diff --git a/src/io/devices/Device.hpp b/src/io/devices/Device.hpp
index bb000602..98666415 100644
--- a/src/io/devices/Device.hpp
+++ b/src/io/devices/Device.hpp
@@ -1,6 +1,8 @@
 #pragma once
 
 #include <string>
+#include <memory>
+#include <iostream>
 #include <filesystem>
 
 #include "../path.hpp"
@@ -13,7 +15,7 @@ namespace io {
         virtual std::filesystem::path resolve(std::string_view path) = 0;
 
         virtual void write(std::string_view path, const void* data, size_t size) = 0;
-        virtual void read(std::string_view path, void* data, size_t size) = 0;
+        virtual std::unique_ptr<std::istream> read(std::string_view path) = 0;
 
         virtual size_t size(std::string_view path) = 0;
 
@@ -43,8 +45,8 @@ namespace io {
             parent->write((root / path).pathPart(), data, size);
         }
 
-        void read(std::string_view path, void* data, size_t size) override {
-            parent->read((root / path).pathPart(), data, size);
+        std::unique_ptr<std::istream> read(std::string_view path) override {
+            return parent->read((root / path).pathPart());
         }
 
         size_t size(std::string_view path) override {
diff --git a/src/io/devices/StdfsDevice.cpp b/src/io/devices/StdfsDevice.cpp
index ad33547d..e5009e00 100644
--- a/src/io/devices/StdfsDevice.cpp
+++ b/src/io/devices/StdfsDevice.cpp
@@ -35,13 +35,13 @@ void StdfsDevice::write(std::string_view path, const void* data, size_t size) {
     output.write((const char*)data, size);
 }
 
-void StdfsDevice::read(std::string_view path, void* data, size_t size) {
+std::unique_ptr<std::istream> StdfsDevice::read(std::string_view path) {
     auto resolved = resolve(path);
-    std::ifstream input(resolved, std::ios::binary);
-    if (!input.is_open()) {
+    auto input = std::make_unique<std::ifstream>(resolved, std::ios::binary);
+    if (!*input) {
         throw std::runtime_error("could not to open file " + resolved.u8string());
     }
-    input.read((char*)data, size);
+    return input;
 }
 
 size_t StdfsDevice::size(std::string_view path) {
diff --git a/src/io/devices/StdfsDevice.hpp b/src/io/devices/StdfsDevice.hpp
index 819dfe4f..9112f2f9 100644
--- a/src/io/devices/StdfsDevice.hpp
+++ b/src/io/devices/StdfsDevice.hpp
@@ -7,7 +7,7 @@ namespace io {
 
         std::filesystem::path resolve(std::string_view path) override;
         void write(std::string_view path, const void* data, size_t size) override;
-        void read(std::string_view path, void* data, size_t size) override;
+        std::unique_ptr<std::istream> read(std::string_view path) override;
         size_t size(std::string_view path) override;
         bool exists(std::string_view path) override;
         bool isdir(std::string_view path) override;
diff --git a/src/io/io.cpp b/src/io/io.cpp
index a9ee86de..efb241d4 100644
--- a/src/io/io.cpp
+++ b/src/io/io.cpp
@@ -5,6 +5,7 @@
 #include <fstream>
 #include <iostream>
 #include <memory>
+#include <sstream>
 #include <stdexcept>
 
 #include "coders/commons.hpp"
@@ -60,12 +61,16 @@ io::directory_iterator::directory_iterator(const io::path& folder)
 }
 
 io::rafile::rafile(const io::path& filename)
-    : file(io::resolve(filename), std::ios::binary | std::ios::ate) {
-    if (!file) {
+    : file(std::make_unique<std::ifstream>(io::resolve(filename), std::ios::binary | std::ios::ate)) {
+    if (!*file) {
         throw std::runtime_error("could not to open file " + filename.string());
     }
-    filelength = file.tellg();
-    file.seekg(0);
+    filelength = file->tellg();
+    file->seekg(0);
+}
+
+io::rafile::rafile(std::unique_ptr<std::istream> file, size_t length)
+    : file(std::move(file)), filelength(length) {
 }
 
 size_t io::rafile::length() const {
@@ -73,11 +78,11 @@ size_t io::rafile::length() const {
 }
 
 void io::rafile::seekg(std::streampos pos) {
-    file.seekg(pos);
+    file->seekg(pos);
 }
 
 void io::rafile::read(char* buffer, std::streamsize size) {
-    file.read(buffer, size);
+    file->read(buffer, size);
 }
 
 bool io::write_bytes(
@@ -96,8 +101,17 @@ bool io::read(const io::path& filename, char* data, size_t size) {
     if (device == nullptr) {
         return false;
     }
-    device->read(filename.pathPart(), data, size);
-    return true;
+    auto stream = io::read(filename);
+    stream->read(data, size);
+    return stream->good();
+}
+
+std::unique_ptr<std::istream> io::read(const io::path& filename) {
+    auto device = io::get_device(filename.entryPoint());
+    if (device == nullptr) {
+        throw std::runtime_error("io-device not found: " + filename.entryPoint());
+    }
+    return device->read(filename.pathPart());
 }
 
