diff --git a/go.mod b/go.mod
index 2ce031c..dbf11ec 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 	golang.org/x/crypto v0.27.0
 	gopkg.in/yaml.v3 v3.0.1
 	maunium.net/go/mauflag v1.0.0
-	maunium.net/go/mautrix v0.21.1-0.20241013141433-5cccf93cdc6a
+	maunium.net/go/mautrix v0.21.1-0.20241013193325-8d9caf0d55f4
 )
 
 require (
diff --git a/go.sum b/go.sum
index a219cd8..baaf9b0 100644
--- a/go.sum
+++ b/go.sum
@@ -66,5 +66,5 @@ gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 maunium.net/go/mauflag v1.0.0 h1:YiaRc0tEI3toYtJMRIfjP+jklH45uDHtT80nUamyD4M=
 maunium.net/go/mauflag v1.0.0/go.mod h1:nLivPOpTpHnpzEh8jEdSL9UqO9+/KBJFmNRlwKfkPeA=
-maunium.net/go/mautrix v0.21.1-0.20241013141433-5cccf93cdc6a h1:faC83lFuKSS9wTrR2pa1mm0JZkUHa5NA6eA0LVQSrDs=
-maunium.net/go/mautrix v0.21.1-0.20241013141433-5cccf93cdc6a/go.mod h1:yIs8uVcl3ZiTuDzAYmk/B4/z9dQqegF0rcOWV4ncgko=
+maunium.net/go/mautrix v0.21.1-0.20241013193325-8d9caf0d55f4 h1:LCVNEHiOT5N2J8OTC95TEdHqffDXoxnz1awcTh7XmyI=
+maunium.net/go/mautrix v0.21.1-0.20241013193325-8d9caf0d55f4/go.mod h1:yIs8uVcl3ZiTuDzAYmk/B4/z9dQqegF0rcOWV4ncgko=
diff --git a/web/src/api/client.ts b/web/src/api/client.ts
index 7fa84e5..39ba557 100644
--- a/web/src/api/client.ts
+++ b/web/src/api/client.ts
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import { CachedEventDispatcher } from "../util/eventdispatcher.ts"
-import type RPCClient from "./rpc.ts"
+import RPCClient, { SendMessageParams } from "./rpc.ts"
 import { StateStore } from "./statestore.ts"
 import type {
 	ClientState,
@@ -49,12 +49,12 @@ export default class Client {
 		}
 	}
 
-	async sendMessage(roomID: RoomID, text: string, mediaPath?: string): Promise<void> {
-		const room = this.store.rooms.get(roomID)
+	async sendMessage(params: SendMessageParams): Promise<void> {
+		const room = this.store.rooms.get(params.room_id)
 		if (!room) {
 			throw new Error("Room not found")
 		}
-		const dbEvent = await this.rpc.sendMessage(roomID, text, mediaPath)
+		const dbEvent = await this.rpc.sendMessage(params)
 		if (!room.eventsByRowID.has(dbEvent.rowid)) {
 			room.pendingEvents.push(dbEvent.rowid)
 			room.applyEvent(dbEvent, true)
diff --git a/web/src/api/rpc.ts b/web/src/api/rpc.ts
index 2cea8a1..6349421 100644
--- a/web/src/api/rpc.ts
+++ b/web/src/api/rpc.ts
@@ -20,6 +20,7 @@ import type {
 	EventID,
 	EventRowID,
 	EventType,
+	Mentions,
 	PaginationResponse,
 	RPCCommand,
 	RPCEvent,
@@ -41,6 +42,14 @@ export class ErrorResponse extends Error {
 	}
 }
 
+export interface SendMessageParams {
+	room_id: RoomID
+	text: string
+	media_path?: string
+	reply_to?: EventID
+	mentions?: Mentions
+}
+
 export default abstract class RPCClient {
 	public readonly connect: CachedEventDispatcher<ConnectionEvent> = new CachedEventDispatcher()
 	public readonly event: EventDispatcher<RPCEvent> = new EventDispatcher()
@@ -110,8 +119,8 @@ export default abstract class RPCClient {
 		}, this.cancelRequest.bind(this, request_id))
 	}
 
