diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..410d4a1
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,5 @@
+/.github export-ignore
+/tests export-ignore
+/.gitignore export-ignore
+/Makefile export-ignore
+/phpunit.xml.dist export-ignore
diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..ef7eb61
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+github: [nyholm, jderusse]
diff --git a/.github/workflows/.editorconfig b/.github/workflows/.editorconfig
new file mode 100644
index 0000000..7bd3346
--- /dev/null
+++ b/.github/workflows/.editorconfig
@@ -0,0 +1,2 @@
+[*.yml]
+indent_size = 2
diff --git a/.github/workflows/branch_alias.yml b/.github/workflows/branch_alias.yml
new file mode 100644
index 0000000..6c27511
--- /dev/null
+++ b/.github/workflows/branch_alias.yml
@@ -0,0 +1,76 @@
+name: Update branch alias
+
+on:
+  push:
+    tags: ['*']
+
+jobs:
+  branch-alias:
+    name: Update branch alias
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 8.0
+          coverage: none
+
+      - name: Find branch alias
+        id: find_alias
+        run: |
+          TAG=$(echo $GITHUB_REF | cut -d'/' -f 3)
+          echo "Last tag was $TAG"
+          ARR=(${TAG//./ })
+          ARR[1]=$((${ARR[1]}+1))
+          echo ::set-output name=alias::${ARR[0]}.${ARR[1]}
+
+      - name: Checkout main repo
+        run: |
+          git clone --branch master https://${{ secrets.BOT_GITHUB_TOKEN }}:x-oauth-basic@github.com/async-aws/aws aws
+
+      - name: Update branch alias
+        run: |
+          cd aws/src/Service/XRay
+          CURRENT_ALIAS=$(composer config extra.branch-alias.dev-master | cut -d'-' -f 1)
+
+          # If there is a current value on the branch alias
+          if [ ! -z $CURRENT_ALIAS ]; then
+            NEW_ALIAS=${{ steps.find_alias.outputs.alias }}
+            CURRENT_ARR=(${CURRENT_ALIAS//./ })
+            NEW_ARR=(${NEW_ALIAS//./ })
+
+            if [ ${CURRENT_ARR[0]} -gt ${NEW_ARR[0]} ]; then
+                echo "The current value for major version is larger"
+                exit 1;
+            fi
+
+            if [ ${CURRENT_ARR[0]} -eq ${NEW_ARR[0]} ] && [ ${CURRENT_ARR[1]} -gt ${NEW_ARR[1]} ]; then
+                echo "The current value for minor version is larger"
+                exit 1;
+            fi
+          fi
+
+          composer config extra.branch-alias.dev-master ${{ steps.find_alias.outputs.alias }}-dev
+
+      - name: Commit & push the new files
+        run: |
+          echo "::group::git status"
+          cd aws
+          git status
+          echo "::endgroup::"
+
+          git add -N .
+          if [[ $(git diff --numstat | wc -l) -eq 0 ]]; then
+            echo "No changes found. Exiting."
+            exit 0;
+          fi
+
+          git config --local user.email "github@async-aws.com"
+          git config --local user.name "AsyncAws Bot"
+
+          echo "::group::git push"
+          git add .
