diff --git a/Userland/Applications/HexEditor/HexDocument.cpp b/Userland/Applications/HexEditor/HexDocument.cpp
index 07dfd8bdd4..8498e733e4 100644
--- a/Userland/Applications/HexEditor/HexDocument.cpp
+++ b/Userland/Applications/HexEditor/HexDocument.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "HexDocument.h"
+#include <LibCore/Stream.h>
 
 void HexDocument::set(size_t position, u8 value)
 {
@@ -57,20 +58,20 @@ void HexDocumentMemory::clear_changes()
     m_changes.clear();
 }
 
-bool HexDocumentMemory::write_to_file(NonnullRefPtr<Core::File> file)
+bool HexDocumentMemory::write_to_file(Core::Stream::File& file)
 {
-    if (!file->seek(0))
+    if (file.seek(0, SeekMode::SetPosition).is_error())
         return false;
-    if (!file->write(m_buffer.data(), m_buffer.size()))
+    if (file.write(m_buffer).is_error())
         return false;
     for (auto& change : m_changes) {
-        file->seek(change.key, SeekMode::SetPosition);
-        file->write(&change.value, 1);
+        file.seek(change.key, SeekMode::SetPosition).release_value_but_fixme_should_propagate_errors();
+        file.write({ &change.value, 1 }).release_value_but_fixme_should_propagate_errors();
     }
     return true;
 }
 
-ErrorOr<NonnullOwnPtr<HexDocumentFile>> HexDocumentFile::create(NonnullRefPtr<Core::File> file)
+ErrorOr<NonnullOwnPtr<HexDocumentFile>> HexDocumentFile::create(NonnullOwnPtr<Core::Stream::File> file)
 {
     auto document = TRY(adopt_nonnull_own_or_enomem(new HexDocumentFile(move(file))));
     // FIXME: Remove this hackery
@@ -79,42 +80,43 @@ ErrorOr<NonnullOwnPtr<HexDocumentFile>> HexDocumentFile::create(NonnullRefPtr<Co
     return document;
 }
 
-HexDocumentFile::HexDocumentFile(NonnullRefPtr<Core::File> file)
-    : m_file(file)
+HexDocumentFile::HexDocumentFile(NonnullOwnPtr<Core::Stream::File> file)
+    : m_file(move(file))
 {
 }
 
 void HexDocumentFile::write_to_file()
 {
     for (auto& change : m_changes) {
-        m_file->seek(change.key, SeekMode::SetPosition);
-        m_file->write(&change.value, 1);
+        m_file->seek(change.key, SeekMode::SetPosition).release_value_but_fixme_should_propagate_errors();
+        m_file->write({ &change.value, 1 }).release_value_but_fixme_should_propagate_errors();
     }
     clear_changes();
     // make sure the next get operation triggers a read
     m_buffer_file_pos = m_file_size + 1;
 }
 
-bool HexDocumentFile::write_to_file(NonnullRefPtr<Core::File> file)
+bool HexDocumentFile::write_to_file(Core::Stream::File& file)
 {
-    if (!file->truncate(size())) {
+    if (file.truncate(size()).is_error()) {
         return false;
     }
 
-    if (!file->seek(0) || !m_file->seek(0)) {
+    if (file.seek(0, SeekMode::SetPosition).is_error() || m_file->seek(0, SeekMode::SetPosition).is_error()) {
         return false;
     }
 
     while (true) {
-        auto copy_buffer = m_file->read(64 * KiB);
+        Array<u8, 64 * KiB> buffer;
+        auto copy_buffer = m_file->read(buffer).release_value_but_fixme_should_propagate_errors();
         if (copy_buffer.size() == 0)
             break;
-        file->write(copy_buffer.data(), copy_buffer.size());
+        file.write(copy_buffer).release_value_but_fixme_should_propagate_errors();
     }
 
     for (auto& change : m_changes) {
-        file->seek(change.key, SeekMode::SetPosition);
-        file->write(&change.value, 1);
+        file.seek(change.key, SeekMode::SetPosition).release_value_but_fixme_should_propagate_errors();
+        file.write({ &change.value, 1 }).release_value_but_fixme_should_propagate_errors();
     }
 
     return true;
@@ -152,24 +154,23 @@ void HexDocumentFile::clear_changes()
     m_changes.clear();
 }
 
