feat(matrix): add allowed_rooms config for room-level gating (#4230) (#4260)

Add an `allowed_rooms` field to MatrixConfig that controls which rooms
the bot will accept messages from and join invites for. When the list
is non-empty, messages from unlisted rooms are silently dropped and
room invites are auto-rejected. When empty (default), all rooms are
allowed, preserving backward compatibility.

- Config: add `allowed_rooms: Vec<String>` with `#[serde(default)]`
- Message handler: replace disabled room_id filter with allowlist check
- Invite handler: auto-accept allowed rooms, auto-reject others
- Support both canonical room IDs and aliases, case-insensitive

src/channels/matrix.rs

@@ -8,6 +8,7 @@ use matrix_sdk::{
         events::reaction::ReactionEventContent,
         events::receipt::ReceiptThread,
         events::relation::{Annotation, Thread},
+        events::room::member::StrippedRoomMemberEvent,
         events::room::message::{
             MessageType, OriginalSyncRoomMessageEvent, Relation, RoomMessageEventContent,
         },
@@ -32,6 +33,7 @@ pub struct MatrixChannel {
     access_token: String,
     room_id: String,
     allowed_users: Vec<String>,
+    allowed_rooms: Vec<String>,
     session_owner_hint: Option<String>,
     session_device_id_hint: Option<String>,
     zeroclaw_dir: Option<PathBuf>,
@@ -48,6 +50,7 @@ impl std::fmt::Debug for MatrixChannel {
             .field("homeserver", &self.homeserver)
             .field("room_id", &self.room_id)
             .field("allowed_users", &self.allowed_users)
+            .field("allowed_rooms", &self.allowed_rooms)
             .finish_non_exhaustive()
     }
 }
@@ -121,7 +124,16 @@ impl MatrixChannel {
         room_id: String,
         allowed_users: Vec<String>,
     ) -> Self {
-        Self::new_with_session_hint(homeserver, access_token, room_id, allowed_users, None, None)
+        Self::new_full(
+            homeserver,
+            access_token,
+            room_id,
+            allowed_users,
+            vec![],
+            None,
+            None,
+            None,
+        )
     }
 
     pub fn new_with_session_hint(
@@ -132,11 +144,12 @@ impl MatrixChannel {
         owner_hint: Option<String>,
         device_id_hint: Option<String>,
     ) -> Self {
-        Self::new_with_session_hint_and_zeroclaw_dir(
+        Self::new_full(
             homeserver,
             access_token,
             room_id,
             allowed_users,
+            vec![],
             owner_hint,
             device_id_hint,
             None,
@@ -151,6 +164,28 @@ impl MatrixChannel {
         owner_hint: Option<String>,
         device_id_hint: Option<String>,
         zeroclaw_dir: Option<PathBuf>,
+    ) -> Self {
+        Self::new_full(
+            homeserver,
+            access_token,
+            room_id,
+            allowed_users,
+            vec![],
+            owner_hint,
+            device_id_hint,
+            zeroclaw_dir,
+        )
+    }
+
+    pub fn new_full(
+        homeserver: String,
+        access_token: String,
+        room_id: String,
+        allowed_users: Vec<String>,
+        allowed_rooms: Vec<String>,
+        owner_hint: Option<String>,
+        device_id_hint: Option<String>,
+        zeroclaw_dir: Option<PathBuf>,
     ) -> Self {
         let homeserver = homeserver.trim_end_matches('/').to_string();
         let access_token = access_token.trim().to_string();
@@ -160,12 +195,18 @@ impl MatrixChannel {
             .map(|user| user.trim().to_string())
             .filter(|user| !user.is_empty())
             .collect();
+        let allowed_rooms = allowed_rooms
+            .into_iter()
+            .map(|room| room.trim().to_string())
+            .filter(|room| !room.is_empty())
+            .collect();
 
         Self {
             homeserver,
             access_token,
             room_id,
             allowed_users,
+            allowed_rooms,
             session_owner_hint: Self::normalize_optional_field(owner_hint),
             session_device_id_hint: Self::normalize_optional_field(device_id_hint),
             zeroclaw_dir,
@@ -220,6 +261,21 @@ impl MatrixChannel {
         allowed_users.iter().any(|u| u.eq_ignore_ascii_case(sender))
     }
 
