diff --git a/core/auth.js b/core/auth.js
index 8632a1f3..7e66a8f4 100644
--- a/core/auth.js
+++ b/core/auth.js
@@ -120,43 +120,48 @@ function authHandler(request, response) {
 			response.writeHead(303, {"Location": formData.return, "Set-Cookie": cookie});
 			response.end();
 		} else {
-			var html = new TextDecoder("UTF-8").decode(File.readFile("core/auth.html"));
-			var contents = "";
+			File.readFile("core/auth.html").then(function(data) {
+				var html = new TextDecoder("UTF-8").decode(data);
+				var contents = "";
 
-			if (entry) {
-				if (sessionIsNew) {
-					contents += '<div>Welcome back, ' + entry.name + '.</div>\n';
+				if (entry) {
+					if (sessionIsNew) {
+						contents += '<div>Welcome back, ' + entry.name + '.</div>\n';
+					} else {
+						contents += '<div>You are already logged in, ' + entry.name + '.</div>\n';
+					}
+					contents += '<div><a href="/login/logout">Logout</a></div>\n';
 				} else {
-					contents += '<div>You are already logged in, ' + entry.name + '.</div>\n';
+					contents += '<form method="POST">\n';
+					if (loginError) {
+						contents += "<p>" + loginError + "</p>\n";
+					}
+					contents += '<div id="auth_greeting"><b>Halt.  Who goes there?</b></div>\n'
+					contents += '<div id="auth">\n';
+					contents += '<div id="auth_login">\n'
+					if (noAdministrator()) {
+						contents += '<div class="notice">There is currently no administrator.  You will be made administrator.</div>\n';
+					}
+					contents += '<div><label for="name">Name:</label> <input type="text" id="name" name="name" value=""></div>\n';
+					contents += '<div><label for="password">Password:</label> <input type="password" id="password" name="password" value=""></div>\n';
+					contents += '<div id="confirmPassword" style="display: none"><label for="confirm">Confirm:</label> <input type="password" id="confirm" name="confirm" value=""></div>\n';
+					contents += '<div><input type="checkbox" id="register" name="register" value="1" onchange="showHideConfirm()"> <label for="register">Register a new account</label></div>\n';
+					contents += '<div><input id="loginButton" type="submit" name="submit" value="Login"></div>\n';
+					contents += '</div>';
+					contents += '<div class="auth_or"> - or - </div>';
+					contents += '<div id="auth_guest">\n';
+					contents += '<input id="guestButton" type="submit" name="submit" value="Proceeed as Guest">\n';
+					contents += '</div>\n';
+					contents += '</div>\n';
+					contents += '</form>';
 				}
-				contents += '<div><a href="/login/logout">Logout</a></div>\n';
-			} else {
-				contents += '<form method="POST">\n';
-				if (loginError) {
-					contents += "<p>" + loginError + "</p>\n";
-				}
-				contents += '<div id="auth_greeting"><b>Halt.  Who goes there?</b></div>\n'
-				contents += '<div id="auth">\n';
-				contents += '<div id="auth_login">\n'
-				if (noAdministrator()) {
-					contents += '<div class="notice">There is currently no administrator.  You will be made administrator.</div>\n';
-				}
-				contents += '<div><label for="name">Name:</label> <input type="text" id="name" name="name" value=""></div>\n';
-				contents += '<div><label for="password">Password:</label> <input type="password" id="password" name="password" value=""></div>\n';
-				contents += '<div id="confirmPassword" style="display: none"><label for="confirm">Confirm:</label> <input type="password" id="confirm" name="confirm" value=""></div>\n';
-				contents += '<div><input type="checkbox" id="register" name="register" value="1" onchange="showHideConfirm()"> <label for="register">Register a new account</label></div>\n';
-				contents += '<div><input id="loginButton" type="submit" name="submit" value="Login"></div>\n';
-				contents += '</div>';
-				contents += '<div class="auth_or"> - or - </div>';
-				contents += '<div id="auth_guest">\n';
-				contents += '<input id="guestButton" type="submit" name="submit" value="Proceeed as Guest">\n';
-				contents += '</div>\n';
-				contents += '</div>\n';
-				contents += '</form>';
-			}
-			var text = html.replace("<!--SESSION-->", contents);
-			response.writeHead(200, {"Content-Type": "text/html; charset=utf-8", "Set-Cookie": cookie, "Content-Length": text.length});
-			response.end(text);
+				var text = html.replace("<!--SESSION-->", contents);
+				response.writeHead(200, {"Content-Type": "text/html; charset=utf-8", "Set-Cookie": cookie, "Content-Length": text.length});
+				response.end(text);
+			}).catch(function(error) {
+				response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Connection": "close"});
+				response.end("404 File not found");
+			});
 		}
 	} else if (request.uri == "/login/logout") {
 		removeSession(session);
diff --git a/core/core.js b/core/core.js
index 4ff0599d..de9ef811 100644
--- a/core/core.js
+++ b/core/core.js
@@ -138,48 +138,14 @@ async function getSessionProcessBlob(blobId, session, options) {
 	return getProcessBlob(blobId, 'session_' + session, actualOptions);
 }
 
