diff --git a/matrix-send b/matrix-send
index 3d5f606..4d6e5f6 100755
--- a/matrix-send
+++ b/matrix-send
@@ -1,220 +1,363 @@
-#!/usr/bin/env sh
-# matrix-send: send a message to a Matrix room
+#!/usr/bin/env lua
+--[[
+	The GPLv2 License (GPLv2)
+	Copyright (c) 2022 Jeremy Baxter
+	
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+	
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+	GNU General Public License for more details.
+	
+	You should have received a copy of the GNU General Public License
+	along with this program.	If not, see <http://www.gnu.org/licenses/>.
+]]--
 
-version="1.1"
+require "luarocks.loader"
+getopt = require "posix.unistd".getopt
+mkdir = require "posix.sys.stat".mkdir
+bname = require "posix.libgen".basename
+http = require "socket.http"
+cjson = require "cjson"
+ltn12 = require "ltn12"
 
-###########################
-#### Generic Functions ####
-###########################
+ version = "2.0"
+ confdir = string.gsub("~/.config/matrix-send", '~', os.getenv("HOME"), 1)
+confpath = confdir .. "/config.lua"
+confvarv = os.getenv("MATRIXSEND_CONFIG")
+hostname = io.input("/etc/hostname"):read("l")
 
-error () {
-	printf "\033[31;1merror:\033[0m $1\n"
-	exit 1
-}
+json = {}
+ uri = {}
+  sh = os.execute
 
-conf_error () {
-	printf "\033[31;1mconfiguration error:\033[0m $1\n"
-	exit 2
-}
+-----------------
+--- Functions ---
+-----------------
 
-warning () {
-	printf "\033[93;1mwarning:\033[0m $1\n"
-}
-
-vargrep () {
-	printf "$2\n" | grep "$1" $3
-}
-
-usage () {
-	printf "usage: matrix-send [-t type] [-C config] [-chV] message room\n"
-	exit 1
-}
-
-help () {
-	cat <<EOF
-matrix-send: send a message to a Matrix room
-Options:
-   -t type:    change default event type
- -C config:    use a custom configuration file
-	-c:    clear cached access tokens
-	-h:    show this help menu
-	-V:    show version and program information
-
-For more information, type 'man matrix-send'.
-https://codeberg.org/jtbx/matrix-send
-EOF
-	exit 0
-}
-
-version () {
-	cat <<EOF
-matrix-send: send a message to a Matrix room
-Version $version
-
-matrix-send is licensed under the GNU General Public License v2.
-Made in New Zealand
-https://codeberg.org/jtbx/matrix-send
-EOF
-	exit 0
-}
-
-##################################
-#### Configuration Directives ####
-##################################
-
-Server () {
-	[ -z $1 ] && conf_error "No argument for directive Server"
-	server="$1"
-}
-
-Username () {
-	[ -z $1 ] && conf_error "No argument for directive Username"
-	username="$1"
-}
-
-Password () {
-	[ -z $1 ] && conf_error "No argument(s) for directive Password"
-	password="$@"
-}
-
-AccessToken () {
-	[ -z $1 ] && conf_error "No argument for directive AccessToken"
-	manualAuth="true"
-	token="$1"
-}
-
-CacheLocation () {
-	[ -z $1 ] && conf_error "No argument for directive CacheLocation"
-	if vargrep "^/.+$" "$1" -Eq || \
-		vargrep "^~.+$" "$1" -Eq;
-	then cacheloc="$1";
-	else conf_error "Cache location is not valid (does not begin with / or ~)"; fi
-}
-
-DefaultEvent () {
-	[ -z $1 ] && conf_error "No argument for directive DefaultEvent"
-	if vargrep "m\.(text|notice)" "$1" -Eq
-	then defaultevent="$1"
-	else conf_error "Invalid default event type"; fi
-}
-
-##################################
-#### Configuration Statements ####
-##################################
-
-NoCache () {
-	nocache="true"
-}
-
-PrettyPrint () {
-	prettyprint="true"
-}
-
-############################
-#### Specific Functions ####
-############################
-
-GetAccessToken () {
-	[ -z "$manualAuth" ] && printf "Getting access token...\n"
-	if [ "$manualAuth" = "true" ];
-	then printf "";
-	else token=$(curl -s -XPOST -d "{"'"'"type"'"'":"'"'"m.login.password"'"'", "'"'"user"'"'":"'"'"$username"'"'", "'"'"password"'"'":"'"'"$password"'"'"}" "https://$server/_matrix/client/r0/login" | grep -oE 'syt_.+_...................._......');
-	fi
-}
-
-CacheAccessToken () {
-	if [ "$nocache" = "true" ];
-	then printf "";
+-- Returns true if the given file name file exists, otherwise returns false.
+function fileexists(file)
+	local f, err = io.open(file, 'r')
+	if f then
+		f:close()
+		return true
 	else
-		mkdir -p "$cacheloc/matrix-send"
-		printf "$token\n" > "$cacheloc/matrix-send/access-token";
-	fi
-}
+		return false, err
+	end
+end
 
