diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3369f83248d..d889e805e1c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -188,11 +188,13 @@ jobs:
       - name: Build Thrift Classes
         run: |
           mkdir -p ./lib/php/test/Resources/packages/php
+          mkdir -p ./lib/php/test/Resources/packages/phpi
           mkdir -p ./lib/php/test/Resources/packages/phpv
           mkdir -p ./lib/php/test/Resources/packages/phpvo
           mkdir -p ./lib/php/test/Resources/packages/phpjs
           mkdir -p ./lib/php/test/Resources/packages/phpcm
           compiler/cpp/thrift --gen php:nsglobal="Basic" -r --out ./lib/php/test/Resources/packages/php lib/php/test/Resources/ThriftTest.thrift
+          compiler/cpp/thrift --gen php:inlined,nsglobal="BasicInline" -r --out ./lib/php/test/Resources/packages/phpi lib/php/test/Resources/ThriftTest.thrift
           compiler/cpp/thrift --gen php:validate,nsglobal="Validate" -r --out ./lib/php/test/Resources/packages/phpv lib/php/test/Resources/ThriftTest.thrift
           compiler/cpp/thrift --gen php:validate,oop,nsglobal="ValidateOop" -r --out ./lib/php/test/Resources/packages/phpvo lib/php/test/Resources/ThriftTest.thrift
           compiler/cpp/thrift --gen php:json,nsglobal="Json" -r --out ./lib/php/test/Resources/packages/phpjs lib/php/test/Resources/ThriftTest.thrift
diff --git a/lib/php/lib/Protocol/TProtocol.php b/lib/php/lib/Protocol/TProtocol.php
index 400078a82d4..a486f0b691a 100644
--- a/lib/php/lib/Protocol/TProtocol.php
+++ b/lib/php/lib/Protocol/TProtocol.php
@@ -266,19 +266,33 @@ public static function skipBinary($itrans, $type)
     {
         switch ($type) {
             case TType::BOOL:
-                return $itrans->readAll(1);
+                $itrans->readAll(1);
+
+                return 1;
             case TType::BYTE:
-                return $itrans->readAll(1);
+                $itrans->readAll(1);
+
+                return 1;
             case TType::I16:
-                return $itrans->readAll(2);
+                $itrans->readAll(2);
+
+                return 2;
             case TType::I32:
-                return $itrans->readAll(4);
+                $itrans->readAll(4);
+
+                return 4;
             case TType::I64:
-                return $itrans->readAll(8);
+                $itrans->readAll(8);
+
+                return 8;
             case TType::DOUBLE:
-                return $itrans->readAll(8);
+                $itrans->readAll(8);
+
+                return 8;
             case TType::UUID:
-                return $itrans->readAll(16);
+                $itrans->readAll(16);
+
+                return 16;
             case TType::STRING:
                 $len = unpack('N', $itrans->readAll(4));
                 $len = $len[1];
@@ -286,7 +300,9 @@ public static function skipBinary($itrans, $type)
                     $len = 0 - (($len - 1) ^ 0xffffffff);
                 }
 
-                return 4 + $itrans->readAll($len);
+                $itrans->readAll($len);
+
+                return 4 + $len;
 
             case TType::STRUCT:
                 $result = 0;
@@ -294,13 +310,15 @@ public static function skipBinary($itrans, $type)
                     $ftype = 0;
                     $fid = 0;
                     $data = $itrans->readAll(1);
+                    $result += 1;
                     $arr = unpack('c', $data);
                     $ftype = $arr[1];
                     if ($ftype == TType::STOP) {
                         break;
                     }
                     // I16 field id
-                    $result += $itrans->readAll(2);
+                    $itrans->readAll(2);
+                    $result += 2;
                     $result += self::skipBinary($itrans, $ftype);
                 }
 
diff --git a/lib/php/test/Integration/Lib/Protocol/TProtocolInlinedTest.php b/lib/php/test/Integration/Lib/Protocol/TProtocolInlinedTest.php
new file mode 100644
index 00000000000..f0e1958fcb2
--- /dev/null
+++ b/lib/php/test/Integration/Lib/Protocol/TProtocolInlinedTest.php
@@ -0,0 +1,77 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Integration\Lib\Protocol;
+
+use BasicInline\ThriftTest\Bonk;
+use BasicInline\ThriftTest\VersioningTestV1;
+use BasicInline\ThriftTest\VersioningTestV2;
+use PHPUnit\Framework\TestCase;
+use Thrift\Transport\TMemoryBuffer;
+
+/***
+ * This test suite depends on running the compiler against the ./Resources/ThriftTest.thrift file:
+ * lib/php/test$ ../../../compiler/cpp/thrift --gen php:inlined,nsglobal="BasicInline" -r --out ./Resources/packages/phpi ./Resources/ThriftTest.thrift
+ */
+class TProtocolInlinedTest extends TestCase
+{
+    public static function setUpBeforeClass(): void
+    {
+        if (!is_dir(__DIR__ . '/../../../Resources/packages/phpi')) {
+            self::fail(
+                'Before running Integration test suite, you must run the Thrift compiler against the ThriftTest.thrift file in the ./Resources directory with the php:inlined generator.'
