Index: binaries/data/config/default.cfg
===================================================================
--- binaries/data/config/default.cfg
+++ binaries/data/config/default.cfg
@@ -396,6 +396,11 @@
 [mod]
 enabledmods = "mod public"
 
+[modio.v1]
+baseurl = "https://api.mod.io/v1"
+api_key = "acf8fc07e3a8e9228ef4d5704c1659a1"
+nameid = "0ad"
+
 [network]
 duplicateplayernames = false      ; Rename joining player to "User (2)" if "User" is already connected, otherwise prohibit join.
 lateobservers = everyone          ; Allow observers to join the game after it started. Possible values: everyone, buddies, disabled.
Index: binaries/data/mods/mod/gui/modmod/modmod.xml
===================================================================
--- binaries/data/mods/mod/gui/modmod/modmod.xml
+++ binaries/data/mods/mod/gui/modmod/modmod.xml
@@ -187,7 +187,7 @@
 
 		<object type="button" style="ModernButtonRed" size="100%-576 100%-44 100%-392 100%-16" hotkey="cancel">
 			<translatableAttribute id="caption">Cancel</translatableAttribute>
-			<action on="Press">closePage();</action>
+			<action on="Press">warn(uneval(Engine.ModIoGetMods()));</action>
 		</object>
 
 		<object name="saveConfigurationButton" type="button" style="ModernButtonRed" size="100%-388 100%-44 100%-204 100%-16">
Index: source/ps/ModIo.h
===================================================================
--- /dev/null
+++ source/ps/ModIo.h
@@ -0,0 +1,61 @@
+/* Copyright (C) 2017 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. 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.
+ *
+ * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDED_MODIO
+#define INCLUDED_MODIO
+
+#include <string>
+
+#include "lib/external_libraries/curl.h"
+
+#include "scriptinterface/ScriptInterface.h"
+
+class ModIo
+{
+	NONCOPYABLE(ModIo);
+public:
+	ModIo();
+	~ModIo();
+
+	const std::vector<std::map<std::string, std::string>>& GetMods(const ScriptInterface& scriptinterface);
+
+private:
+	static size_t ReceiveCallback(void* buffer, size_t size, size_t nmemb, void* userp);
+
+	bool ParseGameIdResponse(const ScriptInterface& scriptInterface);
+	bool ParseModsResponse(const ScriptInterface& scriptInterface);
+
+	void PrintMods();
+
+	// Url parts
+	std::string m_BaseUrl;
+	std::string m_GamesRequest;
+	std::string m_GameId;
+
+	// Query parameters
+	std::string m_ApiKey;
+	std::string m_IdQuery;
+
+	CURL* m_Curl;
+	curl_slist* m_Headers;
+	char m_ErrorBuffer[CURL_ERROR_SIZE];
+	std::string m_ResponseData;
+
+	std::vector<std::map<std::string, std::string>> m_ModData;
+};
+
+#endif // INCLUDED_MODIO
Index: source/ps/ModIo.cpp
===================================================================
--- /dev/null
+++ source/ps/ModIo.cpp
@@ -0,0 +1,277 @@
+/* Copyright (C) 2017 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. 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.
+ *
+ * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// TODO: This looks like it might be useful to others, MIT? 
+
+// TODO: Comment on why we handle things this way (not relying on user input, not trusting the remote too much, etc.)
+
+#include "precompiled.h"
+
+#include "ModIo.h"
+
+#include "ps/CLogger.h"
+#include "ps/ConfigDB.h"
+#include "scriptinterface/ScriptConversions.h"
+
+ModIo::ModIo()
+	: m_GamesRequest("/games")
+{
+	CFG_GET_VAL("modio.v1.baseurl", m_BaseUrl);
+	{
+		std::string api_key;
+		CFG_GET_VAL("modio.v1.api_key", api_key);
+		m_ApiKey = "api_key=" + api_key;
+	}
+	{
+		std::string nameid;
+		CFG_GET_VAL("modio.v1.nameid", nameid);
+		m_IdQuery = "nameid="+nameid;
+	}
+
+	// Initialise everything except Win32 sockets (because our networking
+	// system already inits those)
+	curl_global_init(CURL_GLOBAL_ALL & ~CURL_GLOBAL_WIN32);
+// TODO we should only do this in one single place (same for shutdown, currently we do it here and in the userreporter)
+
+	m_Curl = curl_easy_init();
+	ENSURE(m_Curl);
+
+	// TODO: Do we actually care?