-ClearCache () {
-	[ -e "$cacheloc/matrix-send/access-token" ] || printf "There is no cache to be cleared.\n"
-	[ -e "$cacheloc/matrix-send/access-token" ] && rm -rf "$cacheloc/matrix-send/" && printf "Cleared cache\n"
-	exit 0
-}
+-- Makes an HTTP POST request to uri and sends body. Returns the output of the HTTP server.
+function post(uri, body)
+	local respbody = {} -- for the response body
+	local result, respcode, respheaders, respstatus = http.request {
+			method = "POST",
+			url = uri,
+			source = ltn12.source.string(body),
+			headers = {
+					["content-type"] = "application/json",
+					["content-length"] = tostring(#body)
+			},
+			sink = ltn12.sink.table(respbody)
+	}
+	return table.concat(respbody)
+end
 
-Send () {
-	if [ -z "$prettyprint" ]
-	then curl -s -XPOST -d "{"'"'"msgtype"'"'":"'"'"$mtype"'"'", "'"'"body"'"'":"'"'"$message"'"'"}" "https://$server/_matrix/client/r0/rooms/%21$roomid/send/m.room.message?access_token=$token"
-	else curl -s -XPOST -d "{"'"'"msgtype"'"'":"'"'"$mtype"'"'", "'"'"body"'"'":"'"'"$message"'"'"}" "https://$server/_matrix/client/r0/rooms/%21$roomid/send/m.room.message?access_token=$token" | jq
-	fi
-}
+-- Makes an HTTP PUT request to uri and sends body. Returns the output of the HTTP server.
+function put(uri, body)
+	local respbody = {} -- for the response body
+	local result, respcode, respheaders, respstatus = http.request {
+			method = "PUT",
+			url = uri,
+			source = ltn12.source.string(body),
+			headers = {
+					["content-type"] = "application/json",
+					["content-length"] = tostring(#body)
+			},
+			sink = ltn12.sink.table(respbody)
+	}
+	return table.concat(respbody)
+end
 
-########################
-#### Initial checks ####
-########################
+-- Prints a message to stdout in the following format:
+-- matrix-send: s
+function msg(s)
+	io.stdout:write(string.format("%s: %s\n", bname(arg[0]), s))
+end
 
-[ -e /usr/local/bin/curl ] || [ -e /usr/bin/curl ] || error "curl not found"
+-- Prints an error message to stderr in the following format:
+-- matrix-send: s
+-- After that, exits and returns 1 to the OS.
+function panic(s)
+	io.stderr:write(string.format("%s: %s\n", bname(arg[0]), s))
+	os.exit(1)
+end
 
-[ -z "$1" ] && usage
-CacheLocation "$HOME/.cache"
-while getopts :t:C:chV opt
-do
-	case $opt in
-		t)
-			if vargrep "m\.(text|notice)" "$OPTARG" -Eq
-			then
-				mtype="$OPTARG"
-				optind="$OPTIND"
-			else error "Type not valid (-t)"
-			fi
-		;;
-		C)
-			if vargrep "^~" "$OPTARG" -Eq
-			then config="$OPTARG"
-			elif vargrep "^/" "$OPTARG" -Eq
-			then config="$OPTARG"
-			else error "Configuration file location not valid (-C)"
-			fi
-		;;
-		c) ClearCache ;;
-		h) help ;;
-		V) version ;;
-	esac
-done
-unset OPTARG
-unset OPTIND
+-- Prints an error message to stderr in the following format:
+-- matrix-send: confpath: s
+-- After that, exits and returns 1 to the OS.
+function confpanic(s)
+	panic(string.format("%s: %s", bname(confpath), s))
+	os.exit(1)
+end
 
-###############################
-#### Configuration loading ####
-###############################
+--[[
+	The configuration file for matrix-send is written in Lua format.
+	Here is a list of all possible options in the configuration file.
+	Default values appear after the '=' sign.
 
