diff --git a/Makefile b/Makefile
index 5782039b43..9c7dd8975f 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ clean: clear-cache
 	rm -rf build/artifacts/*
 
 clear-cache:
-	php build/aws-clear-cache.php
+	php build/WorkflowCommandRunner.php clear-cache
 
 test:
 	AWS_ACCESS_KEY_ID=foo AWS_SECRET_ACCESS_KEY=bar AWS_SESSION_TOKEN= \
@@ -33,10 +33,10 @@ test:
 
 test-phar: package
 	[ -f build/artifacts/behat.phar ] || (cd build/artifacts && \
-	wget https://github.com/Behat/Behat/releases/download/v3.0.15/behat.phar)
+	wget https://github.com/Behat/Behat/releases/download/v3.13.0/behat.phar)
 	[ -f build/artifacts/phpunit.phar ] || (cd build/artifacts && \
 	wget https://phar.phpunit.de/phpunit.phar)
-	php -dopcache.enable_cli=1 build/phar-test-runner.php --format=progress
+	php -dopcache.enable_cli=1 build/WorkflowCommandRunner.php phar-test-runner --format=progress
 
 coverage:
 	@AWS_ACCESS_KEY_ID=foo AWS_SECRET_ACCESS_KEY=bar AWS_CSM_ENABLED=false \
@@ -78,7 +78,7 @@ smoke-noassumerole:
 
 # Packages the phar and zip
 package:
-	php build/packager.php $(SERVICE)
+	php build/WorkflowCommandRunner.php package$(if $(SERVICE), --service=$(SERVICE),)
 
 api-get-phpdocumentor:
 	mkdir -p build/artifacts
@@ -89,19 +89,19 @@ api: api-get-phpdocumentor
 	[ -d build/artifacts/staging ] || make package
 	# Delete a previously built API build to avoid the prompt.
 	rm -rf build/artifacts/docs
-	php build/remove-method-annotations.php
+	php build/WorkflowCommandRunner.php remove-method-annotations
 	php build/artifacts/phpDocumentor.phar run --config build/docs/phpdoc.dist.xml
-	php build/normalize-docs-files.php
+	php build/WorkflowCommandRunner.php normalize-docs-files
 	make api-models
 	make redirect-map
 
 api-models:
 	# Build custom docs
-	php build/docs.php $(if $(ISSUE_LOGGING_ENABLED),--issue-logging-enabled,)
+	php build/WorkflowCommandRunner.php docs $(if $(ISSUE_LOGGING_ENABLED),--issue-logging-enabled,)
 
 redirect-map:
 	# Build redirect map
-	php build/build-redirect-map.php
+	php build/WorkflowCommandRunner.php build-redirect-map
 
 api-show:
 	open build/artifacts/docs/index.html
@@ -110,23 +110,23 @@ api-package:
 	zip -r build/artifacts/aws-docs-api.zip build/artifacts/docs/build
 
 api-manifest:
-	php build/build-manifest.php
+	php build/WorkflowCommandRunner.php build-manifest
 	make clear-cache
 
 # Compiles JSON data files and prints the names of PHP data files created or
 # updated.
 compile-json:
-	php -dopcache.enable_cli=1 build/compile-json.php
+	php -dopcache.enable_cli=1 build/WorkflowCommandRunner.php compile-json
 	git diff --name-only | grep ^src/data/.*\.json\.php$ || true
 
 annotate-clients: clean
-	php build/annotate-clients.php --all
+	php build/WorkflowCommandRunner.php annotate-clients --all
 
 annotate-client-locator: clean
-	php build/annotate-client-locator.php
+	php build/WorkflowCommandRunner.php annotate-client-locator
 
 build-manifest:
-	php build/build-manifest.php >/dev/null
+	php build/WorkflowCommandRunner.php build-manifest >/dev/null
 
 build: | build-manifest compile-json annotate-clients annotate-client-locator
 
@@ -159,7 +159,7 @@ tag: check-tag
 release: check-tag package
 	git push origin master
 	git push origin $(TAG)
-	php build/gh-release.php $(TAG)
+	php build/WorkflowCommandRunner.php gh-release --tag=$(TAG)
 
