diff --git a/README.md b/README.md
index f427005..b13c02c 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,7 @@ Publish (node -> Cloudflare relay):
 
 ```sh
 cargo run -p ec-node -- wt-publish \
-  --url https://relay.cloudflare.mediaoverquic.com/ \
+  --url https://interop-relay.cloudflare.mediaoverquic.com/ \
   --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%2Frelay.cloudflare.mediaoverquic.com%2F&name=la-nbc
+https://every.channel/watch?url=https%3A%2F%2Finterop-relay.cloudflare.mediaoverquic.com%2F&name=la-nbc
 ```
 
 Coverage:
diff --git a/apps/web/app.js b/apps/web/app.js
index 0800605..1a2e388 100644
--- a/apps/web/app.js
+++ b/apps/web/app.js
@@ -6,7 +6,7 @@
 // Use an ESM CDN that rewrites bare module specifiers.
 import "https://esm.sh/@kixelated/hang@0.7.4/watch/element.js";
 
-const DEFAULT_RELAY_URL = "https://relay.cloudflare.mediaoverquic.com/";
+const DEFAULT_RELAY_URL = "https://interop-relay.cloudflare.mediaoverquic.com/";
 
 function $(id) {
   const el = document.getElementById(id);
diff --git a/evolution/proposals/ECP-0063-cloudflare-moq-webtransport.md b/evolution/proposals/ECP-0063-cloudflare-moq-webtransport.md
index f9f5b95..4526dbb 100644
--- a/evolution/proposals/ECP-0063-cloudflare-moq-webtransport.md
+++ b/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://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://interop-relay.cloudflare.mediaoverquic.com/`).
 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.
 
@@ -41,9 +41,10 @@ Out of scope (explicitly deferred):
 ### Relay default
 
 Default relay endpoint is:
-- `https://relay.cloudflare.mediaoverquic.com/`
+- `https://interop-relay.cloudflare.mediaoverquic.com/`
 
 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.
 
 ### Web player
 
diff --git a/nix/modules/ec-node.nix b/nix/modules/ec-node.nix
index 0e8487a..1390da1 100644
--- a/nix/modules/ec-node.nix
+++ b/nix/modules/ec-node.nix
@@ -48,7 +48,7 @@ in
 
     relayUrl = lib.mkOption {
       type = lib.types.str;
-      default = "https://relay.cloudflare.mediaoverquic.com/";
+      default = "https://interop-relay.cloudflare.mediaoverquic.com/";
       description = "MoQ relay URL for ec-node wt-publish.";
     };