-void HexDocumentFile::set_file(NonnullRefPtr<Core::File> file)
+void HexDocumentFile::set_file(NonnullOwnPtr<Core::Stream::File> file)
 {
-    m_file = file;
+    m_file = move(file);
 
-    off_t size = 0;
-    if (!file->seek(0, SeekMode::FromEndPosition, &size)) {
+    if (auto result = m_file->seek(0, SeekMode::FromEndPosition); result.is_error())
         m_file_size = 0;
-    } else {
-        m_file_size = size;
-    }
-    file->seek(0, SeekMode::SetPosition);
+    else
+        m_file_size = result.value();
+
+    m_file->seek(0, SeekMode::SetPosition).release_value_but_fixme_should_propagate_errors();
 
     clear_changes();
     // make sure the next get operation triggers a read
     m_buffer_file_pos = m_file_size + 1;
 }
 
-NonnullRefPtr<Core::File> HexDocumentFile::file() const
+NonnullOwnPtr<Core::Stream::File> const& HexDocumentFile::file() const
 {
     return m_file;
 }
@@ -177,8 +178,8 @@ NonnullRefPtr<Core::File> HexDocumentFile::file() const
 void HexDocumentFile::ensure_position_in_buffer(size_t position)
 {
     if (position < m_buffer_file_pos || position >= m_buffer_file_pos + m_buffer.size()) {
-        m_file->seek(position, SeekMode::SetPosition);
-        m_file->read(m_buffer.data(), m_buffer.size());
+        m_file->seek(position, SeekMode::SetPosition).release_value_but_fixme_should_propagate_errors();
+        m_file->read(m_buffer).release_value_but_fixme_should_propagate_errors();
         m_buffer_file_pos = position;
     }
 }
diff --git a/Userland/Applications/HexEditor/HexDocument.h b/Userland/Applications/HexEditor/HexDocument.h
index 2bfb7f3c66..e18d87c1f3 100644
--- a/Userland/Applications/HexEditor/HexDocument.h
+++ b/Userland/Applications/HexEditor/HexDocument.h
@@ -50,7 +50,7 @@ public:
     size_t size() const override;
     Type type() const override;
     void clear_changes() override;
-    bool write_to_file(NonnullRefPtr<Core::File> file);
+    bool write_to_file(Core::Stream::File& file);
 
 private:
     ByteBuffer m_buffer;
@@ -58,16 +58,16 @@ private:
 
 class HexDocumentFile final : public HexDocument {
 public:
-    static ErrorOr<NonnullOwnPtr<HexDocumentFile>> create(NonnullRefPtr<Core::File> file);
+    static ErrorOr<NonnullOwnPtr<HexDocumentFile>> create(NonnullOwnPtr<Core::Stream::File> file);
     virtual ~HexDocumentFile() = default;
 
     HexDocumentFile(HexDocumentFile&&) = default;
     HexDocumentFile(HexDocumentFile const&) = delete;
 
-    void set_file(NonnullRefPtr<Core::File> file);
-    NonnullRefPtr<Core::File> file() const;
+    void set_file(NonnullOwnPtr<Core::Stream::File> file);
+    NonnullOwnPtr<Core::Stream::File> const& file() const;
     void write_to_file();
-    bool write_to_file(NonnullRefPtr<Core::File> file);
+    bool write_to_file(Core::Stream::File& file);
     Cell get(size_t position) override;
     u8 get_unchanged(size_t position) override;
     size_t size() const override;
@@ -75,10 +75,10 @@ public:
     void clear_changes() override;
 
 private:
-    explicit HexDocumentFile(NonnullRefPtr<Core::File> file);
+    explicit HexDocumentFile(NonnullOwnPtr<Core::Stream::File> file);
     void ensure_position_in_buffer(size_t position);
 
-    NonnullRefPtr<Core::File> m_file;
+    NonnullOwnPtr<Core::Stream::File> m_file;
     size_t m_file_size;
 
