diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index 0a94fc7ed..4fb5bf90b 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -27,6 +27,7 @@ class StyleLayer;
 class StyleLayerGroup;
 class StyleSource;
 class Texturepool;
+class FileSource;
 class View;
 
 class Map : private util::noncopyable {
@@ -64,7 +65,7 @@ public:
     void toggleClass(const std::string &name);
     const std::vector<std::string> &getAppliedClasses() const;
     void setDefaultTransitionDuration(uint64_t duration_milliseconds = 0);
-    void setStyleJSON(std::string newStyleJSON);
+    void setStyleJSON(std::string newStyleJSON, const std::string &base = "");
     std::string getStyleJSON() const;
     void setAccessToken(std::string access_token);
     std::string getAccessToken() const;
@@ -111,6 +112,7 @@ public:
 
 public:
     inline const TransformState &getState() const { return state; }
+    inline std::shared_ptr<FileSource> getFileSource() const { return fileSource; }
     inline std::shared_ptr<Style> getStyle() const { return style; }
     inline std::shared_ptr<GlyphAtlas> getGlyphAtlas() { return glyphAtlas; }
     inline std::shared_ptr<GlyphStore> getGlyphStore() { return glyphStore; }
@@ -150,6 +152,14 @@ private:
     void renderLayers(std::shared_ptr<StyleLayerGroup> group);
     void renderLayer(std::shared_ptr<StyleLayer> layer_desc, RenderPass pass);
 
+private:
+    bool async = false;
+    std::shared_ptr<uv::loop> loop;
+    uv_thread_t thread;
+    uv_async_t *async_terminate = nullptr;
+    uv_async_t *async_render = nullptr;
+    uv_async_t *async_cleanup = nullptr;
+
 private:
     // If cleared, the next time the render thread attempts to render the map, it will *actually*
     // render the map.
@@ -170,6 +180,8 @@ private:
     Transform transform;
     TransformState state;
 
+    std::shared_ptr<FileSource> fileSource;
+
     std::shared_ptr<Style> style;
     std::shared_ptr<GlyphAtlas> glyphAtlas;
     std::shared_ptr<GlyphStore> glyphStore;
@@ -189,13 +201,6 @@ private:
 
     std::set<std::shared_ptr<StyleSource>> activeSources;
 
-private:
-    bool async = false;
-    std::shared_ptr<uv::loop> loop;
-    uv_thread_t thread;
-    uv_async_t *async_terminate = nullptr;
-    uv_async_t *async_render = nullptr;
-    uv_async_t *async_cleanup = nullptr;
 };
 
 }
diff --git a/include/mbgl/map/sprite.hpp b/include/mbgl/map/sprite.hpp
index 969f15c16..967f1d661 100644
--- a/include/mbgl/map/sprite.hpp
+++ b/include/mbgl/map/sprite.hpp
@@ -14,7 +14,7 @@
 
 namespace mbgl {
 
-class Map;
+class FileSource;
 
 class SpritePosition {
 public:
@@ -33,11 +33,11 @@ public:
 class Sprite : public std::enable_shared_from_this<Sprite>, private util::noncopyable {
 private:
     struct Key {};
-    void load();
+    void load(const std::shared_ptr<FileSource> &fileSource);
 
 public:
     Sprite(const Key &, const std::string& base_url, float pixelRatio);
-    static std::shared_ptr<Sprite> Create(const std::string& base_url, float pixelRatio);
+    static std::shared_ptr<Sprite> Create(const std::string& base_url, float pixelRatio, const std::shared_ptr<FileSource> &fileSource);
 
     const SpritePosition &getSpritePosition(const std::string& name) const;
 
diff --git a/include/mbgl/text/glyph_store.hpp b/include/mbgl/text/glyph_store.hpp
index fbfd0dde6..e0c0391c7 100644
--- a/include/mbgl/text/glyph_store.hpp
+++ b/include/mbgl/text/glyph_store.hpp
@@ -14,6 +14,7 @@
 
 namespace mbgl {
 
+class FileSource;
 
 class SDFGlyph {
 public:
@@ -46,7 +47,7 @@ private:
 
 class GlyphPBF {
 public:
-    GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange);
+    GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const std::shared_ptr<FileSource> &fileSource);
 
     void parse(FontStack &stack);
 
