diff --git a/purple-websocket.c b/purple-websocket.c
index 55eb371..0554766 100644
--- a/purple-websocket.c
+++ b/purple-websocket.c
@@ -463,7 +463,7 @@ static void ws_connect_cb(gpointer data, gint source, const gchar *error_message
 }
 
 PurpleWebsocket *purple_websocket_connect(PurpleAccount *account,
-		const char *url, const char *protocol,
+		const char *url, const char *protocol, const char *cookies,
 		PurpleWebsocketCallback callback, void *user_data) {
 	gboolean ssl = FALSE;
 
@@ -515,6 +515,8 @@ Sec-WebSocket-Key: %s\r\n\
 Sec-WebSocket-Version: 13\r\n", path, host, ws->key);
 		if (protocol)
 			g_string_append_printf(request, "Sec-WebSocket-Protocol: %s\r\n", protocol);
+		if (cookies)
+			g_string_append_printf(request, "Cookie: %s\r\n", cookies);
 		g_string_append(request, "\r\n");
 
 		ws->output.len = request->len;
diff --git a/purple-websocket.h b/purple-websocket.h
index 0416750..0f3eae0 100644
--- a/purple-websocket.h
+++ b/purple-websocket.h
@@ -17,7 +17,7 @@ typedef enum _PurpleWebsocketOp {
 
 typedef void (*PurpleWebsocketCallback)(PurpleWebsocket *ws, gpointer user_data, PurpleWebsocketOp op, const guchar *msg, size_t len);
 
-PurpleWebsocket *purple_websocket_connect(PurpleAccount *account, const char *url, const char *protocol, PurpleWebsocketCallback callback, void *user_data);
+PurpleWebsocket *purple_websocket_connect(PurpleAccount *account, const char *url, const char *protocol, const char *cookies, PurpleWebsocketCallback callback, void *user_data);
 void purple_websocket_send(PurpleWebsocket *ws, PurpleWebsocketOp op, const guchar *msg, size_t len);
 void purple_websocket_abort(PurpleWebsocket *ws);
 
diff --git a/slack-api.c b/slack-api.c
index 287e7ec..75eb2da 100644
--- a/slack-api.c
+++ b/slack-api.c
@@ -108,19 +108,6 @@ static void api_run(SlackAccount *sa) {
 	api_retry(call);
 }
 
-static GString *slack_api_encode_url(SlackAccount *sa, const char *pfx, const char *endpoint, va_list qargs) {
-	GString *url = g_string_new(NULL);
-	g_string_printf(url, "%s/%s%s?token=%s", sa->api_url, pfx, endpoint, sa->token);
-
-	const char *param;
-	while ((param = va_arg(qargs, const char*))) {
-		const char *val = va_arg(qargs, const char*);
-		g_string_append_printf(url, "&%s=%s", param, purple_url_encode(val));
-	}
-
-	return url;
-}
-
 static char *slack_api_encode_post_request(SlackAccount *sa, const char *url, va_list qargs) {
 	GString *request;
 	gchar *host = NULL, *path = NULL;
@@ -128,29 +115,41 @@ static char *slack_api_encode_post_request(SlackAccount *sa, const char *url, va
 
 	GString *postdata;
 	const char *param;
-	gboolean sep = FALSE;
 
-	postdata = g_string_new("{");
+	// Just a long random number.
+	guint64 delim = ((guint64)g_random_int() << 32) | (guint64)g_random_int();
+
+	postdata = g_string_new("");
+	g_string_printf(postdata, "-----------------------------%" G_GUINT64_FORMAT "\r\n", delim);
 	while ((param = va_arg(qargs, const char*))) {
 		const char *val = va_arg(qargs, const char*);
-		if (sep)
-			g_string_append_c(postdata, ',');
-		append_json_string(postdata, param);
-		g_string_append_c(postdata, ':');
-		append_json_string(postdata, val);
-		sep = TRUE;
+		g_string_append_printf(postdata, "\
+Content-Disposition: form-data; name=\"%s\"\r\n\
+\r\n\
+%s\r\n\
+-----------------------------%" G_GUINT64_FORMAT "\r\n",
+			param, val, delim);
 	}
-	g_string_append_c(postdata, '}');
+
+	g_string_append_printf(postdata,
+"Content-Disposition: form-data; name=\"token\"\r\n\
+\r\n\
+%s\r\n\
+-----------------------------%" G_GUINT64_FORMAT "\r\n",
+		sa->token, delim);
 