+            );
+        }
+    }
+
+    public function testInlinedReaderSkipsUnknownAndMismatchedFields(): void
+    {
+        $writer = new VersioningTestV2([
+            'begin_in_both' => 1,
+            'newint' => 2,
+            'newbyte' => 3,
+            'newshort' => 4,
+            'newlong' => 5,
+            'newdouble' => 6.25,
+            'newstruct' => new Bonk([
+                'message' => 'skip me',
+                'type' => 7,
+            ]),
+            'newlist' => [8, 9],
+            'newset' => [10, 11],
+            'newmap' => [12 => 13],
+            'newstring' => 'skip me too',
+            'end_in_both' => 14,
+        ]);
+
+        $buffer = '';
+        $writer->write($buffer);
+
+        $transport = new TMemoryBuffer($buffer);
+        $reader = new VersioningTestV1();
+        $reader->read($transport);
+
+        $this->assertSame(1, $reader->begin_in_both);
+        $this->assertNull($reader->old_string);
+        $this->assertSame(14, $reader->end_in_both);
+        $this->assertSame(0, (int)$transport->available());
+    }
+}
diff --git a/lib/php/test/Makefile.am b/lib/php/test/Makefile.am
index b6a53256e2b..674b07160cb 100644
--- a/lib/php/test/Makefile.am
+++ b/lib/php/test/Makefile.am
@@ -21,11 +21,13 @@ PHPUNIT=php $(top_srcdir)/vendor/bin/phpunit
 
 stubs: Resources/ThriftTest.thrift
 	mkdir -p ./Resources/packages/php
+	mkdir -p ./Resources/packages/phpi
 	mkdir -p ./Resources/packages/phpv
 	mkdir -p ./Resources/packages/phpvo
 	mkdir -p ./Resources/packages/phpjs
 	mkdir -p ./Resources/packages/phpcm
 	$(THRIFT) --gen php:nsglobal="Basic" -r --out ./Resources/packages/php Resources/ThriftTest.thrift
+	$(THRIFT) --gen php:inlined,nsglobal="BasicInline" -r --out ./Resources/packages/phpi Resources/ThriftTest.thrift
 	$(THRIFT) --gen php:validate,nsglobal="Validate" -r --out ./Resources/packages/phpv Resources/ThriftTest.thrift
 	$(THRIFT) --gen php:validate,oop,nsglobal="ValidateOop" -r --out ./Resources/packages/phpvo Resources/ThriftTest.thrift
 	$(THRIFT) --gen php:json,nsglobal="Json" -r --out ./Resources/packages/phpjs Resources/ThriftTest.thrift
diff --git a/lib/php/test/Unit/Lib/Base/Fixture/ComplexStruct.php b/lib/php/test/Unit/Lib/Base/Fixture/ComplexStruct.php
new file mode 100644
index 00000000000..124fae017b7
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Base/Fixture/ComplexStruct.php
@@ -0,0 +1,112 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Base\Fixture;
+
+use Thrift\Base\TBase;
+use Thrift\Type\TType;
+
+class ComplexStruct extends TBase
+{
+    public static $_TSPEC = [
+        1 => [
+            'var' => 'flag',
+            'type' => TType::BOOL,
+        ],
+        2 => [
+            'var' => 'name',
+            'type' => TType::STRING,
+        ],
+        3 => [
+            'var' => 'child',
+            'type' => TType::STRUCT,
+            'class' => NestedStruct::class,
+        ],
+        4 => [
+            'var' => 'mapField',
+            'type' => TType::MAP,
+            'ktype' => TType::STRING,
+            'vtype' => TType::I32,
+            'key' => [
+                'type' => TType::STRING,
+            ],
+            'val' => [
+                'type' => TType::I32,
+            ],
+        ],
+        5 => [
+            'var' => 'listField',
+            'type' => TType::LST,
+            'etype' => TType::STRUCT,
+            'elem' => [
+                'type' => TType::STRUCT,
+                'class' => NestedStruct::class,
+            ],
+        ],
+        6 => [
+            'var' => 'setField',
+            'type' => TType::SET,
+            'etype' => TType::I16,
+            'elem' => [
+                'type' => TType::I16,
+            ],
+        ],
+        7 => [
+            'var' => 'mapOfLists',
+            'type' => TType::MAP,
+            'ktype' => TType::I32,
+            'vtype' => TType::LST,
+            'key' => [
+                'type' => TType::I32,
+            ],
+            'val' => [
+                'type' => TType::LST,
+                'etype' => TType::I32,
+                'elem' => [
+                    'type' => TType::I32,
+                ],
+            ],
+        ],
+        8 => [
+            'var' => 'optionalField',
+            'type' => TType::STRING,
+        ],
+    ];
+
+    public $flag = null;
+    public $name = null;
+    public $child = null;
+    public $mapField = null;
+    public $listField = null;
+    public $setField = null;
+    public $mapOfLists = null;
+    public $optionalField = null;
+
+    public function read($input)
+    {
+        return $this->_read(self::class, self::$_TSPEC, $input);
+    }
+
+    public function write($output)
+    {
+        return $this->_write('ComplexStruct', self::$_TSPEC, $output);
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Base/Fixture/NestedStruct.php b/lib/php/test/Unit/Lib/Base/Fixture/NestedStruct.php
new file mode 100644
index 00000000000..742581368f8
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Base/Fixture/NestedStruct.php
@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Base\Fixture;
+
+use Thrift\Base\TBase;
+use Thrift\Type\TType;
+
+class NestedStruct extends TBase
+{
+    public static $_TSPEC = [
+        1 => [
+            'var' => 'value',
+            'type' => TType::STRING,
+        ],
+    ];
+
+    public $value = null;
+
+    public function read($input)
+    {
+        return $this->_read(self::class, self::$_TSPEC, $input);
+    }
+
+    public function write($output)
+    {
+        return $this->_write('NestedStruct', self::$_TSPEC, $output);
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Base/TBaseTest.php b/lib/php/test/Unit/Lib/Base/TBaseTest.php
new file mode 100644
index 00000000000..3808aaae9a5
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Base/TBaseTest.php
@@ -0,0 +1,136 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Base;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Base\Fixture\ComplexStruct;
+use Test\Thrift\Unit\Lib\Base\Fixture\NestedStruct;
+use Thrift\Protocol\TBinaryProtocol;
+use Thrift\Transport\TMemoryBuffer;
+use Thrift\Type\TType;
+
+class TBaseTest extends TestCase
+{
+    public function testConstructorHydratesKnownFieldsFromSpec(): void
+    {
+        $struct = new ComplexStruct(