@@ -62,7 +63,7 @@ private:
 // Manages Glyphrange PBF loading.
 class GlyphStore {
 public:
-    GlyphStore();
+    GlyphStore(const std::shared_ptr<FileSource> &fileSource);
 
     // Block until all specified GlyphRanges of the specified font stack are loaded.
     void waitForGlyphRanges(const std::string &fontStack, const std::set<GlyphRange> &glyphRanges);
@@ -81,6 +82,7 @@ public:
     std::string glyphURL;
 
 private:
+    const std::shared_ptr<FileSource> fileSource;
     std::unordered_map<std::string, std::map<GlyphRange, std::unique_ptr<GlyphPBF>>> ranges;
     std::unordered_map<std::string, std::unique_ptr<FontStack>> stacks;
     std::mutex mtx;
diff --git a/include/mbgl/util/filesource.hpp b/include/mbgl/util/filesource.hpp
new file mode 100644
index 000000000..5d5143dbf
--- /dev/null
+++ b/include/mbgl/util/filesource.hpp
@@ -0,0 +1,47 @@
+#ifndef MBGL_UTIL_FILESOURCE
+#define MBGL_UTIL_FILESOURCE
+
+#include <string>
+#include <memory>
+#include <functional>
+
+namespace uv {
+class loop;
+}
+
+namespace mbgl {
+
+namespace platform {
+class Response;
+}
+
+enum class ResourceType : uint8_t {
+    Unknown,
+    Tile,
+    Glyphs,
+    Image,
+    JSON
+};
+
+class FileSource {
+public:
+    FileSource(const std::shared_ptr<uv::loop> &loop);
+
+    void setBase(const std::string &value);
+    const std::string &getBase() const;
+
+    void load(ResourceType type, const std::string &url, std::function<void(platform::Response *)> callback);
+
+private:
+    std::shared_ptr<uv::loop> loop;
+
+    // Stores a URL that is used as a base for loading resources with relative path.
+    std::string base;
+
+    // Stores the absolute path to the cache directory.
+    const std::string cache;
+};
+
+}
+
+#endif
diff --git a/src/map/map.cpp b/src/map/map.cpp
index b7a9db505..e394b71b0 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -18,6 +18,7 @@
 #include <mbgl/style/style_bucket.hpp>
 #include <mbgl/util/texturepool.hpp>
 #include <mbgl/geometry/sprite_atlas.hpp>
+#include <mbgl/util/filesource.hpp>
 
 #include <algorithm>
 #include <memory>
@@ -29,15 +30,16 @@
 using namespace mbgl;
 
 Map::Map(View& view)
-    : view(view),
+    : loop(std::make_shared<uv::loop>()),
+      view(view),
       transform(view),
+      fileSource(std::make_shared<FileSource>(loop)),
       style(std::make_shared<Style>()),
       glyphAtlas(std::make_shared<GlyphAtlas>(1024, 1024)),
-      glyphStore(std::make_shared<GlyphStore>()),
+      glyphStore(std::make_shared<GlyphStore>(fileSource)),
       spriteAtlas(std::make_shared<SpriteAtlas>(512, 512)),
       texturepool(std::make_shared<Texturepool>()),
-      painter(*this),
-      loop(std::make_shared<uv::loop>()) {
+      painter(*this) {
 
     view.initialize(this);
 