-function readFileUtf8(fileName) {
-	let data = File.readFile(fileName);
+async function readFileUtf8(fileName) {
+	let data = await File.readFile(fileName);
 	data = utf8Decode(data);
 	return data;
 }
 
 let gManifestCache = {};
 
-async function getManifest(fileName) {
-	let oldEntry = gManifestCache[fileName];
-	let stat = await File.stat(fileName);
-	if (oldEntry) {
-		if (oldEntry.stat.mtime == stat.mtime && oldEntry.stat.size == stat.size) {
-			return oldEntry.manifest;
-		}
-	}
-
-	let manifest = [];
-	let lines = readFileUtf8(fileName).split("\n").map(x => x.trimRight());
-	for (let i = 0; i < lines.length; i++) {
-		if (lines[i].substring(0, 4) == "//! ") {
-			manifest.push(lines[i].substring(4));
-		}
-	}
-	let result;
-	try {
-		if (manifest.length) {
-			result = JSON.parse(manifest.join("\n"));
-		}
-	} catch (error) {
-		print("ERROR: getManifest(" + fileName + "): ", error);
-		// Oh well.  No manifest.
-	}
-
-	gManifestCache[fileName] = {
-		stat: stat,
-		manifest: result,
-	};
-
-	return result;
-}
-
 async function getProcessBlob(blobId, key, options) {
 	var process = gProcesses[key];
 	if (!process
@@ -319,15 +285,6 @@ function setGlobalSettings(settings) {
 	}
 }
 
-try {
-	var data = readFileUtf8(kGlobalSettingsFile);
-	if (data) {
-		gGlobalSettings = JSON.parse(data);
-	}
-} catch (error) {
-	print("Error loading settings from " + kGlobalSettingsFile + ": " + error);
-}
-
 var kStaticFiles = [
 	{uri: '/', path: 'index.html', type: 'text/html; charset=UTF-8'},
 	{uri: '/style.css', path: 'style.css', type: 'text/css; charset=UTF-8'},
@@ -351,7 +308,7 @@ function startsWithBytes(data, bytes) {
 async function staticFileHandler(request, response, blobId, uri) {
 	for (var i in kStaticFiles) {
 		if (uri === kStaticFiles[i].uri) {
-			var data = File.readFile("core/" + kStaticFiles[i].path);
+			var data = await File.readFile("core/" + kStaticFiles[i].path);
 			response.writeHead(200, {"Content-Type": kStaticFiles[i].type, "Content-Length": data.byteLength});
 			response.end(data);
 			return;
@@ -403,7 +360,7 @@ async function blobHandler(request, response, blobId, uri) {
 		for (var i in kStaticFiles) {
 			if (uri === kStaticFiles[i].uri) {
 				found = true;
-				var data = File.readFile("core/" + kStaticFiles[i].path);
+				var data = await File.readFile("core/" + kStaticFiles[i].path);
 				response.writeHead(200, {"Content-Type": kStaticFiles[i].type, "Content-Length": data.byteLength});
 				response.end(data);
 				break;
@@ -483,41 +440,56 @@ ssb.onConnectionsChanged = function() {
 	broadcastEvent('onConnectionsChanged', []);
 }
 