+            ComplexStruct::$_TSPEC,
+            [
+                'flag' => true,
+                'name' => 'hydrated',
+            ]
+        );
+
+        $this->assertTrue($struct->flag);
+        $this->assertSame('hydrated', $struct->name);
+        $this->assertNull($struct->child);
+    }
+
+    public function testWakeupPreservesExistingState(): void
+    {
+        $struct = $this->createComplexStruct();
+
+        /** @var ComplexStruct $restored */
+        $restored = unserialize(serialize($struct));
+
+        $this->assertEquals($struct, $restored);
+    }
+
+    public function testReadAndWriteRoundTripNestedContainers(): void
+    {
+        $restored = $this->roundTrip($this->createComplexStruct());
+
+        $this->assertTrue($restored->flag);
+        $this->assertSame('root', $restored->name);
+        $this->assertInstanceOf(NestedStruct::class, $restored->child);
+        $this->assertSame('child', $restored->child->value);
+        $this->assertSame(['alpha' => 1, 'beta' => 2], $restored->mapField);
+        $this->assertCount(2, $restored->listField);
+        $this->assertSame('first', $restored->listField[0]->value);
+        $this->assertSame('second', $restored->listField[1]->value);
+        $this->assertSame([10 => true, 20 => true], $restored->setField);
+        $this->assertSame([1 => [3, 4], 2 => [5]], $restored->mapOfLists);
+        $this->assertNull($restored->optionalField);
+    }
+
+    public function testReadSkipsUnknownAndUnexpectedFields(): void
+    {
+        $transport = new TMemoryBuffer();
+        $protocol = new TBinaryProtocol($transport);
+
+        $protocol->writeStructBegin('ComplexStruct');
+
+        $protocol->writeFieldBegin('flag', TType::STRING, 1);
+        $protocol->writeString('ignored');
+        $protocol->writeFieldEnd();
+
+        $protocol->writeFieldBegin('unknown', TType::I32, 99);
+        $protocol->writeI32(123);
+        $protocol->writeFieldEnd();
+
+        $protocol->writeFieldBegin('name', TType::STRING, 2);
+        $protocol->writeString('kept');
+        $protocol->writeFieldEnd();
+
+        $protocol->writeFieldStop();
+        $protocol->writeStructEnd();
+
+        $struct = new ComplexStruct();
+        $struct->read(new TBinaryProtocol($transport));
+
+        $this->assertNull($struct->flag);
+        $this->assertSame('kept', $struct->name);
+        $this->assertNull($struct->child);
+    }
+
+    private function roundTrip(ComplexStruct $struct): ComplexStruct
+    {
+        $transport = new TMemoryBuffer();
+        $writer = new TBinaryProtocol($transport);
+        $struct->write($writer);
+
+        $copy = new ComplexStruct();
+        $copy->read(new TBinaryProtocol($transport));
+
+        return $copy;
+    }
+
+    private function createComplexStruct(): ComplexStruct
+    {
+        $child = new NestedStruct(NestedStruct::$_TSPEC, ['value' => 'child']);
+        $first = new NestedStruct(NestedStruct::$_TSPEC, ['value' => 'first']);
+        $second = new NestedStruct(NestedStruct::$_TSPEC, ['value' => 'second']);
+
+        return new ComplexStruct(
+            ComplexStruct::$_TSPEC,
+            [
+                'flag' => true,
+                'name' => 'root',
+                'child' => $child,
+                'mapField' => ['alpha' => 1, 'beta' => 2],
+                'listField' => [$first, $second],
+                'setField' => [10 => true, 20 => true],
+                'mapOfLists' => [1 => [3, 4], 2 => [5]],
+            ]
+        );
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Exception/ExceptionTypesTest.php b/lib/php/test/Unit/Lib/Exception/ExceptionTypesTest.php
new file mode 100644
index 00000000000..249656299e0
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Exception/ExceptionTypesTest.php
@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Exception;
+
+use PHPUnit\Framework\TestCase;
+use Thrift\Exception\TProtocolException;
+use Thrift\Exception\TTransportException;
+
+class ExceptionTypesTest extends TestCase
+{
+    public function testProtocolExceptionPreservesMessageAndCode(): void
+    {
+        $exception = new TProtocolException(
+            'invalid payload',
+            TProtocolException::BAD_VERSION
+        );
+
+        $this->assertSame('invalid payload', $exception->getMessage());
+        $this->assertSame(TProtocolException::BAD_VERSION, $exception->getCode());
+    }
+
+    public function testTransportExceptionPreservesMessageAndCode(): void
+    {
+        $exception = new TTransportException(
+            'timed out',
+            TTransportException::TIMED_OUT
+        );
+
+        $this->assertSame('timed out', $exception->getMessage());
+        $this->assertSame(TTransportException::TIMED_OUT, $exception->getCode());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Exception/TApplicationExceptionTest.php b/lib/php/test/Unit/Lib/Exception/TApplicationExceptionTest.php
new file mode 100644
index 00000000000..b43cf14f227
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Exception/TApplicationExceptionTest.php
@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Exception;
+
+use PHPUnit\Framework\TestCase;
+use Thrift\Exception\TApplicationException;
+use Thrift\Protocol\TBinaryProtocol;
+use Thrift\Transport\TMemoryBuffer;
+use Thrift\Type\TType;
+
+class TApplicationExceptionTest extends TestCase
+{
+    public function testWriteAndReadRoundTripMessageAndCode(): void
+    {
+        $transport = new TMemoryBuffer();
+        $writer = new TBinaryProtocol($transport);
+
+        $written = new TApplicationException(
+            'boom',
+            TApplicationException::INTERNAL_ERROR
+        );
+        $written->write($writer);
+
+        $read = new TApplicationException();
+        $read->read(new TBinaryProtocol($transport));
+
+        $this->assertSame('boom', $read->getMessage());
+        $this->assertSame(TApplicationException::INTERNAL_ERROR, $read->getCode());
+    }
+
+    public function testWriteOmitsFalsyMessageAndCodeFields(): void
+    {
+        $transport = new TMemoryBuffer();
+        $protocol = new TBinaryProtocol($transport);
+
+        (new TApplicationException())->write($protocol);
+
+        $this->assertSame(chr(TType::STOP), $transport->getBuffer());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Fixture/ProcessorSpy.php b/lib/php/test/Unit/Lib/Fixture/ProcessorSpy.php
