diff --git a/data/include/join/json.hpp b/data/include/join/json.hpp
index abd67d6d..110eea4e 100644
--- a/data/include/join/json.hpp
+++ b/data/include/join/json.hpp
@@ -880,7 +880,7 @@ namespace join
          * @param data data to append to output stream.
          * @param size data size.
          */
-        inline void append (const char* data, uint32_t size)
+        inline void append (const char* data, size_t size)
         {
             if (JOIN_UNLIKELY (size > sizeof (_buffer) - _size))
             {
diff --git a/data/include/join/pack.hpp b/data/include/join/pack.hpp
index 97290bee..7c7d41c5 100644
--- a/data/include/join/pack.hpp
+++ b/data/include/join/pack.hpp
@@ -32,6 +32,7 @@
 #include <join/value_builder.hpp>
 #include <join/value.hpp>
 #include <join/utils.hpp>
+#include <join/utf8.hpp>
 #include <join/sax.hpp>
 
 // C++.
@@ -691,47 +692,134 @@ namespace join
         size_t _depth = 0;
     };
 
+    /**
+     * @brief MessagePack deserialization mode.
+     */
+    enum class PackReadMode : uint32_t
+    {
+        None = 0,                    /**< no read mode set. */
+        ValidateEncoding = 1L << 0,  /**< validate UTF-8 encoding of strings. */
+        StopParsingOnDone = 1L << 1, /**< stop parsing on done. */
+    };
+
+    /**
+     * @brief perform binary AND on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return bitset result of binary AND on PackReadMode.
+     */
+    constexpr PackReadMode operator& (PackReadMode a, PackReadMode b) noexcept
+    {
+        return PackReadMode (static_cast<uint32_t> (a) & static_cast<uint32_t> (b));
+    }
+
+    /**
+     * @brief perform binary OR on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return bitset result of binary OR on PackReadMode.
+     */
+    constexpr PackReadMode operator| (PackReadMode a, PackReadMode b) noexcept
+    {
+        return PackReadMode (static_cast<uint32_t> (a) | static_cast<uint32_t> (b));
+    }
+
+    /**
+     * @brief perform binary XOR on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return bitset result of binary XOR on PackReadMode.
+     */
+    constexpr PackReadMode operator^ (PackReadMode a, PackReadMode b) noexcept
+    {
+        return PackReadMode (static_cast<uint32_t> (a) ^ static_cast<uint32_t> (b));
+    }
+
+    /**
+     * @brief perform binary NOT on PackReadMode.
+     * @param a bitset.
+     * @return bitset result of binary NOT on PackReadMode.
+     */
+    constexpr PackReadMode operator~(PackReadMode a) noexcept
+    {
+        return PackReadMode (~static_cast<uint32_t> (a));
+    }
+
+    /**
+     * @brief perform binary AND assignment on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return reference to updated bitset.
+     */
+    constexpr const PackReadMode& operator&= (PackReadMode& a, PackReadMode b) noexcept
+    {
+        return a = a & b;
+    }
+
+    /**
+     * @brief perform binary OR assignment on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return reference to updated bitset.
+     */
+    constexpr const PackReadMode& operator|= (PackReadMode& a, PackReadMode b) noexcept
+    {
+        return a = a | b;
+    }
+
+    /**
+     * @brief perform binary XOR assignment on PackReadMode.
+     * @param a bitset.
+     * @param b other bitset.
+     * @return reference to updated bitset.
+     */
+    constexpr const PackReadMode& operator^= (PackReadMode& a, PackReadMode b) noexcept
+    {
+        return a = a ^ b;
+    }
+
     /**
      * @brief message pack reader class.
      */
-    class PackReader
+    template <PackReadMode ReadMode = PackReadMode::None>
+    class BasicPackReader
     {
     public:
         /**
          * @brief default constructor.
          */
-        PackReader () = default;
+        BasicPackReader () = default;
 
         /**
          * @brief copy constructor.
          * @param other object to copy.
          */
-        PackReader (const PackReader& other) = delete;
+        BasicPackReader (const BasicPackReader& other) = delete;
 
         /**
          * @brief copy assignment.
          * @param other object to copy.
          * @return a reference of the current object.
          */
-        PackReader& operator= (const PackReader& other) = delete;
+        BasicPackReader& operator= (const BasicPackReader& other) = delete;
 
         /**
          * @brief move constructor.
          * @param other object to move.
          */
-        PackReader (PackReader&& other) = delete;
+        BasicPackReader (BasicPackReader&& other) = delete;
 
         /**
          * @brief move assignment.
          * @param other object to move.
          * @return a reference of the current object.
          */
-        PackReader& operator= (PackReader&& other) = delete;
+        BasicPackReader& operator= (BasicPackReader&& other) = delete;
 