-var auth = require("auth");
-var httpd = require("httpd");
-httpd.all("/login", auth.handler);
-httpd.all("", function(request, response) {
-	var match;
-	if (request.uri === "/" || request.uri === "") {
-		response.writeHead(303, {"Location": 'http://' + request.headers.host + gGlobalSettings.index, "Content-Length": "0"});
-		return response.end();
-	} else if (match = /^(\/~[^\/]+\/[^\/]+)(\/?.*)$/.exec(request.uri)) {
-		return blobHandler(request, response, match[1], match[2]);
-	} else if (match = /^\/([&\%][^\.]{44}(?:\.\w+)?)(\/?.*)/.exec(request.uri)) {
-		return blobHandler(request, response, match[1], match[2]);
-	} else if (match = /^\/static(\/.*)/.exec(request.uri)) {
-		return staticFileHandler(request, response, null, match[1]);
-	} else if (match = /^(.*)(\/save)$/.exec(request.uri)) {
-		return blobHandler(request, response, match[1], match[2]);
-	} else if (match = /^\/trace$/.exec(request.uri)) {
-		var data = trace();
-		response.writeHead(404, {"Content-Type": "application/json; charset=utf-8", "Content-Length": data.length.toString()});
-		return response.end(data);
-	} else if (request.uri == "/robots.txt") {
-		return blobHandler(request, response, null, request.uri);
-	} else if ((match = /^\/.well-known\/(.*)/.exec(request.uri)) && request.uri.indexOf("..") == -1) {
-		var data = File.readFile("data/global/.well-known/" + match[1]);
+async function loadSettings() {
+	try {
+		var data = await readFileUtf8(kGlobalSettingsFile);
 		if (data) {
-			response.writeHead(200, {"Content-Type": "text/plain", "Content-Length": data.length});
-			response.end(data);
-		} else {
-			response.writeHead(404, {"Content-Type": "text/plain", "Content-Length": "File not found".length});
-			response.end("File not found");
+			gGlobalSettings = JSON.parse(data);
 		}
-	} else {
-		var data = "File not found.";
-		response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": data.length.toString()});
-		return response.end(data);
+	} catch (error) {
+		print("Error loading settings from " + kGlobalSettingsFile + ": " + error);
 	}
+}
+
+loadSettings().then(function() {
+	var auth = require("auth");
+	var httpd = require("httpd");
+	httpd.all("/login", auth.handler);
+	httpd.all("", function(request, response) {
+		var match;
+		if (request.uri === "/" || request.uri === "") {
+			response.writeHead(303, {"Location": 'http://' + request.headers.host + gGlobalSettings.index, "Content-Length": "0"});
+			return response.end();
+		} else if (match = /^(\/~[^\/]+\/[^\/]+)(\/?.*)$/.exec(request.uri)) {
+			return blobHandler(request, response, match[1], match[2]);
+		} else if (match = /^\/([&\%][^\.]{44}(?:\.\w+)?)(\/?.*)/.exec(request.uri)) {
+			return blobHandler(request, response, match[1], match[2]);
+		} else if (match = /^\/static(\/.*)/.exec(request.uri)) {
+			return staticFileHandler(request, response, null, match[1]);
+		} else if (match = /^(.*)(\/save)$/.exec(request.uri)) {
+			return blobHandler(request, response, match[1], match[2]);
+		} else if (match = /^\/trace$/.exec(request.uri)) {
+			var data = trace();
+			response.writeHead(404, {"Content-Type": "application/json; charset=utf-8", "Content-Length": data.length.toString()});
+			return response.end(data);
+		} else if (request.uri == "/robots.txt") {
+			return blobHandler(request, response, null, request.uri);
+		} else if ((match = /^\/.well-known\/(.*)/.exec(request.uri)) && request.uri.indexOf("..") == -1) {
+			var data = File.readFile("data/global/.well-known/" + match[1]);
+			if (data) {
+				response.writeHead(200, {"Content-Type": "text/plain", "Content-Length": data.length});
+				response.end(data);
+			} else {
+				response.writeHead(404, {"Content-Type": "text/plain", "Content-Length": "File not found".length});
+				response.end("File not found");
+			}
+		} else {
+			var data = "File not found.";
+			response.writeHead(404, {"Content-Type": "text/plain; charset=utf-8", "Content-Length": data.length.toString()});
+			return response.end(data);
+		}
+	});
+	httpd.registerSocketHandler("/app/socket", app.socket);
+}).catch(function(error) {
+	print('Failed to load settings.');
 });
-httpd.registerSocketHandler("/app/socket", app.socket);
diff --git a/src/file.c b/src/file.c
index c0041724..50f603de 100644
--- a/src/file.c
+++ b/src/file.c
@@ -45,41 +45,84 @@ void tf_file_init(JSContext* context) {
 	JS_FreeValue(context, global);
 }
 