 # Tags the repo and publishes a release.
 full_release: tag release
diff --git a/build/Command/AbstractCommand.php b/build/Command/AbstractCommand.php
new file mode 100644
index 0000000000..2c6bae518f
--- /dev/null
+++ b/build/Command/AbstractCommand.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace AwsBuild\Command;
+
+abstract class AbstractCommand implements CommandInterface
+{
+    protected bool $verbose = false;
+    private ?string $projectRoot;
+
+    public function __construct(?string $projectRoot = null)
+    {
+        $this->projectRoot = $projectRoot ?? dirname(__DIR__, 2);
+    }
+
+    public function execute(array $args): int
+    {
+        if (in_array('--help', $args, true) || in_array('-h', $args, true)) {
+            $name = $this->getName();
+            $this->output($name);
+            $this->output(str_repeat('-', strlen($name)));
+            $this->output($this->getDescription());
+            $this->output('');
+            $this->output('Usage:');
+            $this->output('  ' . $this->getUsage());
+            return 0;
+        }
+
+        if (in_array('--verbose', $args, true) || in_array('-v', $args, true)) {
+            $this->verbose = true;
+        }
+
+        return $this->doExecute($args);
+    }
+
+    abstract protected function doExecute(array $args): int;
+
+    protected function output(string $msg): void
+    {
+        fwrite(STDOUT, $msg . "\n");
+    }
+
+    protected function error(string $msg): void
+    {
+        fwrite(STDERR, "[ERROR] $msg\n");
+    }
+
+    protected function verbose(string $msg): void
+    {
+        if ($this->verbose) {
+            fwrite(STDOUT, $msg . "\n");
+        }
+    }
+
+    protected function parseOptions(array $args): array
+    {
+        $options = [];
+        foreach ($args as $arg) {
+            if (str_starts_with($arg, '--')) {
+                $arg = substr($arg, 2);
+                if (str_contains($arg, '=')) {
+                    [$key, $value] = explode('=', $arg, 2);
+                    $options[$key] = $value;
+                } else {
+                    $options[$arg] = true;
+                }
+            }
+        }
+        return $options;
+    }
+
+    protected function getProjectRoot(): string
+    {
+        return $this->projectRoot;
+    }
+
+    protected static function getBuildDir(): string
+    {
+        return dirname(__DIR__);
+    }
+}
diff --git a/build/Command/AnnotateClientLocatorCommand.php b/build/Command/AnnotateClientLocatorCommand.php
new file mode 100644
index 0000000000..7eb676d7cb
--- /dev/null
+++ b/build/Command/AnnotateClientLocatorCommand.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class AnnotateClientLocatorCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'annotate-client-locator';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Updates @method annotations on the Aws\Sdk class.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php annotate-client-locator';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $namespaces = array_map(function (array $manifest) {
+            return $manifest['namespace'];
+        }, array_values(\Aws\manifest()));
+
+        sort($namespaces);
+        $annotations = [];
+        foreach ($namespaces as $namespace) {
+            $mrClient = "\\Aws\\{$namespace}\\{$namespace}MultiRegionClient";
+            $mrClient = class_exists($mrClient) ? $mrClient : "\\Aws\\MultiRegionClient";
+
+            $annotations[] = " * @method \\Aws\\{$namespace}\\{$namespace}Client"
+                . " create{$namespace}(array \$args = [])";
+            $annotations[] = " * @method $mrClient"
+                . " createMultiRegion{$namespace}(array \$args = [])";
+        }
+
+        $previousAnnotationPattern = '/^\* @method'
+            . ' \\\\Aws\\\\(?:[a-zA-Z0-9\\\\]+)Client'
+            . ' create(?:[a-zA-Z0-9]+)\\(array \$args = \\[\\]\\)/';
+
+        $updater = new \ClassAnnotationUpdater(
+            new \ReflectionClass(\Aws\Sdk::class),
+            $annotations,
+            '',
+            $previousAnnotationPattern
+        );
+        $updater->update();
+
+        return 0;
+    }
+}
diff --git a/build/Command/AnnotateClientsCommand.php b/build/Command/AnnotateClientsCommand.php
new file mode 100644
index 0000000000..ab2f6260bc
--- /dev/null
+++ b/build/Command/AnnotateClientsCommand.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class AnnotateClientsCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'annotate-clients';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Adds @method annotations to service client classes.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php annotate-clients [--all] [--class=<FQCN>] [--tag=<git-tag>]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $options = $this->parseOptions($args) + ['class' => [], 'tag' => []];
+
+        // make sure all options are arrays
+        array_walk($options, function (&$value) {
+            if (!is_array($value)) {
+                $value = [$value];
+            }
+        });
+
+        if (isset($options['all'])) {
+            $options['class'] = \Aws\flatmap(\Aws\manifest(), function (array $manifest) {
+                return $this->getClientClasses($manifest['namespace']);
+            });
+        }
+
+        foreach ($options['tag'] as $tag) {
+            if ('latest' === $tag) {
+                $tag = trim(`git tag | tail -n 1`);
+            }
+
+            exec("git diff-index --name-only --cached $tag", $files);
+            $alteredApiFiles = array_filter($files, function ($file) {
+                return preg_match('/api-2.json$/', $file);
+            });
+
+            $clientsWithChangedApis = \Aws\flatmap($alteredApiFiles, function ($file) {
+                $file = str_replace('src/data/', '', $file);
+                $endpoint = substr($file, 0, strpos($file, '/'));
+                return $this->getClientClasses(\Aws\manifest($endpoint)['namespace']);
+            });
+            $options['class'] = \Aws\flatmap(
+                [$options['class'], $clientsWithChangedApis],
+                function ($class) { return $class; }
+            );
+        }
+
+        foreach ($options['class'] as $classToUpdate) {
+            $annotator = new \ClientAnnotator($classToUpdate);
+
+            if (!$annotator->updateApiMethodAnnotations()) {
+                trigger_error(
+                    "Unable to update annotations on $classToUpdate",
+                    E_USER_WARNING
+                );
+            }
+        }
+
+        return 0;
+    }
+
+    private function getClientClasses(string $namespace): array
+    {
+        $clients = ["Aws\\{$namespace}\\{$namespace}Client"];
+        if (class_exists("Aws\\{$namespace}\\{$namespace}MultiRegionClient")) {
+            $clients[] = "Aws\\{$namespace}\\{$namespace}MultiRegionClient";
+        }
+
+        return $clients;
+    }
+}
diff --git a/build/Command/BuildChangelogCommand.php b/build/Command/BuildChangelogCommand.php
new file mode 100644
index 0000000000..5d74d08b6f
--- /dev/null
+++ b/build/Command/BuildChangelogCommand.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace AwsBuild\Command;
+
+use Aws\Build\Changelog\ChangelogBuilder;
+
+final class BuildChangelogCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'build-changelog';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Builds CHANGELOG.md from next-release entries.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php build-changelog [-v]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $params = [];
+        $params['verbose'] = $this->verbose;
+        $params['base_dir'] = $this->getProjectRoot() . '/';
+
+        $changelogBuilder = new ChangelogBuilder($params);
+
+        $changelogBuilder->buildChangelog();
+
+        // Omit fixEndpointFile() call - method doesn't exist on ChangelogBuilder
+
+        $changelogBuilder->cleanNextReleaseFolder();
+
+        return 0;
+    }
+}
diff --git a/build/Command/BuildManifestCommand.php b/build/Command/BuildManifestCommand.php
new file mode 100644
index 0000000000..4097f472f8
--- /dev/null
+++ b/build/Command/BuildManifestCommand.php
@@ -0,0 +1,135 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class BuildManifestCommand extends AbstractCommand
+{
+    private const COMPATIBLE_API_VERSIONS = [
+        'apigateway' => [
+            'latest' => [
+                '2015-06-01',
+            ],
+        ],
+        'cloudfront' => [
+            'latest' => [
+                '2016-01-13',
+                '2015-09-17',
+            ],
+            '2015-07-27' => [
+                '2015-04-17',
+                '2014-11-06'
+            ],
+        ],
+        'ec2' => [
+            'latest' => [
+                '2015-04-15',
+            ],
+        ],
+        'events' => [
+            'latest' => [
+                '2014-02-03',
+            ],
+        ],
+        'inspector' => [
+            'latest' => [
+                '2015-08-18',
+            ]
+        ],
+    ];
+
+    public function getName(): string
+    {
+        return 'build-manifest';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Rebuilds src/data/manifest.json.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php build-manifest';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $projectRoot = $this->getProjectRoot();
+
+        // Create a list of possible namespaces
+        $possibleNamespaces = [];
+        $skip = ['.', '..', 'Api', 'data', 'Multipart', 'Signature'];
+        foreach (scandir($projectRoot . '/src') as $dir) {
+            if (!in_array($dir, $skip) && is_dir($projectRoot . '/src/' . $dir)) {
+                $possibleNamespaces[strtolower($dir)] = $dir;
+            }
+        }
+
+        $manifest = [];
+        foreach (glob($projectRoot . '/src/data/**/**/api-2.json') as $file) {
+            $model = json_decode(file_get_contents($file), true);
+            preg_match('@src/data/([^/]+)/[0-9]{4}-[0-9]{2}-[0-9]{2}/api-2.json$@', $file, $matches);
+            $identifier = $matches[1];
+            $metadata = $model['metadata'] + ['compatibleApiVersions' => []];
+            if (empty($manifest[$identifier])) {
+                // Calculate a namespace for the service.
+                $ns = isset($metadata['serviceAbbreviation'])
+                    ? $metadata['serviceAbbreviation']
+                    : $metadata['serviceFullName'];
+                $ns = str_replace(['Amazon', 'AWS', 'Beta', '(', ')', ' ', '/', '-'], '', $ns);
+
+                // check if it's a grandfathered namespace
+                $grandfatheredServices = json_decode(
+                    file_get_contents($projectRoot . '/src/data/grandfathered-services.json'),
+                    true
+                )['grandfathered-services'];
+                if (!in_array($ns, $grandfatheredServices)) {
+                    $ns = str_replace(' ', '', ucwords($metadata['serviceId']));
+                }
+
+                if (!isset($possibleNamespaces[strtolower($ns)])) {
+                    throw new \Exception('NS not found: ' . $ns);
+                }
+
+                $ns = $possibleNamespaces[strtolower($ns)];
+
+                $manifest[$identifier] = [
+                    'namespace' => $ns,
+                    'versions' => [],
+                ];
+            }
+
+            $manifest[$identifier]['versions'][$metadata['apiVersion']]
+                = $metadata['apiVersion'];
+
+            $serviceIdentifier = isset($metadata['serviceId'])
+                ? str_replace(' ', '_', strtolower($metadata['serviceId']))
+                : '';
+
+            if (!empty($serviceIdentifier)) {
+                $manifest[$identifier]['serviceIdentifier'] = $serviceIdentifier;
+            }
+        }
+
+        foreach ($manifest as $identifier => &$metadata) {
+            $metadata['versions']['latest'] = max(array_keys($metadata['versions']));
+            foreach ($metadata['versions'] as $name => $version) {
+                if (isset(self::COMPATIBLE_API_VERSIONS[$identifier][$name])) {
+                    foreach (self::COMPATIBLE_API_VERSIONS[$identifier][$name] as $compatVersion) {
+                        $metadata['versions'][$compatVersion]
+                            = $metadata['versions'][$name];
+                    }
+                }
+            }
+
+            krsort($metadata['versions']);
+        }
+
+        $data = json_encode($manifest, JSON_PRETTY_PRINT);
+        $file = $projectRoot . '/src/data/manifest.json';
+        file_put_contents($file, "$data\n");
+
+        $this->output("Wrote the following data to {$file}:\n>>>>>\n{$data}<<<<<");
+        return 0;
+    }
+}
diff --git a/build/Command/BuildRedirectMapCommand.php b/build/Command/BuildRedirectMapCommand.php
new file mode 100644
index 0000000000..3320f57659
--- /dev/null
+++ b/build/Command/BuildRedirectMapCommand.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace AwsBuild\Command;