new file mode 100644
index 00000000000..c0005dcca5c
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Fixture/ProcessorSpy.php
@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Fixture;
+
+use Thrift\Protocol\TProtocol;
+
+class ProcessorSpy
+{
+    public function process(TProtocol $input, TProtocol $output)
+    {
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Protocol/Fixture/JsonProtocolStub.php b/lib/php/test/Unit/Lib/Protocol/Fixture/JsonProtocolStub.php
new file mode 100644
index 00000000000..07f9602a8be
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Protocol/Fixture/JsonProtocolStub.php
@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Protocol\Fixture;
+
+use Thrift\Transport\TTransport;
+
+class JsonProtocolStub
+{
+    private $transport;
+    public $readChars = [];
+
+    public function __construct(TTransport $transport)
+    {
+        $this->transport = $transport;
+    }
+
+    public function getTransport(): TTransport
+    {
+        return $this->transport;
+    }
+
+    public function readJSONSyntaxChar(string $char): void
+    {
+        $this->readChars[] = $char;
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Protocol/Fixture/SimpleJsonProtocolStub.php b/lib/php/test/Unit/Lib/Protocol/Fixture/SimpleJsonProtocolStub.php
new file mode 100644
index 00000000000..e61795ea020
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Protocol/Fixture/SimpleJsonProtocolStub.php
@@ -0,0 +1,39 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Protocol\Fixture;
+
+use Thrift\Transport\TMemoryBuffer;
+
+class SimpleJsonProtocolStub
+{
+    private $transport;
+
+    public function __construct(TMemoryBuffer $transport)
+    {
+        $this->transport = $transport;
+    }
+
+    public function getTransport(): TMemoryBuffer
+    {
+        return $this->transport;
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Protocol/JsonContextTest.php b/lib/php/test/Unit/Lib/Protocol/JsonContextTest.php
new file mode 100644
index 00000000000..a7f569e5c8e
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Protocol/JsonContextTest.php
@@ -0,0 +1,116 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Protocol;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Protocol\Fixture\JsonProtocolStub;
+use Thrift\Protocol\JSON\BaseContext;
+use Thrift\Protocol\JSON\ListContext;
+use Thrift\Protocol\JSON\LookaheadReader;
+use Thrift\Protocol\JSON\PairContext;
+use Thrift\Transport\TMemoryBuffer;
+use Thrift\Transport\TTransport;
+
+class JsonContextTest extends TestCase
+{
+    public function testBaseContextDefaults(): void
+    {
+        $context = new BaseContext();
+
+        $this->assertFalse($context->escapeNum());
+        $this->assertNull($context->write());
+        $this->assertNull($context->read());
+    }
+
+    public function testListContextWritesCommasAfterFirstElement(): void
+    {
+        $transport = new TMemoryBuffer();
+        $context = new ListContext(new JsonProtocolStub($transport));
+
+        $context->write();
+        $context->write();
+        $context->write();
+
+        $this->assertSame(',,', $transport->getBuffer());
+    }
+
+    public function testListContextReadsCommasAfterFirstElement(): void
+    {
+        $protocol = new JsonProtocolStub(new TMemoryBuffer());
+        $context = new ListContext($protocol);
+
+        $context->read();
+        $context->read();
+        $context->read();
+
+        $this->assertCount(2, $protocol->readChars);
+        $this->assertSame([',', ','], $protocol->readChars);
+    }
+
+    public function testPairContextWritesColonsAndCommas(): void
+    {
+        $transport = new TMemoryBuffer();
+        $context = new PairContext(new JsonProtocolStub($transport));
+
+        $this->assertTrue($context->escapeNum());
+
+        $context->write();
+        $this->assertTrue($context->escapeNum());
+
+        $context->write();
+        $this->assertFalse($context->escapeNum());
+
+        $context->write();
+        $this->assertTrue($context->escapeNum());
+
+        $this->assertSame(':,', $transport->getBuffer());
+    }
+
+    public function testPairContextReadsColonsAndCommas(): void
+    {
+        $protocol = new JsonProtocolStub(new TMemoryBuffer());
+        $context = new PairContext($protocol);
+
+        $context->read();
+        $context->read();
+        $context->read();
+
+        $this->assertCount(2, $protocol->readChars);
+        $this->assertSame([':', ','], $protocol->readChars);
+    }
+
+    public function testLookaheadReaderCachesPeekedValue(): void
+    {
+        $transport = $this->createMock(TTransport::class);
+        $transport->expects($this->exactly(2))
+            ->method('readAll')
+            ->with(1)
+            ->willReturnOnConsecutiveCalls('a', 'b');
+
+        $reader = new LookaheadReader(new JsonProtocolStub($transport));
+
+        $this->assertSame('a', $reader->peek());
+        $this->assertSame('a', $reader->peek());
+        $this->assertSame('a', $reader->read());
+        $this->assertSame('b', $reader->read());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Protocol/SimpleJsonContextTest.php b/lib/php/test/Unit/Lib/Protocol/SimpleJsonContextTest.php
new file mode 100644
index 00000000000..b80c66e61e8
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Protocol/SimpleJsonContextTest.php
@@ -0,0 +1,94 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Protocol;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Protocol\Fixture\SimpleJsonProtocolStub;
+use Thrift\Exception\TException;
+use Thrift\Protocol\SimpleJSON\CollectionMapKeyException;
+use Thrift\Protocol\SimpleJSON\Context;
+use Thrift\Protocol\SimpleJSON\ListContext;
+use Thrift\Protocol\SimpleJSON\MapContext;
+use Thrift\Protocol\SimpleJSON\StructContext;
+use Thrift\Transport\TMemoryBuffer;
+
+class SimpleJsonContextTest extends TestCase
+{
+    public function testContextDefaults(): void
+    {
+        $context = new Context();
+
+        $this->assertNull($context->write());
+        $this->assertFalse($context->isMapKey());
+    }
+
+    public function testListContextWritesCommasAfterFirstElement(): void
+    {
+        $transport = new TMemoryBuffer();