+          git commit -m "Update branch alias"
+          git push
+          echo "::endgroup::"
diff --git a/.github/workflows/checks.yml b/.github/workflows/checks.yml
new file mode 100644
index 0000000..1a72276
--- /dev/null
+++ b/.github/workflows/checks.yml
@@ -0,0 +1,27 @@
+name: BC Check
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  roave-bc-check:
+    name: Roave BC Check
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Modify composer.json
+        run: |
+          sed -i -re 's/"require": \{/"minimum-stability": "dev","prefer-stable": true,"require": \{/' composer.json
+          cat composer.json
+
+          git config --local user.email "github@async-aws.com"
+          git config --local user.name "AsyncAws Bot"
+          git commit -am "Allow unstable dependencies"
+
+      - name: Roave BC Check
+        uses: docker://nyholm/roave-bc-check-ga
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..1f7c850
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,38 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    strategy:
+      max-parallel: 10
+      matrix:
+        php: ['7.2', '7.3', '7.4', '8.0']
+
+    steps:
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Initialize tests
+        run: make initialize
+
+      - name: Download dependencies
+        run: |
+          composer config minimum-stability dev
+          composer req symfony/phpunit-bridge --no-update
+          composer update --no-interaction --prefer-dist --optimize-autoloader --prefer-stable
+
+      - name: Run tests
+        run: ./vendor/bin/simple-phpunit
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4ef8091
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/vendor/
+*.cache
+composer.lock
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..457d417
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,7 @@
+# Change Log
+
+## NOT RELEASED
+
+## 0.1.0
+
+First version
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..50402d9
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2021 Jérémy Derussé, Tobias Nyholm
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..850dffc
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,12 @@
+.EXPORT_ALL_VARIABLES:
+
+initialize: start-docker
+start-docker:
+	echo "Noop"
+
+test: initialize
+	./vendor/bin/simple-phpunit
+
+clean: stop-docker
+stop-docker:
+	echo "Noop"
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..36196f9
--- /dev/null
+++ b/README.md
@@ -0,0 +1,20 @@
+# AsyncAws X-Ray Client
+
+![](https://github.com/async-aws/x-ray/workflows/Tests/badge.svg?branch=master)
+![](https://github.com/async-aws/x-ray/workflows/BC%20Check/badge.svg?branch=master)
+
+An API client for XRay.
+
+## Install
+
+```cli
+composer require async-aws/x-ray
+```
+
+## Documentation
+
+See https://async-aws.com/clients/x-ray.html for documentation.
+
+## Contribute
+
+Contributions are welcome and appreciated. Please read https://async-aws.com/contribute/
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..76df50c
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,33 @@
+{
+    "name": "async-aws/x-ray",
+    "type": "library",
+    "description": "XRay client, part of the AWS SDK provided by AsyncAws.",
+    "keywords": [
+        "aws",
+        "amazon",
+        "sdk",
+        "async-aws",
+        "x-ray"
+    ],
+    "license": "MIT",
+    "require": {
+        "php": "^7.2.5 || ^8.0",
+        "ext-json": "*",
+        "async-aws/core": "^1.9"
+    },
+    "extra": {
+        "branch-alias": {
+            "dev-master": "0.1-dev"
+        }
+    },
+    "autoload": {
+        "psr-4": {
+            "AsyncAws\\XRay\\": "src"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "AsyncAws\\XRay\\Tests\\": "tests/"
+        }
+    }
+}
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
new file mode 100644
index 0000000..9894ce3
--- /dev/null
+++ b/phpunit.xml.dist
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+         backupGlobals="false"
+         colors="true"
+         bootstrap="vendor/autoload.php"
+         failOnRisky="true"
+         failOnWarning="true"
+>
+  <coverage>
+    <include>
+      <directory>./src</directory>
+    </include>
+  </coverage>
+  <php>
+    <ini name="error_reporting" value="-1"/>
+  </php>
+  <testsuites>
+    <testsuite name="Test Suite">
+      <directory>./tests/</directory>
+    </testsuite>
+  </testsuites>
+</phpunit>
diff --git a/src/Exception/InvalidRequestException.php b/src/Exception/InvalidRequestException.php
new file mode 100644
index 0000000..eaa85ea
--- /dev/null
+++ b/src/Exception/InvalidRequestException.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace AsyncAws\XRay\Exception;
+
+use AsyncAws\Core\Exception\Http\ClientException;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+/**
+ * The request is missing required parameters or has invalid parameters.
+ */
+final class InvalidRequestException extends ClientException
+{
+    protected function populateResult(ResponseInterface $response): void
+    {
+        $data = $response->toArray(false);
+
+        if (null !== $v = (isset($data['message']) ? (string) $data['message'] : null)) {
+            $this->message = $v;
+        }
+    }
+}
diff --git a/src/Exception/ThrottledException.php b/src/Exception/ThrottledException.php
new file mode 100644
index 0000000..4f28864
--- /dev/null
+++ b/src/Exception/ThrottledException.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace AsyncAws\XRay\Exception;
+
+use AsyncAws\Core\Exception\Http\ClientException;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+/**
+ * The request exceeds the maximum number of requests per second.