-# Load configuration
-if [ -e "$config" ]; 
-then . "$config"
+	login = {
+		-- The Matrix server to use.
+		server = nil,
+
+		-- The user to log in to.
+		username = nil,
+
+		-- The password for the user.
+		password = nil,
+
+		-- The access token to use (instead of credentials).
+		-- If token equals nil, credentials are used.
+		-- If token is not nil, credentials are ignored.
+		token = nil
+
+		-- The server value needs to be provided.
+		-- You can choose to login with user credentials or a
+		-- token. One of them needs to be provided.
+	}
+
+	cache = {
+		-- The path to cache access tokens at.
+		location = "~/.cache/matrix-send",
+
+		-- Disable caching access tokens?
+		disable = false
+	}
+
+	rooms = {
+		-- Room aliases.
+		-- Here you can add aliases for rooms,
+		-- instead of having to type the confusing
+		-- Room ID every single time you send a message.
+		-- Examples:
+		--my_alias = "!AbCdEfGhIjKl:burger.land",
+		--lounge = "!MnOpQrSTuVWxYz:gaming.bruvs"
+		-- When you want to send to a Matrix room, you
+		-- can just type the alias instead of the long Room ID.
+	}
+
+	advanced = {
+		-- The default event type.
+		-- Can be either m.text or m.notice.
+		event = "m.text"
+	}
+--]]
+
+-- Default configuration file
+default_config = [[
+-- Default configuration file for matrix-send
+-- In comments, here is a simple example configuration.
+
+--login = {
+--	server = "matrix.envs.net",
+--	username = "john",
+--	password = "examplepassword
+--}
+
+-- You could also do it this way:
+
+--login.server = "matrix.envs.net"
+--login.username = "john"
+--login.password = "examplepassword"
+
+-- Both configurations do the same thing.
+
+-- See matrix-send.conf(5) for more information
+-- on configuration files.
+]]
+
+------------------------------------
+--- Default configuration values ---
+------------------------------------
+
+-- Initialise tables
+login = {}
+cache = {}
+rooms = {}
+advanced = {}
+
+-- Cache location
+cache.location = "~/.cache/matrix-send"
+
+-- Disable caching access tokens?
+cache.disable = false
+
+-- Message type
+advanced.event = "m.text"
+
+----------------------
+--- Initial checks ---
+----------------------
+
+if arg[1] == nil then
+	io.stderr:write("usage: " .. bname(arg[0]) .. " [-t type] [-c config] [-ChV] message room\n")
+	os.exit(1)
+end
+
+if confvarv then
+	if fileexists(confvarv) then
+		confpath = os.getenv("MATRIXSEND_CONFIG")
+	else
+		local _, err = fileexists(os.getenv("MATRIXSEND_CONFIG"))
+		panic("error opening " .. err)
+	end
+end
+
+if not fileexists(confpath) then
+	mkdir(confdir)
+	f = io.open(confpath, 'w')
+	f:write(default_config)
+	f:close()
+end
+dofile(confpath)
+
+cache.location = string.gsub(cache.location, '~', os.getenv("HOME"), 1)
+
+-- Make sure all required values are set
+if not login.server then
+	 confpanic("required value 'login.server' left unset")
+end
+
+-- login.token always supersedes login.username and password
+if not login.token then
+	if not login.username then
+		 confpanic("required value 'login.username' left unset")
+	elseif not login.password then
+		 confpanic("required value 'login.password' left unset")
+	end
+end
+
+-- Parse options
+for opt, optarg, ind in getopt(arg, ':Cc:t:V') do
+	optind = ind
+	if opt == 'C' then
+		msg("clearing cache")
+		os.execute("rm -rf " .. cache.location) -- TODO: replace this os.execute line
+		os.exit(0)
+	elseif opt == 'c' then
+		confpath = optarg
+	elseif opt == 't' then
+		if optarg:match("m%.text")
+		or optarg:match("m%.notice") then
+			advanced.event = optarg
+		else panic("unknown message type '" .. optarg .. "'")
+		end
+	elseif opt == 'V' then
+		io.stdout:write("matrix-send version " .. version .. '\n')
+		io.stdout:write(_VERSION .. '\n')
+		os.exit(0)
+	elseif opt == '?' then
+		panic("unknown option " .. arg[optind-1])
+		os.exit(1)
+	elseif opt == ':' then
+		panic("missing argument for option " .. arg[optind-1])
+		os.exit(1)
+	end
+end
+
+if optind == nil then
+	message = arg[1]
+	room = arg[2]
 else
-	warning "~/.config/matrix-send.conf doesn't exist; creating it"
-	mkdir -p $HOME/.config
-	touch $HOME/.config/matrix-send.conf
-fi
+	message = arg[optind+1]
+	room = arg[optind+2]
+end
 