     Array<u8, 2048> m_buffer;
diff --git a/Userland/Applications/HexEditor/HexEditor.cpp b/Userland/Applications/HexEditor/HexEditor.cpp
index 0a776c642b..ab20f05d6b 100644
--- a/Userland/Applications/HexEditor/HexEditor.cpp
+++ b/Userland/Applications/HexEditor/HexEditor.cpp
@@ -63,7 +63,7 @@ ErrorOr<void> HexEditor::open_new_file(size_t size)
     return {};
 }
 
-void HexEditor::open_file(NonnullRefPtr<Core::File> file)
+void HexEditor::open_file(NonnullOwnPtr<Core::Stream::File> file)
 {
     m_document = HexDocumentFile::create(move(file)).release_value_but_fixme_should_propagate_errors();
     set_content_length(m_document->size());
@@ -135,16 +135,16 @@ void HexEditor::set_selection(size_t position, size_t length)
     scroll_position_into_view(position);
     update_status();
 }
-bool HexEditor::save_as(NonnullRefPtr<Core::File> new_file)
+bool HexEditor::save_as(NonnullOwnPtr<Core::Stream::File> new_file)
 {
     if (m_document->type() == HexDocument::Type::File) {
         auto& file_document = static_cast<HexDocumentFile&>(*m_document);
-        if (!file_document.write_to_file(new_file))
+        if (!file_document.write_to_file(*new_file))
             return false;
-        file_document.set_file(new_file);
+        file_document.set_file(move(new_file));
     } else {
         auto& memory_document = static_cast<HexDocumentMemory&>(*m_document);
-        if (!memory_document.write_to_file(new_file))
+        if (!memory_document.write_to_file(*new_file))
             return false;
         m_document = HexDocumentFile::create(move(new_file)).release_value_but_fixme_should_propagate_errors();
     }
diff --git a/Userland/Applications/HexEditor/HexEditor.h b/Userland/Applications/HexEditor/HexEditor.h
index d7e085b49c..7207134e4d 100644
--- a/Userland/Applications/HexEditor/HexEditor.h
+++ b/Userland/Applications/HexEditor/HexEditor.h
@@ -35,10 +35,10 @@ public:
 
     size_t buffer_size() const { return m_document->size(); }
     ErrorOr<void> open_new_file(size_t size);
-    void open_file(NonnullRefPtr<Core::File> file);
+    void open_file(NonnullOwnPtr<Core::Stream::File> file);
     ErrorOr<void> fill_selection(u8 fill_byte);
     Optional<u8> get_byte(size_t position);
-    bool save_as(NonnullRefPtr<Core::File>);
+    bool save_as(NonnullOwnPtr<Core::Stream::File>);
     bool save();
 
     bool undo();
diff --git a/Userland/Applications/HexEditor/HexEditorWidget.cpp b/Userland/Applications/HexEditor/HexEditorWidget.cpp
index bc6f490da6..0ac4bc9471 100644
--- a/Userland/Applications/HexEditor/HexEditorWidget.cpp
+++ b/Userland/Applications/HexEditor/HexEditorWidget.cpp
@@ -17,7 +17,7 @@
 #include <AK/StringBuilder.h>
 #include <Applications/HexEditor/HexEditorWindowGML.h>
 #include <LibConfig/Client.h>
-#include <LibCore/File.h>
+#include <LibCore/Stream.h>
 #include <LibDesktop/Launcher.h>
 #include <LibFileSystemAccessClient/Client.h>
 #include <LibGUI/Action.h>
@@ -121,11 +121,11 @@ HexEditorWidget::HexEditorWidget()
         if (!request_close())
             return;
 
-        auto response = FileSystemAccessClient::Client::the().try_open_file_deprecated(window(), {}, Core::StandardPaths::home_directory(), Core::OpenMode::ReadWrite);
+        auto response = FileSystemAccessClient::Client::the().open_file(window(), {}, Core::StandardPaths::home_directory(), Core::Stream::OpenMode::ReadWrite);
         if (response.is_error())
             return;
 