+ */
+final class ThrottledException extends ClientException
+{
+    protected function populateResult(ResponseInterface $response): void
+    {
+        $data = $response->toArray(false);
+
+        if (null !== $v = (isset($data['message']) ? (string) $data['message'] : null)) {
+            $this->message = $v;
+        }
+    }
+}
diff --git a/src/Input/PutTraceSegmentsRequest.php b/src/Input/PutTraceSegmentsRequest.php
new file mode 100644
index 0000000..7456e24
--- /dev/null
+++ b/src/Input/PutTraceSegmentsRequest.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace AsyncAws\XRay\Input;
+
+use AsyncAws\Core\Exception\InvalidArgument;
+use AsyncAws\Core\Input;
+use AsyncAws\Core\Request;
+use AsyncAws\Core\Stream\StreamFactory;
+
+final class PutTraceSegmentsRequest extends Input
+{
+    /**
+     * A string containing a JSON document defining one or more segments or subsegments.
+     *
+     * @required
+     *
+     * @var string[]|null
+     */
+    private $traceSegmentDocuments;
+
+    /**
+     * @param array{
+     *   TraceSegmentDocuments?: string[],
+     *   @region?: string,
+     * } $input
+     */
+    public function __construct(array $input = [])
+    {
+        $this->traceSegmentDocuments = $input['TraceSegmentDocuments'] ?? null;
+        parent::__construct($input);
+    }
+
+    public static function create($input): self
+    {
+        return $input instanceof self ? $input : new self($input);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getTraceSegmentDocuments(): array
+    {
+        return $this->traceSegmentDocuments ?? [];
+    }
+
+    /**
+     * @internal
+     */
+    public function request(): Request
+    {
+        // Prepare headers
+        $headers = ['content-type' => 'application/json'];
+
+        // Prepare query
+        $query = [];
+
+        // Prepare URI
+        $uriString = '/TraceSegments';
+
+        // Prepare Body
+        $bodyPayload = $this->requestBody();
+        $body = empty($bodyPayload) ? '{}' : json_encode($bodyPayload, 4194304);
+
+        // Return the Request
+        return new Request('POST', $uriString, $query, $headers, StreamFactory::create($body));
+    }
+
+    /**
+     * @param string[] $value
+     */
+    public function setTraceSegmentDocuments(array $value): self
+    {
+        $this->traceSegmentDocuments = $value;
+
+        return $this;
+    }
+
+    private function requestBody(): array
+    {
+        $payload = [];
+        if (null === $v = $this->traceSegmentDocuments) {
+            throw new InvalidArgument(sprintf('Missing parameter "TraceSegmentDocuments" for "%s". The value cannot be null.', __CLASS__));
+        }
+
+        $index = -1;
+        $payload['TraceSegmentDocuments'] = [];
+        foreach ($v as $listValue) {
+            ++$index;
+            $payload['TraceSegmentDocuments'][$index] = $listValue;
+        }
+
+        return $payload;
+    }
+}
diff --git a/src/Result/PutTraceSegmentsResult.php b/src/Result/PutTraceSegmentsResult.php
new file mode 100644
index 0000000..1f78803
--- /dev/null
+++ b/src/Result/PutTraceSegmentsResult.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace AsyncAws\XRay\Result;
+
+use AsyncAws\Core\Response;
+use AsyncAws\Core\Result;
+use AsyncAws\XRay\ValueObject\UnprocessedTraceSegment;
+
+class PutTraceSegmentsResult extends Result
+{
+    /**
+     * Segments that failed processing.
+     */
+    private $unprocessedTraceSegments;
+
+    /**
+     * @return UnprocessedTraceSegment[]
+     */
+    public function getUnprocessedTraceSegments(): array
+    {
+        $this->initialize();
+
+        return $this->unprocessedTraceSegments;
+    }
+
+    protected function populateResult(Response $response): void
+    {
+        $data = $response->toArray();
+
+        $this->unprocessedTraceSegments = empty($data['UnprocessedTraceSegments']) ? [] : $this->populateResultUnprocessedTraceSegmentList($data['UnprocessedTraceSegments']);
+    }
+
+    /**
+     * @return UnprocessedTraceSegment[]
+     */
+    private function populateResultUnprocessedTraceSegmentList(array $json): array
+    {
+        $items = [];
+        foreach ($json as $item) {
+            $items[] = new UnprocessedTraceSegment([
+                'Id' => isset($item['Id']) ? (string) $item['Id'] : null,
+                'ErrorCode' => isset($item['ErrorCode']) ? (string) $item['ErrorCode'] : null,
+                'Message' => isset($item['Message']) ? (string) $item['Message'] : null,
+            ]);
+        }
+
+        return $items;
+    }
+}
diff --git a/src/ValueObject/UnprocessedTraceSegment.php b/src/ValueObject/UnprocessedTraceSegment.php
new file mode 100644
index 0000000..d7e1b80
--- /dev/null
+++ b/src/ValueObject/UnprocessedTraceSegment.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace AsyncAws\XRay\ValueObject;
+
+/**
+ * Information about a segment that failed processing.
