diff --git a/README.md b/README.md
index 0c75d95..06d1f9f 100644
--- a/README.md
+++ b/README.md
@@ -228,8 +228,8 @@ src/
 
 | Metric | Value |
 |---|---|
-| PHP source files | 19 |
-| Source lines | ~720 |
+| PHP source files | 20 |
+| Source lines | ~810 |
 | Test files | 13 |
 | Test lines | ~700 |
 | External runtime dependencies | 1 (kariricode/property-inspector) |
diff --git a/src/Attribute/Serialize.php b/src/Attribute/Serialize.php
index dc12ce6..a311dc8 100644
--- a/src/Attribute/Serialize.php
+++ b/src/Attribute/Serialize.php
@@ -7,7 +7,12 @@
 /**
  * Marks a property for serialization control.
  *
- * Parameters: name (wire-name override), groups (string[]), format-specific options.
+ * Parameters: name (wire-name override), groups (string[]), ignore (bool).
+ * Properties without this attribute are included automatically using their property name.
+ *
+ * @package KaririCode\Serializer\Attribute
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
  */
 #[\Attribute(\Attribute::TARGET_PROPERTY)]
 final readonly class Serialize
diff --git a/src/Configuration/SerializerConfiguration.php b/src/Configuration/SerializerConfiguration.php
index 3e00c6a..7ece789 100644
--- a/src/Configuration/SerializerConfiguration.php
+++ b/src/Configuration/SerializerConfiguration.php
@@ -4,6 +4,13 @@
 
 namespace KaririCode\Serializer\Configuration;
 
+/**
+ * Immutable configuration value object for the serializer engine.
+ *
+ * @package KaririCode\Serializer\Configuration
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class SerializerConfiguration
 {
     public function __construct(
diff --git a/src/Contract/EncoderRegistry.php b/src/Contract/EncoderRegistry.php
index aa9bf49..8dafa79 100644
--- a/src/Contract/EncoderRegistry.php
+++ b/src/Contract/EncoderRegistry.php
@@ -4,6 +4,13 @@
 
 namespace KaririCode\Serializer\Contract;
 
+/**
+ * Contract for format-encoder registries.
+ *
+ * @package KaririCode\Serializer\Contract
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 interface EncoderRegistry
 {
     public function register(Encoder $encoder): void;
diff --git a/src/Core/InMemoryEncoderRegistry.php b/src/Core/InMemoryEncoderRegistry.php
index d424168..f30a0ee 100644
--- a/src/Core/InMemoryEncoderRegistry.php
+++ b/src/Core/InMemoryEncoderRegistry.php
@@ -8,6 +8,15 @@
 use KaririCode\Serializer\Contract\EncoderRegistry;
 use KaririCode\Serializer\Exception\SerializationException;
 
+/**
+ * In-memory encoder registry backed by a plain PHP array.
+ *
+ * Throws SerializationException on duplicate registration or unknown format lookup.
+ *
+ * @package KaririCode\Serializer\Core
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final class InMemoryEncoderRegistry implements EncoderRegistry
 {
     /** @var array<string, Encoder> */
diff --git a/src/Core/SerializationContextImpl.php b/src/Core/SerializationContextImpl.php
index 080a70a..c0d65a6 100644
--- a/src/Core/SerializationContextImpl.php
+++ b/src/Core/SerializationContextImpl.php
@@ -6,6 +6,16 @@
 
 use KaririCode\Serializer\Contract\SerializationContext;
 
+/**
+ * Immutable serialization context carrying the active format and parameters.
+ *
+ * Uses the named-constructor pattern: instantiate via `SerializationContextImpl::create()`.
+ * `withFormat()` and `withParameters()` return new instances (full immutability).
+ *
+ * @package KaririCode\Serializer\Core
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class SerializationContextImpl implements SerializationContext
 {
     /**
diff --git a/src/Core/SerializerEngine.php b/src/Core/SerializerEngine.php
index a93b5a5..4bac6e8 100644
--- a/src/Core/SerializerEngine.php
+++ b/src/Core/SerializerEngine.php
@@ -12,6 +12,8 @@
  * Central serialization orchestrator.
  *
  * Delegates to format-specific encoders via the registry.
+ * Resolves the active format from the request or falls back to the
+ * configured default, then delegates encode/decode to the matching encoder.
  *
  * @package KaririCode\Serializer\Core
  * @author  Walmir Silva <walmir.silva@kariricode.org>
@@ -34,20 +36,20 @@ public function __construct(
     public function serialize(array $data, ?string $format = null, array $parameters = []): SerializationResult
     {
         $config = $this->configuration ?? new SerializerConfiguration();
-        $fmt = $format ?? $config->defaultFormat;
-        $encoder = $this->registry->resolve($fmt);
+        $resolvedFormat = $format ?? $config->defaultFormat;
+        $encoder = $this->registry->resolve($resolvedFormat);
 