-static void _free_array_buffer_data(JSRuntime* runtime, void* opaque, void* ptr) {
-	free(ptr);
+static const int k_file_read_max = 4 * 1024 * 1024;
+
+static void _file_read_close_callback(uv_fs_t* req)
+{
+	uv_fs_req_cleanup(req);
+	free(req);
+}
+
+static void _file_read_read_callback(uv_fs_t* req)
+{
+	uv_fs_req_cleanup(req);
+	tf_task_t* task = req->loop->data;
+	JSContext* context = tf_task_get_context(task);
+	promiseid_t promise = (promiseid_t)(intptr_t)req->data;
+	if (req->result >= 0)
+	{
+		JSValue arrayBuffer = JS_NewArrayBufferCopy(context, (uint8_t*)(req + 1), req->result);
+		JSValue global = JS_GetGlobalObject(context);
+		JSValue constructor = JS_GetPropertyStr(context, global, "Uint8Array");
+		JSValue typedArray = JS_CallConstructor(context, constructor, 1, &arrayBuffer);
+		JS_FreeValue(context, constructor);
+		JS_FreeValue(context, global);
+		JS_FreeValue(context, arrayBuffer);
+		tf_task_resolve_promise(task, promise, typedArray);
+		JS_FreeValue(context, typedArray);
+	}
+	else
+	{
+		tf_task_reject_promise(task, promise, JS_ThrowInternalError(context, uv_strerror(req->result)));
+	}
+	int result = uv_fs_close(req->loop, req, req->file, _file_read_close_callback);
+	if (result < 0)
+	{
+		free(req);
+	}
+}
+
+static void _file_read_open_callback(uv_fs_t* req)
+{
+	uv_fs_req_cleanup(req);
+	tf_task_t* task = req->loop->data;
+	JSContext* context = tf_task_get_context(task);
+	promiseid_t promise = (promiseid_t)(intptr_t)req->data;
+	if (req->result >= 0)
+	{
+		uv_buf_t buf = { .base = (char*)(req + 1), .len = k_file_read_max };
+		uv_file file = req->result;
+		int result = uv_fs_read(req->loop, req, file, &buf, 1, 0, _file_read_read_callback);
+		if (result < 0)
+		{
+			tf_task_reject_promise(task, promise, JS_ThrowInternalError(context, uv_strerror(result)));
+			result = uv_fs_close(req->loop, req, file, _file_read_close_callback);
+		}
+	}
+	else
+	{
+		tf_task_reject_promise(task, promise, JS_ThrowInternalError(context, uv_strerror(req->result)));
+		free(req);
+	}
 }
 
 static JSValue _file_read_file(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv) {
+	void* task = JS_GetContextOpaque(context);
 	const char* file_name = JS_ToCString(context, argv[0]);
-	FILE* file = fopen(file_name, "rb");
-	JS_FreeCString(context, file_name);
-	if (!file) {
-		return JS_NULL;
-	}
 
