diff --git a/tests/Cases/TCCTest.php b/tests/Cases/TCCTest.php
new file mode 100644
index 0000000..67cb785
--- /dev/null
+++ b/tests/Cases/TCCTest.php
@@ -0,0 +1,202 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * This file is part of DTM-PHP.
+ *
+ * @license  https://github.com/dtm-php/dtm-client/blob/master/LICENSE
+ */
+namespace DtmClientTest\Cases;
+
+use DtmClient\Api\ApiInterface;
+use DtmClient\Api\RequestBranch;
+use DtmClient\BranchIdGeneratorInterface;
+use DtmClient\Constants\Operation;
+use DtmClient\Constants\Protocol;
+use DtmClient\Constants\TransType;
+use DtmClient\Grpc\Message\DtmRequest;
+use DtmClient\TCC;
+use DtmClient\TransContext;
+
+/**
+ * @internal
+ * @coversNothing
+ */
+class TCCTest extends AbstractTestCase
+{
+    public function testInit()
+    {
+        $api = \Mockery::mock(ApiInterface::class);
+        $branchIdGenerator = \Mockery::mock(BranchIdGeneratorInterface::class);
+
+        $api->shouldReceive('generateGid')->andReturn('GidStub');
+
+        $tcc = new TCC($api, $branchIdGenerator);
+        $tcc->init();
+        $this->assertSame('GidStub', TransContext::getGid());
+        $this->assertSame(TransType::TCC, TransContext::getTransType());
+        $this->assertSame('', TransContext::getBranchId());
+
+        $tcc->init('test');
+        $this->assertSame('test', TransContext::getGid());
+    }
+
+    public function testGlobalTransaction()
+    {
+        $api = \Mockery::mock(ApiInterface::class);
+        $branchIdGenerator = \Mockery::mock(BranchIdGeneratorInterface::class);
+
+        $api->shouldReceive('generateGid')->andReturn('GlobalTransactionGidStub');
+        $api->shouldReceive('prepare')->andReturnTrue();
+        $api->shouldReceive('abort')->andReturnTrue();
+        $api->shouldReceive('submit')->andReturnTrue();
+
+        $tcc = new TCC($api, $branchIdGenerator);
+
+        $tcc->globalTransaction(function () {
+            // Used only in test cases
+            TransContext::set(static::class . 'globalTransaction', 1);
+        }, 'GidStub');
+        $this->assertSame('GidStub', TransContext::getGid());
+        $this->assertSame(TransType::TCC, TransContext::getTransType());
+        $this->assertSame('', TransContext::getBranchId());
+        $this->assertSame(1, TransContext::get(static::class . 'globalTransaction'));
+    }
+
+    public function testCallBranchUseJsonRpcProtocol()
+    {
+        $api = \Mockery::mock(ApiInterface::class);
+        $branchIdGenerator = \Mockery::mock(BranchIdGeneratorInterface::class);
+
+        $branchIdGenerator->shouldReceive('generateSubBranchId')->andReturn('BranchIdStub');
+
+        $api->shouldReceive('getProtocol')->andReturn(Protocol::JSONRPC_HTTP);
+        $api->shouldReceive('registerBranch')->andReturnUsing(function ($data) {
+            TransContext::set(static::class . 'registerBranchBody', $data);
+        });
+        $api->shouldReceive('transRequestBranch')->andReturnUsing(function ($data) {
+            return $data;
+        });
+
+        TransContext::setGid('testGid');
+
+        $tcc = new TCC($api, $branchIdGenerator);
+
+        $response = $tcc->callBranch(
+            ['data' => 'test'],
+            '127.0.0.1/try',
+            '127.0.0.1/confirm',
+            '127.0.0.1/cancel'
+        );
+
+        $branchRequest = new RequestBranch();
+        $branchRequest->method = 'POST';
+        $branchRequest->url = '127.0.0.1/try';
+        $branchRequest->branchId = 'BranchIdStub';
+        $branchRequest->op = Operation::TRY;
+        $branchRequest->body = ['data' => 'test'];
+
+        $this->assertEquals($branchRequest, $response);
+        $this->assertSame([
+            'data' => json_encode(['data' => 'test']),
+            'branch_id' => 'BranchIdStub',