+ */
+final class UnprocessedTraceSegment
+{
+    /**
+     * The segment's ID.
+     */
+    private $id;
+
+    /**
+     * The error that caused processing to fail.
+     */
+    private $errorCode;
+
+    /**
+     * The error message.
+     */
+    private $message;
+
+    /**
+     * @param array{
+     *   Id?: null|string,
+     *   ErrorCode?: null|string,
+     *   Message?: null|string,
+     * } $input
+     */
+    public function __construct(array $input)
+    {
+        $this->id = $input['Id'] ?? null;
+        $this->errorCode = $input['ErrorCode'] ?? null;
+        $this->message = $input['Message'] ?? null;
+    }
+
+    public static function create($input): self
+    {
+        return $input instanceof self ? $input : new self($input);
+    }
+
+    public function getErrorCode(): ?string
+    {
+        return $this->errorCode;
+    }
+
+    public function getId(): ?string
+    {
+        return $this->id;
+    }
+
+    public function getMessage(): ?string
+    {
+        return $this->message;
+    }
+}
diff --git a/src/XRayClient.php b/src/XRayClient.php
new file mode 100644
index 0000000..d49a2e1
--- /dev/null
+++ b/src/XRayClient.php
@@ -0,0 +1,124 @@
+<?php
+
+namespace AsyncAws\XRay;
+
+use AsyncAws\Core\AbstractApi;
+use AsyncAws\Core\AwsError\AwsErrorFactoryInterface;
+use AsyncAws\Core\AwsError\JsonRestAwsErrorFactory;
+use AsyncAws\Core\Configuration;
+use AsyncAws\Core\RequestContext;
+use AsyncAws\XRay\Exception\InvalidRequestException;
+use AsyncAws\XRay\Exception\ThrottledException;
+use AsyncAws\XRay\Input\PutTraceSegmentsRequest;
+use AsyncAws\XRay\Result\PutTraceSegmentsResult;
+
+class XRayClient extends AbstractApi
+{
+    /**
+     * Uploads segment documents to Amazon Web Services X-Ray. The X-Ray SDK generates segment documents and sends them to
+     * the X-Ray daemon, which uploads them in batches. A segment document can be a completed segment, an in-progress
+     * segment, or an array of subsegments.
+     *
+     * @see https://docs.aws.amazon.com/xray/index.html
+     * @see https://docs.aws.amazon.com/xray/latest/api/API_PutTraceSegments.html
+     * @see https://docs.aws.amazon.com/aws-sdk-php/v3/api/api-xray-2016-04-12.html#puttracesegments
+     *
+     * @param array{
+     *   TraceSegmentDocuments: string[],
+     *   @region?: string,
+     * }|PutTraceSegmentsRequest $input
+     *
+     * @throws InvalidRequestException
+     * @throws ThrottledException
+     */
+    public function putTraceSegments($input): PutTraceSegmentsResult
+    {
+        $input = PutTraceSegmentsRequest::create($input);
+        $response = $this->getResponse($input->request(), new RequestContext(['operation' => 'PutTraceSegments', 'region' => $input->getRegion(), 'exceptionMapping' => [
+            'InvalidRequestException' => InvalidRequestException::class,
+            'ThrottledException' => ThrottledException::class,
+        ]]));
+
+        return new PutTraceSegmentsResult($response);
+    }
+
+    protected function getAwsErrorFactory(): AwsErrorFactoryInterface
+    {
+        return new JsonRestAwsErrorFactory();
+    }
+
+    protected function getEndpointMetadata(?string $region): array
+    {
+        if (null === $region) {
+            $region = Configuration::DEFAULT_REGION;
+        }
+
+        switch ($region) {
+            case 'cn-north-1':
+            case 'cn-northwest-1':
+                return [
+                    'endpoint' => "https://xray.$region.amazonaws.com.cn",
+                    'signRegion' => $region,
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'us-gov-east-1':
+            case 'us-gov-west-1':
+                return [
+                    'endpoint' => "https://xray.$region.amazonaws.com",
+                    'signRegion' => $region,
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-east-1':
+                return [