+	// Capture error messages
+	curl_easy_setopt(m_Curl, CURLOPT_ERRORBUFFER, m_ErrorBuffer);
+
+	// Disable signal handlers (required for multithreaded applications)
+	curl_easy_setopt(m_Curl, CURLOPT_NOSIGNAL, 1L);
+
+	// To minimise security risks, don't support redirects
+	curl_easy_setopt(m_Curl, CURLOPT_FOLLOWLOCATION, 0L);
+
+	// Set IO callbacks
+	curl_easy_setopt(m_Curl, CURLOPT_WRITEFUNCTION, ReceiveCallback);
+	curl_easy_setopt(m_Curl, CURLOPT_WRITEDATA, this);
+
+	m_Headers = NULL;
+	std::string ua = "User-Agent: 0ad ";
+	ua += curl_version();
+	ua += " (https://play0ad.com/)";
+	m_Headers = curl_slist_append(m_Headers, ua.c_str());
+	// TODO more?
+	curl_easy_setopt(m_Curl, CURLOPT_HTTPHEADER, m_Headers);
+
+
+	// we only accept indices from JS when downloading something later on (security)
+}
+
+ModIo::~ModIo()
+{
+	curl_slist_free_all(m_Headers);
+	curl_easy_cleanup(m_Curl);
+	curl_global_cleanup(); // TODO
+}
+
+size_t ModIo::ReceiveCallback(void* buffer, size_t size, size_t nmemb, void* userp)
+{
+	ModIo* self = static_cast<ModIo*>(userp);
+
+	self->m_ResponseData += std::string((char*)buffer, (char*)buffer+size*nmemb);
+
+	return size*nmemb;
+}
+
+const std::vector<std::map<std::string, std::string>>& ModIo::GetMods(const ScriptInterface& scriptInterface)
+{
+	m_ModData.clear();
+
+	// Get the game id if we didn't fetch it already
+	if (m_GameId.empty())
+	{
+		std::string url = m_BaseUrl+m_GamesRequest+"?"+m_ApiKey+"&"+m_IdQuery;
+		curl_easy_setopt(m_Curl, CURLOPT_URL, url.c_str());
+		CURLcode err = curl_easy_perform(m_Curl);
+
+		if (err != CURLE_OK)
+		{
+			LOGERROR("Server said no: %d", err);
+			return m_ModData;
+		}
+
+		if (!ParseGameIdResponse(scriptInterface))
+			return m_ModData;
+	}
+
+	// Get the actual mods
+	std::string url = m_BaseUrl+m_GamesRequest+m_GameId+"/mods?"+m_ApiKey;
+	curl_easy_setopt(m_Curl, CURLOPT_URL, url.c_str());
+	CURLcode err = curl_easy_perform(m_Curl);
+	if (err != CURLE_OK)
+	{
+		LOGERROR("Server said no to mods %d", err);
+		return m_ModData;
+	}
+
+	if (!ParseModsResponse(scriptInterface))
+		m_ModData.clear(); // Failed during parsing, make sure we don't provide partial data
+
+	PrintMods();
+
+	return m_ModData;
+}
+
+#define FAIL(...) STMT(LOGERROR(__VA_ARGS__); return false;)
+
+/**
+ * Parses the current content of m_ResponseData to extract m_GameId.
+ *
+ * The JSON data is expected to look like
+ * { "data": [{"id": 42, ...}, ...], ... }
+ * where we are only interested in the value of the id property.
+ *
+ * @returns true iff it successfully parsed the id.