-	sendMessage(room_id: RoomID, text: string, media_path?: string): Promise<RawDBEvent> {
-		return this.request("send_message", { room_id, text, media_path })
+	sendMessage(params: SendMessageParams): Promise<RawDBEvent> {
+		return this.request("send_message", params)
 	}
 
 	sendEvent(room_id: RoomID, type: EventType, content: Record<string, unknown>): Promise<RawDBEvent> {
diff --git a/web/src/api/types/mxtypes.ts b/web/src/api/types/mxtypes.ts
index 2764f02..2318f7e 100644
--- a/web/src/api/types/mxtypes.ts
+++ b/web/src/api/types/mxtypes.ts
@@ -64,11 +64,17 @@ export interface MemberEventContent {
 	reason?: string
 }
 
+export interface Mentions {
+	user_ids: UserID[]
+	room: boolean
+}
+
 export interface BaseMessageEventContent {
 	msgtype: string
 	body: string
 	formatted_body?: string
 	format?: "org.matrix.custom.html"
+	"m.mentions"?: Mentions
 }
 
 export interface TextMessageEventContent extends BaseMessageEventContent {
diff --git a/web/src/ui/MessageComposer.css b/web/src/ui/MessageComposer.css
index 81d7972..d4fe1c2 100644
--- a/web/src/ui/MessageComposer.css
+++ b/web/src/ui/MessageComposer.css
@@ -1,18 +1,23 @@
 div.message-composer {
-	display: flex;
 	border-top: 1px solid #ccc;
-	> textarea {
-		flex: 1;
-		resize: none;
-		font-family: sans-serif;
-		height: auto;
-		padding: .5rem;
-		border: none;
-		outline: none;
-	}
-	> button {
-		padding: .5rem;
-		border: none;
-		background: none;
+
+	> div.input-area {
+		display: flex;
+
+		> textarea {
+			flex: 1;
+			resize: none;
+			font-family: sans-serif;
+			height: auto;
+			padding: .5rem;
+			border: none;
+			outline: none;
+		}
+
+		> button {
+			padding: .5rem;
+			border: none;
+			background: none;
+		}
 	}
 }
diff --git a/web/src/ui/MessageComposer.tsx b/web/src/ui/MessageComposer.tsx
index 3b23579..d28e615 100644
--- a/web/src/ui/MessageComposer.tsx
+++ b/web/src/ui/MessageComposer.tsx
@@ -13,39 +13,68 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-import React, { use, useCallback, useState } from "react"
-import { RoomStateStore } from "../api/statestore.ts"
+import React, { use, useCallback, useRef, useState } from "react"
+import { RoomStateStore } from "@/api/statestore.ts"
+import { MemDBEvent, Mentions } from "@/api/types"
 import { ClientContext } from "./ClientContext.ts"
+import ReplyBody from "./timeline/ReplyBody.tsx"
 import "./MessageComposer.css"
 
 interface MessageComposerProps {
 	room: RoomStateStore
+	setTextRows: (rows: number) => void
+	replyTo: MemDBEvent | null
+	closeReply: () => void
 }
 
-const MessageComposer = ({ room }: MessageComposerProps) => {
+const MessageComposer = ({ room, replyTo, setTextRows, closeReply }: MessageComposerProps) => {
 	const client = use(ClientContext)!
 	const [text, setText] = useState("")
+	const textRows = useRef(1)
 	const sendMessage = useCallback((evt: React.FormEvent) => {
 		evt.preventDefault()
+		if (text === "") {
+			return
+		}
 		setText("")
-		client.sendMessage(room.roomID, text)
+		setTextRows(1)
+		textRows.current = 1
+		closeReply()
+		const room_id = room.roomID
+		const mentions: Mentions = {
+			user_ids: [],
+			room: false,
+		}
+		if (replyTo) {
+			mentions.user_ids.push(replyTo.sender)
+		}
+		client.sendMessage({ room_id, text, reply_to: replyTo?.event_id, mentions })
 			.catch(err => window.alert("Failed to send message: " + err))
-	}, [text, room, client])
+	}, [setTextRows, closeReply, replyTo, text, room, client])
+	const onKeyDown = useCallback((evt: React.KeyboardEvent) => {
+		if (evt.key === "Enter" && !evt.shiftKey) {
+			sendMessage(evt)
+		}
+	}, [sendMessage])
+	const onChange = useCallback((evt: React.ChangeEvent<HTMLTextAreaElement>) => {
+		setText(evt.target.value)
+		textRows.current = evt.target.value.split("\n").length
+		setTextRows(textRows.current)
+	}, [setTextRows])
 	return <div className="message-composer">
-		<textarea
-			autoFocus
-			rows={text.split("\n").length}
-			value={text}
-			onKeyDown={evt => {
-				if (evt.key === "Enter" && !evt.shiftKey) {
-					sendMessage(evt)
-				}
-			}}
-			onChange={evt => setText(evt.target.value)}
-			placeholder="Send a message"
-			id="message-composer"
-		/>
-		<button onClick={sendMessage}>Send</button>
+		{replyTo && <ReplyBody room={room} event={replyTo} onClose={closeReply}/>}
+		<div className="input-area">
+			<textarea
+				autoFocus
+				rows={textRows.current}
+				value={text}
+				onKeyDown={onKeyDown}
+				onChange={onChange}
+				placeholder="Send a message"
+				id="message-composer"
+			/>
+			<button onClick={sendMessage}>Send</button>
+		</div>
 	</div>
 }
 
