subprotocol in the CONNECT response, so we attempt a few protocol overrides to select
-        // the correct IETF draft encoding for SETUP.
+        // Establish a MoQ session. First try native negotiation as-selected by the relay.
+        // If that fails, fall back to explicit protocol overrides for relays that omit protocol
+        // selection in CONNECT responses.
         let client = moq_lite::Client::new().with_publish(publish);
 
+        match client.connect(wt.clone()).await {
+            Ok(session) => {
+                tracing::info!("connected to relay (native protocol negotiation)");
+                return Ok(session);
+            }
+            Err(err) => {
+                tracing::debug!(err = %err, "native MoQ SETUP failed; trying protocol overrides");
+            }
+        }
+
         // These correspond to IETF draft ALPNs as used by moq-lite/web code.
         // We use string literals here since moq-lite does not currently expose these constants.
         let attempts: [&str; 4] = ["moqt-16", "moqt-15", "moq-00", ""];

evolution/proposals/ECP-0063-cloudflare-moq-webtransport.md

@@ -8,7 +8,7 @@ Adopt Cloudflare's MoQ relay preview as the default "global" distribution layer
 
 Concrete changes:
 
-1. `ec-node` gains a WebTransport MoQ publisher path that can publish a live CMAF (fMP4) stream to a relay URL (default: `https://interop-relay.cloudflare.mediaoverquic.com/`).
+1. `ec-node` gains a WebTransport MoQ publisher path that can publish a live CMAF (fMP4) stream to a relay URL (default: `https://cdn.moq.dev/anon`).
 2. `every.channel` (the deployed static site) becomes a real web watcher by embedding a WebTransport-capable MoQ player component (`<hang-watch>`).
 3. The existing WebRTC/WS bootstrap directory/relay remains temporarily for compatibility, but is treated as deprecated once MoQ/WebTransport is stable.
 
@@ -41,10 +41,10 @@ Out of scope (explicitly deferred):
 ### Relay default
 
 Default relay endpoint is:
-- `https://interop-relay.cloudflare.mediaoverquic.com/`
+- `https://cdn.moq.dev/anon`
 
 Nodes may override via CLI flags for self-hosted relays or future Cloudflare relay endpoints.
-As of February 20, 2026, the production relay endpoint (`https://relay.cloudflare.mediaoverquic.com/`) is observed to close sessions immediately after MoQ `SETUP` for current clients, while the interop relay completes `SETUP` and `ANNOUNCE` tests.
+As of February 21, 2026, browser sessions against `https://interop-relay.cloudflare.mediaoverquic.com/` are observed to stall/fail during MoQ session establishment with current web clients, while `https://cdn.moq.dev/anon` establishes browser sessions in Chrome.
 
 ### Web player
 

nix/modules/ec-node.nix

@@ -48,7 +48,7 @@ in
 
     relayUrl = lib.mkOption {
       type = lib.types.str;
-      default = "https://interop-relay.cloudflare.mediaoverquic.com/";
+      default = "https://cdn.moq.dev/anon";
       description = "MoQ relay URL for ec-node wt-publish.";
     };