+                    'endpoint' => 'https://xray-fips.us-east-1.amazonaws.com',
+                    'signRegion' => 'us-east-1',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-east-2':
+                return [
+                    'endpoint' => 'https://xray-fips.us-east-2.amazonaws.com',
+                    'signRegion' => 'us-east-2',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-gov-east-1':
+                return [
+                    'endpoint' => 'https://xray-fips.us-gov-east-1.amazonaws.com',
+                    'signRegion' => 'us-gov-east-1',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-gov-west-1':
+                return [
+                    'endpoint' => 'https://xray-fips.us-gov-west-1.amazonaws.com',
+                    'signRegion' => 'us-gov-west-1',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-west-1':
+                return [
+                    'endpoint' => 'https://xray-fips.us-west-1.amazonaws.com',
+                    'signRegion' => 'us-west-1',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+            case 'fips-us-west-2':
+                return [
+                    'endpoint' => 'https://xray-fips.us-west-2.amazonaws.com',
+                    'signRegion' => 'us-west-2',
+                    'signService' => 'xray',
+                    'signVersions' => ['v4'],
+                ];
+        }
+
+        return [
+            'endpoint' => "https://xray.$region.amazonaws.com",
+            'signRegion' => $region,
+            'signService' => 'xray',
+            'signVersions' => ['v4'],
+        ];
+    }
+}
diff --git a/tests/.gitignore b/tests/.gitignore
new file mode 100644
index 0000000..e69de29
diff --git a/tests/Integration/XRayClientTest.php b/tests/Integration/XRayClientTest.php
new file mode 100644
index 0000000..f280b08
--- /dev/null
+++ b/tests/Integration/XRayClientTest.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace AsyncAws\XRay\Tests\Integration;
+
+use AsyncAws\Core\Credentials\NullProvider;
+use AsyncAws\Core\Test\TestCase;
+use AsyncAws\XRay\Input\PutTraceSegmentsRequest;
+use AsyncAws\XRay\XRayClient;
+
+class XRayClientTest extends TestCase
+{
+    public function testPutTraceSegments(): void
+    {
+        self::markTestIncomplete('Cannot test PutTraceSegments.');
+
+        $client = $this->getClient();
+
+        $input = new PutTraceSegmentsRequest([
+            'TraceSegmentDocuments' => [
+                json_encode([
+                    'name' => 'service-foo',
+                    'id' => '1111111111111111',
+                    'trace_id' => '1-58406520-a006649127e371903a2de979',
+                    'start_time' => 1480615200.010,
+                    'end_time' => 1480615200.090,
+                ]),
+            ],
+        ]);
+        $result = $client->putTraceSegments($input);
+
+        $result->resolve();
+
+        self::assertSame([], $result->getUnprocessedTraceSegments());
+    }
+
+    private function getClient(): XRayClient
+    {
+        self::fail('Not implemented');
+
+        return new XRayClient([
+            'endpoint' => 'http://localhost',
+        ], new NullProvider());
+    }
+}
diff --git a/tests/Unit/Input/PutTraceSegmentsRequestTest.php b/tests/Unit/Input/PutTraceSegmentsRequestTest.php
new file mode 100644
index 0000000..72e88dd
--- /dev/null
+++ b/tests/Unit/Input/PutTraceSegmentsRequestTest.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace AsyncAws\XRay\Tests\Unit\Input;
+
+use AsyncAws\Core\Test\TestCase;
+use AsyncAws\XRay\Input\PutTraceSegmentsRequest;
+
+class PutTraceSegmentsRequestTest extends TestCase
+{
+    public function testRequest(): void
+    {
+        $input = new PutTraceSegmentsRequest([
+            'TraceSegmentDocuments' => [
+                json_encode([
+                    'name' => 'service-foo',
+                    'id' => '1111111111111111',