diff --git a/web/src/ui/RoomView.tsx b/web/src/ui/RoomView.tsx
index bac2631..1a504e6 100644
--- a/web/src/ui/RoomView.tsx
+++ b/web/src/ui/RoomView.tsx
@@ -13,9 +13,11 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-import { getMediaURL } from "../api/media.ts"
-import { RoomStateStore } from "../api/statestore.ts"
-import { useNonNullEventAsState } from "../util/eventdispatcher.ts"
+import { useCallback, useState } from "react"
+import { getMediaURL } from "@/api/media.ts"
+import { RoomStateStore } from "@/api/statestore.ts"
+import { MemDBEvent } from "@/api/types"
+import { useNonNullEventAsState } from "@/util/eventdispatcher.ts"
 import MessageComposer from "./MessageComposer.tsx"
 import TimelineView from "./timeline/TimelineView.tsx"
 import "./RoomView.css"
@@ -46,10 +48,13 @@ const onKeyDownRoomView = (evt: React.KeyboardEvent) => {
 }
 
 const RoomView = ({ room }: RoomViewProps) => {
+	const [replyTo, setReplyTo] = useState<MemDBEvent | null>(null)
+	const [textRows, setTextRows] = useState(1)
+	const closeReply = useCallback(() => setReplyTo(null), [])
 	return <div className="room-view" onKeyDown={onKeyDownRoomView} tabIndex={-1}>
 		<RoomHeader room={room}/>
-		<TimelineView room={room}/>
-		<MessageComposer room={room}/>
+		<TimelineView room={room} textRows={textRows} replyTo={replyTo} setReplyTo={setReplyTo}/>
+		<MessageComposer room={room} setTextRows={setTextRows} replyTo={replyTo} closeReply={closeReply}/>
 	</div>
 }
 
diff --git a/web/src/ui/roomlist/RoomList.tsx b/web/src/ui/roomlist/RoomList.tsx
index 041632e..bf6cbd0 100644
--- a/web/src/ui/roomlist/RoomList.tsx
+++ b/web/src/ui/roomlist/RoomList.tsx
@@ -13,7 +13,7 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-import React, { use, useCallback, useState } from "react"
+import React, { use, useCallback, useRef, useState } from "react"
 import { toSearchableString } from "@/api/statestore.ts"
 import type { RoomID } from "@/api/types"
 import { useNonNullEventAsState } from "@/util/eventdispatcher.ts"
@@ -28,6 +28,7 @@ interface RoomListProps {
 
 const RoomList = ({ setActiveRoom, activeRoomID }: RoomListProps) => {
 	const roomList = useNonNullEventAsState(use(ClientContext)!.store.roomList)
+	const roomFilterRef = useRef<HTMLInputElement>(null)
 	const [roomFilter, setRoomFilter] = useState("")
 	const [realRoomFilter, setRealRoomFilter] = useState("")
 	const clickRoom = useCallback((evt: React.MouseEvent) => {
@@ -51,6 +52,7 @@ const RoomList = ({ setActiveRoom, activeRoomID }: RoomListProps) => {
 			className="room-search"
 			type="text"
 			placeholder="Search rooms"
+			ref={roomFilterRef}
 		/>
 		<div className="room-list">
 			{reverseMap(roomList, room =>
diff --git a/web/src/ui/timeline/ReplyBody.css b/web/src/ui/timeline/ReplyBody.css
index 526f466..c4a34bb 100644
--- a/web/src/ui/timeline/ReplyBody.css
+++ b/web/src/ui/timeline/ReplyBody.css
@@ -3,7 +3,7 @@ blockquote.reply-body {
 	border-left: 2px solid #aaa;
 	padding: .25rem .5rem;
 