+
+use Aws\Build\Docs\RedirectMapBuilder;
+
+final class BuildRedirectMapCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'build-redirect-map';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Builds the docs redirect map (artifacts/docs/package.redirects.conf).';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php build-redirect-map';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $path = self::getBuildDir() . '/artifacts/docs/package.redirects.conf';
+        $apiProvider = \Aws\Api\ApiProvider::defaultProvider();
+
+        $builder = new RedirectMapBuilder($apiProvider, $path);
+        $builder->build();
+
+        $this->output('Redirect map built.');
+        return 0;
+    }
+}
diff --git a/build/Command/BuildServiceCommand.php b/build/Command/BuildServiceCommand.php
new file mode 100644
index 0000000000..2e415d1fd8
--- /dev/null
+++ b/build/Command/BuildServiceCommand.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class BuildServiceCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'build-service';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Generates a service client + exception class from an API model.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php build-service --namespace=<Ns> --model=<path> [--clientPath=<path>] [--exceptionPath=<path>]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $options = $this->parseOptions($args);
+
+        if (empty($options['namespace']) || empty($options['model'])) {
+            $this->error(
+                "You must specify a namespace (--namespace=) and path to an api model "
+                . "(--model=) to build a service"
+            );
+            return 1;
+        }
+
+        $options['model'] = \Aws\load_compiled_json($options['model']);
+        $options['namespace'] = ucfirst($options['namespace']);
+
+        $projectRoot = $this->getProjectRoot();
+        $options += [
+            'clientPath' => $projectRoot
+                . "/src/{$options['namespace']}/{$options['namespace']}Client.php",
+            'exceptionPath' => $projectRoot
+                . "/src/{$options['namespace']}/Exception/{$options['namespace']}Exception.php",
+        ];
+
+        (new \ServiceBuilder(
+            $options['namespace'],
+            $options['model'],
+            $options['clientPath'],
+            $options['exceptionPath']
+        ))
+            ->buildClient()
+            ->buildException();
+
+        return 0;
+    }
+}
diff --git a/build/Command/ClearCacheCommand.php b/build/Command/ClearCacheCommand.php
new file mode 100644
index 0000000000..03cdf6e186
--- /dev/null
+++ b/build/Command/ClearCacheCommand.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class ClearCacheCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'clear-cache';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Clears the JMESPath compiled cache directory.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php clear-cache';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        \JmesPath\Env::cleanCompileDir();
+        $this->output('JMESPath cache cleared.');
+        return 0;
+    }
+}
diff --git a/build/Command/CommandInterface.php b/build/Command/CommandInterface.php
new file mode 100644
index 0000000000..5b6900ebf3
--- /dev/null
+++ b/build/Command/CommandInterface.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace AwsBuild\Command;
+
+interface CommandInterface
+{
+    public function getName(): string;
+
+    public function getDescription(): string;
+
+    public function getUsage(): string;
+
+    public function execute(array $args): int;
+}
diff --git a/build/Command/CompileJsonCommand.php b/build/Command/CompileJsonCommand.php
new file mode 100644
index 0000000000..e5e40129e8
--- /dev/null
+++ b/build/Command/CompileJsonCommand.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class CompileJsonCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'compile-json';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Compiles src/data/**/*.json files into PHP arrays.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php compile-json';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $dataDir = realpath($this->getProjectRoot() . '/src/data');
+        $dataFilesIterator = \Aws\recursive_dir_iterator($dataDir);
+        $count = 0;
+
+        foreach (new \RegexIterator($dataFilesIterator, '/\.json$/') as $dataFile) {
+            (new \JsonCompiler($dataFile))
+                ->compile("$dataFile.php");
+            $count++;
+        }
+
+        $this->output("Compiled $count JSON files.");
+        return 0;
+    }
+}
diff --git a/build/Command/DocsCommand.php b/build/Command/DocsCommand.php
new file mode 100644
index 0000000000..2e0d467867
--- /dev/null
+++ b/build/Command/DocsCommand.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace AwsBuild\Command;
+
+use Aws\Build\Docs\DocsBuilder;
+
+final class DocsCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'docs';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Generates custom API documentation over the phpDocumentor output.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php docs [--issue-logging-enabled]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $buildDir = self::getBuildDir();
+        $projectRoot = $this->getProjectRoot();
+
+        // Setup directories.
+        $xmlObj = simplexml_load_file($buildDir . '/docs/phpdoc.dist.xml');
+        $xmlJson = json_encode($xmlObj);
+        $config = json_decode($xmlJson, true);
+        $outputDir = $buildDir . '/artifacts/docs';
+        $apiProvider = \Aws\Api\ApiProvider::defaultProvider();
+
+        // Extract the built homepage into a template file.
+        $xml = new \DOMDocument();
+        @$xml->loadHTMLFile($buildDir . '/artifacts/docs/index.html');
+        $ele = $xml->getElementById('content');
+        $ele->nodeValue = '{{ contents }}';
+        $template = $xml->saveHTML();
+
+        $sourceDirs = array_map(function ($dirRelativeToProjectRoot) use ($projectRoot) {
+            return $projectRoot . '/' . $dirRelativeToProjectRoot;
+        }, is_array($config['version']['api']['source']['path'])
+            ? $config['version']['api']['source']['path']
+            : [$config['version']['api']['source']['path']]
+        );
+        $sourceFiles = [];
+        foreach ($sourceDirs as $dir) {
+            $sourceFiles = array_merge(
+                $sourceFiles,
+                array_filter(
+                    array_map('realpath', iterator_to_array(\Aws\recursive_dir_iterator($dir))),
+                    function ($path) {
+                        return preg_match('/(?<!\.json)\.php/', $path);
+                    }
+                )
+            );
+        }
+
+        $options = $this->parseOptions($args);
+        $issueLoggingEnabled = isset($options['issue-logging-enabled']);
+
+        // Generate API docs
+        $builder = new DocsBuilder(
+            $apiProvider,
+            $outputDir,
+            $template,
+            'http://docs.aws.amazon.com/aws-sdk-php/v3/api/',
+            [],
+            $sourceFiles,
+            $issueLoggingEnabled
+        );
+        $builder->build();
+
+        return 0;
+    }
+}
diff --git a/build/Command/GhReleaseCommand.php b/build/Command/GhReleaseCommand.php
new file mode 100644
index 0000000000..92b2b21078
--- /dev/null
+++ b/build/Command/GhReleaseCommand.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace AwsBuild\Command;
+
+use GuzzleHttp\Psr7\Uri;
+use GuzzleHttp\Psr7;
+
+final class GhReleaseCommand extends AbstractCommand
+{
+    private const MAX_ATTEMPTS = 3;
+
+    public function getName(): string
+    {
+        return 'gh-release';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Creates a GitHub release and uploads aws.phar / aws.zip.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'OAUTH_TOKEN=<token> php build/WorkflowCommandRunner.php gh-release --tag=<X.Y.Z>';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $options = $this->parseOptions($args);
+
+        $token = getenv('OAUTH_TOKEN');
+        if (!$token) {
+            $this->error('An OAUTH_TOKEN environment variable is required');
+            return 1;
+        }
+
+        if (empty($options['tag'])) {
+            $this->error('A --tag option is required. Usage: gh-release --tag=X.Y.Z');
+            return 1;
+        }
+
+        $tag = $options['tag'];
+        $owner = 'aws';
+        $repo = 'aws-sdk-php';
+
+        // Grab and validate the tag annotation
+        chdir($this->getProjectRoot());
+        $message = `chag contents -t "$tag"`;
+        if (!$message) {
+            $this->error('Chag could not find or parse the tag');
+            return 1;
+        }
+
+        // Add retry middleware
+        $stack = \GuzzleHttp\HandlerStack::create();
+        $stack->push(\GuzzleHttp\Middleware::retry(
+            function ($retries, $request, $response) {
+                $statusCode = $response->getStatusCode();
+                if ($retries < self::MAX_ATTEMPTS && !in_array($statusCode, [200, 201, 202])) {
+                    $this->output("Attempt failed with status code {$statusCode}: "
+                        . $response->getBody());
+                    return true;
+                }
+                return false;
+            },
+            function ($retries) {
+                return 1000 * (1 + $retries);
+            }
+        ));
+
+        // Create a GitHub client.
+        $client = new \GuzzleHttp\Client([
+            'base_uri' => 'https://api.github.com/',
+            'headers' => ['Authorization' => "token $token"],
+            'handler' => $stack,
+        ]);
+
+        // Create a Github client with no retry middleware
+        $uploadClient = new \GuzzleHttp\Client([
+            'base_uri' => 'https://api.github.com/',
+            'headers' => ['Authorization' => "token $token"]
+        ]);
+
+        // Publish the release
+        $response = $client->post("repos/{$owner}/{$repo}/releases", [
+            'json' => [
+                'tag_name'   => $tag,
+                'name'       => "Version {$tag}",
+                'body'       => $message,
+            ]
+        ]);
+        $releaseBody = json_decode($response->getBody(), true);
+
+        // Grab the location of the new release
+        $url = $response->getHeaderLine('Location');
+        $this->output("Release successfully published to: $url");
+
+        // Uploads go to uploads.github.com
+        $uploadUrl = new Uri($url);
+        $uploadUrl = $uploadUrl->withHost('uploads.github.com');
+
+        // Upload aws.zip
+        $zipAttempts = $this->retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, 'aws.zip');
+        if ($zipAttempts === false) {
+            $this->output("aws.zip upload failed after " . self::MAX_ATTEMPTS . " attempts.");
+        } else {
+            $this->output("aws.zip upload succeeded after {$zipAttempts} attempt(s).");
+        }
+
+        // Upload aws.phar
+        $pharAttempts = $this->retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, 'aws.phar');
+        if ($pharAttempts === false) {
+            $this->output("aws.phar upload failed after " . self::MAX_ATTEMPTS . " attempts.");
+        } else {
+            $this->output("aws.phar upload succeeded after {$pharAttempts} attempt(s).");
+        }
+
+        return 0;
+    }
+
+    /**
+     * Attempts an artifact upload and retries up to MAX_ATTEMPTS times
+     *
+     * @return bool|int
+     */
+    private function retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, $filename)
+    {
+        $isSuccessful = false;
+        $attempts = 0;
+        $filetype = substr($filename, strpos($filename, '.') + 1);
+        $buildDir = self::getBuildDir();
+
+        while (!$isSuccessful && $attempts < self::MAX_ATTEMPTS) {
+            try {
+                $attempts++;
+                $response = $uploadClient->post("{$uploadUrl}/assets?name={$filename}", [
+                    'headers' => ['Content-Type' => "application/{$filetype}"],
+                    'body'    => Psr7\Utils::tryFopen($buildDir . "/artifacts/{$filename}", 'r')
+                ]);
+                $this->output("{$filename} uploaded to: " . json_decode($response->getBody(), true)['browser_download_url']);
+                $isSuccessful = true;
+            } catch (\GuzzleHttp\Exception\ServerException $e) {
+                $this->output("{$filename} failed to upload:");
+                $this->error($e->getMessage());
+
+                // Fetch and inspect assets for failed downloads
+                $response = $client->get("/repos/{$owner}/{$repo}/releases/{$releaseBody['id']}/assets", []);
+                $assets = json_decode($response->getBody(), true);
+
+                foreach ($assets as $asset) {
+                    if ($asset['state'] !== 'uploaded') {
+                        try {
