diff --git a/crates/ruma-client-api/src/room.rs b/crates/ruma-client-api/src/room.rs
index 2253f495..0db0f03d 100644
--- a/crates/ruma-client-api/src/room.rs
+++ b/crates/ruma-client-api/src/room.rs
@@ -6,6 +6,7 @@ pub mod get_event_by_timestamp;
 pub mod get_room_event;
 #[cfg(feature = "unstable-msc3266")]
 pub mod get_summary;
+pub mod initial_sync;
 pub mod report_content;
 pub mod report_room;
 pub mod upgrade_room;
diff --git a/crates/ruma-client-api/src/room/initial_sync.rs b/crates/ruma-client-api/src/room/initial_sync.rs
new file mode 100644
index 00000000..6557bc6b
--- /dev/null
+++ b/crates/ruma-client-api/src/room/initial_sync.rs
@@ -0,0 +1,94 @@
+//! `GET /_matrix/client/*/rooms/{roomId}/initialSync`
+//!
+//! DEPRECATED
+
+pub mod v3 {
+    //! `/v3/` ([spec])
+    //!
+    //! [spec]: https://spec.matrix.org/latest/client-server-api/#get_matrixclientv3roomsroomidinitialsync
+
+    use ruma_common::{
+        api::{request, response, Metadata},
+        metadata,
+        serde::Raw,
+        OwnedRoomId,
+    };
+    use ruma_events::{
+        room::member::MembershipState, AnyRoomAccountDataEvent, AnyStateEvent, AnyTimelineEvent,
+    };
+    use serde::{Deserialize, Serialize};
+
+    use crate::room::Visibility;
+
+    const METADATA: Metadata = metadata! {
+        method: GET,
+        rate_limited: false,
+        authentication: AccessToken,
+        history: {
+            1.0 => "/_matrix/client/r0/rooms/:room_id/initialSync",
+            1.1 => "/_matrix/client/v3/rooms/:room_id/initialSync",
+        }
+    };
+
+    /// Request type for the `get_room_event` endpoint.
+    #[request(error = crate::Error)]
+    pub struct Request {
+        /// The ID of the room.
+        #[ruma_api(path)]
+        pub room_id: OwnedRoomId,
+
+        /// Limit messages chunks size
+        #[ruma_api(query)]
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub limit: Option<usize>,
+    }
+
+    /// Response type for the `get_room_event` endpoint.
+    #[response(error = crate::Error)]
+    pub struct Response {
+        /// The private data that this user has attached to this room.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub account_data: Option<Vec<Raw<AnyRoomAccountDataEvent>>>,
+
+        /// The user’s membership state in this room. One of: [invite, join, leave, ban].
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub membership: Option<MembershipState>,
+
+        /// The pagination chunk for this room.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub messages: Option<PaginationChunk>,
+
+        /// The ID of this room.
+        pub room_id: OwnedRoomId,
+
+        /// If the user is a member of the room this will be the current state of the room as a
+        /// list of events. If the user has left the room this will be the state of the room when
+        /// they left it.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub state: Option<Vec<Raw<AnyStateEvent>>>,
+
+        /// Whether this room is visible to the /publicRooms API or not.
+        /// One of: [private, public].
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub visibility: Option<Visibility>,
+    }
+
+    /// Page of timeline events
+    #[derive(Clone, Debug, Default, Deserialize, Serialize)]
+    pub struct PaginationChunk {
+        /// If the user is a member of the room this will be a list of the most recent messages
+        /// for this room. If the user has left the room this will be the messages that preceded
+        /// them leaving. This array will consist of at most limit elements.
+        pub chunk: Vec<Raw<AnyTimelineEvent>>,
+
+        /// A token which correlates to the end of chunk. Can be passed to
+        /// /rooms/<room_id>/messages to retrieve later events.
+        pub end: String,
+
+        /// A token which correlates to the start of chunk. Can be passed to
+        /// /rooms/<room_id>/messages to retrieve earlier events. If no earlier events are
+        /// available, this property may be omitted from the response.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub start: Option<String>,
+    }
+}