+        $context = new ListContext(new SimpleJsonProtocolStub($transport));
+
+        $context->write();
+        $context->write();
+        $context->write();
+
+        $this->assertSame(',,', $transport->getBuffer());
+    }
+
+    public function testStructContextWritesColonsAndCommas(): void
+    {
+        $transport = new TMemoryBuffer();
+        $context = new StructContext(new SimpleJsonProtocolStub($transport));
+
+        $context->write();
+        $context->write();
+        $context->write();
+
+        $this->assertSame(':,', $transport->getBuffer());
+    }
+
+    public function testMapContextTogglesMapKeyState(): void
+    {
+        $transport = new TMemoryBuffer();
+        $context = new MapContext(new SimpleJsonProtocolStub($transport));
+
+        $this->assertTrue($context->isMapKey());
+
+        $context->write();
+        $this->assertFalse($context->isMapKey());
+
+        $context->write();
+        $this->assertTrue($context->isMapKey());
+
+        $context->write();
+        $this->assertFalse($context->isMapKey());
+
+        $this->assertSame(':,', $transport->getBuffer());
+    }
+
+    public function testCollectionMapKeyExceptionPreservesMessage(): void
+    {
+        $exception = new CollectionMapKeyException('bad key');
+
+        $this->assertInstanceOf(TException::class, $exception);
+        $this->assertSame('bad key', $exception->getMessage());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Protocol/TProtocolTest.php b/lib/php/test/Unit/Lib/Protocol/TProtocolTest.php
new file mode 100644
index 00000000000..b75c09e87f7
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Protocol/TProtocolTest.php
@@ -0,0 +1,284 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Protocol;
+
+use PHPUnit\Framework\TestCase;
+use Thrift\Exception\TProtocolException;
+use Thrift\Protocol\TBinaryProtocol;
+use Thrift\Protocol\TProtocol;
+use Thrift\Transport\TMemoryBuffer;
+use Thrift\Type\TType;
+
+class TProtocolTest extends TestCase
+{
+    /**
+     * @dataProvider skipScalarDataProvider
+     */
+    public function testSkipScalarValues(int $type, string $writerMethod, $value): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol) use ($writerMethod, $value): void {
+                $protocol->{$writerMethod}($value);
+            }
+        );
+        $transport = new TMemoryBuffer($buffer);
+        $protocol = new TBinaryProtocol($transport);
+
+        $this->assertSame(strlen($buffer), $protocol->skip($type));
+        $this->assertSame(0, (int)$transport->available());
+    }
+
+    public function skipScalarDataProvider(): iterable
+    {
+        yield 'bool' => [
+            TType::BOOL,
+            'writeBool',
+            true,
+        ];
+        yield 'byte' => [
+            TType::BYTE,
+            'writeByte',
+            7,
+        ];
+        yield 'i16' => [
+            TType::I16,
+            'writeI16',
+            1024,
+        ];
+        yield 'i32' => [
+            TType::I32,
+            'writeI32',
+            65536,
+        ];
+        yield 'i64' => [
+            TType::I64,
+            'writeI64',
+            1099511627776,
+        ];
+        yield 'double' => [
+            TType::DOUBLE,
+            'writeDouble',
+            3.14,
+        ];
+        yield 'string' => [
+            TType::STRING,
+            'writeString',
+            'skip me',
+        ];
+        yield 'uuid' => [
+            TType::UUID,
+            'writeUuid',
+            '12345678-1234-5678-1234-567812345678',
+        ];
+    }
+
+    public function testSkipStruct(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeStructBegin('Example');
+                $protocol->writeFieldBegin('flag', TType::BOOL, 1);
+                $protocol->writeBool(true);
+                $protocol->writeFieldEnd();
+                $protocol->writeFieldBegin('name', TType::STRING, 2);
+                $protocol->writeString('value');
+                $protocol->writeFieldEnd();
+                $protocol->writeFieldStop();
+                $protocol->writeStructEnd();
+            }
+        );
+
+        $transport = new TMemoryBuffer($buffer);
+        $protocol = new TBinaryProtocol($transport);
+
+        $this->assertSame(strlen($buffer), $protocol->skip(TType::STRUCT));
+        $this->assertSame(0, (int)$transport->available());
+    }
+
+    public function testSkipMap(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeMapBegin(TType::I32, TType::STRING, 2);
+                $protocol->writeI32(1);
+                $protocol->writeString('a');
+                $protocol->writeI32(2);
+                $protocol->writeString('bc');
+                $protocol->writeMapEnd();
+            }
+        );
+
+        $transport = new TMemoryBuffer($buffer);
+        $protocol = new TBinaryProtocol($transport);
+
+        $this->assertSame(strlen($buffer), $protocol->skip(TType::MAP));
+        $this->assertSame(0, (int)$transport->available());
+    }
+
+    public function testSkipSet(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeSetBegin(TType::I16, 2);
+                $protocol->writeI16(10);
+                $protocol->writeI16(20);
+                $protocol->writeSetEnd();
+            }
+        );
+
+        $transport = new TMemoryBuffer($buffer);
+        $protocol = new TBinaryProtocol($transport);
+
+        $this->assertSame(strlen($buffer), $protocol->skip(TType::SET));
+        $this->assertSame(0, (int)$transport->available());
+    }
+
+    public function testSkipList(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeListBegin(TType::STRING, 2);
+                $protocol->writeString('first');
+                $protocol->writeString('second');
+                $protocol->writeListEnd();
+            }
+        );
+
+        $transport = new TMemoryBuffer($buffer);
+        $protocol = new TBinaryProtocol($transport);
+
+        $this->assertSame(strlen($buffer), $protocol->skip(TType::LST));
+        $this->assertSame(0, (int)$transport->available());
+    }
+
+    public function testSkipThrowsForUnknownType(): void
+    {
+        $protocol = new TBinaryProtocol(new TMemoryBuffer());
+
+        $this->expectException(TProtocolException::class);
+        $this->expectExceptionCode(TProtocolException::INVALID_DATA);
+