 	request = g_string_new(NULL);
 	g_string_append_printf(request, "\
 POST /%s HTTP/1.0\r\n\
 Host: %s\r\n\
-Authorization: Bearer %s\r\n\
-Content-Type: application/json;charset=utf-8\r\n\
-Content-Length: %" G_GSIZE_FORMAT "\r\n\
-\r\n",
-		path, host, sa->token, postdata->len);
+Content-Type: multipart/form-data; boundary=---------------------------%" G_GUINT64_FORMAT "\r\n\
+Content-Length: %" G_GSIZE_FORMAT "\r\n",
+		path, host, delim, postdata->len);
+
+	if (sa->d_cookie) {
+		g_string_append_printf(request, "Cookie: d=%s\r\n", sa->d_cookie);
+	}
+	g_string_append(request, "\r\n");
 	g_string_append(request, postdata->str);
 
 	g_free(host);
@@ -174,18 +173,6 @@ static void slack_api_call_url(SlackAccount *sa, SlackAPICallback callback, gpoi
 		api_retry(call);
 }
 
-void slack_api_get(SlackAccount *sa, SlackAPICallback callback, gpointer user_data, const char *endpoint, ...)
-{
-	va_list qargs;
-	va_start(qargs, endpoint);
-	GString *url = slack_api_encode_url(sa, "", endpoint, qargs);
-	va_end(qargs);
-
-	slack_api_call_url(sa, callback, user_data, url->str, NULL);
-
-	g_string_free(url, TRUE);
-}
-
 void slack_api_post(SlackAccount *sa, SlackAPICallback callback, gpointer user_data, const gchar *endpoint, ...)
 {
 	GString *url = g_string_new(NULL);
diff --git a/slack-api.h b/slack-api.h
index 6463da0..6415a46 100644
--- a/slack-api.h
+++ b/slack-api.h
@@ -10,7 +10,6 @@ PurpleConnectionError slack_api_connection_error(const gchar *error);
 typedef struct _SlackAPICall SlackAPICall;
 typedef gboolean SlackAPICallback(SlackAccount *sa, gpointer user_data, json_value *json, const char *error);
 
-void slack_api_get(SlackAccount *sa, SlackAPICallback *callback, gpointer user_data, const char *endpoint, /* const char *query_param1, const char *query_value1, */ ...) G_GNUC_NULL_TERMINATED;
 void slack_api_post(SlackAccount *sa, SlackAPICallback *callback, gpointer user_data, const char *endpoint, /* const char *query_param1, const char *query_value1, */ ...) G_GNUC_NULL_TERMINATED;
 void slack_api_disconnect(SlackAccount *sa);
 
diff --git a/slack-auth.c b/slack-auth.c
index b1422ae..62ffcbb 100644
--- a/slack-auth.c
+++ b/slack-auth.c
@@ -37,7 +37,7 @@ slack_auth_login_signin_cb(SlackAccount *sa, gpointer user_data, json_value *jso
 static void
 slack_auth_login_user(SlackAccount *sa, const char *user_id) {
 	slack_login_step(sa);
-	slack_api_get(sa, slack_auth_login_signin_cb,
+	slack_api_post(sa, slack_auth_login_signin_cb,
 		NULL, "auth.signin",
 		"user", user_id,
 		"password", purple_account_get_password(sa->account),
@@ -81,7 +81,7 @@ slack_auth_login_findteam_cb(SlackAccount *sa, gpointer user_data, json_value *j
 	/* now validate that the user exists and get their ID. */
 	slack_login_step(sa);
 	if (strchr(sa->email, '@'))
-		slack_api_get(sa, slack_auth_login_finduser_cb,
+		slack_api_post(sa, slack_auth_login_finduser_cb,
 			NULL, "auth.findUser",
 			"email", sa->email,
 			"team", sa->team.id,
@@ -94,7 +94,7 @@ slack_auth_login_findteam_cb(SlackAccount *sa, gpointer user_data, json_value *j
 void
 slack_auth_login(SlackAccount *sa) {
 	/* validate the team and get it's ID */
-	slack_api_get(sa, slack_auth_login_findteam_cb,
+	slack_api_post(sa, slack_auth_login_findteam_cb,
 		NULL, "auth.findTeam",
 		"domain", sa->host,
 		NULL);
diff --git a/slack-blist.c b/slack-blist.c
index 5f7612d..b039a48 100644
--- a/slack-blist.c
+++ b/slack-blist.c
@@ -145,7 +145,7 @@ struct roomlist_expand {
 };
 
