diff --git a/connector/connector.go b/connector/connector.go
index 48fc9e7..c2edda4 100644
--- a/connector/connector.go
+++ b/connector/connector.go
@@ -59,6 +59,9 @@ type Connector interface {
 	// Leave a channel
 	Leave(roomId RoomID)
 
+	// Search for users
+	SearchForUsers(query string) ([]UserSearchResult, error)
+
 	// Send an event. Returns the ID of the created remote message.
 	// This ID is used to deduplicate messages: if it comes back, it should have the same Id
 	// than the one returned here.
@@ -153,6 +156,11 @@ type RoomInfo struct {
 	Picture SMediaObject `json:"picture"`
 }
 
+type UserSearchResult struct {
+	ID          UserID `json:"id"`
+	DisplayName string `json:"display_name"`
+}
+
 type MediaObject interface {
 	Filename() string
 	Size() int64
diff --git a/connector/external/external.go b/connector/external/external.go
index 637e69e..c40d55b 100644
--- a/connector/external/external.go
+++ b/connector/external/external.go
@@ -49,6 +49,7 @@ const (
 	JOIN          = "join"
 	INVITE        = "invite"
 	LEAVE         = "leave"
+	SEARCH        = "search"
 	SEND          = "send"
 	CLOSE         = "close"
 
@@ -64,8 +65,9 @@ const (
 	// reply messages
 	// ezbr -> external: all must wait for a reply!
 	// external -> ezbr: only CACHE_GET produces a reply
-	REP_OK    = "rep_ok"
-	REP_ERROR = "rep_error"
+	REP_OK             = "rep_ok"
+	REP_SEARCH_RESULTS = "rep_search_results"
+	REP_ERROR          = "rep_error"
 )
 
 // ----
@@ -226,6 +228,16 @@ func (m *extMessageWithData) UnmarshalJSON(jj []byte) error {
 		}
 		m.Data = &ev.Data
 		return nil
+	case REP_SEARCH_RESULTS:
+		var ev struct {
+			Data []UserSearchResult `json:"data"`
+		}
+		err := json.Unmarshal(jj, &ev)
+		if err != nil {
+			return err
+		}
+		m.Data = ev.Data
+		return nil
 	case JOINED, LEFT, CACHE_PUT, CACHE_GET, REP_OK, REP_ERROR:
 		return nil
 	default:
@@ -428,6 +440,19 @@ func (ext *External) Leave(room RoomID) {
 	}
 }
 
+func (ext *External) SearchForUsers(query string) ([]UserSearchResult, error) {
+	rep, err := ext.cmd(extMessage{
+		MsgType: SEARCH,
+	}, query)
+	if err != nil {
+		return nil, err
+	}
+	if rep.MsgType != REP_SEARCH_RESULTS {
+		return nil, fmt.Errorf("Invalid result type from external: %s", rep.MsgType)
+	}
+	return rep.Data.([]UserSearchResult), nil
+}
+
 func (ext *External) Send(event *Event) (string, error) {
 	rep, err := ext.cmd(extMessage{
 		MsgType: SEND,
diff --git a/connector/irc/irc.go b/connector/irc/irc.go
index bf36dfe..cf93893 100644
--- a/connector/irc/irc.go
+++ b/connector/irc/irc.go
@@ -198,6 +198,11 @@ func (irc *IRC) Leave(roomId RoomID) {
 	irc.conn.Cmd.Part(ch)
 }
 
+func (irc *IRC) SearchForUsers(query string) ([]UserSearchResult, error) {
+	// TODO
+	return nil, fmt.Errorf("Not implemented")
+}
+
 func (irc *IRC) Send(event *Event) (string, error) {
 	if irc.conn == nil {
 		return "", fmt.Errorf("Not connected")
diff --git a/connector/mattermost/mattermost.go b/connector/mattermost/mattermost.go
index 9410126..4490f2a 100644
--- a/connector/mattermost/mattermost.go
+++ b/connector/mattermost/mattermost.go
@@ -253,6 +253,11 @@ func (mm *Mattermost) Leave(roomId RoomID) {
 	// Not supported? TODO
 }
 
+func (mm *Mattermost) SearchForUsers(query string) ([]UserSearchResult, error) {
+	// TODO
+	return nil, fmt.Errorf("Not implemented")
+}
+
 func (mm *Mattermost) Send(event *Event) (string, error) {
 	post := &model.Post{
 		Message: event.Text,
diff --git a/connector/xmpp/xmpp.go b/connector/xmpp/xmpp.go
index 1f77fdf..483c75e 100644
--- a/connector/xmpp/xmpp.go
+++ b/connector/xmpp/xmpp.go
@@ -306,6 +306,11 @@ func (xm *XMPP) Leave(roomId RoomID) {
 	xm.conn.LeaveMUC(string(roomId))
 }
 