+                            $response = $uploadClient->delete("/repos/{$owner}/{$repo}/releases/assets/{$asset['id']}", []);
+
+                            if ($response->getStatusCode() == 204) {
+                                $this->output("Failed upload of {$asset['name']} at {$asset['browser_download_url']} has successfully been deleted.");
+                            } else {
+                                $this->output("Failed upload of {$asset['name']} at {$asset['browser_download_url']} was unable to be deleted.");
+                            }
+                        } catch (\GuzzleHttp\Exception\ClientException $e) {
+                            $response = $e->getResponse();
+                            if ($response->getStatusCode() == 204) {
+                                $this->output("Failed upload of {$asset['name']} at {$asset['browser_download_url']} has successfully been deleted.");
+                            } else {
+                                $this->output("Failed upload of {$asset['name']} at {$asset['browser_download_url']} was unable to be deleted.");
+                                $this->error($e->getMessage());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        if ($isSuccessful) {
+            return $attempts;
+        }
+
+        return false;
+    }
+}
diff --git a/build/Command/ListCommand.php b/build/Command/ListCommand.php
new file mode 100644
index 0000000000..e27fd9d617
--- /dev/null
+++ b/build/Command/ListCommand.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class ListCommand extends AbstractCommand
+{
+    private array $commandMap;
+
+    public function __construct(array $commandMap)
+    {
+        parent::__construct();
+        $this->commandMap = $commandMap;
+    }
+
+    public function getName(): string
+    {
+        return 'list';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Lists all available commands with descriptions.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php list';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $this->output('Available commands:');
+        $this->output('');
+
+        $maxLen = 0;
+        $commands = [];
+        foreach ($this->commandMap as $name => $class) {
+            if ($name === 'list') {
+                $commands[$name] = $this->getDescription();
+            } else {
+                $command = new $class();
+                $commands[$name] = $command->getDescription();
+            }
+            $maxLen = max($maxLen, strlen($name));
+        }
+
+        foreach ($commands as $name => $description) {
+            $this->output(sprintf("  %-{$maxLen}s  %s", $name, $description));
+        }
+
+        return 0;
+    }
+}
diff --git a/build/Command/NormalizeDocsFilesCommand.php b/build/Command/NormalizeDocsFilesCommand.php
new file mode 100644
index 0000000000..31eaae2270
--- /dev/null
+++ b/build/Command/NormalizeDocsFilesCommand.php
@@ -0,0 +1,272 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class NormalizeDocsFilesCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'normalize-docs-files';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Normalizes phpDocumentor HTML output and copies static assets.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php normalize-docs-files';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $buildDir = self::getBuildDir();
+        $parentDirectory = $buildDir . '/artifacts/docs';
+        $classesDirectory = "$parentDirectory/classes";
+        $namespacesDirectory = "$parentDirectory/namespaces";
+        $packagesDirectory = "$parentDirectory/packages";
+
+        // Process classes and namespaces directories
+        $this->normalizeAndMoveFiles($namespacesDirectory, "namespace-");
+        $this->normalizeAndMoveFiles($classesDirectory, "class-");
+        $this->normalizeAndMoveFiles($packagesDirectory, "package-");
+
+        // Update hrefs in HTML files
+        $this->updateHtmlHrefs($parentDirectory);
+
+        // Updates search index urls with generated api pages
+        $this->updateSearchIndex($parentDirectory . '/js/searchIndex.js');
+
+        // Add the SNS validator notice
+        $this->insertSnsValidatorNotice($parentDirectory);
+
+        // Move static assets
+        $this->copyDirectory($buildDir . '/docs/static', $parentDirectory . '/static');
+        $this->copyDirectory($buildDir . '/docs/js', $parentDirectory . '/js');
+        $this->copyDirectory($buildDir . '/docs/css', $parentDirectory . '/css');
+
+        // Remove unnecessary files/directories
+        $removableDirs = ['classes', 'files', 'graphs', 'indices', 'namespaces', 'packages', 'reports'];
+
+        foreach ($removableDirs as $dir) {
+            $this->deleteDirectory("{$parentDirectory}/{$dir}");
+        }
+
+        $this->output("All tasks completed.");
+        return 0;
+    }
+
+    private function normalizeAndMoveFiles(string $directory, string $prefix): void
+    {
+        $files = glob($directory . '/*');
+        foreach ($files as $file) {
+            if (is_file($file)) {
+                $basename = ucfirst(basename($file));
+                $modifiedBasename = str_replace("-", ".", $basename);
+                $newFilename = $prefix . $modifiedBasename;
+                $newPath = dirname($directory) . '/' . $newFilename;
+                rename($file, $newPath);
+                $this->output("Moved and renamed $file to $newPath");
+            }
+        }
+    }
+
+    private function updateHtmlHrefs(string $directory): void
+    {
+        $htmlFiles = glob($directory . '/*.html');
+        foreach ($htmlFiles as $file) {
+            $doc = new \DOMDocument();
+            @$doc->loadHTMLFile($file);
+
+            // Remove <base> tags
+            while (($baseTags = $doc->getElementsByTagName('base')) && $baseTags->length) {
+                $baseTag = $baseTags->item(0);
+                $baseTag->parentNode->removeChild($baseTag);
+            }
+
+            $links = $doc->getElementsByTagName('a');
+
+            foreach ($links as $link) {
+                if ($link->hasAttribute('href')) {
+                    $href = $link->getAttribute('href');
+                    $href = preg_replace_callback(
+                        '/(namespaces|classes|packages)\/([a-zA-Z])/',
+                        function ($matches) {
+                            if ($matches[1] === 'classes') {
+                                $prefix = 'class';
+                            } else {
+                                $prefix = substr($matches[1], 0, -1);
+                            }
+
+                            return $prefix . '-' . strtoupper($matches[2]);
+                        },
+                        $href
+                    );
+                    $href = preg_replace_callback(
+                        '/(namespace-|class-|package-)([\w-]+)\.html/',
+                        function ($matches) {
+                            $suffix = str_replace("-", ".", $matches[2]);
+                            return $matches[1] . $suffix . '.html';
+                        },
+                        $href
+                    );
+                    $link->setAttribute('href', $href);
+                }
+            }
+
+            // Remove <aside> tags with class "phpdocumentor-element-found-in"
+            $asides = $doc->getElementsByTagName('aside');
+            $asidesToRemove = [];
+
+            foreach ($asides as $aside) {
+                if ($aside->getAttribute('class') === 'phpdocumentor-element-found-in') {
+                    $asidesToRemove[] = $aside;
+                }
+            }
+
+            foreach ($asidesToRemove as $asideToRemove) {
+                $asideToRemove->parentNode->removeChild($asideToRemove);
+            }
+
+            $divs = $doc->getElementsByTagName('div');
+
+            foreach ($divs as $div) {
+                if ($div->getAttribute('class') === 'phpdocumentor-modal-content') {
+                    $preTags = $div->getElementsByTagName('pre');
+
+                    foreach ($preTags as $pre) {
+                        if ($pre->hasAttribute('data-src') && strpos($pre->getAttribute('data-src'), 'files/') === 0) {
+                            $div->parentNode->removeChild($div);
+                            break;
+                        }
+                    }
+                }
+            }
+
+            $doc->saveHTMLFile($file);
+            $this->output("Updated hrefs in $file");
+        }
+    }
+
+    private function updateSearchIndex(string $filePath): void
+    {
+        $content = file_get_contents($filePath);
+        if ($content === false) {
+            $this->output("Failed to read file: $filePath");
+            return;
+        }
+
+        $pattern = '/("url":\s*")((?:classes|namespaces)\/)([^"]+)(")/';
+        $replacement = function ($matches) {
+            $newPrefix = str_replace(['classes/', 'namespaces/'], ['class-', 'namespace-'], $matches[2]);
+            $remainder = ucfirst($matches[3]);
+            $remainder = preg_replace('/-/', '.', $remainder);
+
+            return $matches[1] . $newPrefix . $remainder . $matches[4];
+        };
+
+        $updatedContent = preg_replace_callback($pattern, $replacement, $content);
+
+        $result = file_put_contents($filePath, $updatedContent);
+        if ($result === false) {
+            $this->output("Failed to write updated content to file: $filePath");
+        } else {
+            $this->output("File updated successfully: $filePath");
+        }
+    }
+
+    private function insertSnsValidatorNotice(string $directory): void
+    {
+        $targetFile = $directory . '/class-Aws.Sns.MessageValidator.html';
+
+        if (!file_exists($targetFile)) {
+            $this->output("SNS MessageValidator class file not found");
+            return;
+        }
+
+        $doc = new \DOMDocument();
+        @$doc->loadHTMLFile($targetFile);
+
+        $titleElement = null;
+        $h2Elements = $doc->getElementsByTagName('h2');
+        foreach ($h2Elements as $h2) {
+            if ($h2->getAttribute('class') === 'phpdocumentor-content__title') {
+                $titleElement = $h2;
+                break;
+            }
+        }
+
+        if (!$titleElement) {
+            $this->output("Could not find title element in MessageValidator documentation");
+            return;
+        }
+
+        $noticeDiv = $doc->createElement('div');
+        $noticeDiv->setAttribute('class', 'phpdocumentor-admonition');
+
+        $headerParagraph = $doc->createElement('p');
+        $icon = $doc->createElement('i');
+        $icon->setAttribute('class', 'fas fa-question-circle phpdocumentor-admonition__icon');
+        $headerParagraph->appendChild($icon);
+
+        $contentParagraph = $doc->createElement('p');
+        $textBefore = $doc->createTextNode('This class is maintained in ');
+        $link = $doc->createElement('a', 'aws-php-sns-message-validator');
+        $link->setAttribute('href', 'https://github.com/aws/aws-php-sns-message-validator');
+
+        $contentParagraph->appendChild($textBefore);
+        $contentParagraph->appendChild($link);
+
+        $noticeDiv->appendChild($headerParagraph);
+        $noticeDiv->appendChild($contentParagraph);
+
+        $titleElement->parentNode->insertBefore($noticeDiv, $titleElement->nextSibling);
+
+        $doc->saveHTMLFile($targetFile);
+        $this->output("Added SNS validator notice to MessageValidator documentation");
+    }
+
+    private function copyDirectory(string $src, string $dst): void
+    {
+        if (!file_exists($dst)) {
+            mkdir($dst, 0777, true);
+        }
+
+        $dir = opendir($src);
+        while (false !== ($file = readdir($dir))) {
+            if ($file != '.' && $file != '..') {
+                if (is_dir($src . '/' . $file)) {
+                    $this->copyDirectory($src . '/' . $file, $dst . '/' . $file);
+                } else {
+                    copy($src . '/' . $file, $dst . '/' . $file);
+                }
+            }
+        }
+
+        closedir($dir);
+    }
+
+    private function deleteDirectory(string $dir): bool
+    {
+        if (!is_dir($dir)) {
+            return false;
+        }
+
+        $handle = opendir($dir);
+
+        while (false !== ($file = readdir($handle))) {
+            if ($file != '.' && $file != '..') {
+                $path = $dir . '/' . $file;
+                if (is_dir($path)) {
+                    $this->deleteDirectory($path);
+                } else {
+                    unlink($path);
+                }
+            }
+        }
+        closedir($handle);
+
+        return rmdir($dir);
+    }
+}
diff --git a/build/Command/OptionDocsCommand.php b/build/Command/OptionDocsCommand.php
new file mode 100644
index 0000000000..ee94802a93
--- /dev/null