-	&:hover {
+	&:hover, &.composer {
 		border-color: black;
 
 		> div.message-text {
@@ -17,7 +17,6 @@ blockquote.reply-body {
 		-webkit-box-orient: vertical;
 		overflow: hidden;
 		color: #666;
-
 	}
 
 	> div.reply-sender {
@@ -29,5 +28,24 @@ blockquote.reply-body {
 			height: 1rem;
 			margin-right: .25rem;
 		}
+
+		> button.close-reply {
+			display: flex;
+			margin-left: auto;
+			align-items: center;
+			background: none;
+			border: none;
+			border-radius: .25rem;
+			padding: 0;
+
+			> svg {
+				height: 24px;
+				width: 24px;
+			}
+
+			&:hover {
+				background-color: #ccc;
+			}
+		}
 	}
 }
diff --git a/web/src/ui/timeline/ReplyBody.tsx b/web/src/ui/timeline/ReplyBody.tsx
index 4588b8a..b1ae263 100644
--- a/web/src/ui/timeline/ReplyBody.tsx
+++ b/web/src/ui/timeline/ReplyBody.tsx
@@ -15,37 +15,45 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import { getAvatarURL } from "@/api/media.ts"
 import type { RoomStateStore } from "@/api/statestore.ts"
-import type { EventID, MemberEventContent } from "@/api/types"
+import type { EventID, MemDBEvent, MemberEventContent } from "@/api/types"
 import { TextMessageBody } from "./content/MessageBody.tsx"
+import CloseButton from "@/icons/close.svg?react"
 import "./ReplyBody.css"
 
-interface ReplyBodyProps {
+interface BaseReplyBodyProps {
 	room: RoomStateStore
-	eventID: EventID
+	eventID?: EventID
+	event?: MemDBEvent
+	onClose?: () => void
 }
 
-const ReplyBody = ({ room, eventID }: ReplyBodyProps) => {
-	const evt = room.eventsByID.get(eventID)
-	if (!evt) {
-		return <blockquote className="reply-body">
-			Reply to {eventID}
-		</blockquote>
+type ReplyBodyProps = BaseReplyBodyProps & ({eventID: EventID } | {event: MemDBEvent })
+
+const ReplyBody = ({ room, eventID, event, onClose }: ReplyBodyProps) => {
+	if (!event) {
+		event = room.eventsByID.get(eventID!)
+		if (!event) {
+			return <blockquote className="reply-body">
+				Reply to {eventID}
+			</blockquote>
+		}
 	}
-	const memberEvt = room.getStateEvent("m.room.member", evt.sender)
+	const memberEvt = room.getStateEvent("m.room.member", event.sender)
 	const memberEvtContent = memberEvt?.content as MemberEventContent | undefined
-	return <blockquote className="reply-body">
+	return <blockquote className={`reply-body ${onClose ? "composer" : ""}`}>
 		<div className="reply-sender">
-			<div className="sender-avatar" title={evt.sender}>
+			<div className="sender-avatar" title={event.sender}>
 				<img
 					className="avatar"
 					loading="lazy"
-					src={getAvatarURL(evt.sender, memberEvtContent?.avatar_url)}
+					src={getAvatarURL(event.sender, memberEvtContent?.avatar_url)}
 					alt=""
 				/>
 			</div>
-			<span className="event-sender">{memberEvtContent?.displayname ?? evt.sender}</span>
+			<span className="event-sender">{memberEvtContent?.displayname ?? event.sender}</span>
+			{onClose && <button className="close-reply" onClick={onClose}><CloseButton/></button>}
 		</div>
-		<TextMessageBody room={room} event={evt}/>
+		<TextMessageBody room={room} event={event}/>
 	</blockquote>
 }
 