-	long size = 0;
-	if (fseek(file, 0, SEEK_END) == 0) {
-		size = ftell(file);
+	promiseid_t promise = tf_task_allocate_promise(task);
+	uv_fs_t* req = malloc(sizeof(uv_fs_t) + k_file_read_max);
+	*req = (uv_fs_t)
+	{
+		.data = (void*)(intptr_t)promise,
+	};
+	int result = uv_fs_open(tf_task_get_loop(task), req, file_name, UV_FS_O_RDONLY, 0, _file_read_open_callback);
+	if (result < 0)
+	{
+		tf_task_reject_promise(task, promise, JS_ThrowInternalError(context, uv_strerror(result)));
 	}
-	if (size >= 0 &&
-		size < 4 * 1024 * 1024 &&
-		fseek(file, 0, SEEK_SET) == 0) {
-		uint8_t* data = malloc(size);
-		if (data &&
-			fread(data, 1, size, file) == (size_t)size) {
-			JSValue arrayBuffer = JS_NewArrayBuffer(context, data, size, _free_array_buffer_data, NULL, false);
-			JSValue global = JS_GetGlobalObject(context);
-			JSValue constructor = JS_GetPropertyStr(context, global, "Uint8Array");
-			JSValue typedArray = JS_CallConstructor(context, constructor, 1, &arrayBuffer);
-			JS_FreeValue(context, constructor);
-			JS_FreeValue(context, global);
-			JS_FreeValue(context, arrayBuffer);
-			return typedArray;
-		} else if (data) {
-			free(data);
-		}
-	}
-	return JS_NULL;
+	JS_FreeCString(context, file_name);
+	return tf_task_get_promise(task, promise);
 }
 
 static JSValue _file_write_file(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv) {
diff --git a/src/task.c b/src/task.c
index 25536bcf..b5f04909 100644
--- a/src/task.c
+++ b/src/task.c
@@ -1142,6 +1142,7 @@ tf_task_t* tf_task_create() {
 	tf_task_t* task = malloc(sizeof(tf_task_t));
 	*task = (tf_task_t) { 0 };
 	task->_loop = uv_loop_new();
+	task->_loop->data = task;
 	++_count;
 	task->_runtime = JS_NewRuntime();
 	task->_context = JS_NewContext(task->_runtime);
diff --git a/src/tests.c b/src/tests.c
index 7293d383..9f67cdc8 100644
--- a/src/tests.c
+++ b/src/tests.c
@@ -480,6 +480,36 @@ static void _test_socket(const tf_test_options_t* options)
 	unlink("out/test.js");
 }
 
+static void _test_file(const tf_test_options_t* options)
+{
+	FILE* file = fopen("out/test.js", "w");
+	fprintf(file,
+		"'use strict';\n"
+		"File.readFile('out/test.js').then(function(data) {\n"
+		"	print('READ', utf8Decode(data));\n"
+		"}).catch(function(error) {\n"
+		"	print('ERROR', error);\n"
+		"	exit(1);\n"
+		"});\n"
+		"File.readFile('out/missing.txt').then(function(data) {\n"
+		"	print('READ', utf8Decode(data));\n"
+		"	exit(1);\n"
+		"}).catch(function(error) {\n"
+		"	print('expected error', error);\n"
+		"});\n");
+	fclose(file);
+
+	char command[256];
+	snprintf(command, sizeof(command), "%s run --ssb-port=0 -s out/test.js", options->exe_path);
+	printf("%s\n", command);
+	int result = system(command);
+	printf("returned %d\n", WEXITSTATUS(result));
+	assert(WIFEXITED(result));
+	assert(WEXITSTATUS(result) == 0);
+
+	unlink("out/test.js");
+}
+
 static void _tf_test_run(const tf_test_options_t* options, const char* name, void (*test)(const tf_test_options_t* options))
 {
 	bool specified = false;
@@ -521,5 +551,6 @@ void tf_tests(const tf_test_options_t* options)
 	_tf_test_run(options, "icu", _test_icu);
 	_tf_test_run(options, "uint8array", _test_uint8array);
 	_tf_test_run(options, "socket", _test_socket);
+	_tf_test_run(options, "file", _test_file);
 	printf("Tests completed.\n");
 }