+++ b/build/Command/OptionDocsCommand.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class OptionDocsCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'option-docs';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Prints docblock option documentation for a client class.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php option-docs [--class=<FQCN>] [--format=<fmt>]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $options = $this->parseOptions($args);
+
+        $clientName = $options['class'] ?? 'Aws\\AwsClient';
+        $type = $options['format'] ?? 'docblock';
+
+        $clientArgs = call_user_func([$clientName, 'getArguments']);
+        ksort($clientArgs);
+
+        switch ($type) {
+            case 'docblock':
+                $this->generateDocblock($clientArgs);
+                break;
+            default:
+                $this->error('Unknown type: ' . $type);
+                return 1;
+        }
+
+        return 0;
+    }
+
+    private function generateDocblock(array $args): void
+    {
+        foreach ($args as $name => $value) {
+            if (!isset($value['doc']) || !empty($value['internal'])) {
+                continue;
+            }
+
+            $docs = $value['doc'];
+            $modifiers = [];
+
+            if (isset($value['valid'])) {
+                $modifiers[] = implode('|', $value['valid']);
+            }
+
+            if (!empty($value['required'])) {
+                $modifiers[] = 'required';
+            }
+
+            if (isset($value['default']) && !is_callable($value['default'])) {
+                $modifiers[] = 'default=' . \Aws\describe_type($value['default']);
+            }
+
+            if ($modifiers) {
+                $docs = '(' . implode(', ', $modifiers) . ') ' . $docs;
+            }
+
+            $docs = '* - ' . $name . ': ' . $docs;
+            $this->output(wordwrap($docs, 70, "\n*   ") . "\n");
+        }
+    }
+}
diff --git a/build/Command/PackageCommand.php b/build/Command/PackageCommand.php
new file mode 100644
index 0000000000..ca36a677cd
--- /dev/null
+++ b/build/Command/PackageCommand.php
@@ -0,0 +1,84 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class PackageCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'package';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Packages aws.phar and aws.zip for a release.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php package [--service=<name>]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $buildDir = self::getBuildDir();
+        $projectRoot = $this->getProjectRoot();
+        $stageDirectory = $buildDir . '/artifacts/staging';
+        $burgomaster = new \Burgomaster($stageDirectory, $projectRoot . '/');
+        $autoloaderFilename = 'aws-autoloader.php';
+
+        $metaFiles = ['README.md', 'LICENSE', 'NOTICE', 'CHANGELOG.md'];
+        foreach ($metaFiles as $file) {
+            $burgomaster->deepCopy($file, $file);
+        }
+
+        $sdkFiles = new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator(realpath($projectRoot . '/src'))
+        );
+        $sdkFiles = new \CallbackFilterIterator($sdkFiles, function (\SplFileInfo $file) {
+            return !in_array($file->getBasename('.php'), [
+                'docs-2.json',
+                'examples-1.json',
+            ]);
+        });
+
+        $burgomaster->recursiveCopy('src', 'Aws', ['php', 'php.gz'], $sdkFiles);
+        $burgomaster->recursiveCopy('vendor/aws/aws-php-sns-message-validator/src', 'Aws/Sns');
+        $burgomaster->recursiveCopy('vendor/mtdowling/jmespath.php/src', 'JmesPath');
+        $burgomaster->recursiveCopy('vendor/guzzlehttp/guzzle/src', 'GuzzleHttp');
+        $burgomaster->recursiveCopy('vendor/guzzlehttp/psr7/src', 'GuzzleHttp/Psr7');
+        $burgomaster->recursiveCopy('vendor/guzzlehttp/promises/src', 'GuzzleHttp/Promise');
+        $burgomaster->recursiveCopy('vendor/psr/http-message/src', 'Psr/Http/Message');
+
+        $autoloaderContents = [
+            'Aws/functions.php',
+            'GuzzleHttp/functions_include.php',
+            'JmesPath/JmesPath.php',
+        ];
+
+        if (file_exists($projectRoot . '/vendor/symfony/polyfill-intl-idn')) {
+            $burgomaster->recursiveCopy($projectRoot . '/vendor/symfony/polyfill-intl-idn', 'Symfony/Polyfill/Intl/Idn');
+            array_push($autoloaderContents, 'Symfony/Polyfill/Intl/Idn/bootstrap.php');
+        }
+
+        if (file_exists($projectRoot . '/vendor/psr/http-client/src')) {
+            $burgomaster->recursiveCopy($projectRoot . '/vendor/psr/http-client/src', 'Psr/Http/Client');
+        }
+
+        $burgomaster->createAutoloader($autoloaderContents, $autoloaderFilename);
+
+        $burgomaster->createZip($buildDir . "/artifacts/aws.zip");
+        $burgomaster->createPhar(
+            $buildDir . "/artifacts/aws.phar",
+            null,
+            $autoloaderFilename,
+            'aws-' . \Aws\Sdk::VERSION . '.phar'
+        );
+
+        $burgomaster->startSection('test-phar');
+        $burgomaster->exec('php ' . $buildDir . '/WorkflowCommandRunner.php test-phar');
+        $burgomaster->endSection();
+
+        return 0;
+    }
+}
diff --git a/build/Command/PharTestRunnerCommand.php b/build/Command/PharTestRunnerCommand.php
new file mode 100644
index 0000000000..7b0c4f1f5f
--- /dev/null
+++ b/build/Command/PharTestRunnerCommand.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class PharTestRunnerCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'phar-test-runner';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Runs the PHPUnit + Behat test suites against the phar artifacts.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php phar-test-runner [-- phpunit/behat options]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $script = <<<'INLINE_PHP'
+            require '%BUILD_DIR%' . '/artifacts/aws.phar';
+            require '%BUILD_DIR%' . '/artifacts/phpunit.phar';
+            require '%BUILD_DIR%' . '/artifacts/behat.phar';    
+    INLINE_PHP;
+
+        $buildDir = addslashes(self::getBuildDir());
+        $script = str_replace('%BUILD_DIR%', $buildDir, $script);
+        $output = [];
+        $exitCode = 0;
+        exec('php -r ' . escapeshellarg($script) . ' 2>&1', $output, $exitCode);
+
+        $outputStr = implode("\n", $output);
+
+        if ($exitCode !== 0) {
+            $this->error("Phar test failed (exit code $exitCode):\n$outputStr");
+            return 1;
+        }
+
+        $this->output($outputStr);
+
+        return 0;
+    }
+}
diff --git a/build/Command/RemoveMethodAnnotationsCommand.php b/build/Command/RemoveMethodAnnotationsCommand.php
new file mode 100644
index 0000000000..c131086a03
--- /dev/null
+++ b/build/Command/RemoveMethodAnnotationsCommand.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class RemoveMethodAnnotationsCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'remove-method-annotations';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Strips @method annotations before doc generation.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php remove-method-annotations';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $directoryPath = self::getBuildDir() . '/artifacts/staging/Aws';
+        $fileSuffix = 'Client.php';
+        $this->removeMethodAnnotations($directoryPath, $fileSuffix);
+
+        return 0;
+    }
+
+    private function removeMethodAnnotations(string $dir, string $fileSuffix): void
+    {
+        $iterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($dir));
+
+        foreach ($iterator as $file) {
+            if ($file->isDir()) {
+                continue;
+            }
+
+            if (str_ends_with($file->getPathname(), $fileSuffix)) {
+                $filePath = $file->getRealPath();
+                $content = file_get_contents($filePath);
+
+                // Regular expression to match @method annotations
+                $pattern = '/^\s*\*\s+@method\s+[^\n]+\n/m';
+
+                if (preg_match($pattern, $content)) {
+                    $newContent = preg_replace($pattern, '', $content);
+                    file_put_contents($filePath, $newContent);
+                    $this->output("Method annotations removed from: $filePath");
+                }
+            }
+        }
+    }
+}
diff --git a/build/Command/RemoveServiceCommand.php b/build/Command/RemoveServiceCommand.php
new file mode 100644
index 0000000000..81bd3e55a1
--- /dev/null
+++ b/build/Command/RemoveServiceCommand.php
@@ -0,0 +1,543 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class RemoveServiceCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'remove-service';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Removes all resources for a given AWS service from the SDK codebase.';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php remove-service'
+            . ' --service-id=<identifier> [--commit=true|false] [--dry-run] [--verbose|-v]';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $options = $this->parseOptions($args);
+
+        if (empty($options['service-id'])) {
+            $this->error('Missing required option --service-id');
+            $this->output('');
+            $this->output('Usage:');
+            $this->output('  ' . $this->getUsage());
+            return 1;
+        }
+
+        $serviceId = $options['service-id'];
+        $commit = !isset($options['commit']) || $options['commit'] !== 'false';
+        $dryRun = isset($options['dry-run']);
+
+        $serviceInfo = $this->resolveService($serviceId);
+        if ($serviceInfo === null) {
+            $this->error("Unable to resolve service: \"{$serviceId}\"");
+            return 1;
+        }
+
+        if ($dryRun) {
+            $this->printDryRunSummary($serviceInfo);
+            return 0;
+        }
+
+        $namespace = $serviceInfo['namespace'];
+        $serviceKey = $serviceInfo['serviceKey'];
+
+        try {
+            $this->verbose("Deleting client folder src/{$namespace}/...");
+            $this->deleteClientFolder($namespace);
+            $this->verbose("Deleting client folder src/{$namespace}/... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to delete client folder: " . $e->getMessage());
+            return 1;
+        }
+
+        try {
+            $this->verbose("Removing Sdk.php annotations for {$namespace}...");
+            $this->removeSdkAnnotations($namespace);
+            $this->verbose("Removing Sdk.php annotations for {$namespace}... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to remove Sdk.php annotations: " . $e->getMessage());
+            return 1;
+        }
+
+        try {
+            $this->verbose("Deleting data folder src/data/{$serviceKey}/...");
+            $this->deleteDataFolder($serviceKey);
+            $this->verbose("Deleting data folder src/data/{$serviceKey}/... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to delete data folder: " . $e->getMessage());
+            return 1;
+        }
+
+        try {
+            $this->verbose("Removing {$namespace} from grandfathered-services.json...");
+            $this->removeFromGrandfatheredJson($namespace);
+            $this->verbose("Removing {$namespace} from grandfathered-services.json... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to remove from grandfathered-services.json: " . $e->getMessage());
+            return 1;
+        }
+
+        try {
+            $this->verbose("Removing {$serviceKey} from manifest.json...");
+            $this->removeFromManifest($serviceKey);
+            $this->verbose("Removing {$serviceKey} from manifest.json... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to remove from manifest.json: " . $e->getMessage());
+            return 1;
+        }
+
+        try {
+            $this->verbose("Creating changelog entry for {$serviceKey}...");
+            $this->createChangelogEntry($serviceKey, $namespace);
+            $this->verbose("Creating changelog entry for {$serviceKey}... done");
+        } catch (\Exception $e) {
+            $this->error("Failed to create changelog entry: " . $e->getMessage());
+            return 1;
+        }
+
+        if ($commit) {
+            $this->verbose("Committing changes for {$namespace}...");
+            $this->gitCommit($serviceKey, $namespace);
+            $this->verbose("Committing changes for {$namespace}... done");
+        }
+
+        $this->output("Successfully removed service: {$namespace}");
+        return 0;
+    }
+
+    /**
+     * Resolves a service from the manifest using a three-tier case-insensitive lookup.
+     *
+     * Lookup priority:
+     *   1. Match against manifest keys (Service_Key)
+     *   2. Match against namespace values
+     *   3. Match against serviceIdentifier values
+     *
+     * @param string $input The user-provided service identifier
+     * @return array|null Associative array with serviceKey, namespace, serviceIdentifier or null
+     */
+    private function resolveService(string $input): ?array
+    {
+        $manifestPath = $this->getProjectRoot() . '/src/data/manifest.json';