 util::Buffer<ubyte> io::read_bytes_buffer(const path& file) {
@@ -112,15 +126,17 @@ std::unique_ptr<ubyte[]> io::read_bytes(
     auto& device = io::require_device(filename.entryPoint());
     length = device.size(filename.pathPart());
     auto data = std::make_unique<ubyte[]>(length);
-    device.read(filename.pathPart(), data.get(), length);
-    return data;
+    auto stream = io::read(filename);
+    stream->read(reinterpret_cast<char*>(data.get()), length);
+    return stream->good() ? std::move(data) : nullptr;
 }
 
 std::vector<ubyte> io::read_bytes(const path& filename) {
     auto& device = io::require_device(filename.entryPoint());
     size_t length = device.size(filename.pathPart());
     std::vector<ubyte> data(length);
-    device.read(filename.pathPart(), data.data(), length);
+    auto stream = io::read(filename);
+    stream->read(reinterpret_cast<char*>(data.data()), length);
     return data;
 }
 
@@ -163,15 +179,10 @@ dv::value io::read_toml(const path& file) {
 }
 
 std::vector<std::string> io::read_list(const io::path& filename) {
-    std::ifstream file(resolve(filename)); // FIXME
-    if (!file) {
-        throw std::runtime_error(
-            "could not to open file " + filename.string()
-        );
-    }
+    auto stream = io::read(filename);
     std::vector<std::string> lines;
     std::string line;
-    while (std::getline(file, line)) {
+    while (std::getline(*stream, line)) {
         util::trim(line);
         if (line.length() == 0) continue;
         if (line[0] == '#') continue;
diff --git a/src/io/io.hpp b/src/io/io.hpp
index 14541eea..ba63688e 100644
--- a/src/io/io.hpp
+++ b/src/io/io.hpp
@@ -15,21 +15,33 @@
 namespace io {
     class Device;
 
+    /// @brief Set device for the entry-point
     void set_device(const std::string& name, std::shared_ptr<Device> device);
+    
+    /// @brief Remove device by entry-point
     void remove_device(const std::string& name);
+    
+    /// @brief Get device by entry-point
     std::shared_ptr<Device> get_device(const std::string& name);
+    
+    /// @brief Get device by entry-point or throw exception
     Device& require_device(const std::string& name);
 
+    /// @brief Create subdevice for the entry-point
+    /// @param name subdevice entry-point
+    /// @param parent parent device entry-point
+    /// @param root root path for the subdevice
     void create_subdevice(
         const std::string& name, const std::string& parent, const path& root
     );
 
     /// @brief Read-only random access file
     class rafile {
-        std::ifstream file;
+        std::unique_ptr<std::istream> file;
         size_t filelength;
     public:
         rafile(const path& filename);
+        rafile(std::unique_ptr<std::istream> file, size_t length);
 
         void seekg(std::streampos pos);
         void read(char* buffer, std::streamsize size);
@@ -131,6 +143,7 @@ namespace io {
     );
 
     bool read(const io::path& file, char* data, size_t size);
+    std::unique_ptr<std::istream> read(const io::path& file);
     util::Buffer<ubyte> read_bytes_buffer(const path& file);
     std::unique_ptr<ubyte[]> read_bytes(const path& file, size_t& length);
     std::vector<ubyte> read_bytes(const path& file);
@@ -140,21 +153,38 @@ namespace io {
     /// @param file *.json or *.bjson file
     dv::value read_json(const path& file);
     
+    /// @brief Read BJSON file
     dv::value read_binary_json(const path& file);
     
     /// @brief Read TOML file
     /// @param file *.toml file
     dv::value read_toml(const path& file);
 
+    /// @brief Read list of strings from the file
     std::vector<std::string> read_list(const io::path& file);
 
+    /// @brief Check if path is a regular file 
     bool is_regular_file(const io::path& file);
-    bool is_directory(const io::path& file);
-    bool exists(const io::path& file);
+
+    /// @brief Check if path is a directory
+    bool is_directory(const io::path& path);
+
+    /// @brief Check if file or directory exists
+    bool exists(const io::path& path);
+
+    /// @brief Create directory
     bool create_directory(const io::path& file);
+
+    /// @brief Create directories recursively
     bool create_directories(const io::path& file);
+
+    /// @brief Remove file or empty directory
     bool remove(const io::path& file);
+
+    /// @brief Remove all files and directories in the folder recursively
     uint64_t remove_all(const io::path& file);
+
+    /// @brief Get file size in bytes 
     size_t file_size(const io::path& file);
 
     std::filesystem::path resolve(const io::path& file);