@@ -184,10 +186,11 @@ void Map::setup() {
     painter.setup();
 }
 
-void Map::setStyleJSON(std::string newStyleJSON) {
+void Map::setStyleJSON(std::string newStyleJSON, const std::string &base) {
     styleJSON.swap(newStyleJSON);
     sprite.reset();
     style->loadJSON((const uint8_t *)styleJSON.c_str());
+    fileSource->setBase(base);
     glyphStore->setURL(style->glyph_url);
     update();
 }
@@ -208,7 +211,7 @@ std::shared_ptr<Sprite> Map::getSprite() {
     const float pixelRatio = state.getPixelRatio();
     const std::string &sprite_url = style->getSpriteURL();
     if (!sprite || sprite->pixelRatio != pixelRatio) {
-        sprite = Sprite::Create(sprite_url, pixelRatio);
+        sprite = Sprite::Create(sprite_url, pixelRatio, fileSource);
     }
 
     return sprite;
diff --git a/src/map/sprite.cpp b/src/map/sprite.cpp
index 68453de52..f396fec07 100644
--- a/src/map/sprite.cpp
+++ b/src/map/sprite.cpp
@@ -5,6 +5,7 @@
 
 #include <string>
 #include <mbgl/platform/platform.hpp>
+#include <mbgl/util/filesource.hpp>
 #include <mbgl/util/uv.hpp>
 #include <mbgl/util/std.hpp>
 
@@ -20,9 +21,9 @@ SpritePosition::SpritePosition(uint16_t x, uint16_t y, uint16_t width, uint16_t
       pixelRatio(pixelRatio) {
 }
 
-std::shared_ptr<Sprite> Sprite::Create(const std::string& base_url, float pixelRatio) {
+std::shared_ptr<Sprite> Sprite::Create(const std::string& base_url, float pixelRatio, const std::shared_ptr<FileSource> &fileSource) {
     std::shared_ptr<Sprite> sprite(std::make_shared<Sprite>(Key(), base_url, pixelRatio));
-    sprite->load();
+    sprite->load(fileSource);
     return sprite;
 }
 
@@ -49,7 +50,7 @@ Sprite::operator bool() const {
 // Note: This is a separate function that must be called exactly once after creation
 // The reason this isn't part of the constructor is that calling shared_from_this() in
 // the constructor fails.
-void Sprite::load() {
+void Sprite::load(const std::shared_ptr<FileSource> &fileSource) {
     if (!valid) {
         // Treat a non-existent sprite as a successfully loaded empty sprite.
         loadedImage = true;
@@ -60,7 +61,7 @@ void Sprite::load() {
 
     std::shared_ptr<Sprite> sprite = shared_from_this();
 
-    platform::request_http(jsonURL, [sprite](platform::Response *res) {
+    fileSource->load(ResourceType::JSON, jsonURL, [sprite](platform::Response *res) {
         if (res->code == 200) {
             sprite->body.swap(res->body);
             sprite->parseJSON();
@@ -73,7 +74,7 @@ void Sprite::load() {
         }
     });
 
-    platform::request_http(spriteURL, [sprite](platform::Response *res) {
+    fileSource->load(ResourceType::Image, spriteURL, [sprite](platform::Response *res) {
         if (res->code == 200) {
             sprite->image.swap(res->body);
             sprite->parseImage();
diff --git a/src/map/tile_data.cpp b/src/map/tile_data.cpp
index 57ad6944b..a94eb00fb 100644
--- a/src/map/tile_data.cpp
+++ b/src/map/tile_data.cpp
@@ -4,6 +4,7 @@
 
 #include <mbgl/util/token.hpp>
 #include <mbgl/util/string.hpp>
+#include <mbgl/util/filesource.hpp>
 
 using namespace mbgl;
 