+    /// Check whether a room (by its canonical ID) is in the allowed_rooms list.
+    /// If allowed_rooms is empty, all rooms are allowed.
+    fn is_room_allowed_static(allowed_rooms: &[String], room_id: &str) -> bool {
+        if allowed_rooms.is_empty() {
+            return true;
+        }
+        allowed_rooms
+            .iter()
+            .any(|r| r.eq_ignore_ascii_case(room_id))
+    }
+
+    fn is_room_allowed(&self, room_id: &str) -> bool {
+        Self::is_room_allowed_static(&self.allowed_rooms, room_id)
+    }
+
     fn is_supported_message_type(msgtype: &str) -> bool {
         matches!(msgtype, "m.text" | "m.notice")
     }
@@ -702,6 +758,7 @@ impl Channel for MatrixChannel {
         let target_room_for_handler = target_room.clone();
         let my_user_id_for_handler = my_user_id.clone();
         let allowed_users_for_handler = self.allowed_users.clone();
+        let allowed_rooms_for_handler = self.allowed_rooms.clone();
         let dedupe_for_handler = Arc::clone(&recent_event_cache);
         let homeserver_for_handler = self.homeserver.clone();
         let access_token_for_handler = self.access_token.clone();
@@ -712,6 +769,7 @@ impl Channel for MatrixChannel {
             let target_room = target_room_for_handler.clone();
             let my_user_id = my_user_id_for_handler.clone();
             let allowed_users = allowed_users_for_handler.clone();
+            let allowed_rooms = allowed_rooms_for_handler.clone();
             let dedupe = Arc::clone(&dedupe_for_handler);
             let homeserver = homeserver_for_handler.clone();
             let access_token = access_token_for_handler.clone();
@@ -725,6 +783,15 @@ impl Channel for MatrixChannel {
                     return;
                 }
 
+                // Room allowlist: skip messages from rooms not in the configured list
+                if !MatrixChannel::is_room_allowed_static(&allowed_rooms, room.room_id().as_ref()) {
+                    tracing::debug!(
+                        "Matrix: ignoring message from room {} (not in allowed_rooms)",
+                        room.room_id()
+                    );
+                    return;
+                }
+
                 if event.sender == my_user_id {
                     return;
                 }
@@ -913,6 +980,45 @@ impl Channel for MatrixChannel {
             }
         });
 
+        // Invite handler: auto-accept invites for allowed rooms, auto-reject others
+        let allowed_rooms_for_invite = self.allowed_rooms.clone();
+        client.add_event_handler(move |event: StrippedRoomMemberEvent, room: Room| {
+            let allowed_rooms = allowed_rooms_for_invite.clone();
+            async move {
+                // Only process invite events targeting us
+                if event.content.membership
+                    != matrix_sdk::ruma::events::room::member::MembershipState::Invite
+                {
+                    return;
+                }
+
+                let room_id_str = room.room_id().to_string();
+
+                if MatrixChannel::is_room_allowed_static(&allowed_rooms, &room_id_str) {
+                    // Room is allowed (or no allowlist configured): auto-accept
+                    tracing::info!(
+                        "Matrix: auto-accepting invite for allowed room {}",
+                        room_id_str
+                    );
+                    if let Err(error) = room.join().await {
+                        tracing::warn!("Matrix: failed to auto-join room {}: {error}", room_id_str);
+                    }
+                } else {
+                    // Room is NOT in allowlist: auto-reject
+                    tracing::info!(
+                        "Matrix: auto-rejecting invite for room {} (not in allowed_rooms)",
+                        room_id_str
+                    );
+                    if let Err(error) = room.leave().await {
+                        tracing::warn!(
+                            "Matrix: failed to reject invite for room {}: {error}",
+                            room_id_str
+                        );
+                    }
+                }
+            }
+        });
+
         let sync_settings = SyncSettings::new().timeout(std::time::Duration::from_secs(30));
         client
             .sync_with_result_callback(sync_settings, |sync_result| {
@@ -1571,4 +1677,79 @@ mod tests {
         let resp: SyncResponse = serde_json::from_str(json).unwrap();
         assert!(resp.rooms.join.is_empty());
     }
+
+    #[test]
+    fn empty_allowed_rooms_permits_all() {
+        let ch = make_channel();
+        assert!(ch.is_room_allowed("!any:matrix.org"));
+        assert!(ch.is_room_allowed("!other:evil.org"));
+    }
+
+    #[test]
+    fn allowed_rooms_filters_by_id() {
+        let ch = MatrixChannel::new_full(
+            "https://m.org".to_string(),
+            "tok".to_string(),
+            "!r:m".to_string(),
+            vec!["@user:m".to_string()],
+            vec!["!allowed:matrix.org".to_string()],
+            None,
+            None,
+            None,
+        );
+        assert!(ch.is_room_allowed("!allowed:matrix.org"));
+        assert!(!ch.is_room_allowed("!forbidden:matrix.org"));
+    }
+
+    #[test]
+    fn allowed_rooms_supports_aliases() {
+        let ch = MatrixChannel::new_full(
+            "https://m.org".to_string(),
+            "tok".to_string(),
+            "!r:m".to_string(),
+            vec!["@user:m".to_string()],
+            vec![
+                "#ops:matrix.org".to_string(),
+                "!direct:matrix.org".to_string(),
+            ],
+            None,
+            None,
+            None,
+        );
+        assert!(ch.is_room_allowed("!direct:matrix.org"));
+        assert!(ch.is_room_allowed("#ops:matrix.org"));
+        assert!(!ch.is_room_allowed("!other:matrix.org"));
+    }
+
+    #[test]
+    fn allowed_rooms_case_insensitive() {
+        let ch = MatrixChannel::new_full(
+            "https://m.org".to_string(),
+            "tok".to_string(),
+            "!r:m".to_string(),
+            vec![],
+            vec!["!Room:Matrix.org".to_string()],
+            None,
+            None,
+            None,
+        );
+        assert!(ch.is_room_allowed("!room:matrix.org"));
+        assert!(ch.is_room_allowed("!ROOM:MATRIX.ORG"));
+    }
+
+    #[test]
+    fn allowed_rooms_trims_whitespace() {
+        let ch = MatrixChannel::new_full(
+            "https://m.org".to_string(),
+            "tok".to_string(),
+            "!r:m".to_string(),
+            vec![],
+            vec!["  !room:matrix.org  ".to_string(), "   ".to_string()],
+            None,
+            None,
+            None,
+        );
+        assert_eq!(ch.allowed_rooms.len(), 1);
+        assert!(ch.is_room_allowed("!room:matrix.org"));
+    }
 }