+                    'trace_id' => '1-58406520-a006649127e371903a2de979',
+                    'start_time' => 1480615200.010,
+                    'end_time' => 1480615200.090,
+                ]),
+            ],
+        ]);
+
+        // see https://docs.aws.amazon.com/xray/latest/api/API_PutTraceSegments.html
+        $expected = '
+            POST /TraceSegments HTTP/1.0
+            Content-Type: application/json
+
+            {
+            "TraceSegmentDocuments": [
+                "{\"name\":\"service-foo\",\"id\":\"1111111111111111\",\"trace_id\":\"1-58406520-a006649127e371903a2de979\",\"start_time\":1480615200.01,\"end_time\":1480615200.09}"
+            ]
+        }
+                ';
+
+        self::assertRequestEqualsHttpRequest($expected, $input->request());
+    }
+}
diff --git a/tests/Unit/Result/PutTraceSegmentsResultTest.php b/tests/Unit/Result/PutTraceSegmentsResultTest.php
new file mode 100644
index 0000000..506ad23
--- /dev/null
+++ b/tests/Unit/Result/PutTraceSegmentsResultTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace AsyncAws\XRay\Tests\Unit\Result;
+
+use AsyncAws\Core\Response;
+use AsyncAws\Core\Test\Http\SimpleMockedResponse;
+use AsyncAws\Core\Test\TestCase;
+use AsyncAws\XRay\Result\PutTraceSegmentsResult;
+use AsyncAws\XRay\ValueObject\UnprocessedTraceSegment;
+use Psr\Log\NullLogger;
+use Symfony\Component\HttpClient\MockHttpClient;
+
+class PutTraceSegmentsResultTest extends TestCase
+{
+    public function testPutTraceSegmentsResult(): void
+    {
+        // see https://docs.aws.amazon.com/xray/latest/APIReference/API_PutTraceSegments.html
+        $response = new SimpleMockedResponse('{
+   "UnprocessedTraceSegments": [ 
+      { 
+         "ErrorCode": "1",
+         "Id": "1111111111111111",
+         "Message": "Error"
+      }
+   ]
+}');
+
+        $client = new MockHttpClient($response);
+        $result = new PutTraceSegmentsResult(new Response($client->request('POST', 'http://localhost'), $client, new NullLogger()));
+        $unprocessedTraceSegments = $result->getUnprocessedTraceSegments();
+
+        self::assertIsArray($unprocessedTraceSegments);
+        self::assertCount(1, $unprocessedTraceSegments);
+        self::assertInstanceOf(UnprocessedTraceSegment::class, $unprocessedTraceSegments[0]);
+        self::assertSame('1', $unprocessedTraceSegments[0]->getErrorCode());
+        self::assertSame('1111111111111111', $unprocessedTraceSegments[0]->getId());
+        self::assertSame('Error', $unprocessedTraceSegments[0]->getMessage());
+    }
+}
diff --git a/tests/Unit/XRayClientTest.php b/tests/Unit/XRayClientTest.php
new file mode 100644
index 0000000..0253aac
--- /dev/null
+++ b/tests/Unit/XRayClientTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace AsyncAws\XRay\Tests\Unit;
+
+use AsyncAws\Core\Credentials\NullProvider;
+use AsyncAws\Core\Test\TestCase;
+use AsyncAws\XRay\Input\PutTraceSegmentsRequest;
+use AsyncAws\XRay\Result\PutTraceSegmentsResult;
+use AsyncAws\XRay\XRayClient;
+use Symfony\Component\HttpClient\MockHttpClient;
+
+class XRayClientTest extends TestCase
+{
+    public function testPutTraceSegments(): void
+    {
+        $client = new XRayClient([], new NullProvider(), new MockHttpClient());
+
+        $input = new PutTraceSegmentsRequest([
+            'TraceSegmentDocuments' => [
+                json_encode([
+                    'name' => 'service-foo',
+                    'id' => '1111111111111111',
+                    'trace_id' => '1-58406520-a006649127e371903a2de979',
+                    'start_time' => 1480615200.010,
+                    'end_time' => 1480615200.090,
+                ]),
+            ],
+        ]);
+        $result = $client->putTraceSegments($input);
+
+        self::assertInstanceOf(PutTraceSegmentsResult::class, $result);
+        self::assertFalse($result->info()['resolved']);
+    }
+}