@@ -38,7 +39,7 @@ void TileData::request() {
 
     // Note: Somehow this feels slower than the change to request_http()
     std::weak_ptr<TileData> weak_tile = shared_from_this();
-    req = platform::request_http(url, [weak_tile](platform::Response *res) {
+    map.getFileSource()->load(ResourceType::Tile, url, [weak_tile](platform::Response *res) {
         std::shared_ptr<TileData> tile = weak_tile.lock();
         if (!tile || tile->state == State::obsolete) {
             // noop. Tile is obsolete and we're now just waiting for the refcount
@@ -55,7 +56,7 @@ void TileData::request() {
             fprintf(stderr, "[%s] tile loading failed: %d, %s\n", tile->url.c_str(), res->code, res->error_message.c_str());
 #endif
         }
-    }, map.getLoop());
+    });
 }
 
 void TileData::cancel() {
diff --git a/src/text/glyph_store.cpp b/src/text/glyph_store.cpp
index fe4f7de9c..4b90b51c2 100644
--- a/src/text/glyph_store.cpp
+++ b/src/text/glyph_store.cpp
@@ -7,6 +7,7 @@
 #include <mbgl/util/constants.hpp>
 #include <mbgl/util/token.hpp>
 #include <mbgl/util/math.hpp>
+#include <mbgl/util/filesource.hpp>
 #include <mbgl/platform/platform.hpp>
 #include <uv.h>
 #include <algorithm>
@@ -135,7 +136,7 @@ void FontStack::lineWrap(Shaping &shaping, const float lineHeight, const float m
     align(shaping, justify, horizontalAlign, verticalAlign, maxLineLength, lineHeight, line);
 }
 
-GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange)
+GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, GlyphRange glyphRange, const std::shared_ptr<FileSource> &fileSource)
     : future(promise.get_future().share())
 {
     // Load the glyph set URL
@@ -152,7 +153,7 @@ GlyphPBF::GlyphPBF(const std::string &glyphURL, const std::string &fontStack, Gl
     fprintf(stderr, "%s\n", url.c_str());
 #endif
 
-    platform::request_http(url, [&](platform::Response *res) {
+    fileSource->load(ResourceType::Glyphs, url, [&](platform::Response *res) {
         if (res->code != 200) {
             // Something went wrong with loading the glyph pbf. Pass on the error to the future listeners.
             const std::string msg = util::sprintf<255>("[ERROR] failed to load glyphs (%d): %s\n", res->code, res->error_message.c_str());
@@ -226,7 +227,7 @@ void GlyphPBF::parse(FontStack &stack) {
     data.clear();
 }
 
-GlyphStore::GlyphStore() {}
+GlyphStore::GlyphStore(const std::shared_ptr<FileSource> &fileSource) : fileSource(fileSource) {}
 
 void GlyphStore::setURL(const std::string &url) {
     glyphURL = url;
@@ -269,7 +270,7 @@ std::shared_future<GlyphPBF &> GlyphStore::loadGlyphRange(const std::string &fon
     auto range_it = rangeSets.find(range);
     if (range_it == rangeSets.end()) {
         // We don't have this glyph set yet for this font stack.
-        range_it = rangeSets.emplace(range, std::make_unique<GlyphPBF>(glyphURL, fontStack, range)).first;
+        range_it = rangeSets.emplace(range, std::make_unique<GlyphPBF>(glyphURL, fontStack, range, fileSource)).first;
     }
 
     return range_it->second->getFuture();
diff --git a/src/util/filesource.cpp b/src/util/filesource.cpp
new file mode 100644
index 000000000..a910d2519
--- /dev/null
+++ b/src/util/filesource.cpp
@@ -0,0 +1,27 @@
+#include <mbgl/util/filesource.hpp>
+#include <mbgl/platform/platform.hpp>
+
+namespace mbgl {
+
+FileSource::FileSource(const std::shared_ptr<uv::loop> &loop)
+    : loop(loop) {}
+
+
+void FileSource::setBase(const std::string &value) {
+    base = value;
+}
+
+const std::string &FileSource::getBase() const {
+    return base;
+}
+
+void FileSource::load(ResourceType type, const std::string &url, std::function<void(platform::Response *)> callback) {
+    // convert relative URLs to absolute URLs
+
+    // try to load from disk (not yet)
+
+    // load from the internet
+    platform::request_http(url, callback, loop);
+}
+
+}
\ No newline at end of file