+        $protocol->skip(999);
+    }
+
+    /**
+     * @dataProvider skipScalarDataProvider
+     */
+    public function testSkipBinaryScalarValues(int $type, string $writerMethod, $value): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol) use ($writerMethod, $value): void {
+                $protocol->{$writerMethod}($value);
+            }
+        );
+
+        $this->assertSkipBinaryConsumesBuffer($buffer, $type);
+    }
+
+    public function testSkipBinaryStruct(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeStructBegin('Example');
+                $protocol->writeFieldBegin('flag', TType::BOOL, 1);
+                $protocol->writeBool(true);
+                $protocol->writeFieldEnd();
+                $protocol->writeFieldBegin('name', TType::STRING, 2);
+                $protocol->writeString('value');
+                $protocol->writeFieldEnd();
+                $protocol->writeFieldStop();
+                $protocol->writeStructEnd();
+            }
+        );
+
+        $this->assertSkipBinaryConsumesBuffer($buffer, TType::STRUCT);
+    }
+
+    public function testSkipBinaryMap(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeMapBegin(TType::I32, TType::STRING, 2);
+                $protocol->writeI32(1);
+                $protocol->writeString('a');
+                $protocol->writeI32(2);
+                $protocol->writeString('bc');
+                $protocol->writeMapEnd();
+            }
+        );
+
+        $this->assertSkipBinaryConsumesBuffer($buffer, TType::MAP);
+    }
+
+    public function testSkipBinaryList(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeListBegin(TType::STRING, 2);
+                $protocol->writeString('first');
+                $protocol->writeString('second');
+                $protocol->writeListEnd();
+            }
+        );
+
+        $this->assertSkipBinaryConsumesBuffer($buffer, TType::LST);
+    }
+
+    public function testSkipBinarySet(): void
+    {
+        $buffer = $this->buildBinaryBuffer(
+            function (TBinaryProtocol $protocol): void {
+                $protocol->writeSetBegin(TType::DOUBLE, 2);
+                $protocol->writeDouble(3.14);
+                $protocol->writeDouble(6.28);
+                $protocol->writeSetEnd();
+            }
+        );
+
+        $this->assertSkipBinaryConsumesBuffer($buffer, TType::SET);
+    }
+
+    public function testSkipBinaryThrowsForUnknownType(): void
+    {
+        $this->expectException(TProtocolException::class);
+        $this->expectExceptionCode(TProtocolException::INVALID_DATA);
+
+        TProtocol::skipBinary(new TMemoryBuffer(), 999);
+    }
+
+    private function buildBinaryBuffer(callable $writer): string
+    {
+        $transport = new TMemoryBuffer();
+        $protocol = new TBinaryProtocol($transport);
+        $writer($protocol);
+
+        return $transport->getBuffer();
+    }
+
+    private function assertSkipBinaryConsumesBuffer(string $buffer, int $type): void
+    {
+        $transport = new TMemoryBuffer($buffer);
+
+        $this->assertSame(strlen($buffer), TProtocol::skipBinary($transport, $type));
+        $this->assertSame(0, (int)$transport->available());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Server/Fixture/ServerStub.php b/lib/php/test/Unit/Lib/Server/Fixture/ServerStub.php
new file mode 100644
index 00000000000..ea8749bbee7
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Server/Fixture/ServerStub.php
@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Server\Fixture;
+
+use Thrift\Server\TServer;
+
+class ServerStub extends TServer
+{
+    public function serve()
+    {
+    }
+
+    public function stop()
+    {
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Server/Fixture/ServerTransportStub.php b/lib/php/test/Unit/Lib/Server/Fixture/ServerTransportStub.php
new file mode 100644
index 00000000000..cb7a9fd24c6
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Server/Fixture/ServerTransportStub.php
@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Server\Fixture;
+
+use Thrift\Server\TServerTransport;
+
+class ServerTransportStub extends TServerTransport
+{
+    private $acceptedTransport;
+
+    public function __construct($acceptedTransport)
+    {
+        $this->acceptedTransport = $acceptedTransport;
+    }
+
+    public function listen()
+    {
+    }
+
+    public function close()
+    {
+    }
+
+    protected function acceptImpl()
+    {
+        return $this->acceptedTransport;
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Server/TServerTest.php b/lib/php/test/Unit/Lib/Server/TServerTest.php
new file mode 100644
index 00000000000..70ff39776ad
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Server/TServerTest.php
@@ -0,0 +1,60 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Server;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\ReflectionHelper;
+use Test\Thrift\Unit\Lib\Server\Fixture\ServerStub;
+use Thrift\Factory\TProtocolFactory;
+use Thrift\Factory\TTransportFactoryInterface;
+use Thrift\Server\TServerTransport;
+
+class TServerTest extends TestCase
+{
+    use ReflectionHelper;
+
+    public function testConstructorStoresCollaborators(): void
+    {
+        $processor = new \stdClass();
+        $transport = $this->createMock(TServerTransport::class);
+        $inputTransportFactory = $this->createMock(TTransportFactoryInterface::class);
+        $outputTransportFactory = $this->createMock(TTransportFactoryInterface::class);
+        $inputProtocolFactory = $this->createMock(TProtocolFactory::class);
+        $outputProtocolFactory = $this->createMock(TProtocolFactory::class);
+
+        $server = new ServerStub(
+            $processor,
+            $transport,
+            $inputTransportFactory,
+            $outputTransportFactory,
+            $inputProtocolFactory,
+            $outputProtocolFactory
+        );
+
+        $this->assertSame($processor, $this->getPropertyValue($server, 'processor_'));
+        $this->assertSame($transport, $this->getPropertyValue($server, 'transport_'));
+        $this->assertSame($inputTransportFactory, $this->getPropertyValue($server, 'inputTransportFactory_'));
+        $this->assertSame($outputTransportFactory, $this->getPropertyValue($server, 'outputTransportFactory_'));
