diff --git a/src/SlashCommands.js b/src/SlashCommands.js
new file mode 100644
index 0000000000..08d68331f8
--- /dev/null
+++ b/src/SlashCommands.js
@@ -0,0 +1,312 @@
+/*
+Copyright 2015 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+var MatrixClientPeg = require("./MatrixClientPeg");
+var dis = require("./dispatcher");
+var encryption = require("./encryption");
+
+var reject = function(msg) {
+    return {
+        error: msg
+    };
+};
+
+var success = function(promise) {
+    return {
+        promise: promise
+    };
+};
+
+var commands = {
+    // Change your nickname
+    nick: function(room_id, args) {
+        if (args) {
+            return success(
+                MatrixClientPeg.get().setDisplayName(args)
+            );
+        }
+        return reject("Usage: /nick <display_name>");
+    },
+
+    encrypt: function(room_id, args) {
+        if (args == "on") {
+            var client = MatrixClientPeg.get();
+            var members = client.getRoom(room_id).currentState.members;
+            var user_ids = Object.keys(members);
+            return success(
+                encryption.enableEncryption(client, room_id, user_ids)
+            );
+        }
+        if (args == "off") {
+            var client = MatrixClientPeg.get();
+            return success(
+                encryption.disableEncryption(client, room_id)
+            );
+
+        }
+        return reject("Usage: encrypt <on/off>");
+    },
+
+    // Change the room topic
+    topic: function(room_id, args) {
+        if (args) {
+            return success(
+                MatrixClientPeg.get().setRoomTopic(room_id, args)
+            );
+        }
+        return reject("Usage: /topic <topic>");
+    },
+
+    // Invite a user
+    invite: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+)$/);
+            if (matches) {
+                return success(
+                    MatrixClientPeg.get().invite(room_id, matches[1])
+                );
+            }
+        }
+        return reject("Usage: /invite <userId>");
+    },
+
+    // Join a room
+    join: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+)$/);
+            if (matches) {
+                var room_alias = matches[1];
+                if (room_alias[0] !== '#') {
+                    return reject("Usage: /join #alias:domain");
+                }
+                if (!room_alias.match(/:/)) {
+                    var domain = MatrixClientPeg.get().credentials.userId.replace(/^.*:/, '');
+                    room_alias += ':' + domain;
+                }
+
+                // Try to find a room with this alias
+                var rooms = MatrixClientPeg.get().getRooms();
+                var roomId;
+                for (var i = 0; i < rooms.length; i++) {
+                    var aliasEvents = rooms[i].currentState.getStateEvents(
+                        "m.room.aliases"
+                    );
+                    for (var j = 0; j < aliasEvents.length; j++) {
+                        var aliases = aliasEvents[j].getContent().aliases || [];
+                        for (var k = 0; k < aliases.length; k++) {
+                            if (aliases[k] === room_alias) {
+                                roomId = rooms[i].roomId;
+                                break;
+                            }
+                        }
+                        if (roomId) { break; }
+                    }
+                    if (roomId) { break; }
+                }
+                if (roomId) { // we've already joined this room, view it.
+                    dis.dispatch({
+                        action: 'view_room',
+                        room_id: roomId
+                    });
+                    return success();
+                }
+                else {
+                    // attempt to join this alias.
+                    return success(
+                        MatrixClientPeg.get().joinRoom(room_alias).then(
+                        function(room) {
+                            dis.dispatch({
+                                action: 'view_room',
+                                room_id: room.roomId
+                            });
+                        })
+                    );
+                }
+            }
+        }
+        return reject("Usage: /join <room_alias>");
+    },
+
+    part: function(room_id, args) {
+        var targetRoomId;
+        if (args) {
+            var matches = args.match(/^(\S+)$/);
+            if (matches) {
+                var room_alias = matches[1];
+                if (room_alias[0] !== '#') {
+                    return reject("Usage: /part [#alias:domain]");
+                }
+                if (!room_alias.match(/:/)) {
+                    var domain = MatrixClientPeg.get().credentials.userId.replace(/^.*:/, '');
+                    room_alias += ':' + domain;
+                }
+
+                // Try to find a room with this alias
+                var rooms = MatrixClientPeg.get().getRooms();
+                for (var i = 0; i < rooms.length; i++) {
+                    var aliasEvents = rooms[i].currentState.getStateEvents(
+                        "m.room.aliases"
+                    );
+                    for (var j = 0; j < aliasEvents.length; j++) {
+                        var aliases = aliasEvents[j].getContent().aliases || [];
+                        for (var k = 0; k < aliases.length; k++) {
+                            if (aliases[k] === room_alias) {
+                                targetRoomId = rooms[i].roomId;
+                                break;
+                            }
+                        }
+                        if (targetRoomId) { break; }
+                    }