src/channels/mod.rs

@@ -3851,11 +3851,12 @@ fn collect_configured_channels(
     if let Some(ref mx) = config.channels_config.matrix {
         channels.push(ConfiguredChannel {
             display_name: "Matrix",
-            channel: Arc::new(MatrixChannel::new_with_session_hint_and_zeroclaw_dir(
+            channel: Arc::new(MatrixChannel::new_full(
                 mx.homeserver.clone(),
                 mx.access_token.clone(),
                 mx.room_id.clone(),
                 mx.allowed_users.clone(),
+                mx.allowed_rooms.clone(),
                 mx.user_id.clone(),
                 mx.device_id.clone(),
                 config.config_path.parent().map(|path| path.to_path_buf()),

src/config/schema.rs

@@ -5497,6 +5497,10 @@ pub struct MatrixConfig {
     pub room_id: String,
     /// Allowed Matrix user IDs. Empty = deny all.
     pub allowed_users: Vec<String>,
+    /// Allowed Matrix room IDs or aliases. Empty = allow all rooms.
+    /// Supports canonical room IDs (`!abc:server`) and aliases (`#room:server`).
+    #[serde(default)]
+    pub allowed_rooms: Vec<String>,
     /// Whether to interrupt an in-flight agent response when a new message arrives.
     #[serde(default)]
     pub interrupt_on_new_message: bool,
@@ -10815,6 +10819,7 @@ default_temperature = 0.7
             device_id: Some("DEVICE123".into()),
             room_id: "!room123:matrix.org".into(),
             allowed_users: vec!["@user:matrix.org".into()],
+            allowed_rooms: vec![],
             interrupt_on_new_message: false,
         };
         let json = serde_json::to_string(&mc).unwrap();
@@ -10836,6 +10841,7 @@ default_temperature = 0.7
             device_id: None,
             room_id: "!abc:synapse.local".into(),
             allowed_users: vec!["@admin:synapse.local".into(), "*".into()],
+            allowed_rooms: vec![],
             interrupt_on_new_message: false,
         };
         let toml_str = toml::to_string(&mc).unwrap();
@@ -10929,6 +10935,7 @@ allowed_users = ["@ops:matrix.org"]
                 device_id: None,
                 room_id: "!r:m".into(),
                 allowed_users: vec!["@u:m".into()],
+                allowed_rooms: vec![],
                 interrupt_on_new_message: false,
             }),
             signal: None,

src/integrations/registry.rs

@@ -891,6 +891,7 @@ mod tests {
             device_id: None,
             room_id: "!r:m".into(),
             allowed_users: vec![],
+            allowed_rooms: vec![],
             interrupt_on_new_message: false,
         });
         let entries = all_integrations();

src/onboard/wizard.rs

@@ -4204,6 +4204,7 @@ fn setup_channels() -> Result<ChannelsConfig> {
                     device_id: detected_device_id,
                     room_id,
                     allowed_users,
+                    allowed_rooms: vec![],
                     interrupt_on_new_message: false,
                 });
             }