diff --git a/trunk/doc/CHANGELOG.md b/trunk/doc/CHANGELOG.md
index 381f1d40b..a2436754f 100644
--- a/trunk/doc/CHANGELOG.md
+++ b/trunk/doc/CHANGELOG.md
@@ -8,6 +8,7 @@ The changelog for SRS.
 
 ## SRS 4.0 Changelog
 
+* v4.0, 2022-01-14, Support api_port to specify the WebRTC API port. v4.0.224
 * v4.0, 2022-01-13, Merge [#2873](https://github.com/ossrs/srs/pull/2873): LiveSource: Refine fetch for external exposed interface. (#2873). v4.0.223
 * v4.0, 2022-01-13, Add conf/lighthouse.conf for LightHouse. v4.0.222
 * v4.0, 2022-01-12, Refine the running homepage. v4.0.221
diff --git a/trunk/research/api-server/static-dir/index.html b/trunk/research/api-server/static-dir/index.html
index d54b70289..684848da3 100755
--- a/trunk/research/api-server/static-dir/index.html
+++ b/trunk/research/api-server/static-dir/index.html
@@ -63,8 +63,8 @@
         if (true) {
             const prefix = `players/?schema=${window.location.protocol.replace(':', '')}`;
             const httpPort = window.location.port || (window.location.protocol === 'http:' ? 80 : 443);
-            // If not 8080, user should proxy to the default port.
-            const query = parseInt(window.location.port) === 8080 ? '' : `&port=${httpPort}`;
+            // If not 8080, user should proxy both stream and API to the default port.
+            const query = parseInt(window.location.port) === 8080 ? '' : `&port=${httpPort}&api_port=${httpPort}`;
             document.getElementById("enPlayer").setAttribute('href', `${prefix}${query}`);
             document.getElementById("cnPlayer").setAttribute('href', `${prefix}${query}`);
         }
diff --git a/trunk/research/players/js/srs.sdk.js b/trunk/research/players/js/srs.sdk.js
index ed5276b50..af4f48837 100644
--- a/trunk/research/players/js/srs.sdk.js
+++ b/trunk/research/players/js/srs.sdk.js
@@ -267,6 +267,7 @@ function SrsRtcPlayerAsync() {
     //      webrtc://r.ossrs.net/live/livestream
     // or specifies the API port:
     //      webrtc://r.ossrs.net:11985/live/livestream
+    //      webrtc://r.ossrs.net/live/livestream?api_port=11985
     // or autostart the play:
     //      webrtc://r.ossrs.net/live/livestream?autostart=true
     // or change the app from live to myapp:
@@ -438,8 +439,9 @@ function SrsRtcPlayerAsync() {
                     } else if (window.location.href.indexOf('https://') === 0) {
                         ret.port = 443;
                     } else {
+                        // Allow use api_port to specify the WebRTC API port.
                         // For WebRTC, SRS use 1985 as default API port.
-                        ret.port = 1985;
+                        ret.port = ret.user_query.api_port || 1985;
                     }
                 }
             }
diff --git a/trunk/src/core/srs_core_version4.hpp b/trunk/src/core/srs_core_version4.hpp
index c67b5f8ee..c9415a650 100644
--- a/trunk/src/core/srs_core_version4.hpp
+++ b/trunk/src/core/srs_core_version4.hpp
@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       4
 #define VERSION_MINOR       0
-#define VERSION_REVISION    223
+#define VERSION_REVISION    224
 
 #endif