+        $this->assertSame($inputProtocolFactory, $this->getPropertyValue($server, 'inputProtocolFactory_'));
+        $this->assertSame($outputProtocolFactory, $this->getPropertyValue($server, 'outputProtocolFactory_'));
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Server/TServerTransportTest.php b/lib/php/test/Unit/Lib/Server/TServerTransportTest.php
new file mode 100644
index 00000000000..3e99f5f6426
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Server/TServerTransportTest.php
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Server;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Server\Fixture\ServerTransportStub;
+use Thrift\Exception\TTransportException;
+use Thrift\Transport\TTransport;
+
+class TServerTransportTest extends TestCase
+{
+    public function testAcceptReturnsTransportFromImplementation(): void
+    {
+        $transport = $this->createMock(TTransport::class);
+        $serverTransport = new ServerTransportStub($transport);
+
+        $this->assertSame($transport, $serverTransport->accept());
+    }
+
+    public function testAcceptRejectsNullTransport(): void
+    {
+        $serverTransport = new ServerTransportStub(null);
+
+        $this->expectException(TTransportException::class);
+        $this->expectExceptionMessage('accept() may not return NULL');
+
+        $serverTransport->accept();
+    }
+}
diff --git a/lib/php/test/Unit/Lib/StoredMessageProtocolTest.php b/lib/php/test/Unit/Lib/StoredMessageProtocolTest.php
new file mode 100644
index 00000000000..88089146070
--- /dev/null
+++ b/lib/php/test/Unit/Lib/StoredMessageProtocolTest.php
@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib;
+
+use PHPUnit\Framework\TestCase;
+use Thrift\Protocol\TProtocol;
+use Thrift\StoredMessageProtocol;
+use Thrift\Transport\TTransport;
+use Thrift\Type\TMessageType;
+
+class StoredMessageProtocolTest extends TestCase
+{
+    public function testReadMessageBeginReturnsStoredValues(): void
+    {
+        $transport = $this->createMock(TTransport::class);
+        $protocol = $this->createMock(TProtocol::class);
+        $protocol->expects($this->once())
+            ->method('getTransport')
+            ->willReturn($transport);
+
+        $stored = new StoredMessageProtocol($protocol, 'ping', TMessageType::ONEWAY, 99);
+
+        $name = '';
+        $type = 0;
+        $seqid = 0;
+        $stored->readMessageBegin($name, $type, $seqid);
+
+        $this->assertSame('ping', $name);
+        $this->assertSame(TMessageType::ONEWAY, $type);
+        $this->assertSame(99, $seqid);
+        $this->assertSame($transport, $stored->getTransport());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/TMultiplexedProcessorTest.php b/lib/php/test/Unit/Lib/TMultiplexedProcessorTest.php
new file mode 100644
index 00000000000..83bebe50d70
--- /dev/null
+++ b/lib/php/test/Unit/Lib/TMultiplexedProcessorTest.php
@@ -0,0 +1,146 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Fixture\ProcessorSpy;
+use Thrift\Exception\TException;
+use Thrift\Protocol\TProtocol;
+use Thrift\StoredMessageProtocol;
+use Thrift\TMultiplexedProcessor;
+use Thrift\Transport\TTransport;
+use Thrift\Type\TMessageType;
+
+class TMultiplexedProcessorTest extends TestCase
+{
+    public function testProcessDispatchesToRegisteredService(): void
+    {
+        $transport = $this->createMock(TTransport::class);
+        $input = $this->createMock(TProtocol::class);
+        $output = $this->createMock(TProtocol::class);
+        $processor = $this->createMock(ProcessorSpy::class);
+
+        $input->expects($this->once())
+            ->method('readMessageBegin')
+            ->willReturnCallback(function (&$name, &$type, &$seqid): int {
+                $name = 'Calculator:add';
+                $type = TMessageType::CALL;
+                $seqid = 42;
+
+                return 0;
+            });
+        $input->expects($this->once())
+            ->method('getTransport')
+            ->willReturn($transport);
+
+        $processor->expects($this->once())
+            ->method('process')
+            ->with(
+                $this->isInstanceOf(StoredMessageProtocol::class),
+                $this->identicalTo($output)
+            )
+            ->willReturnCallback(function (StoredMessageProtocol $decoratedInput, TProtocol $decoratedOutput) use ($output) {
+                $name = '';
+                $type = 0;
+                $seqid = 0;
+                $decoratedInput->readMessageBegin($name, $type, $seqid);
+
+                TestCase::assertSame('add', $name);
+                TestCase::assertSame(TMessageType::CALL, $type);
+                TestCase::assertSame(42, $seqid);
+                TestCase::assertSame($output, $decoratedOutput);
+
+                return 'processed';
+            });
+
+        $multiplexedProcessor = new TMultiplexedProcessor();
+        $multiplexedProcessor->registerProcessor('Calculator', $processor);
+
+        $this->assertSame('processed', $multiplexedProcessor->process($input, $output));
+    }
+
+    public function testProcessRejectsUnexpectedMessageType(): void
+    {
+        $input = $this->createMock(TProtocol::class);
+        $output = $this->createMock(TProtocol::class);
+
+        $input->expects($this->once())
+            ->method('readMessageBegin')
+            ->willReturnCallback(function (&$name, &$type, &$seqid): int {
+                $name = 'Calculator:add';
+                $type = TMessageType::REPLY;
+                $seqid = 1;
+
+                return 0;
+            });
+
+        $this->expectException(TException::class);
+        $this->expectExceptionMessage('This should not have happened!?');
+
+        (new TMultiplexedProcessor())->process($input, $output);
+    }
+
+    public function testProcessRequiresServiceSeparator(): void
+    {
+        $input = $this->createMock(TProtocol::class);
+        $output = $this->createMock(TProtocol::class);
+
+        $input->expects($this->once())
+            ->method('readMessageBegin')
+            ->willReturnCallback(function (&$name, &$type, &$seqid): int {
+                $name = 'add';
+                $type = TMessageType::CALL;
+                $seqid = 1;
+
+                return 0;
+            });
+
+        $this->expectException(TException::class);
+        $this->expectExceptionMessage('Service name not found in message name: add.');