 #define ROOMLIST_CALL(sa, expand, ARGS...) \
-	slack_api_get(sa, roomlist_cb, expand, "conversations.list", "exclude_archived", expand->parent ? "false" : "true", "type", "public_channel,private_channel,mpim,im", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
+	slack_api_post(sa, roomlist_cb, expand, "conversations.list", "exclude_archived", expand->parent ? "false" : "true", "type", "public_channel,private_channel,mpim,im", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
 
 static gboolean roomlist_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {
 	struct roomlist_expand *expand = data;
diff --git a/slack-channel.c b/slack-channel.c
index 66e91b2..2c860d1 100644
--- a/slack-channel.c
+++ b/slack-channel.c
@@ -179,7 +179,7 @@ static gboolean channels_members_cb(SlackAccount *sa, gpointer data, json_value
 	json_value *metadata = json_get_prop_type(json, "response_metadata", object);
 	char *next_cursor = json_get_prop_strptr(metadata, "next_cursor");
 	if (strcmp(next_cursor, "")) {
-		slack_api_get(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, "cursor", next_cursor, NULL);
+		slack_api_post(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, "cursor", next_cursor, NULL);
 	}
 
 	return FALSE;
@@ -206,7 +206,7 @@ static gboolean channels_info_cb(SlackAccount *sa, gpointer data, json_value *js
 	}
 
 	if (purple_account_get_bool(sa->account, "channel_members", TRUE))
-		slack_api_get(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, NULL);
+		slack_api_post(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, NULL);
 
 	if (purple_account_get_bool(sa->account, "open_history", FALSE)) {
 		slack_get_history_unread(sa, &chan->object, json);
@@ -225,7 +225,7 @@ void slack_chat_open(SlackAccount *sa, SlackChannel *chan) {
 
 	serv_got_joined_chat(sa->gc, chan->cid, chan->object.name);
 
-	slack_api_get(sa, channels_info_cb, GINT_TO_POINTER(chan->type), "conversations.info", "channel", chan->object.id, NULL);
+	slack_api_post(sa, channels_info_cb, GINT_TO_POINTER(chan->type), "conversations.info", "channel", chan->object.id, NULL);
 }
 
 static gboolean channels_join_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {
diff --git a/slack-conversation.c b/slack-conversation.c
index 613ab61..51c7420 100644
--- a/slack-conversation.c
+++ b/slack-conversation.c
@@ -16,7 +16,7 @@ static SlackObject *conversation_update(SlackAccount *sa, json_value *json) {
 }
 
 #define CONVERSATIONS_LIST_CALL(sa, ARGS...) \
-	slack_api_get(sa, conversations_list_cb, NULL, "conversations.list", "types", "public_channel,private_channel,mpim,im", "exclude_archived", "true", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
+	slack_api_post(sa, conversations_list_cb, NULL, "conversations.list", "types", "public_channel,private_channel,mpim,im", "exclude_archived", "true", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
 
 static gboolean conversations_list_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {
 	json_value *chans = json_get_prop_type(json, "channels", array);
@@ -101,7 +101,7 @@ static gboolean conversation_counts_cb(SlackAccount *sa, gpointer data, json_val
 
 void slack_conversation_counts(SlackAccount *sa) {
 	/* Private API, not documented. Found by EionRobb (Github). */
-	slack_api_get(sa, conversation_counts_cb, NULL, "users.counts", "mpim_aware", "true", "only_relevant_ims", "true", "simple_unreads", "true", NULL);
+	slack_api_post(sa, conversation_counts_cb, NULL, "users.counts", "mpim_aware", "true", "only_relevant_ims", "true", "simple_unreads", "true", NULL);
 }
 
