diff --git a/src/common.cpp b/src/common.cpp
index 8a6fcf5..79cfc51 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -20,6 +20,8 @@ Result<Value> Value::create(Arena& arena, PodObject* obj) {
       return Value(TRY(Float::create(arena, (PodFloat*)obj)));
     case Tag::Bool:
       return Value(TRY(Bool::create(arena, (PodBool*)obj)));
+    case Tag::ByteArray:
+      return Value(TRY(ByteArray::create(arena, (PodByteArray*)obj)));
     case Tag::String:
       return Value(TRY(String::create(arena, (PodString*)obj)));
     case Tag::Symbol:
@@ -59,6 +61,10 @@ Result<Value> Float::copy(Arena& arena) {
   return Value(Float(TRY(_value.copy(arena))));
 }
 
+Result<Value> ByteArray::copy(Arena& arena) {
+  return Value(ByteArray(TRY(_value.copy(arena))));
+}
+
 Result<Value> String::copy(Arena& arena) {
   return Value(String(TRY(_value.copy(arena))));
 }
diff --git a/src/common.hpp b/src/common.hpp
index 3438751..0733e39 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -47,6 +47,102 @@ class Nil : public Object {
   GcRoot<PodNil> _value;
 };
 
+class ByteArray : public Object {
+ public:
+  ByteArray() {}
+  ByteArray(ByteArray&& rhs) : _value(std::move(rhs._value)) {}
+  ByteArray(GcRoot<PodByteArray>&& val) : _value(std::move(val)) {}
+
+  ByteArray& operator=(ByteArray&& rhs) {
+    _value = std::move(rhs._value);
+    return *this;
+  }
+
+  virtual Tag tag() final { return Tag::String; }
+  virtual PodObject* pod() final { return _value.get(); }
+
+  static Result<ByteArray> create(Arena& arena, PodByteArray* obj) {
+    return ByteArray(TRY(MkGcRoot(obj, arena)));
+  }
+  static Result<ByteArray> create(Arena& arena, char* chars, int64_t size) {
+    auto pod = TRY(arena.alloc<PodByteArray>(size * sizeof(char)));
+
+    memcpy(pod->data, chars, size * sizeof(char32_t));
+    pod->size = size;
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+  static Result<ByteArray> create(Arena& arena, const char* str) {
+    uint64_t size = strlen(str);
+    auto pod = TRY(arena.alloc<PodByteArray>(size * sizeof(char32_t)));
+
+    memcpy(pod->data, str, size);
+    pod->size = size;
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+  uint64_t size() { return _value->size; }
+  virtual Result<Value> copy(Arena& arena) final;
+
+  Result<char32_t> operator[](uint64_t idx) {
+    if (idx >= _value->size) return ErrorCode::IndexOutOfRange;
+    return _value->data[idx];
+  }
+
+  Result<ByteArray> concat(Arena& arena, const char* rhs) {
+    uint64_t rhs_size = strlen(rhs);
+    uint64_t lhs_size = size();
+    uint64_t res_size = lhs_size + rhs_size;
+
+    auto pod = TRY(arena.alloc<PodByteArray>(res_size * sizeof(char)));
+    pod->size = res_size;
+    memcpy(pod->data, _value->data, sizeof(char) * lhs_size);
+    memcpy(pod->data, rhs + lhs_size, sizeof(char) * rhs_size);
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+  Result<ByteArray> concat(Arena& arena, const char* rhs, uint64_t rhs_size) {
+    uint64_t lhs_size = size();
+    uint64_t res_size = lhs_size + rhs_size;
+
+    auto pod = TRY(arena.alloc<PodByteArray>(res_size * sizeof(char)));
+    pod->size = res_size;
+    memcpy(pod->data, _value->data, sizeof(char) * lhs_size);
+    memcpy(pod->data, rhs + lhs_size, sizeof(char) * rhs_size);
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+  Result<ByteArray> concat(Arena& arena, ByteArray& rhs) {
+    uint64_t rhs_size = rhs.size();
+    uint64_t lhs_size = size();
+    uint64_t res_size = lhs_size + rhs_size;
+
+    auto pod = TRY(arena.alloc<PodByteArray>(res_size * sizeof(char)));
+    pod->size = res_size;
+    memcpy(pod->data, _value->data, sizeof(char) * lhs_size);
+    memcpy(pod->data + lhs_size, rhs._value->data, sizeof(char) * rhs_size);
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+  Result<ByteArray> sub(Arena& arena, uint64_t start, uint64_t end) {
+    if (start > end) return ErrorCode::IndexOutOfRange;
+    uint64_t res_size = end - start;
+    auto pod = TRY(arena.alloc<PodByteArray>(res_size * sizeof(char)));
+    pod->size = res_size;
+    memcpy(pod->data, _value->data + start, sizeof(char) * res_size);
+
+    return ByteArray(TRY(MkGcRoot(pod, arena)));
+  }
+
+ private:
+  GcRoot<PodByteArray> _value;
+};
+
 class String : public Object {
  public:
   String() {}
diff --git a/src/pod.hpp b/src/pod.hpp
index 8e7d109..0b12e24 100644
--- a/src/pod.hpp
+++ b/src/pod.hpp
@@ -14,6 +14,7 @@ enum class Tag : uint8_t {
   Symbol,
   Syntax,
   Pair,
+  ByteArray,
 };
 
 template <class T>
@@ -74,6 +75,14 @@ class PodBool final : public PodObject {
   bool value;
 };
 
+class PodByteArray final : public PodObject {
+ public:
+  PodByteArray() : PodObject(Tag::ByteArray){};
+
+  uint64_t size;
+  char data[];
+};
+
 class PodString final : public PodObject {
  public:
   PodString() : PodObject(Tag::String){};
diff --git a/src/reader.hpp b/src/reader.hpp
index d4a2229..4d51cee 100644
--- a/src/reader.hpp
+++ b/src/reader.hpp
@@ -5,7 +5,7 @@
 
 class Reader {
  public:
-  Reader(Arena& arena, String&& str) : _arena(arena), _str(std::move(str)) {}
+  Reader(Arena& arena, String& str) : _arena(arena), _str(str) {}
 
   Result<Value> read_one();
   Result<Value> read_multiple();
@@ -39,6 +39,6 @@ class Reader {
   bool match(char c);
 
   Arena& _arena;
-  String _str;
+  String& _str;
   SourcePosition position_{1, 1, 0};
 };
diff --git a/src/vli.cpp b/src/vli.cpp
index 258fa83..a684972 100644
--- a/src/vli.cpp
+++ b/src/vli.cpp
@@ -2,6 +2,7 @@
 
 #include "arena.hpp"
 #include "common.hpp"
+#include "reader.hpp"
 
 StaticArena<64 * 1024 * 1024> arena;
 
@@ -26,5 +27,9 @@ int main() {
   }
   std::cout << "root count: " << arena.root_count() << "\n";
 
+  auto s = DIEIF(String::create(arena, "(1 2 3 \"foo\")"));
+  auto reader = Reader(arena, s);
+
+  auto r = DIEIF(reader.read_one());
   return 0;
 }