+        $manifest = json_decode(file_get_contents($manifestPath), true);
+        $lowerInput = strtolower($input);
+
+        // Tier 1: Match against manifest keys (Service_Key)
+        foreach ($manifest as $key => $entry) {
+            if (strtolower($key) === $lowerInput) {
+                return [
+                    'serviceKey' => $key,
+                    'namespace' => $entry['namespace'],
+                    'serviceIdentifier' => $entry['serviceIdentifier'],
+                ];
+            }
+        }
+
+        // Tier 2: Match against namespace values
+        foreach ($manifest as $key => $entry) {
+            if (strtolower($entry['namespace']) === $lowerInput) {
+                return [
+                    'serviceKey' => $key,
+                    'namespace' => $entry['namespace'],
+                    'serviceIdentifier' => $entry['serviceIdentifier'],
+                ];
+            }
+        }
+
+        // Tier 3: Match against serviceIdentifier values
+        foreach ($manifest as $key => $entry) {
+            if (strtolower($entry['serviceIdentifier']) === $lowerInput) {
+                return [
+                    'serviceKey' => $key,
+                    'namespace' => $entry['namespace'],
+                    'serviceIdentifier' => $entry['serviceIdentifier'],
+                ];
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Recursively deletes the client folder at src/{Namespace}/.
+     *
+     * Logs a warning and continues if the directory does not exist.
+     *
+     * @param string $namespace The PHP namespace segment (e.g., "S3", "ACMPCA")
+     */
+    private function deleteClientFolder(string $namespace): void
+    {
+        $path = $this->getProjectRoot() . '/src/' . $namespace;
+
+        if (!is_dir($path)) {
+            $this->output("[WARNING] Client folder does not exist: {$path}");
+            return;
+        }
+
+        $iterator = new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator($path, \FilesystemIterator::SKIP_DOTS),
+            \RecursiveIteratorIterator::CHILD_FIRST
+        );
+
+        foreach ($iterator as $item) {
+            if ($item->isDir()) {
+                rmdir($item->getPathname());
+            } else {
+                unlink($item->getPathname());
+            }
+        }
+
+        rmdir($path);
+    }
+
+    /**
+     * Removes @method annotation lines for the given namespace from src/Sdk.php.
+     *
+     * Removes lines containing create{Namespace}( and createMultiRegion{Namespace}(.
+     * Uses string matching (not regex) on each line. Logs a warning if either
+     * annotation line is not found.
+     *
+     * @param string $namespace The PHP namespace segment (e.g., "S3", "ACMPCA")
+     */
+    private function removeSdkAnnotations(string $namespace): void
+    {
+        $sdkPath = $this->getProjectRoot() . '/src/Sdk.php';
+        $content = file_get_contents($sdkPath);
+        $lines = explode("\n", $content);
+
+        $createNeedle = 'create' . $namespace . '(';
+        $multiRegionNeedle = 'createMultiRegion' . $namespace . '(';
+
+        $foundCreate = false;
+        $foundMultiRegion = false;
+        $filteredLines = [];
+
+        foreach ($lines as $line) {
+            if (strpos($line, $createNeedle) !== false
+                && strpos($line, '@method') !== false
+            ) {
+                $foundCreate = true;
+                continue;
+            }
+
+            if (strpos($line, $multiRegionNeedle) !== false
+                && strpos($line, '@method') !== false
+            ) {
+                $foundMultiRegion = true;
+                continue;
+            }
+
+            $filteredLines[] = $line;
+        }
+
+        if (!$foundCreate) {
+            $this->output("[WARNING] Sdk.php annotation not found: {$createNeedle}");
+        }
+
+        if (!$foundMultiRegion) {
+            $this->output("[WARNING] Sdk.php annotation not found: {$multiRegionNeedle}");
+        }
+
+        file_put_contents($sdkPath, implode("\n", $filteredLines));
+    }
+
+    /**
+     * Recursively deletes the data folder at src/data/{serviceKey}/.
+     *
+     * Uses the manifest key (Service_Key), not serviceIdentifier, for the path.
+     * Logs a warning and continues if the directory does not exist.
+     *
+     * @param string $serviceKey The manifest key (e.g., "acm-pca", "apigateway")
+     */
+    private function deleteDataFolder(string $serviceKey): void
+    {
+        $path = $this->getProjectRoot() . '/src/data/' . $serviceKey;
+
+        if (!is_dir($path)) {
+            $this->output("[WARNING] Data folder does not exist: {$path}");
+            return;
+        }
+
+        $iterator = new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator($path, \FilesystemIterator::SKIP_DOTS),
+            \RecursiveIteratorIterator::CHILD_FIRST
+        );
+
+        foreach ($iterator as $item) {
+            if ($item->isDir()) {
+                rmdir($item->getPathname());
+            } else {
+                unlink($item->getPathname());
+            }
+        }
+
+        rmdir($path);
+    }
+
+    /**
+     * Removes the namespace from the grandfathered-services.json file.
+     *
+     * Loads the JSON file, removes the exact-match namespace from the
+     * "grandfathered-services" array, and writes back with JSON_PRETTY_PRINT.
+     * Logs a warning if the namespace is not present.
+     *
+     * @param string $namespace The PHP namespace segment (e.g., "S3", "ACMPCA")
+     */
+    private function removeFromGrandfatheredJson(string $namespace): void
+    {
+        $path = $this->getProjectRoot() . '/src/data/grandfathered-services.json';
+        $data = json_decode(file_get_contents($path), true);
+
+        $services = $data['grandfathered-services'];
+        $index = array_search($namespace, $services, true);
+
+        if ($index === false) {
+            $this->output("[WARNING] Namespace \"{$namespace}\" not found in grandfathered-services.json");
+            return;
+        }
+
+        array_splice($services, $index, 1);
+        $data['grandfathered-services'] = $services;
+
+        file_put_contents($path, json_encode($data, JSON_PRETTY_PRINT) . "\n");
+
+        // Now generate the PHP version of this file
+        $jsonCompiler = new \JsonCompiler($path);
+        $jsonCompiler->compile("$path.php");
+    }
+
+    /**
+     * Removes the service entry from the manifest.json file.
+     *
+     * Loads src/data/manifest.json, removes the entry keyed by $serviceKey,
+     * and writes back with JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES.
+     *
+     * @param string $serviceKey The manifest key (e.g., "acm-pca", "s3")
+     */
+    private function removeFromManifest(string $serviceKey): void
+    {
+        $root = $this->getProjectRoot();
+        $jsonPath = $root . '/src/data/manifest.json';
+
+        $manifest = json_decode(file_get_contents($jsonPath), true);
+        unset($manifest[$serviceKey]);
+
+        // Write manifest.json
+        file_put_contents(
+            $jsonPath,
+            json_encode($manifest, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n"
+        );
+
+        // Generate the PHP version of this file
+        $jsonCompiler = new \JsonCompiler($jsonPath);
+        $jsonCompiler->compile("$jsonPath.php");
+    }
+
+    /**
+     * Creates a changelog entry for the service removal.
+     *
+     * Creates the .changes/nextrelease/ directory if it does not exist,
+     * then writes a remove-{serviceKey}.json file with the standard
+     * changelog JSON structure.
+     *
+     * @param string $serviceKey The manifest key (e.g., "acm-pca", "s3")
+     * @param string $namespace The PHP namespace segment (e.g., "S3", "ACMPCA")
+     */
+    private function createChangelogEntry(string $serviceKey, string $namespace): void
+    {
+        $dir = $this->getProjectRoot() . '/.changes/nextrelease';
+
+        if (!is_dir($dir)) {
+            mkdir($dir, 0755, true);
+        }
+
+        $entry = [
+            [
+                'type' => 'api-change',
+                'category' => $namespace,
+                'description' => "Removes the `{$namespace}` service, which has been deprecated.",
+            ],
+        ];
+
+        file_put_contents(
+            $dir . '/remove-' . $serviceKey . '.json',
+            json_encode($entry, JSON_PRETTY_PRINT) . "\n"
+        );
+    }
+
+    /**
+     * Stages all changes and commits with a service removal message.
+     *
+     * Runs `git add -A` followed by `git commit -m "Remove {Namespace} service"`.
+     * On failure of either command, prints the git error output and exits
+     * with a non-zero code.
+     *
+     * @param string $namespace The PHP namespace segment (e.g., "S3", "ACMPCA")
+     */
+    private function gitCommit(string $serviceKey, string $namespace): void
+    {
+        $root = $this->getProjectRoot();
+        $paths = [
+            $root . '/src/' . $namespace,
+            $root . '/src/data/' . $serviceKey,
+            $root . '/src/Sdk.php',
+            $root . '/src/data/manifest.json',
+            $root . '/src/data/manifest.json.php',
+            $root . '/src/data/grandfathered-services.json',
+            $root . '/src/data/grandfathered-services.json.php',
+            $root . '/.changes/nextrelease/remove-' . $serviceKey . '.json',
+        ];
+
+        $output = [];
+        $exitCode = 0;
+        $escapedPaths = implode(' ', array_map('escapeshellarg', $paths));
+        exec('git add ' . $escapedPaths . ' 2>&1', $output, $exitCode);
+        if ($exitCode !== 0) {
+            $errorMessage = 'git add failed: ' . implode("\n", $output);
+            $this->error($errorMessage);
+
+            throw new \RuntimeException($errorMessage);
+        }
+
+        $output = [];
+        $message = "Remove {$namespace} service";
+        exec('git commit -m ' . escapeshellarg($message) . ' 2>&1', $output, $exitCode);
+        if ($exitCode !== 0) {
+            $errorMessage = 'git commit failed: ' . implode("\n", $output);
+            $this->error($errorMessage);
+
+            throw new \RuntimeException($errorMessage);
+        }
+    }
+
+    /**
+     * Prints a dry-run summary of what the removal tool would do.
+     *
+     * Checks existence of folders/files, reads Sdk.php for annotation lines,
+     * checks grandfathered lists, shows manifest entry and changelog content
+     * preview. Does not modify any files.
+     *
+     * @param array $serviceInfo Associative array with serviceKey, namespace, serviceIdentifier
+     */
+    private function printDryRunSummary(array $serviceInfo): void
+    {
+        $serviceKey = $serviceInfo['serviceKey'];
+        $namespace = $serviceInfo['namespace'];
+        $serviceIdentifier = $serviceInfo['serviceIdentifier'];
+        $root = $this->getProjectRoot();
+
+        $this->output('=== Dry Run Summary ===');
+        $this->output("Service Key: {$serviceKey}");
+        $this->output("Namespace: {$namespace}");
+        $this->output("Service Identifier: {$serviceIdentifier}");
+        $this->output('');
+
+        // Client folder
+        $clientPath = $root . '/src/' . $namespace;
+        $clientExists = is_dir($clientPath) ? 'EXISTS' : 'NOT FOUND';
+        $this->output("[Client Folder] src/{$namespace}/ - {$clientExists}");
+
+        // Data folder
+        $dataPath = $root . '/src/data/' . $serviceKey;
+        $dataExists = is_dir($dataPath) ? 'EXISTS' : 'NOT FOUND';
+        $this->output("[Data Folder] src/data/{$serviceKey}/ - {$dataExists}");
+
+        // Sdk.php annotations
+        $sdkPath = $root . '/src/Sdk.php';
+        $createNeedle = 'create' . $namespace . '(';
+        $multiRegionNeedle = 'createMultiRegion' . $namespace . '(';
+
+        $this->output('');
+        $this->output('[Sdk.php Annotations]');
+
+        if (file_exists($sdkPath)) {
+            $sdkContent = file_get_contents($sdkPath);
+            $sdkLines = explode("\n", $sdkContent);
+            $foundCreate = false;
+            $foundMultiRegion = false;
+
+            foreach ($sdkLines as $line) {
+                if (strpos($line, $createNeedle) !== false
+                    && strpos($line, '@method') !== false
+                ) {
+                    $this->output('  Would remove: ' . trim($line));
+                    $foundCreate = true;
+                }
+                if (strpos($line, $multiRegionNeedle) !== false
+                    && strpos($line, '@method') !== false
+                ) {
+                    $this->output('  Would remove: ' . trim($line));
+                    $foundMultiRegion = true;
+                }
+            }
+
+            if (!$foundCreate) {
+                $this->output("  Annotation not found: {$createNeedle}");
+            }
+            if (!$foundMultiRegion) {
+                $this->output("  Annotation not found: {$multiRegionNeedle}");