+
+        (new TMultiplexedProcessor())->process($input, $output);
+    }
+
+    public function testProcessRequiresKnownServiceName(): void
+    {
+        $input = $this->createMock(TProtocol::class);
+        $output = $this->createMock(TProtocol::class);
+
+        $input->expects($this->once())
+            ->method('readMessageBegin')
+            ->willReturnCallback(function (&$name, &$type, &$seqid): int {
+                $name = 'Missing:add';
+                $type = TMessageType::CALL;
+                $seqid = 1;
+
+                return 0;
+            });
+
+        $multiplexedProcessor = new TMultiplexedProcessor();
+        $multiplexedProcessor->registerProcessor('Other', $this->createMock(ProcessorSpy::class));
+
+        $this->expectException(TException::class);
+        $this->expectExceptionMessage('Service name not found: Missing.');
+
+        $multiplexedProcessor->process($input, $output);
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Transport/Fixture/BufferedReadTransport.php b/lib/php/test/Unit/Lib/Transport/Fixture/BufferedReadTransport.php
new file mode 100644
index 00000000000..2cc6629355a
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Transport/Fixture/BufferedReadTransport.php
@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Transport\Fixture;
+
+use Thrift\Transport\TTransport;
+
+class BufferedReadTransport extends TTransport
+{
+    private $chunks;
+    public $readRequests = [];
+
+    public function __construct(array $chunks)
+    {
+        $this->chunks = $chunks;
+    }
+
+    public function isOpen()
+    {
+        return true;
+    }
+
+    public function open()
+    {
+    }
+
+    public function close()
+    {
+    }
+
+    public function read($len)
+    {
+        $this->readRequests[] = $len;
+
+        return array_shift($this->chunks);
+    }
+
+    public function write($buf)
+    {
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Transport/TTransportTest.php b/lib/php/test/Unit/Lib/Transport/TTransportTest.php
new file mode 100644
index 00000000000..60bb92b5bf1
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Transport/TTransportTest.php
@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Transport;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Transport\Fixture\BufferedReadTransport;
+
+class TTransportTest extends TestCase
+{
+    public function testReadAllKeepsReadingUntilRequestedLengthIsSatisfied(): void
+    {
+        $transport = new BufferedReadTransport(['ab', 'cd']);
+
+        $this->assertSame('abcd', $transport->readAll(4));
+        $this->assertSame([4, 2], $transport->readRequests);
+    }
+
+    public function testFlushIsNoOp(): void
+    {
+        $transport = new BufferedReadTransport([]);
+
+        $this->assertNull($transport->flush());
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Type/Fixture/CachedConstantStub.php b/lib/php/test/Unit/Lib/Type/Fixture/CachedConstantStub.php
new file mode 100644
index 00000000000..0ccfb0d05c8
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Type/Fixture/CachedConstantStub.php
@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Type\Fixture;
+
+use Thrift\Type\TConstant;
+
+class CachedConstantStub extends TConstant
+{
+    protected static $ITEM;
+    public static $initCalls = 0;
+
+    // phpcs:ignore PSR1.Methods.CamelCapsMethodName.NotCamelCaps
+    protected static function init_ITEM()
+    {
+        static::$initCalls++;
+
+        $value = new \stdClass();
+        $value->value = static::$initCalls;
+
+        return $value;
+    }
+}
diff --git a/lib/php/test/Unit/Lib/Type/TypeConstantsTest.php b/lib/php/test/Unit/Lib/Type/TypeConstantsTest.php
new file mode 100644
index 00000000000..4d27edf0440
--- /dev/null
+++ b/lib/php/test/Unit/Lib/Type/TypeConstantsTest.php
@@ -0,0 +1,70 @@
+<?php
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+namespace Test\Thrift\Unit\Lib\Type;
+
+use PHPUnit\Framework\TestCase;
+use Test\Thrift\Unit\Lib\Type\Fixture\CachedConstantStub;
+use Thrift\Type\TMessageType;
+use Thrift\Type\TType;
+
+class TypeConstantsTest extends TestCase
+{
+    public function testConstantValuesAreInitializedLazilyAndCached(): void
+    {
+        $first = CachedConstantStub::get('ITEM');
+        $second = CachedConstantStub::get('ITEM');
+
+        $this->assertSame(1, CachedConstantStub::$initCalls);
+        $this->assertSame($first, $second);
+        $this->assertSame(1, $first->value);
+    }
+
+    public function testMessageTypeConstantsRemainStable(): void
+    {
+        $this->assertSame(1, TMessageType::CALL);
+        $this->assertSame(2, TMessageType::REPLY);
+        $this->assertSame(3, TMessageType::EXCEPTION);
+        $this->assertSame(4, TMessageType::ONEWAY);
+    }
+
+    public function testTypeConstantsRemainStable(): void
+    {
+        $this->assertSame(0, TType::STOP);
+        $this->assertSame(1, TType::VOID);
+        $this->assertSame(2, TType::BOOL);
+        $this->assertSame(3, TType::BYTE);
+        $this->assertSame(TType::BYTE, TType::I08);
+        $this->assertSame(4, TType::DOUBLE);
+        $this->assertSame(6, TType::I16);
+        $this->assertSame(8, TType::I32);
+        $this->assertSame(10, TType::I64);
+        $this->assertSame(11, TType::STRING);
+        $this->assertSame(TType::STRING, TType::UTF7);
+        $this->assertSame(12, TType::STRUCT);
+        $this->assertSame(13, TType::MAP);
+        $this->assertSame(14, TType::SET);
+        $this->assertSame(15, TType::LST);
+        $this->assertSame(16, TType::UUID);
+        $this->assertSame(TType::UUID, TType::UTF8);
+        $this->assertSame(17, TType::UTF16);
+    }
+}
diff --git a/lib/php/test/bootstrap.php b/lib/php/test/bootstrap.php
index c6291e51798..f3c37ba89c6 100644
--- a/lib/php/test/bootstrap.php
+++ b/lib/php/test/bootstrap.php
@@ -6,6 +6,7 @@
 
 $loader = new ThriftClassLoader();
 $loader->registerNamespace('Basic', __DIR__ . '/Resources/packages/php');
+$loader->registerNamespace('BasicInline', __DIR__ . '/Resources/packages/phpi');
 $loader->registerNamespace('Validate', __DIR__ . '/Resources/packages/phpv');
 $loader->registerNamespace('ValidateOop', __DIR__ . '/Resources/packages/phpvo');
 $loader->registerNamespace('Json', __DIR__ . '/Resources/packages/phpjs');