         /**
          * @brief destroy instance.
          */
-        ~PackReader () = default;
+        ~BasicPackReader () = default;
 
         /**
          * @brief deserialize a document.
@@ -818,6 +906,11 @@ namespace join
             {
                 if (JOIN_LIKELY (readValue (document, handler, 0) == 0))
                 {
+                    if constexpr ((ReadMode & PackReadMode::StopParsingOnDone) != PackReadMode::None)
+                    {
+                        return 0;
+                    }
+
                     if (JOIN_LIKELY (document.peek () == std::char_traits<char>::eof ()))
                     {
                         return 0;
@@ -1155,6 +1248,10 @@ namespace join
                 }
 
                 std::string_view output (document.tell (), len);
+                if (JOIN_UNLIKELY (validateString (output) == -1))
+                {
+                    return -1;
+                }
                 document.seek (document.tell () + len);
                 return isKey ? handler.setKey (output) : handler.setString (output);
             }
@@ -1167,11 +1264,34 @@ namespace join
                 return -1;
             }
 
+            if (JOIN_UNLIKELY (validateString (output) == -1))
+            {
+                return -1;
+            }
+
             int result = isKey ? handler.setKey (output) : handler.setString (output);
             cache = std::move (output);
             return result;
         }
 
+        /**
+         * @brief validate the UTF-8 encoding of a string when required by the read mode.
+         * @param value string to validate.
+         * @return 0 on success, -1 otherwise.
+         */
+        static int validateString ([[maybe_unused]] std::string_view value) noexcept
+        {
+            if constexpr ((ReadMode & PackReadMode::ValidateEncoding) != PackReadMode::None)
+            {
+                if (JOIN_UNLIKELY (utf8::validate (value.data (), value.data () + value.size ()) == -1))
+                {
+                    join::lastError = make_error_code (SaxErrc::InvalidEncoding);
+                    return -1;
+                }
+            }
+            return 0;
+        }
+
         /**
          * @brief parse binary data.
          * @param document document to parse.
@@ -1581,6 +1701,9 @@ namespace join
             return ((c >= 0x80) && (c <= 0x8f)) || (c == 0xde) || (c == 0xdf);
         }
     };
+
+    /// MessagePack reader.
+    using PackReader = BasicPackReader<PackReadMode::None>;
 }
 
 #endif
diff --git a/data/include/join/sax_error.hpp b/data/include/join/sax_error.hpp
index 304acab5..99ea87f4 100644
--- a/data/include/join/sax_error.hpp
+++ b/data/include/join/sax_error.hpp
@@ -43,6 +43,7 @@ namespace join
         InvalidParent,     /**< Parent not an array nor an object. */
         InvalidKey,        /**< Key is invalid. */
         InvalidValue,      /**< Value is invalid. */
+        InvalidEncoding,   /**< Character encoding is invalid. */
         ExtraData,         /**< Extra data detected. */
         Truncated          /**< Data is truncated. */
     };
diff --git a/data/src/sax_error.cpp b/data/src/sax_error.cpp
index 1b255fd9..3fa15df1 100644
--- a/data/src/sax_error.cpp
+++ b/data/src/sax_error.cpp
@@ -53,6 +53,8 @@ std::string SaxCategory::message (int code) const
             return "key is invalid";
         case SaxErrc::InvalidValue:
             return "value is invalid";
+        case SaxErrc::InvalidEncoding:
+            return "character encoding is invalid";
         case SaxErrc::ExtraData:
             return "extra data detected";
         case SaxErrc::Truncated:
diff --git a/data/tests/pack_reader_test.cpp b/data/tests/pack_reader_test.cpp
index a7f7bc57..71f890a7 100644
--- a/data/tests/pack_reader_test.cpp
+++ b/data/tests/pack_reader_test.cpp
@@ -209,6 +209,25 @@ TEST (PackReader, deserialize)
         builder.startArray ();
     }
     ASSERT_EQ (PackReader ().deserialize (std::string (1, '\x80'), builder), -1);
+
+    using Stopping = join::BasicPackReader<join::PackReadMode::StopParsingOnDone>;
+    std::stringstream messages (std::string ({'\x01', '\x02', '\xc3'}));
+    ASSERT_EQ (Stopping ().deserialize (messages, value), 0) << join::lastError.message ();
+    ASSERT_EQ (value, 1);
+    ASSERT_EQ (Stopping ().deserialize (messages, value), 0) << join::lastError.message ();
+    ASSERT_EQ (value, 2);
+    ASSERT_EQ (Stopping ().deserialize (messages, value), 0) << join::lastError.message ();
+    ASSERT_EQ (value, true);
+    ASSERT_EQ (Stopping ().deserialize (messages, value), -1);
+    ASSERT_EQ (join::lastError, SaxErrc::Truncated);
+    ASSERT_EQ (Stopping ().deserialize (std::string ({'\x00', '\x00'}), value), 0) << join::lastError.message ();
+
+    using Strict = join::BasicPackReader<join::PackReadMode::ValidateEncoding | join::PackReadMode::StopParsingOnDone>;
+    std::stringstream strict (std::string ({'\xa1', 'a', '\xa1', '\xff'}));
+    ASSERT_EQ (Strict ().deserialize (strict, value), 0) << join::lastError.message ();
+    ASSERT_EQ (value.getString (), "a");
+    ASSERT_EQ (Strict ().deserialize (strict, value), -1);
+    ASSERT_EQ (join::lastError, SaxErrc::InvalidEncoding);
 }
 