+            }
+        } else {
+            $this->output('  Sdk.php not found');
+        }
+
+        // Grandfathered services
+        $this->output('');
+        $this->output('[Grandfathered Services]');
+
+        $gfJsonPath = $root . '/src/data/grandfathered-services.json';
+        if (file_exists($gfJsonPath)) {
+            $gfData = json_decode(file_get_contents($gfJsonPath), true);
+            $inJson = in_array($namespace, $gfData['grandfathered-services'], true);
+            $jsonStatus = $inJson ? 'FOUND - would remove' : 'NOT FOUND';
+            $this->output("  grandfathered-services.json: {$jsonStatus}");
+        } else {
+            $this->output('  grandfathered-services.json: file not found');
+        }
+
+        $gfPhpPath = $root . '/src/data/grandfathered-services.json.php';
+        if (file_exists($gfPhpPath)) {
+            $gfPhpData = include $gfPhpPath;
+            $inPhp = in_array($namespace, $gfPhpData['grandfathered-services'], true);
+            $phpStatus = $inPhp ? 'FOUND - would remove' : 'NOT FOUND';
+            $this->output("  grandfathered-services.json.php: {$phpStatus}");
+        } else {
+            $this->output('  grandfathered-services.json.php: file not found');
+        }
+
+        // Manifest entry
+        $this->output('');
+        $this->output('[Manifest] Would remove from manifest.json and manifest.json.php:');
+        $manifestPath = $root . '/src/data/manifest.json';
+        $manifest = json_decode(file_get_contents($manifestPath), true);
+        if (isset($manifest[$serviceKey])) {
+            $entryJson = json_encode(
+                [$serviceKey => $manifest[$serviceKey]],
+                JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES
+            );
+            $this->output($entryJson);
+        }
+
+        // Changelog entry preview
+        $this->output('');
+        $this->output('[Changelog Entry] Would create .changes/nextrelease/remove-' . $serviceKey . '.json:');
+        $changelogEntry = [
+            [
+                'type' => 'api-change',
+                'category' => $namespace,
+                'description' => "Removes the `{$namespace}` service, which has been deprecated.",
+            ],
+        ];
+        $this->output(json_encode($changelogEntry, JSON_PRETTY_PRINT));
+    }
+
+}
diff --git a/build/Command/TestPharCommand.php b/build/Command/TestPharCommand.php
new file mode 100644
index 0000000000..5219999501
--- /dev/null
+++ b/build/Command/TestPharCommand.php
@@ -0,0 +1,90 @@
+<?php
+
+namespace AwsBuild\Command;
+
+final class TestPharCommand extends AbstractCommand
+{
+    public function getName(): string
+    {
+        return 'test-phar';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Validates the built aws.phar (clients, functions, methods).';
+    }
+
+    public function getUsage(): string
+    {
+        return 'php build/WorkflowCommandRunner.php test-phar';
+    }
+
+    protected function doExecute(array $args): int
+    {
+        $pharPath = self::getBuildDir() . '/artifacts/aws.phar';
+
+        if (!file_exists($pharPath)) {
+            $this->error("Phar not found: $pharPath");
+            return 1;
+        }
+
+        $escapedPharPath = addslashes($pharPath);
+
+        $script = <<<'INLINE_PHP'
+            require '%PHAR_PATH%';
+
+            $conf = [
+                "credentials" => ["key" => "foo", "secret" => "bar"],
+                "region"      => "us-west-2",
+                "version"     => "latest"
+            ];
+
+            $s3 = new \Aws\S3\S3Client($conf);
+            $s3->getPaginator("ListObjects");
+
+            \Aws\DynamoDb\DynamoDbClient::factory($conf);
+
+            \JmesPath\search("foo", ["foo" => "bar"]);
+
+            $functionChecks = [
+                "JmesPath\\search",
+                "Aws\\dir_iterator",
+            ];
+            foreach ($functionChecks as $fn) {
+                if (!function_exists($fn)) {
+                    fwrite(STDERR, $fn . " not found\n");
+                    exit(1);
+                }
+            }
+
+            $classMethodChecks = [
+                "GuzzleHttp\\Promise\\Utils" => "inspect",
+                "GuzzleHttp\\Psr7\\Utils" => "streamFor",
+            ];
+            foreach ($classMethodChecks as $class => $method) {
+                if (!method_exists($class, $method)) {
+                    fwrite(STDERR, $class . "::" . $method . " not found\n");
+                    exit(1);
+                }
+            }
+
+            echo "Version=" . \Aws\Sdk::VERSION;
+    INLINE_PHP;
+
+        $script = str_replace('%PHAR_PATH%', $escapedPharPath, $script);
+
+        $output = [];
+        $exitCode = 0;
+        exec('php -r ' . escapeshellarg($script) . ' 2>&1', $output, $exitCode);
+
+        $outputStr = implode("\n", $output);
+
+        if ($exitCode !== 0) {
+            $this->error("Phar test failed (exit code $exitCode):\n$outputStr");
+            return 1;
+        }
+
+        $this->output($outputStr);
+        return 0;
+    }
+}
diff --git a/build/WorkflowCommandRunner.php b/build/WorkflowCommandRunner.php
new file mode 100644
index 0000000000..dcd17aa2bf
--- /dev/null
+++ b/build/WorkflowCommandRunner.php
@@ -0,0 +1,117 @@
+<?php
+
+namespace AwsBuild;
+
+require dirname(__DIR__) . '/vendor/autoload.php';
+
+use AwsBuild\Command\AnnotateClientLocatorCommand;
+use AwsBuild\Command\AnnotateClientsCommand;
+use AwsBuild\Command\BuildChangelogCommand;
+use AwsBuild\Command\BuildManifestCommand;
+use AwsBuild\Command\BuildRedirectMapCommand;
+use AwsBuild\Command\BuildServiceCommand;
+use AwsBuild\Command\ClearCacheCommand;
+use AwsBuild\Command\CompileJsonCommand;
+use AwsBuild\Command\DocsCommand;
+use AwsBuild\Command\GhReleaseCommand;
+use AwsBuild\Command\ListCommand;
+use AwsBuild\Command\NormalizeDocsFilesCommand;
+use AwsBuild\Command\OptionDocsCommand;
+use AwsBuild\Command\PackageCommand;
+use AwsBuild\Command\PharTestRunnerCommand;
+use AwsBuild\Command\RemoveMethodAnnotationsCommand;
+use AwsBuild\Command\RemoveServiceCommand;
+use AwsBuild\Command\TestPharCommand;
+
+class WorkflowCommandRunner
+{
+    private const COMMANDS = [
+        'list'                       => ListCommand::class,
+        'clear-cache'                => ClearCacheCommand::class,
+        'compile-json'               => CompileJsonCommand::class,
+        'build-redirect-map'         => BuildRedirectMapCommand::class,
+        'phar-test-runner'           => PharTestRunnerCommand::class,
+        'annotate-clients'           => AnnotateClientsCommand::class,
+        'annotate-client-locator'    => AnnotateClientLocatorCommand::class,
+        'build-manifest'             => BuildManifestCommand::class,
+        'build-service'              => BuildServiceCommand::class,
+        'option-docs'                => OptionDocsCommand::class,
+        'test-phar'                  => TestPharCommand::class,
+        'remove-method-annotations'  => RemoveMethodAnnotationsCommand::class,
+        'package'                    => PackageCommand::class,
+        'docs'                       => DocsCommand::class,
+        'gh-release'                 => GhReleaseCommand::class,
+        'normalize-docs-files'       => NormalizeDocsFilesCommand::class,
+        'build-changelog'            => BuildChangelogCommand::class,
+        'remove-service'             => RemoveServiceCommand::class,
+    ];
+
+    public function run(array $argv): int
+    {
+        $commandName = $argv[1] ?? null;
+
+        if ($commandName === null) {
+            return $this->usage();
+        }
+
+        if (!isset(self::COMMANDS[$commandName])) {
+            fwrite(STDERR, "Unknown command: $commandName\n");
+            return $this->usage();
+        }
+
+        [$projectRoot, $args] = $this->parseArgs(array_slice($argv, 2));
+
+        $_SERVER['argv'] = array_merge([$argv[0]], $args);
+        $_SERVER['argc'] = count($_SERVER['argv']);
+
+        $command = $this->createCommand($commandName, $projectRoot);
+
+        return $command->execute($args);
+    }
+
+    private function usage(): int
+    {
+        fwrite(STDERR, "Usage: php build/WorkflowCommandRunner.php <command> [options...]\n");
+        fwrite(STDERR, "Run 'php build/WorkflowCommandRunner.php list' to see available commands.\n");
+        return 1;
+    }
+
+    private function parseArgs(array $args): array
+    {
+        $projectRoot = null;
+        $filtered = [];
+        foreach ($args as $arg) {
+            if (str_starts_with($arg, '--project-root=')) {
+                $projectRoot = substr($arg, strlen('--project-root='));
+            } else {
+                $filtered[] = $arg;
+            }
+        }
+        return [$projectRoot, $filtered];
+    }
+
+    private function createCommand(string $name, ?string $projectRoot): Command\CommandInterface
+    {
+        $class = self::COMMANDS[$name];
+
+        if ($class === ListCommand::class) {
+            return new ListCommand(self::COMMANDS);
+        }
+
+        return new $class($projectRoot);
+    }
+}
+
+// Self-contained autoloader for AwsBuild classes.
+spl_autoload_register(function ($class) {
+    $prefix = 'AwsBuild\\';
+    if (strncmp($prefix, $class, strlen($prefix)) === 0) {
+        $relativeClass = substr($class, strlen($prefix));
+        $file = __DIR__ . '/' . str_replace('\\', '/', $relativeClass) . '.php';
+        if (file_exists($file)) {
+            require $file;
+        }
+    }
+});
+
+exit((new WorkflowCommandRunner())->run($_SERVER['argv']));
diff --git a/build/annotate-client-locator.php b/build/annotate-client-locator.php
deleted file mode 100644
index 1a7ba224b4..0000000000
--- a/build/annotate-client-locator.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-/**
- * This file updates the '@method' annotations on the Aws\Sdk class.
- */
-
-require __DIR__ . '/../vendor/autoload.php';
-
-$namespaces = array_map(function (array $manifest) {
-    return $manifest['namespace'];
-}, array_values(Aws\manifest()));
-
-sort($namespaces);
-$annotations = [];
-foreach ($namespaces as $namespace) {
-    $mrClient = "\\Aws\\{$namespace}\\{$namespace}MultiRegionClient";
-    $mrClient = class_exists($mrClient) ? $mrClient : "\\Aws\\MultiRegionClient";
-
-    $annotations []= " * @method \\Aws\\{$namespace}\\{$namespace}Client"
-        . " create{$namespace}(array \$args = [])";
-    $annotations []= " * @method $mrClient"
-        . " createMultiRegion{$namespace}(array \$args = [])";
-}
-
-$previousAnnotationPattern = '/^\* @method'
-    . ' \\\\Aws\\\\(?:[a-zA-Z0-9\\\\]+)Client'
-    . ' create(?:[a-zA-Z0-9]+)\\(array \$args = \\[\\]\\)/';
-
-$updater = new ClassAnnotationUpdater(
-    new ReflectionClass(\Aws\Sdk::class),
-    $annotations,
-    '',
-    $previousAnnotationPattern
-);
-$updater->update();
diff --git a/build/annotate-clients.php b/build/annotate-clients.php
deleted file mode 100644
index 939e5b3b7c..0000000000
--- a/build/annotate-clients.php
+++ /dev/null
@@ -1,76 +0,0 @@
-<?php
-/**
- * This file is responsible for adding @method annotations to each client class.
- */
-require __DIR__ . '/../vendor/autoload.php';
-
-// parse out --class, --tag, and --all options
-// You can have multiple --class and --tag flags
-//  e.g. php annotate-clients.php --class=Aws\S3\S3Client --class=Aws\Swf\SwfClient
-// Use --class to update the annotation on a class
-// Use --tag to update annotations on clients updated since a given git tag
-// Use --tag=latest to do so comparing against the last release
-// Use --all to update annotations on all clients
-// Combine them at will; each class will only be updated once
-$options = getopt('', ['class:', 'tag:', 'all']) + ['class' => [], 'tag' => []];
-
-// make sure all options are arrays
-array_walk($options, function (&$value) {
-    if (!is_array($value)) {
-        $value = [$value];
-    }
-});
-
-function get_client_classes($namespace) {
-    $clients = ["Aws\\{$namespace}\\{$namespace}Client"];
-    if (class_exists("Aws\\{$namespace}\\{$namespace}MultiRegionClient")) {
-        $clients []= "Aws\\{$namespace}\\{$namespace}MultiRegionClient";
-    }
-
-    return $clients;
-};
-
-if (isset($options['all'])) {
-    // Get all client classes and mark them for update
-    $options['class'] = Aws\flatmap(Aws\manifest(), function (array $manifest) {
-        return get_client_classes($manifest['namespace']);
-    });
-}
-
-foreach ($options['tag'] as $tag) {
-    // Change 'latest' to the last release
-    if ('latest' === $tag) {
-        $tag = trim(`git tag | tail -n 1`);
-    }
-
-    // Find all api-2.json files changed since a given tag. These are service
-    // API definitions; changes here can mean changes to client annotations.
-    exec("git diff-index --name-only --cached $tag", $files);
-    $alteredApiFiles = array_filter($files, function ($file) {
-        return preg_match('/api-2.json$/', $file);