+func (xm *XMPP) SearchForUsers(query string) ([]UserSearchResult, error) {
+	// TODO: search roster
+	return nil, fmt.Errorf("Not implemented")
+}
+
 func (xm *XMPP) Send(event *Event) (string, error) {
 	if event.Attachments != nil && len(event.Attachments) > 0 {
 		for _, at := range event.Attachments {
diff --git a/external/messenger.py b/external/messenger.py
index 9874b5b..6da4808 100755
--- a/external/messenger.py
+++ b/external/messenger.py
@@ -1,8 +1,6 @@
 #!/usr/bin/env python3
 
-# @FIXME: make revUserId work correctly (e.g.: talking to a contact not in your top 20 recent threads will fail) - could we do this with a search request?
 # @FIXME: store the client pickle in the config automatically
-# @FIXME: add a way to search for users and initiate a discussion
 
 import sys
 import json
@@ -31,6 +29,7 @@ SET_ROOM_INFO = "set_room_info"
 JOIN = "join"
 INVITE = "invite"
 LEAVE = "leave"
+SEARCH = "search"
 SEND = "send"
 CLOSE = "close"
 
@@ -47,6 +46,7 @@ CACHE_GET = "cache_get"
 # ezbr -> external: all must wait for a reply!
 # external -> ezbr: only CACHE_GET produces a reply
 REP_OK = "rep_ok"
+REP_SEARCH_RESULTS = "rep_search_results"
 REP_ERROR = "rep_error"
 
 # Event types
@@ -168,13 +168,14 @@ class MessengerBridge:
             return self.getUserId(user)
 
     def revUserId(self, user_id):
-        if user_id in self.rev_uid:
-            return self.rev_uid[user_id]
-        else:
-            # TODO this doesn't work always...
-            # we should try to find the api endpoint that resolves usernames ?
-            # or do a search request and try to find a user that has that username
-            return user_id
+        if user_id not in self.rev_uid:
+            for user in self.client.searchForUsers(user_id):
+                self.getUserId(user)
+
+        if user_id not in self.rev_uid:
+            raise ValueError("User not found: {}".format(user_id))
+
+        return self.rev_uid[user_id]
 
     def getUserShortName(self, user):
         if user.first_name != None:
@@ -277,6 +278,16 @@ class MessengerBridge:
                 uid = self.revUserId(cmd["user"])
                 self.client.addUsersToGroup([uid], cmd["room"])
 
+        elif ty == SEARCH:
+            users = self.client.searchForUsers(cmd["data"])
+            rep = []
+            for user in users:
+                rep.append({
+                    "id": self.getUserId(user),
+                    "display_name": user.name,
+                })
+            return {"_type": REP_SEARCH_RESULTS, "data": rep}
+
         elif ty == SEND:
             event = cmd["data"]
             if event["type"] in [EVENT_MESSAGE, EVENT_ACTION]:
diff --git a/server.go b/server.go
index 294ad7f..84b1893 100644
--- a/server.go
+++ b/server.go
@@ -228,6 +228,7 @@ func handleSystemMessage(mxid string, msg string) {
 		ezbrSystemSend(mxid, "- accounts: list accounts")
 		ezbrSystemSend(mxid, "- join <protocol or account> <room id>: join public chat room")
 		ezbrSystemSend(mxid, "- talk <protocol or account> <user id>: open private conversation to contact")
+		ezbrSystemSend(mxid, "- search <protocol or account> <name>: search for users by name")
 	case "list", "account", "accounts":
 		one := false
 		if accts, ok := registeredAccounts[mxid]; ok {
@@ -271,6 +272,21 @@ func handleSystemMessage(mxid string, msg string) {
 		} else {
 			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
 		}
+	case "search":
+		account := findAccount(mxid, cmd[1])
+		if account != nil {
+			rep, err := account.Conn.SearchForUsers(cmd[2])
+			if err != nil {
+				ezbrSystemSendf(mxid, "Search error: %s", err)
+			} else {
+				ezbrSystemSendf(mxid, "%d users found", len(rep))
+				for i, user := range rep {
+					ezbrSystemSendf(mxid, "- %s (%s)", i+1, user.DisplayName, user.ID)
+				}
+			}
+		} else {
+			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
+		}
 	default:
 		ezbrSystemSend(mxid, "Unrecognized command. Type `help` if you need some help!")
 	}