diff --git a/core/app.js b/core/app.js
index c3b39abf..d3f613ff 100644
--- a/core/app.js
+++ b/core/app.js
@@ -1,7 +1,23 @@
+/**
+ * \file
+ * \defgroup tfapp Tilde Friends App JS
+ * Tilde Friends server-side app wrapper.
+ * @{
+ */
+
+/** \cond */
 import * as core from './core.js';
 
-let gSessionIndex = 0;
+export {App};
+/** \endcond */
 
+/** A sequence number of apps. */
+let g_session_index = 0;
+
+/**
+ ** App constructor.
+ ** @return An app instance.
+ */
 function App() {
 	this._send_queue = [];
 	this.calls = {};
@@ -9,6 +25,12 @@ function App() {
 	return this;
 }
 
+/**
+ ** Create a function wrapper that when called invokes a function on the app
+ ** itself.
+ ** @param api The function and argument names.
+ ** @return A function.
+ */
 App.prototype.makeFunction = function (api) {
 	let self = this;
 	let result = function () {
@@ -32,6 +54,10 @@ App.prototype.makeFunction = function (api) {
 	return result;
 };
 
+/**
+ ** Send a message to the app.
+ ** @param message The message to send.
+ */
 App.prototype.send = function (message) {
 	if (this._send_queue) {
 		if (this._on_output) {
@@ -46,6 +72,11 @@ App.prototype.send = function (message) {
 	}
 };
 
+/**
+ ** App socket handler.
+ ** @param request The HTTP request of the WebSocket connection.
+ ** @param response The HTTP response.
+ */
 exports.app_socket = async function socket(request, response) {
 	let process;
 	let options = {};
@@ -133,7 +164,7 @@ exports.app_socket = async function socket(request, response) {
 				options.packageOwner = packageOwner;
 				options.packageName = packageName;
 				options.url = message.url;
-				let sessionId = 'session_' + (gSessionIndex++).toString();
+				let sessionId = 'session_' + (g_session_index++).toString();
 				if (blobId) {
 					if (message.edit_only) {
 						response.send(
@@ -218,4 +249,4 @@ exports.app_socket = async function socket(request, response) {
 	response.upgrade(100, {});
 };
 
-export {App};
+/** @} */
diff --git a/core/http.js b/core/http.js
index 3a2f051c..17153e1f 100644
--- a/core/http.js
+++ b/core/http.js
@@ -1,8 +1,14 @@
 /**
- * TODOC
- * TODO: document so we can improve this
- * @param {*} url
- * @returns
+ * \file
+ * \defgroup tfhttp Tilde Friends HTTP Client JS
+ * Tilde Friends server-side HTTP client.
+ * @{
+ */
+
+/**
+ * Parse a URL into protocol, host, path, and port parts.
+ * @param url
+ * @returns An object of the URL parts.
  */
 function parseUrl(url) {
 	// XXX: Hack.
@@ -16,9 +22,9 @@ function parseUrl(url) {
 }
 
 /**
- * TODOC
- * @param {*} data
- * @returns
+ * Parse an HTTP response into headers and body content.
+ * @param data The response data, headers and body included.
+ * @returns headers and body data.
  */
 function parseResponse(data) {
 	let firstLine;
@@ -36,15 +42,15 @@ function parseResponse(data) {
 			headers[line.substring(colon)] = line.substring(colon + 1);
 		}
 	}
-	return {body: data};
+	return {headers: headers, body: data};
 }
 
 /**
- * TODOC
- * @param {*} url
- * @param {*} options
- * @param {*} allowed_hosts
- * @returns
+ * Make an HTTP request.
+ * @param url The URL.
+ * @param options Request options.
+ * @param allowed_hosts List of allowed hosts.
+ * @return A promise resolved with the response headers and body.
  */
 export function fetch(url, options, allowed_hosts) {
 	let parsed = parseUrl(url);
@@ -111,3 +117,5 @@ export function fetch(url, options, allowed_hosts) {
 			});
 	});
 }
+
+/** @} */
diff --git a/core/tfrpc.js b/core/tfrpc.js
index a32795d3..3c81ba18 100644
--- a/core/tfrpc.js
+++ b/core/tfrpc.js
@@ -15,8 +15,8 @@ let g_next_id = 1;
 let g_calls = {};
 
 /**
- * TODOC
- * @returns
+ * Check if being called from a browser vs. server-side.
+ * @return true if called from a browser.
  */
 function get_is_browser() {
 	try {