+ */
+bool ModIo::ParseGameIdResponse(const ScriptInterface& scriptInterface)
+{
+	JSContext* cx = scriptInterface.GetContext();
+	JS::RootedValue gameResponse(cx);
+
+	// What the data is expected to look like, and what we need.
+	// There is also a result_count property at the same level as data, which should always be 1 following
+	// our query, but maybe we should check that (nah)
+	if (!scriptInterface.ParseJSON(m_ResponseData, &gameResponse))
+		FAIL("Failed to parse response as JSON.");
+
+	m_ResponseData.clear();
+
+	JS::RootedObject gameResponseObj(cx, gameResponse.toObjectOrNull());
+	// TODO handle it being null, or does JS_GetProperty do that for us?
+	JS::RootedValue dataVal(cx);
+	if (!JS_GetProperty(cx, gameResponseObj, "data", &dataVal))
+		FAIL("data property not in response.");
+
+	// [{"id": 42, ...}, ...]
+	if (!dataVal.isObject())
+		FAIL("data property not an object");
+
+	JS::RootedObject data(cx);
+	data = &dataVal.toObject();
+	u32 length;
+	if (!JS_IsArrayObject(cx, data) || !JS_GetArrayLength(cx, data, &length) || !length)
+		FAIL("data property not an array with at least one element");
+
+	// {"id": 42, ...}
+	JS::RootedValue first(cx);
+	if (!JS_GetElement(cx, data, 0, &first))
+		FAIL("couldn't get first element.");
+
+	int id = -1;
+	if (!ScriptInterface::FromJSProperty(cx, first, "id", id))
+		FAIL("couldn't get id");
+
+	m_GameId = "/" + std::to_string(id);
+	return true;
+}
+
+/**
+ * Parses the current content of m_ResponseData into m_ModData.
+ *
+ * The JSON data is expected to look like
+ * { data: [modobj1, modobj2, ...], ... (including result_count) }
+ * where modobjN has the following structure
+ * { homepage: "url", name: "displayname", nameid: "short-non-whitespace-name",
+ *   summary: "short desc.", modfile: { version: "1.2.4", filename: "asdf.zip",
+ *   filehash: "md5sum", filesize: 1234, download: "someurl" }, ... }.
+ * Only the listed properties are of interest to consumers, and we flatten
+ * the modfile structure as that simplifies handling and there are no conflicts.
+ */
+bool ModIo::ParseModsResponse(const ScriptInterface& scriptInterface)
+{
+	JSContext* cx = scriptInterface.GetContext();
+	JS::RootedValue modResponse(cx);
+
+	if (!scriptInterface.ParseJSON(m_ResponseData, &modResponse))
+		FAIL("Failed to parse response as JSON.");
+
+	m_ResponseData.clear();
+
+	JS::RootedObject modResponseObj(cx, modResponse.toObjectOrNull());
+	// TODO handle it being null, or does JS_GetProperty do that for us?
+	JS::RootedValue dataVal(cx);
+	if (!JS_GetProperty(cx, modResponseObj, "data", &dataVal))
+		FAIL("data property not in response.");
+
+	// [modobj1, modobj2, ... ]
+	if (!dataVal.isObject())
+		FAIL("data property not an object");
+
+	JS::RootedObject data(cx);
+	data = &dataVal.toObject();
+	u32 length;
+	if (!JS_IsArrayObject(cx, data) || !JS_GetArrayLength(cx, data, &length) || !length)
+		FAIL("data property not an array with at least one element");
+
+	m_ModData.clear();
+	m_ModData.reserve(length);
+
+	for (u32 i = 0; i < length; ++i)
+	{
+		JS::RootedValue el(cx);
+		if (!JS_GetElement(cx, data, i, &el) || !el.isObject())
+			FAIL("Failed to get array element object");
+
+		m_ModData.emplace_back();
+		// TODO: Currently the homepage field does not contain a non-null value for any entry.