+                    if (targetRoomId) { break; }
+                }
+            }
+            if (!targetRoomId) {
+                return reject("Unrecognised room alias: " + room_alias);
+            }
+        }
+        if (!targetRoomId) targetRoomId = room_id;
+        return success(
+            MatrixClientPeg.get().leave(targetRoomId).then(
+            function() {
+                dis.dispatch({action: 'view_next_room'});
+            })
+        );
+    },
+
+    // Kick a user from the room with an optional reason
+    kick: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+?)( +(.*))?$/);
+            if (matches) {
+                return success(
+                    MatrixClientPeg.get().kick(room_id, matches[1], matches[3])
+                );
+            }
+        }
+        return reject("Usage: /kick <userId> [<reason>]");
+    },
+
+    // Ban a user from the room with an optional reason
+    ban: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+?)( +(.*))?$/);
+            if (matches) {
+                return success(
+                    MatrixClientPeg.get().ban(room_id, matches[1], matches[3])
+                );
+            }
+        }
+        return reject("Usage: /ban <userId> [<reason>]");
+    },
+
+    // Unban a user from the room
+    unban: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+)$/);
+            if (matches) {
+                // Reset the user membership to "leave" to unban him
+                return success(
+                    MatrixClientPeg.get().unban(room_id, matches[1])
+                );
+            }
+        }
+        return reject("Usage: /unban <userId>");
+    },
+
+    // Define the power level of a user
+    op: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+?)( +(\d+))?$/);
+            var powerLevel = 50; // default power level for op
+            if (matches) {
+                var user_id = matches[1];
+                if (matches.length === 4 && undefined !== matches[3]) {
+                    powerLevel = parseInt(matches[3]);
+                }
+                if (powerLevel !== NaN) {
+                    var room = MatrixClientPeg.get().getRoom(room_id);
+                    if (!room) {
+                        return reject("Bad room ID: " + room_id);
+                    }
+                    var powerLevelEvent = room.currentState.getStateEvents(
+                        "m.room.power_levels", ""
+                    );
+                    return success(
+                        MatrixClientPeg.get().setPowerLevel(
+                            room_id, user_id, powerLevel, powerLevelEvent
+                        )
+                    );
+                }
+            }
+        }
+        return reject("Usage: /op <userId> [<power level>]");
+    },
+
+    // Reset the power level of a user
+    deop: function(room_id, args) {
+        if (args) {
+            var matches = args.match(/^(\S+)$/);
+            if (matches) {
+                var room = MatrixClientPeg.get().getRoom(room_id);
+                if (!room) {
+                    return reject("Bad room ID: " + room_id);
+                }
+
+                var powerLevelEvent = room.currentState.getStateEvents(
+                    "m.room.power_levels", ""
+                );
+                return success(
+                    MatrixClientPeg.get().setPowerLevel(
+                        room_id, args, undefined, powerLevelEvent
+                    )
+                );
+            }
+        }
+        return reject("Usage: /deop <userId>");
+    }
+};
+
+// helpful aliases
+commands.j = commands.join;
+
+module.exports = {
+    /**
+     * Process the given text for /commands and perform them.
+     * @param {string} roomId The room in which the command was performed.
+     * @param {string} input The raw text input by the user.
+     * @return {Object|null} An object with the property 'error' if there was an error
+     * processing the command, or 'promise' if a request was sent out.
+     * Returns null if the input didn't match a command.
+     */
+    processInput: function(roomId, input) {
+        // trim any trailing whitespace, as it can confuse the parser for 
+        // IRC-style commands
+        input = input.replace(/\s+$/, "");
+        if (input[0] === "/" && input[1] !== "/") {
+            var bits = input.match(/^(\S+?)( +(.*))?$/);
+            var cmd = bits[1].substring(1).toLowerCase();
+            var args = bits[3];
+            if (cmd === "me") return null;
+            if (commands[cmd]) {
+                return commands[cmd](roomId, args);
+            }
+            else {
+                return reject("Unrecognised command: " + input);
+            }
+        }
+        return null; // not a command
+    }
+};
diff --git a/src/encryption.js b/src/encryption.js
new file mode 100644
index 0000000000..954bc030db
--- /dev/null
+++ b/src/encryption.js
@@ -0,0 +1,38 @@
+/*
+Copyright 2015 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+function enableEncyption(client, roomId, members) {
+    members = members.slice(0);
+    members.push(client.credentials.userId);
+    // TODO: Check the keys actually match what keys the user has.
+    // TODO: Don't redownload keys each time.
+    return client.downloadKeys(members, "forceDownload").then(function(res) {
+        return client.setRoomEncryption(roomId, {
+            algorithm: "m.olm.v1.curve25519-aes-sha2",
+            members: members,
+        });
+    })
+}
+
+function disableEncryption(client, roomId) {
+    return client.disableRoomEncryption(roomId);
+}
+
+
+module.exports = {
+    enableEncryption: enableEncyption,
+    disableEncryption: disableEncryption,
+}