-# Run checks for essential directives
-[ -z $server ] && conf_error "Server directive is not present"
-[ -z $username ] && conf_error "Username directive is not present"
-[ -z "$password" ] && conf_error "Password directive is not present"
-
-##############
-#### Main ####
-##############
-
-# Get token and cache it (unless NoCache is set)
-[ -e "$cacheloc/matrix-send/access-token" ] && token=$(cat $cacheloc/matrix-send/access-token)
-[ -e "$cacheloc/matrix-send/access-token" ] || GetAccessToken
-CacheAccessToken
-
-if [ -z "$2" ];
-then error "Room ID not specified.";
+if room:match("^!") then
+	room_id = room
 else
-	shift $((OPTIND-1))
-	message="$1"
-	roomid_input="$2"
-	if [ -z "$mtype" ]; then mtype="$defaultevent"; fi;
-	if vargrep '!' "$roomid_input" -qo
-	then roomid="$(printf "$roomid_input" | sed 's/!//g')"
-	else roomid="$roomid_input"; fi
-	Send
-fi
+	if rooms[room] ~= nil then
+		room_id = rooms[room]
+	else
+		panic("alias '" .. room .. "' invalid")
+	end
+end
+
+if fileexists(cache.location .. "/txnid") then
+	txnidf = io.open(cache.location .. "/txnid", 'r')
+	txnid = txnidf:read('l')
+	txnidf:close()
+else
+	txnid = 0
+end
+
+uri.login = string.format("https://%s/_matrix/client/v3/login", login.server)
+
+-- Assemble various JSON messages
+json.message = string.format([[
+{
+	"body": "%s",
+	"msgtype": "%s"
+}
+]], message, advanced.event)
+
+-- Get the access token if credentials are used
+if not login.token then
+	if fileexists(cache.location .. "/token") then
+		cf = io.open(cache.location .. "/token", 'r')
+		login.token = cf:read('l')
+		cf:close()
+	else
+		-- json.login should only be assigned if it needs to be assigned
+		json.login = string.format([[
+		{
+			"identifier": {
+				"type": "m.id.user",
+				"user": "%s"
+			},
+			"initial_device_display_name": "matrix-send@%s",
+			"password": "%s",
+			"type": "m.login.password"
+		}
+
+		]], login.username, hostname, login.password)
+
+		-- Send the request!
+		local body = post(uri.login, json.login)
+
+		-- What else do I call it?
+		local t = cjson.decode(body)
+
+		-- If there was a server side error, print the error and exit.
+		if t.error then
+			panic(login.server .. ": " .. t.error)
+		end
+
+		-- Log the access token
+		login.token = t.access_token
+
+		-- Cache the access token
+		mkdir(cache.location)
+		cf = io.open(cache.location .. "/token", 'w+')
+		cf:write(login.token)
+		cf:close()
+	end
+end
+
+uri.message = string.format("https://%s/_matrix/client/v3/rooms/%s/send/m.room.message/%d?access_token=%s",
+	login.server, room_id, txnid, login.token)
+
+-- Send the message!
+body = put(uri.message, json.message)
+t = cjson.decode(body)
+if t.error then
+	panic(login.server .. ": " .. t.error)
+end
+
+-- Increment txnid and cache
+txnidf = io.open(cache.location .. "/txnid", 'w+')
+txnidf:write(txnid + 1)
+txnidf:close()