+		for (const std::string& prop : {"name", "nameid", "summary"})
+		{
+			std::string val;
+			ScriptInterface::FromJSProperty(cx, el, prop.c_str(), val);
+			m_ModData.back().emplace(prop, val);
+		}
+
+		// Now copy over the modfile part, but without the pointless substructure
+		JS::RootedObject elObj(cx);
+		elObj = &el.toObject();
+		JS::RootedValue modFile(cx);
+		if (!JS_GetProperty(cx, elObj, "modfile", &modFile))
+			FAIL("Failed to get modfile data");
+
+		for (const std::string& prop : {"version", "filename", "filehash", "filesize", "download"})
+		{
+			std::string val;
+			ScriptInterface::FromJSProperty(cx, modFile, prop.c_str(), val);
+			m_ModData.back().emplace(prop, val);
+		}
+	}
+
+	return true;
+}
+
+#undef FAIL
+
+// TODO: nuke this at some point
+void ModIo::PrintMods()
+{
+	printf("[\n");
+	for (const auto& a : m_ModData)
+	{
+		printf("  {\n");
+		for (const auto& b : a)
+		{
+			printf("    \"%s\": \"%s\",\n", b.first.c_str(), b.second.c_str());
+		}
+		printf("  },\n");
+	}
+	printf("]\n");
+}
Index: source/ps/scripting/JSInterface_Mod.h
===================================================================
--- source/ps/scripting/JSInterface_Mod.h
+++ source/ps/scripting/JSInterface_Mod.h
@@ -26,6 +26,8 @@
 	JS::Value GetAvailableMods(ScriptInterface::CxPrivate* pCxPrivate);
 	void RestartEngine(ScriptInterface::CxPrivate* pCxPrivate);
 	void SetMods(ScriptInterface::CxPrivate* pCxPrivate, const std::vector<CStr>& mods);
+
+	JS::Value ModIoGetMods(ScriptInterface::CxPrivate* pCxPrivate);
 }
 
 #endif
Index: source/ps/scripting/JSInterface_Mod.cpp
===================================================================
--- source/ps/scripting/JSInterface_Mod.cpp
+++ source/ps/scripting/JSInterface_Mod.cpp
@@ -27,6 +27,7 @@
 #include "ps/GameSetup/GameSetup.h"
 #include "ps/GameSetup/Paths.h"
 #include "ps/Mod.h"
+#include "ps/ModIo.h"
 #include "ps/Profile.h"
 #include "ps/scripting/JSInterface_Mod.h"
 
@@ -123,9 +124,34 @@
 	g_modsLoaded = mods;
 }
 
+JS::Value JSI_Mod::ModIoGetMods(ScriptInterface::CxPrivate* pCxPrivate)
+{
+	ScriptInterface* scriptInterface = pCxPrivate->pScriptInterface;
+	JSContext* cx = scriptInterface->GetContext();
+	JSAutoRequest rq(cx);
+
+	ModIo modIo;
+
+	JS::RootedValue mods(cx);
+	scriptInterface->Eval("([])", &mods);
+	for (const std::map<std::string, std::string>& mod : modIo.GetMods(*scriptInterface))
+	{
+		JS::RootedValue m(cx);
+		scriptInterface->Eval("({})", &m);
+		for (const std::pair<std::string, std::string>& prop : mod)
+			scriptInterface->SetProperty(m, prop.first.c_str(), prop.second, true);
+		
+		scriptInterface->CallFunctionVoid(mods, "push", m);
+	}
+
+	return mods;
+}
+
 void JSI_Mod::RegisterScriptFunctions(const ScriptInterface& scriptInterface)
 {
 	scriptInterface.RegisterFunction<JS::Value, &JSI_Mod::GetAvailableMods>("GetAvailableMods");
 	scriptInterface.RegisterFunction<void, &JSI_Mod::RestartEngine>("RestartEngine");
 	scriptInterface.RegisterFunction<void, std::vector<CStr>, &JSI_Mod::SetMods>("SetMods");
+
+	scriptInterface.RegisterFunction<JS::Value, &JSI_Mod::ModIoGetMods>("ModIoGetMods");
 }