 SlackObject *slack_conversation_get_conversation(SlackAccount *sa, PurpleConversation *conv) {
@@ -158,7 +158,7 @@ void slack_conversation_retrieve(SlackAccount *sa, const char *sid, SlackConvers
 	struct conversation_retrieve *lookup = g_new(struct conversation_retrieve, 1);
 	lookup->cb = cb;
 	lookup->data = data;
-	slack_api_get(sa, conversation_retrieve_cb, lookup, "conversations.info", "channel", sid, NULL);
+	slack_api_post(sa, conversation_retrieve_cb, lookup, "conversations.info", "channel", sid, NULL);
 }
 
 static gboolean mark_conversation_timer(gpointer data) {
@@ -323,9 +323,9 @@ void slack_get_history(SlackAccount *sa, SlackObject *conv, const char *since, u
 	char count_buf[6] = "";
 	snprintf(count_buf, 5, "%u", MIN(count, SLACK_HISTORY_LIMIT_COUNT));
 	if (thread_ts)
-		slack_api_get(sa, get_history_cb, h, "conversations.replies", "channel", id, "oldest", since ?: "0", "limit", count_buf, "ts", thread_ts, NULL);
+		slack_api_post(sa, get_history_cb, h, "conversations.replies", "channel", id, "oldest", since ?: "0", "limit", count_buf, "ts", thread_ts, NULL);
 	else
-		slack_api_get(sa, get_history_cb, h, "conversations.history", "channel", id, "oldest", since ?: "0", "limit", count_buf, NULL);
+		slack_api_post(sa, get_history_cb, h, "conversations.history", "channel", id, "oldest", since ?: "0", "limit", count_buf, NULL);
 }
 
 void slack_get_history_unread(SlackAccount *sa, SlackObject *conv, json_value *json) {
@@ -353,5 +353,5 @@ static gboolean get_conversation_unread_cb(SlackAccount *sa, gpointer data, json
 void slack_get_conversation_unread(SlackAccount *sa, SlackObject *conv) {
 	const char *id = slack_conversation_id(conv);
 	g_return_if_fail(id);
-	slack_api_get(sa, get_conversation_unread_cb, g_object_ref(conv), "conversations.info", "channel", id, NULL);
+	slack_api_post(sa, get_conversation_unread_cb, g_object_ref(conv), "conversations.info", "channel", id, NULL);
 }
diff --git a/slack-rtm.c b/slack-rtm.c
index 1a84e1f..e32216e 100644
--- a/slack-rtm.c
+++ b/slack-rtm.c
@@ -187,8 +187,15 @@ static gboolean rtm_connect_cb(SlackAccount *sa, gpointer data, json_value *json
 	slack_blist_init(sa);
 
 	slack_login_step(sa);
+
+	gchar *cookie = NULL;
+	if (sa->d_cookie)
+		cookie = g_strconcat("d=", sa->d_cookie, NULL);
+
 	purple_debug_info("slack", "RTM URL: %s\n", url);
-	sa->rtm = purple_websocket_connect(sa->account, url, NULL, rtm_cb, sa);
+	sa->rtm = purple_websocket_connect(sa->account, url, NULL, cookie, rtm_cb, sa);
+
+	g_free(cookie);
 
 	sa->ping_timer = purple_timeout_add_seconds(60, ping_timer, sa);
 	return FALSE;
@@ -232,5 +239,5 @@ void slack_rtm_send(SlackAccount *sa, SlackRTMCallback *callback, gpointer user_
 }
 
 void slack_rtm_connect(SlackAccount *sa) {
-	slack_api_get(sa, rtm_connect_cb, NULL, "rtm.connect", "batch_presence_aware", "1", "presence_sub", "true", NULL);
+	slack_api_post(sa, rtm_connect_cb, NULL, "rtm.connect", "batch_presence_aware", "1", "presence_sub", "true", NULL);
 }
diff --git a/slack-thread.c b/slack-thread.c
index ae86996..714781c 100644
--- a/slack-thread.c
+++ b/slack-thread.c
@@ -251,7 +251,7 @@ static void slack_thread_lookup_ts(SlackAccount *sa, slack_thread_lookup_ts_cb *
 	lookup->rest = g_strdup(rest);
 
 	const char *id = slack_conversation_id(conv);
-	slack_api_get(sa, slack_thread_lookup_ts_history_cb, lookup, "conversations.history", "channel", id, "oldest", start, "latest", end, "inclusive", "1", NULL);
+	slack_api_post(sa, slack_thread_lookup_ts_history_cb, lookup, "conversations.history", "channel", id, "oldest", start, "latest", end, "inclusive", "1", NULL);
 }
 
 static void slack_thread_post_lookup_cb(SlackAccount *sa, SlackObject *conv, gpointer data, const char *thread_ts, const char *msg) {
diff --git a/slack-user.c b/slack-user.c
index 88292b4..3b3d151 100644
--- a/slack-user.c
+++ b/slack-user.c
@@ -120,7 +120,7 @@ static gboolean users_list_cb(SlackAccount *sa, gpointer data, json_value *json,
 