-        $ctx = SerializationContextImpl::create($fmt);
+        $serializationContext = SerializationContextImpl::create($resolvedFormat);
         if ($config->prettyPrint) {
-            $ctx = $ctx->withParameters(['pretty' => true]);
+            $serializationContext = $serializationContext->withParameters(['pretty' => true]);
         }
         if ($parameters !== []) {
-            $ctx = $ctx->withParameters($parameters);
+            $serializationContext = $serializationContext->withParameters($parameters);
         }
 
-        $payload = $encoder->encode($data, $ctx);
+        $payload = $encoder->encode($data, $serializationContext);
 
-        return new SerializationResult($data, $payload, $fmt);
+        return new SerializationResult($data, $payload, $resolvedFormat);
     }
 
     /**
@@ -59,14 +61,14 @@ public function serialize(array $data, ?string $format = null, array $parameters
     public function deserialize(string $payload, ?string $format = null, array $parameters = []): array
     {
         $config = $this->configuration ?? new SerializerConfiguration();
-        $fmt = $format ?? $config->defaultFormat;
-        $encoder = $this->registry->resolve($fmt);
+        $resolvedFormat = $format ?? $config->defaultFormat;
+        $encoder = $this->registry->resolve($resolvedFormat);
 
-        $ctx = SerializationContextImpl::create($fmt);
+        $serializationContext = SerializationContextImpl::create($resolvedFormat);
         if ($parameters !== []) {
-            $ctx = $ctx->withParameters($parameters);
+            $serializationContext = $serializationContext->withParameters($parameters);
         }
 
-        return $encoder->decode($payload, $ctx);
+        return $encoder->decode($payload, $serializationContext);
     }
 }
diff --git a/src/Encoder/CsvEncoder.php b/src/Encoder/CsvEncoder.php
index a33ac14..8921b6c 100644
--- a/src/Encoder/CsvEncoder.php
+++ b/src/Encoder/CsvEncoder.php
@@ -9,9 +9,13 @@
 use KaririCode\Serializer\Exception\SerializationException;
 
 /**
- * Encodes/decodes flat arrays-of-arrays as CSV.
+ * Encodes/decodes flat arrays-of-arrays as RFC 4180-compliant CSV via php://temp.
  *
  * Parameters: separator (string, ','), enclosure (string, '"'), header (bool, true).
+ *
+ * @package KaririCode\Serializer\Encoder
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
  */
 final readonly class CsvEncoder implements Encoder
 {
@@ -38,13 +42,13 @@ public function encode(array $data, SerializationContext $context): string
         if ($hasHeader && \is_array($firstRow)) {
             /** @var array<int|string, string> $keys */
             $keys = array_keys($firstRow);
-            fputcsv($stream, $keys, $separator, $enclosure);
+            fputcsv($stream, $keys, $separator, $enclosure, escape: '\\');
         }
 
         foreach ($data as $row) {
             if (\is_array($row)) {
                 /** @var array<int|string, bool|float|int|string|null> $row */
-                fputcsv($stream, $row, $separator, $enclosure);
+                fputcsv($stream, $row, $separator, $enclosure, escape: '\\');
             }
         }
 
@@ -75,7 +79,7 @@ public function decode(string $payload, SerializationContext $context): array
         }
 
         $rows = array_values(
-            array_map(static fn (string $line) => str_getcsv($line, $separator, $enclosure), $lines),
+            array_map(static fn (string $line) => str_getcsv($line, $separator, $enclosure, escape: '\\'), $lines),
         );
 
         if ($hasHeader && \count($rows) > 1) {
diff --git a/src/Encoder/JsonEncoder.php b/src/Encoder/JsonEncoder.php
index 619de84..350ef65 100644
--- a/src/Encoder/JsonEncoder.php
+++ b/src/Encoder/JsonEncoder.php
@@ -8,6 +8,16 @@
 use KaririCode\Serializer\Contract\SerializationContext;
 use KaririCode\Serializer\Exception\SerializationException;
 
+/**
+ * Encodes/decodes data as RFC 8259-compliant JSON.
+ *
+ * Uses JSON_THROW_ON_ERROR for deterministic error handling.
+ * Supports `pretty` context parameter for human-readable output.
+ *
+ * @package KaririCode\Serializer\Encoder
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class JsonEncoder implements Encoder
 {
     /** @param array<mixed> $data */
diff --git a/src/Encoder/QueryStringEncoder.php b/src/Encoder/QueryStringEncoder.php
index e23c69e..a13f69c 100644
--- a/src/Encoder/QueryStringEncoder.php
+++ b/src/Encoder/QueryStringEncoder.php
@@ -7,7 +7,13 @@
 use KaririCode\Serializer\Contract\Encoder;
 use KaririCode\Serializer\Contract\SerializationContext;
 