-        open_file(response.value());
+        open_file(response.value().filename(), response.value().release_stream());
     });
 
     m_save_action = GUI::CommonActions::make_save_action([&](auto&) {
@@ -142,18 +142,18 @@ HexEditorWidget::HexEditorWidget()
     });
 
     m_save_as_action = GUI::CommonActions::make_save_as_action([&](auto&) {
-        auto response = FileSystemAccessClient::Client::the().try_save_file_deprecated(window(), m_name, m_extension, Core::OpenMode::ReadWrite | Core::OpenMode::Truncate);
+        auto response = FileSystemAccessClient::Client::the().save_file(window(), m_name, m_extension, Core::Stream::OpenMode::ReadWrite | Core::Stream::OpenMode::Truncate);
         if (response.is_error())
             return;
         auto file = response.release_value();
-        if (!m_editor->save_as(file)) {
+        if (!m_editor->save_as(file.release_stream())) {
             GUI::MessageBox::show(window(), "Unable to save file.\n"sv, "Error"sv, GUI::MessageBox::Type::Error);
             return;
         }
 
         window()->set_modified(false);
-        set_path(file->filename());
-        dbgln("Wrote document to {}", file->filename());
+        set_path(file.filename());
+        dbgln("Wrote document to {}", file.filename());
     });
 
     m_undo_action = GUI::CommonActions::make_undo_action([&](auto&) {
@@ -525,11 +525,11 @@ void HexEditorWidget::update_title()
     window()->set_title(builder.to_deprecated_string());
 }
 
-void HexEditorWidget::open_file(NonnullRefPtr<Core::File> file)
+void HexEditorWidget::open_file(String const& filename, NonnullOwnPtr<Core::Stream::File> file)
 {
     window()->set_modified(false);
-    m_editor->open_file(file);
-    set_path(file->filename());
+    m_editor->open_file(move(file));
+    set_path(filename.to_deprecated_string());
 }
 
 bool HexEditorWidget::request_close()
@@ -586,9 +586,9 @@ void HexEditorWidget::drop_event(GUI::DropEvent& event)
             return;
 
         // TODO: A drop event should be considered user consent for opening a file
-        auto response = FileSystemAccessClient::Client::the().try_request_file_deprecated(window(), urls.first().path(), Core::OpenMode::ReadOnly);
+        auto response = FileSystemAccessClient::Client::the().request_file(window(), urls.first().path(), Core::Stream::OpenMode::Read);
         if (response.is_error())
             return;
-        open_file(response.value());
+        open_file(response.value().filename(), response.value().release_stream());
     }
 }
diff --git a/Userland/Applications/HexEditor/HexEditorWidget.h b/Userland/Applications/HexEditor/HexEditorWidget.h
index 7695fb3a58..addddd246f 100644
--- a/Userland/Applications/HexEditor/HexEditorWidget.h
+++ b/Userland/Applications/HexEditor/HexEditorWidget.h
@@ -25,7 +25,7 @@ class HexEditorWidget final : public GUI::Widget {
     C_OBJECT(HexEditorWidget)
 public:
     virtual ~HexEditorWidget() override = default;
-    void open_file(NonnullRefPtr<Core::File>);
+    void open_file(String const& filename, NonnullOwnPtr<Core::Stream::File>);
     void initialize_menubar(GUI::Window&);
     bool request_close();
 
diff --git a/Userland/Applications/HexEditor/main.cpp b/Userland/Applications/HexEditor/main.cpp
index 97cd3e138c..f3311bc0e6 100644
--- a/Userland/Applications/HexEditor/main.cpp
+++ b/Userland/Applications/HexEditor/main.cpp
@@ -53,10 +53,10 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     if (arguments.argc > 1) {
         // FIXME: Using `try_request_file_read_only_approved` doesn't work here since the file stored in the editor is only readable.
-        auto response = FileSystemAccessClient::Client::the().try_request_file_deprecated(window, arguments.strings[1], Core::OpenMode::ReadWrite);
+        auto response = FileSystemAccessClient::Client::the().request_file(window, arguments.strings[1], Core::Stream::OpenMode::ReadWrite);
         if (response.is_error())
             return 1;
-        hex_editor_widget->open_file(response.value());
+        hex_editor_widget->open_file(response.value().filename(), response.value().release_stream());
     }
 
     return app->exec();