diff --git a/d2m/actions/create-room.js b/d2m/actions/create-room.js
index 7f2c799..96a9671 100644
--- a/d2m/actions/create-room.js
+++ b/d2m/actions/create-room.js
@@ -144,6 +144,8 @@ async function _syncRoom(channelID, shouldActuallySync) {
 			return existing // only need to ensure room exists, and it does. return the room ID
 		}
 
+		console.log(`[room sync] to matrix: ${channel.name}`)
+
 		const {spaceID, channelKState} = await channelToKState(channel, guild)
 
 		// sync channel state to room
diff --git a/d2m/actions/register-user.js b/d2m/actions/register-user.js
index 89bac2c..cc5f515 100644
--- a/d2m/actions/register-user.js
+++ b/d2m/actions/register-user.js
@@ -80,13 +80,81 @@ async function ensureSimJoined(user, roomID) {
 
 /**
  * @param {import("discord-api-types/v10").APIUser} user
- * @param {Required<Omit<import("discord-api-types/v10").APIGuildMember, "user">>} member
+ * @param {Omit<import("discord-api-types/v10").APIGuildMember, "user">} member
  */
-async function memberToStateContent(user, member) {
-	return {
-		displayname: member.nick || user.username
+async function memberToStateContent(user, member, guildID) {
+	let displayname = user.username
+	if (member.nick && member.nick !== displayname) displayname = member.nick + " | " + displayname // prepend nick if present
+
+	const content = {
+		displayname,
+		membership: "join",
+		"moe.cadence.ooye.member": {
+		},
+		"uk.half-shot.discord.member": {
+			bot: !!user.bot,
+			displayColor: user.accent_color,
+			id: user.id,
+			username: user.discriminator.length === 4 ? `${user.username}#${user.discriminator}` : `@${user.username}`
+		}
+	}
+
+	if (member.avatar || user.avatar) {
+		// const avatarPath = file.userAvatar(user) // the user avatar only
+		const avatarPath = file.memberAvatar(guildID, user, member) // the member avatar or the user avatar
+		content["moe.cadence.ooye.member"].avatar = avatarPath
+		content.avatar_url = await file.uploadDiscordFileToMxc(avatarPath)
+	}
+
+	return content
+}
+
+function calculateProfileEventContentHash(content) {
+	return `${content.displayname}\u0000${content.avatar_url}`
+}
+
+/**
+ * @param {import("discord-api-types/v10").APIUser} user
+ * @param {Omit<import("discord-api-types/v10").APIGuildMember, "user">} member
+ */
+async function syncUser(user, member, guildID, roomID) {
+	const mxid = await ensureSimJoined(user, roomID)
+	const content = await memberToStateContent(user, member, guildID)
+	const profileEventContentHash = calculateProfileEventContentHash(content)
+	const existingHash = db.prepare("SELECT profile_event_content_hash FROM sim_member WHERE room_id = ? AND mxid = ?").pluck().get(roomID, mxid)
+	// only do the actual sync if the hash has changed since we last looked
+	if (existingHash !== profileEventContentHash) {
+		await api.sendState(roomID, "m.room.member", mxid, content, mxid)
+		db.prepare("UPDATE sim_member SET profile_event_content_hash = ? WHERE room_id = ? AND mxid = ?").run(profileEventContentHash, roomID, mxid)
+	}
+}
+
+async function syncAllUsersInRoom(roomID) {
+	const mxids = db.prepare("SELECT mxid FROM sim_member WHERE room_id = ?").pluck().all(roomID)
+
+	const channelID = db.prepare("SELECT channel_id FROM channel_room WHERE room_id = ?").pluck().get(roomID)
+	assert.ok(typeof channelID === "string")
+	/** @ts-ignore @type {import("discord-api-types/v10").APIGuildChannel} */
+	const channel = discord.channels.get(channelID)
+	const guildID = channel.guild_id
+	assert.ok(typeof guildID === "string")
+
+	for (const mxid of mxids) {
+		const userID = db.prepare("SELECT discord_id FROM sim WHERE mxid = ?").pluck().get(mxid)
+		assert.ok(typeof userID === "string")
+
+		/** @ts-ignore @type {Required<import("discord-api-types/v10").APIGuildMember>} */
+		const member = await discord.snow.guild.getGuildMember(guildID, userID)
+		/** @ts-ignore @type {Required<import("discord-api-types/v10").APIUser>} user */
+		const user = member.user
+		assert.ok(user)
+
+		console.log(`[user sync] to matrix: ${user.username} in ${channel.name}`)
+		await syncUser(user, member, guildID, roomID)
 	}
 }
 
 module.exports.ensureSim = ensureSim
 module.exports.ensureSimJoined = ensureSimJoined
+module.exports.syncUser = syncUser
+module.exports.syncAllUsersInRoom = syncAllUsersInRoom
diff --git a/d2m/actions/send-message.js b/d2m/actions/send-message.js
index fb181d2..2630430 100644
--- a/d2m/actions/send-message.js
+++ b/d2m/actions/send-message.js
@@ -1,5 +1,7 @@
 // @ts-check
 
+const assert = require("assert")
+
 const passthrough = require("../../passthrough")
 const { discord, sync, db } = passthrough
 /** @type {import("../converters/message-to-event")} */
@@ -15,11 +17,14 @@ const createRoom = sync.require("../actions/create-room")
  * @param {import("discord-api-types/v10").GatewayMessageCreateDispatchData} message
  */
 async function sendMessage(message) {
+	assert.ok(message.member)
+
 	const event = messageToEvent.messageToEvent(message)
 	const roomID = await createRoom.ensureRoom(message.channel_id)
 	let senderMxid = null
 	if (!message.webhook_id) {
 		senderMxid = await registerUser.ensureSimJoined(message.author, roomID)
+		await registerUser.syncUser(message.author, message.member, message.guild_id, roomID)
 	}
 	const eventID = await api.sendEvent(roomID, "m.room.message", event, senderMxid)
 	db.prepare("INSERT INTO event_message (event_id, message_id, part) VALUES (?, ?, ?)").run(eventID, message.id, 0) // 0 is primary, 1 is supporting
diff --git a/matrix/file.js b/matrix/file.js
index 137a096..077d527 100644
--- a/matrix/file.js
+++ b/matrix/file.js
@@ -58,5 +58,16 @@ function guildIcon(guild) {
 	return `/icons/${guild.id}/${guild.icon}.png?size=${IMAGE_SIZE}`
 }
 
+function userAvatar(user) {
+	return `/avatars/${user.id}/${user.avatar}.png?size=${IMAGE_SIZE}`
+}
+
+function memberAvatar(guildID, user, member) {
+	if (!member.avatar) return userAvatar(user)
+	return `/guilds/${guildID}/users/${user.id}/avatars/${member.avatar}.png?size=${IMAGE_SIZE}`
+}
+
 module.exports.guildIcon = guildIcon
+module.exports.userAvatar = userAvatar
+module.exports.memberAvatar = memberAvatar
 module.exports.uploadDiscordFileToMxc = uploadDiscordFileToMxc