-/** Encodes/decodes URL query strings (application/x-www-form-urlencoded). */
+/**
+ * Encodes/decodes data as RFC 3986-compliant URL query strings (application/x-www-form-urlencoded).
+ *
+ * @package KaririCode\Serializer\Encoder
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class QueryStringEncoder implements Encoder
 {
     /** @param array<mixed> $data */
diff --git a/src/Encoder/XmlEncoder.php b/src/Encoder/XmlEncoder.php
index 8b2d90c..947b148 100644
--- a/src/Encoder/XmlEncoder.php
+++ b/src/Encoder/XmlEncoder.php
@@ -8,6 +8,16 @@
 use KaririCode\Serializer\Contract\SerializationContext;
 use KaririCode\Serializer\Exception\SerializationException;
 
+/**
+ * Encodes/decodes arrays as application/xml via SimpleXMLElement + DOMDocument.
+ *
+ * Uses `libxml_use_internal_errors` to suppress PHP notices on malformed XML decode.
+ * Supports `root` and `pretty` context parameters.
+ *
+ * @package KaririCode\Serializer\Encoder
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class XmlEncoder implements Encoder
 {
     /** @param array<mixed> $data */
diff --git a/src/Event/SerializationCompletedEvent.php b/src/Event/SerializationCompletedEvent.php
index 83bf620..e8b1e7a 100644
--- a/src/Event/SerializationCompletedEvent.php
+++ b/src/Event/SerializationCompletedEvent.php
@@ -6,6 +6,13 @@
 
 use KaririCode\Serializer\Result\SerializationResult;
 
+/**
+ * Event emitted when a serialization operation completes successfully.
+ *
+ * @package KaririCode\Serializer\Event
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class SerializationCompletedEvent
 {
     public function __construct(public SerializationResult $result, public float $durationMs, public float $timestamp = 0)
diff --git a/src/Event/SerializationStartedEvent.php b/src/Event/SerializationStartedEvent.php
index 6b18915..2217e89 100644
--- a/src/Event/SerializationStartedEvent.php
+++ b/src/Event/SerializationStartedEvent.php
@@ -4,6 +4,13 @@
 
 namespace KaririCode\Serializer\Event;
 
+/**
+ * Event emitted when a serialization operation begins.
+ *
+ * @package KaririCode\Serializer\Event
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class SerializationStartedEvent
 {
     public function __construct(public string $format, public float $timestamp = 0)
diff --git a/src/Exception/SerializationException.php b/src/Exception/SerializationException.php
index ca0198c..ac094a0 100644
--- a/src/Exception/SerializationException.php
+++ b/src/Exception/SerializationException.php
@@ -4,6 +4,15 @@
 
 namespace KaririCode\Serializer\Exception;
 
+/**
+ * Domain exception for all serialization and deserialization failures.
+ *
+ * Uses static factory methods for type-safe construction.
+ *
+ * @package KaririCode\Serializer\Exception
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final class SerializationException extends \RuntimeException
 {
     public static function encodingFailed(string $format, string $reason): self
diff --git a/src/Integration/ProcessorBridge.php b/src/Integration/ProcessorBridge.php
index 226c31d..9d2b847 100644
--- a/src/Integration/ProcessorBridge.php
+++ b/src/Integration/ProcessorBridge.php
@@ -7,6 +7,15 @@
 use KaririCode\Serializer\Core\SerializerEngine;
 use KaririCode\Serializer\Result\SerializationResult;
 
+/**
+ * Bridges the processor-pipeline to the serializer engine.
+ *
+ * Adapts the generic Pipeline interface to format-specific serialization output.
+ *
+ * @package KaririCode\Serializer\Integration
+ * @author  Walmir Silva <walmir.silva@kariricode.org>
+ * @since   3.1.0 ARFA 1.3
+ */
 final readonly class ProcessorBridge
 {
     public function __construct(
diff --git a/src/Result/SerializationResult.php b/src/Result/SerializationResult.php
index 0181be7..2ba7abc 100644
--- a/src/Result/SerializationResult.php
+++ b/src/Result/SerializationResult.php
@@ -7,6 +7,7 @@
 /**
  * Immutable result of a serialization pass.
  *
+ * @package KaririCode\Serializer\Result
  * @author  Walmir Silva <walmir.silva@kariricode.org>
  * @since   3.1.0 ARFA 1.3
  */
diff --git a/tests/Conformance/ImmutableStateTest.php b/tests/Conformance/ImmutableStateTest.php
index d0c11e0..14e8074 100644
--- a/tests/Conformance/ImmutableStateTest.php
+++ b/tests/Conformance/ImmutableStateTest.php
@@ -5,10 +5,14 @@
 namespace KaririCode\Serializer\Tests\Conformance;
 
 use KaririCode\Serializer\Core\SerializationContextImpl;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
 
+#[CoversClass(SerializationContextImpl::class)]
 final class ImmutableStateTest extends TestCase
 {
+    #[Test]
     public function testContextImmutability(): void
     {
         $ctx = SerializationContextImpl::create('json');
@@ -18,6 +22,7 @@ public function testContextImmutability(): void
         $this->assertSame('xml', $ctx2->getFormat());
     }
 
+    #[Test]
     public function testParametersImmutability(): void
     {
         $ctx = SerializationContextImpl::create();