 /**
@@ -1570,6 +1589,39 @@ TEST (PackReader, key)
     ASSERT_TRUE (value.contains (-10));
 }
 
+/**
+ * @brief Test MessagePack parsing with UTF-8 validation.
+ */
+TEST (PackReader, encoding)
+{
+    using Validator = join::BasicPackReader<join::PackReadMode::ValidateEncoding>;
+
+    for (const std::string& document : {std::string ({'\xa2', '\xc3', '\xa9'}), std::string ({'\xc4', '\x01', '\xff'})})
+    {
+        std::stringstream stream (document);
+        join::SaxHandler handler;
+        ASSERT_EQ (Validator ().deserialize (document, handler), 0) << join::lastError.message ();
+        ASSERT_EQ (Validator ().deserialize (stream, handler), 0) << join::lastError.message ();
+    }
+
+    for (const std::string& document : {std::string ({'\xa1', '\xff'}), std::string ({'\x81', '\xa1', '\xff', '\x01'})})
+    {
+        std::stringstream stream (document);
+        join::SaxHandler handler;
+        ASSERT_EQ (Validator ().deserialize (document, handler), -1);
+        ASSERT_EQ (join::lastError, SaxErrc::InvalidEncoding);
+        ASSERT_EQ (Validator ().deserialize (stream, handler), -1);
+        ASSERT_EQ (join::lastError, SaxErrc::InvalidEncoding);
+    }
+
+    Value value;
+    ASSERT_EQ (PackReader ().deserialize (std::string ({'\xa1', '\xff'}), value), 0) << join::lastError.message ();
+    ASSERT_EQ (value.getString (), "\xff");
+    ASSERT_EQ (value.deserialize<Validator> (std::string ({'\xa4', 'I', 'E', 'T', 'F'})), 0)
+        << join::lastError.message ();
+    ASSERT_EQ (value.getString (), "IETF");
+}
+
 /**
  * @brief main function.
  */
diff --git a/data/tests/sax_error_test.cpp b/data/tests/sax_error_test.cpp
index fa007dac..e55641fd 100644
--- a/data/tests/sax_error_test.cpp
+++ b/data/tests/sax_error_test.cpp
@@ -50,6 +50,8 @@ TEST (SaxCategory, message)
                   "parent not an array nor an object");
     EXPECT_STREQ (SaxCategory ().message (static_cast<int> (SaxErrc::InvalidKey)).c_str (), "key is invalid");
     EXPECT_STREQ (SaxCategory ().message (static_cast<int> (SaxErrc::InvalidValue)).c_str (), "value is invalid");
+    EXPECT_STREQ (SaxCategory ().message (static_cast<int> (SaxErrc::InvalidEncoding)).c_str (),
+                  "character encoding is invalid");
     EXPECT_STREQ (SaxCategory ().message (static_cast<int> (SaxErrc::ExtraData)).c_str (), "extra data detected");
     EXPECT_STREQ (SaxCategory ().message (static_cast<int> (SaxErrc::Truncated)).c_str (), "data is truncated");
 }
@@ -64,7 +66,8 @@ TEST (SaxCategory, default_error_condition)
     EXPECT_EQ (SaxCategory ().default_error_condition (2).message (), "parent not an array nor an object");
     EXPECT_EQ (SaxCategory ().default_error_condition (3).message (), "key is invalid");
     EXPECT_EQ (SaxCategory ().default_error_condition (4).message (), "value is invalid");
-    EXPECT_EQ (SaxCategory ().default_error_condition (5).message (), "extra data detected");
+    EXPECT_EQ (SaxCategory ().default_error_condition (5).message (), "character encoding is invalid");
+    EXPECT_EQ (SaxCategory ().default_error_condition (6).message (), "extra data detected");
 }
 
 /**