diff --git a/web/src/ui/timeline/TimelineEvent.tsx b/web/src/ui/timeline/TimelineEvent.tsx
index 12ce124..c3bdaaa 100644
--- a/web/src/ui/timeline/TimelineEvent.tsx
+++ b/web/src/ui/timeline/TimelineEvent.tsx
@@ -13,7 +13,7 @@
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
-import React, { use } from "react"
+import React, { use, useCallback } from "react"
 import { getAvatarURL } from "../../api/media.ts"
 import { RoomStateStore } from "../../api/statestore.ts"
 import { MemDBEvent, MemberEventContent } from "../../api/types"
@@ -33,6 +33,7 @@ export interface TimelineEventProps {
 	room: RoomStateStore
 	evt: MemDBEvent
 	prevEvt: MemDBEvent | null
+	setReplyTo: (evt: MemDBEvent) => void
 }
 
 function getBodyType(evt: MemDBEvent): React.FunctionComponent<EventContentProps> {
@@ -99,7 +100,8 @@ const EventSendStatus = ({ evt }: { evt: MemDBEvent }) => {
 	}
 }
 
-const TimelineEvent = ({ room, evt, prevEvt }: TimelineEventProps) => {
+const TimelineEvent = ({ room, evt, prevEvt, setReplyTo }: TimelineEventProps) => {
+	const wrappedSetReplyTo = useCallback(() => setReplyTo(evt), [evt, setReplyTo])
 	const client = use(ClientContext)!
 	const memberEvt = room.getStateEvent("m.room.member", evt.sender)
 	const memberEvtContent = memberEvt?.content as MemberEventContent | undefined
@@ -127,14 +129,14 @@ const TimelineEvent = ({ room, evt, prevEvt }: TimelineEventProps) => {
 				alt=""
 			/>
 		</div>
-		<div className="event-sender-and-time">
+		<div className="event-sender-and-time" onClick={wrappedSetReplyTo}>
 			<span className="event-sender">{memberEvtContent?.displayname ?? evt.sender}</span>
 			<span className="event-time" title={fullTime}>{shortTime}</span>
 			{(editEventTS && editTime) ? <span className="event-edited" title={editTime}>
 				(edited at {formatShortTime(editEventTS)})
 			</span> : null}
 		</div>
-		<div className="event-time-only">
+		<div className="event-time-only" onClick={wrappedSetReplyTo}>
 			<span className="event-time" title={editTime ? `${fullTime} - ${editTime}` : fullTime}>{shortTime}</span>
 		</div>
 		<div className="event-content">
diff --git a/web/src/ui/timeline/TimelineView.tsx b/web/src/ui/timeline/TimelineView.tsx
index 908100c..51babb1 100644
--- a/web/src/ui/timeline/TimelineView.tsx
+++ b/web/src/ui/timeline/TimelineView.tsx
@@ -14,17 +14,20 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import { use, useCallback, useEffect, useRef } from "react"
-import { RoomStateStore, useRoomTimeline } from "../../api/statestore.ts"
-import { MemDBEvent } from "../../api/types"
+import { RoomStateStore, useRoomTimeline } from "@/api/statestore.ts"
+import { MemDBEvent } from "@/api/types"
 import { ClientContext } from "../ClientContext.ts"
 import TimelineEvent from "./TimelineEvent.tsx"
 import "./TimelineView.css"
 
 interface TimelineViewProps {
 	room: RoomStateStore
+	textRows: number
+	replyTo: MemDBEvent | null
+	setReplyTo: (evt: MemDBEvent) => void
 }
 
-const TimelineView = ({ room }: TimelineViewProps) => {
+const TimelineView = ({ room, textRows, replyTo, setReplyTo }: TimelineViewProps) => {
 	const timeline = useRoomTimeline(room)
 	const client = use(ClientContext)!
 	const loadHistory = useCallback(() => {
@@ -61,7 +64,7 @@ const TimelineView = ({ room }: TimelineViewProps) => {
 			timelineViewRef.current.scrollTop += timelineViewRef.current.scrollHeight - oldScrollHeight.current
 		}
 		prevOldestTimelineRow.current = timeline[0]?.timeline_rowid ?? 0
-	}, [timeline])
+	}, [textRows, replyTo, timeline])
 	useEffect(() => {
 		const topElem = topRef.current
 		if (!topElem) {
@@ -93,7 +96,7 @@ const TimelineView = ({ room }: TimelineViewProps) => {
 					return null
 				}
 				const thisEvt = <TimelineEvent
-					key={entry.rowid} room={room} evt={entry} prevEvt={prevEvt}
+					key={entry.rowid} room={room} evt={entry} prevEvt={prevEvt} setReplyTo={setReplyTo}
 				/>
 				prevEvt = entry
 				return thisEvt