 	char *cursor = json_get_prop_strptr1(json_get_prop(json, "response_metadata"), "next_cursor");
 	if (cursor)
-		slack_api_get(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, "cursor", cursor, NULL);
+		slack_api_post(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, "cursor", cursor, NULL);
 	else
 		slack_login_step(sa);
 	return FALSE;
@@ -128,7 +128,7 @@ static gboolean users_list_cb(SlackAccount *sa, gpointer data, json_value *json,
 
 void slack_users_load(SlackAccount *sa) {
 	// g_hash_table_remove_all(sa->users); /* this isn't really necessary, and we'd prefer to preserve self */
-	slack_api_get(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, NULL);
+	slack_api_post(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, NULL);
 }
 
 struct user_retrieve {
@@ -156,7 +156,7 @@ void slack_user_retrieve(SlackAccount *sa, const char *uid, SlackUserCallback *c
 	struct user_retrieve *lookup = g_new(struct user_retrieve, 1);
 	lookup->cb = cb;
 	lookup->data = data;
-	slack_api_get(sa, user_retrieve_cb, lookup, "users.info", "user", uid, NULL);
+	slack_api_post(sa, user_retrieve_cb, lookup, "users.info", "user", uid, NULL);
 }
 
 static void presence_set(SlackAccount *sa, json_value *json, const char *presence) {
@@ -272,7 +272,7 @@ void slack_get_info(PurpleConnection *gc, const char *who) {
 	if (!user)
 		users_info_cb(sa, g_strdup(who), NULL, NULL);
 	else
-		slack_api_get(sa, users_info_cb, g_strdup(who), "users.info", "user", user->object.id, NULL);
+		slack_api_post(sa, users_info_cb, g_strdup(who), "users.info", "user", user->object.id, NULL);
 }
 
 static void avatar_load_next(SlackAccount *sa);
diff --git a/slack.c b/slack.c
index 5b61b39..0cbcd38 100644
--- a/slack.c
+++ b/slack.c
@@ -282,14 +282,35 @@ static void slack_login(PurpleAccount *account) {
 	/* check if a token has been stored in the password field. */
 	const char *password = purple_account_get_password(sa->account);
 	if(g_regex_match_simple("^xox.-.+", password, 0, 0)) {
-		/* the password is a token, so copy it to the token field */
-		sa->token = g_strdup(password);
+		/* The password is a token. There might be one or two tokens
+		   depending on whether we are using the cookie token or not. */
+		gchar **tokens = g_regex_split_simple(" +", password, 0, 0);
+		gboolean normal_token = FALSE;
+		gboolean cookie_token = FALSE;
+		for (int c = 0; tokens[c] != NULL; c++) {
+			/* copy to the respective token field */
+			if (!cookie_token && strncmp("xoxd-", tokens[c], 5) == 0) {
+				sa->d_cookie = g_strdup(tokens[c]);
+				cookie_token = TRUE;
+			} else if (!normal_token) {
+				sa->token = g_strdup(tokens[c]);
+				normal_token = TRUE;
+			} else {
+				purple_connection_error_reason(
+					purple_account_get_connection(sa->account),
+					PURPLE_CONNECTION_ERROR_AUTHENTICATION_FAILED,
+					"Wrong number of auth tokens.");
+				return;
+			}
+		}
+		g_strfreev(tokens);
 
 		/* set the api url to the property host */
 		sa->api_url = g_strdup_printf("https://%s/api", sa->host);
 
 		/* finally skip the mobile login as we already have a token */
 		sa->login_step = 3;
+
 	} else {
 		if(!password || !*password) {
 			purple_connection_error_reason(
@@ -409,6 +430,7 @@ static void slack_close(PurpleConnection *gc) {
 	g_object_unref(sa->self);
 
 	g_free(sa->api_url);
+	g_free(sa->d_cookie);
 	g_free(sa->token);
 	g_free(sa->email);
 	g_free(sa->host);
diff --git a/slack.h b/slack.h
index 2f6454e..490722a 100644
--- a/slack.h
+++ b/slack.h
@@ -20,6 +20,7 @@ typedef struct _SlackAccount {
 	char *host;
 	char *api_url; /* e.g., "https://slack.com/api" */
 	char *token; /* url encoded */
+	char *d_cookie;
 
 	short login_step;
 	GQueue api_calls; /* SlackAPICall */