From 8a254a33cc799434917e64151963a45d8878d1dd Mon Sep 17 00:00:00 2001
From: Niklas Wojtkowiak <niklas@wojtkowiak.com>
Date: Mon, 23 Feb 2026 14:15:32 -0500
Subject: [PATCH] fix(api): restore backwards compatibility for RTC foci config

---
 conduwuit-example.toml       | 10 ++++++++++
 src/api/client/well_known.rs | 19 ++++++++++++++-----
 src/api/router.rs            |  9 +--------
 src/core/config/mod.rs       | 29 +++++++++++++++++++++++++++++
 4 files changed, 54 insertions(+), 13 deletions(-)

diff --git a/conduwuit-example.toml b/conduwuit-example.toml
index 58c0d95f..7070ef7c 100644
--- a/conduwuit-example.toml
+++ b/conduwuit-example.toml
@@ -1844,6 +1844,16 @@
 #
 #support_mxid =
 
+# **DEPRECATED**: Use `[global.matrix_rtc].foci` instead.
+#
+# A list of MatrixRTC foci URLs which will be served as part of the
+# MSC4143 client endpoint at /.well-known/matrix/client.
+#
+# This option is deprecated and will be removed in a future release.
+# Please migrate to the new `[global.matrix_rtc]` config section.
+#
+#rtc_focus_server_urls = []
+
 [global.blurhashing]
 
 # blurhashing x component, 4 is recommended by https://blurha.sh/
diff --git a/src/api/client/well_known.rs b/src/api/client/well_known.rs
index adc9b89c..46fde4bf 100644
--- a/src/api/client/well_known.rs
+++ b/src/api/client/well_known.rs
@@ -27,7 +27,11 @@ pub(crate) async fn well_known_client(
 		identity_server: None,
 		sliding_sync_proxy: Some(SlidingSyncProxyInfo { url: client_url }),
 		tile_server: None,
-		rtc_foci: vec![],
+		rtc_foci: services
+			.config
+			.matrix_rtc
+			.effective_foci(&services.config.well_known.rtc_focus_server_urls)
+			.to_vec(),
 	})
 }
 
@@ -38,10 +42,15 @@ pub(crate) async fn well_known_client(
 /// homeserver, implementing MSC4143.
 pub(crate) async fn get_rtc_transports(
 	State(services): State<crate::State>,
-) -> Result<impl IntoResponse> {
-	Ok(Json(serde_json::json!({
-		"rtc_foci": services.config.matrix_rtc.foci,
-	})))
+	_body: Ruma<ruma::api::client::discovery::get_rtc_transports::Request>,
+) -> Result<ruma::api::client::discovery::get_rtc_transports::Response> {
+	Ok(ruma::api::client::discovery::get_rtc_transports::Response::new(
+		services
+			.config
+			.matrix_rtc
+			.effective_foci(&services.config.well_known.rtc_focus_server_urls)
+			.to_vec(),
+	))
 }
 
 /// # `GET /.well-known/matrix/support`
diff --git a/src/api/router.rs b/src/api/router.rs
index ed872b2f..3166c2af 100644
--- a/src/api/router.rs
+++ b/src/api/router.rs
@@ -184,14 +184,7 @@ pub fn build(router: Router<State>, server: &Server) -> Router<State> {
 		.ruma_route(&client::put_suspended_status)
 		.ruma_route(&client::well_known_support)
 		.ruma_route(&client::well_known_client)
-		.route(
-			"/_matrix/client/v1/rtc/transports",
-			get(client::get_rtc_transports),
-		)
-		.route(
-			"/_matrix/client/unstable/org.matrix.msc4143/rtc/transports",
-			get(client::get_rtc_transports),
-		)
+		.ruma_route(&client::get_rtc_transports)
 		.route("/_conduwuit/server_version", get(client::conduwuit_server_version))
 		.route("/_continuwuity/server_version", get(client::conduwuit_server_version))
 		.ruma_route(&client::room_initial_sync_route)
diff --git a/src/core/config/mod.rs b/src/core/config/mod.rs
index acde104d..e004a245 100644
--- a/src/core/config/mod.rs
+++ b/src/core/config/mod.rs
@@ -2150,6 +2150,18 @@ pub struct WellKnownConfig {
 	/// If no email or mxid is specified, all of the server's admins will be
 	/// listed.
 	pub support_mxid: Option<OwnedUserId>,
+
+	/// **DEPRECATED**: Use `[global.matrix_rtc].foci` instead.
+	///
+	/// A list of MatrixRTC foci URLs which will be served as part of the
+	/// MSC4143 client endpoint at /.well-known/matrix/client.
+	///
+	/// This option is deprecated and will be removed in a future release.
+	/// Please migrate to the new `[global.matrix_rtc]` config section.
+	///
+	/// default: []
+	#[serde(default)]
+	pub rtc_focus_server_urls: Vec<RtcFocusInfo>,
 }
 
 #[derive(Clone, Copy, Debug, Deserialize, Default)]
@@ -2198,6 +2210,22 @@ pub struct MatrixRtcConfig {
 	pub foci: Vec<RtcFocusInfo>,
 }
 
+impl MatrixRtcConfig {
+	/// Returns the effective foci, falling back to the deprecated
+	/// `rtc_focus_server_urls` if the new config is empty.
+	#[must_use]
+	pub fn effective_foci<'a>(
+		&'a self,
+		deprecated_foci: &'a [RtcFocusInfo],
+	) -> &'a [RtcFocusInfo] {
+		if !self.foci.is_empty() {
+			&self.foci
+		} else {
+			deprecated_foci
+		}
+	}
+}
+
 #[derive(Clone, Debug, Default, Deserialize)]
 #[config_example_generator(filename = "conduwuit-example.toml", section = "global.ldap")]
 pub struct LdapConfig {
@@ -2391,6 +2419,7 @@ const DEPRECATED_KEYS: &[&str] = &[
 	"well_known_support_email",
 	"well_known_support_mxid",
 	"registration_token_file",
+	"well_known.rtc_focus_server_urls",
 ];
 
 impl Config {