+            'confirm' => '127.0.0.1/confirm',
+            'cancel' => '127.0.0.1/cancel',
+            'gid' => 'testGid',
+            'trans_type' => TransType::TCC,
+        ], TransContext::get(static::class . 'registerBranchBody'));
+    }
+
+    public function testCallBranchUseHttpProtocol()
+    {
+        $api = \Mockery::mock(ApiInterface::class);
+        $branchIdGenerator = \Mockery::mock(BranchIdGeneratorInterface::class);
+
+        $branchIdGenerator->shouldReceive('generateSubBranchId')->andReturn('BranchIdStub');
+
+        $api->shouldReceive('getProtocol')->andReturn(Protocol::HTTP);
+        $api->shouldReceive('registerBranch')->andReturnUsing(function ($data) {
+            TransContext::set(static::class . 'registerBranchBody', $data);
+        });
+        $api->shouldReceive('transRequestBranch')->andReturnUsing(function ($data) {
+            return $data;
+        });
+
+        TransContext::setGid('testGid');
+
+        $tcc = new TCC($api, $branchIdGenerator);
+
+        $response = $tcc->callBranch(
+            ['data' => 'test'],
+            '127.0.0.1/try',
+            '127.0.0.1/confirm',
+            '127.0.0.1/cancel'
+        );
+
+        $branchRequest = new RequestBranch();
+        $branchRequest->method = 'POST';
+        $branchRequest->url = '127.0.0.1/try';
+        $branchRequest->branchId = 'BranchIdStub';
+        $branchRequest->op = Operation::TRY;
+        $branchRequest->body = ['data' => 'test'];
+
+        $this->assertEquals($branchRequest, $response);
+        $this->assertSame([
+            'data' => json_encode(['data' => 'test']),
+            'branch_id' => 'BranchIdStub',
+            'confirm' => '127.0.0.1/confirm',
+            'cancel' => '127.0.0.1/cancel',
+            'gid' => 'testGid',
+            'trans_type' => TransType::TCC,
+        ], TransContext::get(static::class . 'registerBranchBody'));
+    }
+
+    public function testCallBranchUseGrpcProtocol()
+    {
+        $api = \Mockery::mock(ApiInterface::class);
+        $branchIdGenerator = \Mockery::mock(BranchIdGeneratorInterface::class);
+
+        $branchIdGenerator->shouldReceive('generateSubBranchId')->andReturn('BranchIdStub');
+
+        $api->shouldReceive('getProtocol')->andReturn(Protocol::GRPC);
+        $api->shouldReceive('registerBranch')->andReturnUsing(function ($data) {
+            TransContext::set(static::class . 'registerBranchBody', $data);
+        });
+        $api->shouldReceive('transRequestBranch')->andReturnUsing(function ($data) {
+            return $data;
+        });
+
+        TransContext::setGid('testGid');
+
+        $tcc = new TCC($api, $branchIdGenerator);
+
+        $message = new DtmRequest();
+
+        $response = $tcc->callBranch(
+            $message,
+            '127.0.0.1/try',
+            '127.0.0.1/confirm',
+            '127.0.0.1/cancel'
+        );
+
+        $branchRequest = new RequestBranch();
+        $branchRequest->grpcArgument = $message;
+        $branchRequest->url = '127.0.0.1/try';
+        $branchRequest->grpcMetadata = [
+            'dtm-gid' => 'testGid',
+            'dtm-trans_type' => TransType::TCC,
+            'dtm-branch_id' => 'BranchIdStub',
+            'dtm-op' => Operation::TRY,
+            'dtm-dtm' => TransContext::getDtm(),
+        ];
+
+        $this->assertEquals($branchRequest, $response);
+        $this->assertSame([
+            'Gid' => 'testGid',
+            'TransType' => TransType::TCC,
+            'BranchID' => 'BranchIdStub',
+            'BusiPayload' => $message->serializeToString(),
+            'Data' => ['confirm' => '127.0.0.1/confirm', 'cancel' => '127.0.0.1/cancel'],
+        ], TransContext::get(static::class . 'registerBranchBody'));
+    }
+}