-    });
-
-    // Find the client classes for each changed API service definition and mark
-    // them for update.
-    $clientsWithChangedApis = Aws\flatmap($alteredApiFiles, function ($file) {
-        $file = str_replace('src/data/', '', $file);
-        $endpoint = substr($file, 0, strpos($file, '/'));
-        return get_client_classes(Aws\manifest($endpoint)['namespace']);
-    });
-    $options['class'] = \Aws\flatmap(
-        [$options['class'], $clientsWithChangedApis],
-        function ($class) { return $class; }
-    );
-}
-
-foreach ($options['class'] as $classToUpdate) {
-    // Update the @method annotations on a client.
-    $annotator = new ClientAnnotator($classToUpdate);
-
-    if (!$annotator->updateApiMethodAnnotations()) {
-        trigger_error(
-            "Unable to update annotations on $classToUpdate",
-            E_USER_WARNING
-        );
-    }
-}
diff --git a/build/aws-clear-cache.php b/build/aws-clear-cache.php
deleted file mode 100644
index a5ec195cfa..0000000000
--- a/build/aws-clear-cache.php
+++ /dev/null
@@ -1,4 +0,0 @@
-<?php
-require __DIR__  . '/../vendor/autoload.php';
-
-\JmesPath\Env::cleanCompileDir();
diff --git a/build/build-manifest.php b/build/build-manifest.php
deleted file mode 100644
index ac33c3cfa1..0000000000
--- a/build/build-manifest.php
+++ /dev/null
@@ -1,115 +0,0 @@
-<?php
-/*
- * This file is responsible for building up the API manifest file, including
- * determining the latest API version and hooking up endpoint prefix names
- * with client namespace names.
- */
-
-$compatibleApiVersions = [
-    'apigateway' => [
-        'latest' => [
-            '2015-06-01',
-        ],
-    ],
-    'cloudfront' => [
-        'latest' => [
-            '2016-01-13',
-            '2015-09-17',
-        ],
-        '2015-07-27' => [
-            '2015-04-17',
-            '2014-11-06'
-        ],
-    ],
-    'ec2' => [
-        'latest' => [
-            '2015-04-15',
-        ],
-    ],
-    'events' => [
-        'latest' => [
-            '2014-02-03',
-        ],
-    ],
-    'inspector' => [
-        'latest' => [
-            '2015-08-18',
-        ]
-    ],
-];
-
-// Create a list of possible namespaces so that we can include it in the
-// manifest.
-$possibleNamespaces = [];
-$skip = ['.', '..', 'Api', 'data', 'Multipart', 'Signature'];
-foreach (scandir(__DIR__ . '/../src') as $dir) {
-    if (!in_array($dir, $skip) && is_dir(__DIR__ . '/../src/' . $dir)) {
-        $possibleNamespaces[strtolower($dir)] = $dir;
-    }
-}
-
-$manifest = [];
-foreach (glob(__DIR__ . '/../src/data/**/**/api-2.json') as $file) {
-    $model = json_decode(file_get_contents($file), true);
-    preg_match('@src/data/([^/]+)/[0-9]{4}-[0-9]{2}-[0-9]{2}/api-2.json$@', $file, $matches);
-    $identifier = $matches[1];
-    $metadata = $model['metadata'] + ['compatibleApiVersions' => []];
-    if (empty($manifest[$identifier])) {
-        // Calculate a namespace for the service.
-        $ns = isset($metadata['serviceAbbreviation'])
-            ? $metadata['serviceAbbreviation']
-            : $metadata['serviceFullName'];
-        $ns = str_replace(['Amazon', 'AWS', 'Beta', '(', ')', ' ', '/', '-'], '', $ns);
-
-        //check if it's a grandfathered namespace
-        $grandfatheredServices = json_decode(
-            file_get_contents(__DIR__ . '/../src/data/grandfathered-services.json'),
-            true
-        )['grandfathered-services'];
-        if (!in_array($ns, $grandfatheredServices)) {
-            $ns = str_replace(' ', '', ucwords($metadata['serviceId']));
-        }
-
-        if (!isset($possibleNamespaces[strtolower($ns)])) {
-            throw new \Exception('NS not found: ' . $ns);
-        }
-
-        $ns = $possibleNamespaces[strtolower($ns)];
-
-        $manifest[$identifier] = [
-            'namespace' => $ns,
-            'versions' => [],
-        ];
-    }
-
-    $manifest[$identifier]['versions'][$metadata['apiVersion']]
-        = $metadata['apiVersion'];
-
-    $serviceIdentifier = isset($metadata['serviceId'])
-        ? str_replace(' ', '_', strtolower($metadata['serviceId']))
-        : '';
-
-    if (!empty($serviceIdentifier)) {
-        $manifest[$identifier]['serviceIdentifier'] = $serviceIdentifier;
-    }
-}
-
-foreach ($manifest as $identifier => &$metadata) {
-    $metadata['versions']['latest'] = max(array_keys($metadata['versions']));
-    foreach ($metadata['versions'] as $name => $version) {
-        if (isset($compatibleApiVersions[$identifier][$name])) {
-            foreach ($compatibleApiVersions[$identifier][$name] as $compatVersion) {
-                $metadata['versions'][$compatVersion]
-                    = $metadata['versions'][$name];
-            }
-        }
-    }
-
-    krsort($metadata['versions']);
-}
-
-$data = json_encode($manifest, JSON_PRETTY_PRINT);
-$file = __DIR__ . '/../src/data/manifest.json';
-file_put_contents($file, "$data\n");
-
-echo "Wrote the following data to {$file}:\n>>>>>\n{$data}<<<<<\n";
diff --git a/build/build-redirect-map.php b/build/build-redirect-map.php
deleted file mode 100644
index b20ce5390d..0000000000
--- a/build/build-redirect-map.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-// Setup autoloading for SDK and build classes.
-require __DIR__ . '/../vendor/autoload.php';
-
-use Aws\Build\Docs\RedirectMapBuilder;
-
-$path = __DIR__ . '/artifacts/docs/package.redirects.conf';
-$apiProvider = \Aws\Api\ApiProvider::defaultProvider();
-
-$builder = new RedirectMapBuilder($apiProvider, $path);
-$builder->build();
diff --git a/build/build-service.php b/build/build-service.php
deleted file mode 100644
index ef969dfd15..0000000000
--- a/build/build-service.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-
-require __DIR__ . '/../vendor/autoload.php';
-require __DIR__ . '/ServiceBuilder.php';
-
-$options = getopt('', [
-    'namespace:',
-    'model:',
-    'clientPath:',
-    'exceptionPath:'
-]);
-
-if (empty($options['namespace']) || empty($options['model'])) {
-    throw new LogicException(
-        "You must specify a namespace (--namespace=) and path to an api model "
-        . "(--model=) to build a service"
-    );
-}
-
-$options['model'] = \Aws\load_compiled_json($options['model']);
-$options['namespace'] = ucfirst($options['namespace']);
-
-$options += [
-    'clientPath' => dirname(__DIR__)
-        . "/src/{$options['namespace']}/{$options['namespace']}Client.php",
-    'exceptionPath' => dirname(__DIR__)
-        . "/src/{$options['namespace']}/Exception/{$options['namespace']}Exception.php",
-];
-
-(new ServiceBuilder(
-    $options['namespace'],
-    $options['model'],
-    $options['clientPath'],
-    $options['exceptionPath']
-))
-    ->buildClient()
-    ->buildException();
diff --git a/build/changelog/build-changelog.php b/build/changelog/build-changelog.php
deleted file mode 100644
index d56d62cbbf..0000000000
--- a/build/changelog/build-changelog.php
+++ /dev/null
@@ -1,19 +0,0 @@
-<?php
-
-require __DIR__ . '/ChangelogBuilder.php';
-
-use Aws\Build\Changelog\ChangelogBuilder;
-
-$params = [];
-
-$options = getopt('v');
-
-$params['verbose'] = isset($option['v']) ? $option['v'] : true;
-
-$changelogBuilder = new ChangelogBuilder($params);
-
-$changelogBuilder->buildChangelog();
-
-$changelogBuilder->fixEndpointFile();
-
-$changelogBuilder->cleanNextReleaseFolder();
diff --git a/build/compile-json.php b/build/compile-json.php
deleted file mode 100644
index 216ea15c8f..0000000000
--- a/build/compile-json.php
+++ /dev/null
@@ -1,12 +0,0 @@
-<?php
-require __DIR__ . '/../vendor/autoload.php';
-
-/**
- * Finds all JSON files in src/data, converts them to PHP files that return
- * arrays, and writes those files to $originalFileName.json.php.
- */
-$dataFilesIterator = \Aws\recursive_dir_iterator(realpath(__DIR__ . '/../src/data'));
-foreach (new RegexIterator($dataFilesIterator, '/\.json$/') as $dataFile) {
-    (new JsonCompiler($dataFile))
-        ->compile("$dataFile.php");
-}
diff --git a/build/docs.php b/build/docs.php
deleted file mode 100644
index 5143f68515..0000000000
--- a/build/docs.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-use Aws\Build\Docs\DocsBuilder;
-
-// Setup autoloading for SDK and build classes.
-$loader = require __DIR__ . '/../vendor/autoload.php';
-
-// Setup directories.
-$xmlObj = simplexml_load_file(__DIR__ . '/docs/phpdoc.dist.xml');
-$xmlJson = json_encode($xmlObj);
-$config = json_decode($xmlJson, true);
-$outputDir = __DIR__ . '/artifacts/docs';
-$apiProvider = \Aws\Api\ApiProvider::defaultProvider();
-
-// Extract the built homepage into a template file.
-$xml = new DOMDocument();
-@$xml->loadHTMLFile(__DIR__ . '/artifacts/docs/index.html');
-$ele = $xml->getElementById('content');
-$ele->nodeValue = '{{ contents }}';
-//$template = str_replace('class="phpdocumentor"', 'class="generated-page"', $xml->saveHTML());
-$template = $xml->saveHTML();
-
-$sourceDirs = array_map(function ($dirRelativeToProjectRoot) {
-    return __DIR__ . '/../' . $dirRelativeToProjectRoot;
-}, is_array($config['version']['api']['source']['path'])
-    ? $config['version']['api']['source']['path']
-    : [$config['version']['api']['source']['path']]
-);
-$sourceFiles = [];
-foreach ($sourceDirs as $dir) {
-    $sourceFiles = array_merge(
-        $sourceFiles,
-        array_filter(
-            array_map('realpath', iterator_to_array(\Aws\recursive_dir_iterator($dir))),
-            function ($path) {
-                return preg_match('/(?<!\.json)\.php/', $path);
-            }
-        )
-    );
-}
-
-$issueLoggingEnabled = isset(getopt(
-    '',
-    array('issue-logging-enabled::')
-)['issue-logging-enabled']);
-
-// Generate API docs
-$builder = new DocsBuilder(
-    $apiProvider,
-    $outputDir,
-    $template,
-    'http://docs.aws.amazon.com/aws-sdk-php/v3/api/',
-    [],
-    $sourceFiles,
-    $issueLoggingEnabled
-);
-$builder->build();
diff --git a/build/gh-release.php b/build/gh-release.php
deleted file mode 100644
index e50a6b4bad..0000000000
--- a/build/gh-release.php
+++ /dev/null
@@ -1,164 +0,0 @@
-<?php
-/*
- * Creates a Github API release using the changelog contents. Attaches aws.zip
- * and aws.phar to the release.
- *
- * The OAUTH_TOKEN environment variable is required.
- *
- *     Usage: php gh-release.php X.Y.Z
- */
-
-require __DIR__ . '/../vendor/autoload.php';
-
-use GuzzleHttp\Psr7\Uri;
-use GuzzleHttp\Psr7;
-
-const MAX_ATTEMPTS = 3;
-
-$owner = 'aws';
-$repo = 'aws-sdk-php';
-$token = getenv('OAUTH_TOKEN') or die('An OAUTH_TOKEN environment variable is required');
-isset($argv[1]) or die('Usage php gh-release.php X.Y.Z');
-$tag = $argv[1];
-
-// Grab and validate the tag annotation
-chdir(dirname(__DIR__));
-$message = `chag contents -t "$tag"` or die('Chag could not find or parse the tag');
-
-// Add retry middleware
-$stack = \GuzzleHttp\HandlerStack::create();
-$stack->push(\GuzzleHttp\Middleware::retry(
-    function ($retries, $request, $response) {
-        $statusCode = $response->getStatusCode();
-        if ($retries < MAX_ATTEMPTS && !in_array($statusCode, [200, 201, 202])) {
-            echo "Attempt failed with status code {$statusCode}: "
-                . $response->getBody();
-            return true;
-        }
-        return false;
-    },
-    function ($retries) {
-        return 1000 * (1 + $retries);
-    }
-));
-
-// Create a GitHub client.
-$client = new GuzzleHttp\Client([
-    'base_uri' => 'https://api.github.com/',
-    'headers' => ['Authorization' => "token $token"],
-    'handler' => $stack,
-]);
-
-// Create a Github client with no retry middleware, to allow for custom retry handling
-$uploadClient = new GuzzleHttp\Client([
-    'base_uri' => 'https://api.github.com/',
-    'headers' => ['Authorization' => "token $token"]
-]);
-
-// Publish the release
-$response = $client->post("repos/${owner}/${repo}/releases", [
-    'json' => [
-        'tag_name'   => $tag,
-        'name'       => "Version {$tag}",
-        'body'       => $message,
-    ]
-]);
-$releaseBody = json_decode($response->getBody(), true);
-
-// Grab the location of the new release
-$url = $response->getHeaderLine('Location');
-echo "Release successfully published to: $url\n";
-
-// Uploads go to uploads.github.com
-$uploadUrl = new Uri($url);
-$uploadUrl = $uploadUrl->withHost('uploads.github.com');
-
-// Upload aws.zip
-$zipAttempts = retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, 'aws.zip');
-if ($zipAttempts === false) {
-    echo "aws.zip upload failed after " . MAX_ATTEMPTS . " attempts.\n";
-} else {
-    echo "aws.zip upload succeeded after {$zipAttempts} attempt(s).\n";
-}
-
-// Upload aws.phar
-$pharAttempts = retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, 'aws.phar');
-if ($pharAttempts === false) {
-    echo "aws.phar upload failed after " . MAX_ATTEMPTS . " attempts.\n";
-} else {
-    echo "aws.phar upload succeeded after {$pharAttempts} attempt(s).\n";
-}
-
-/**
- * Attempts an artifact upload and retries up to MAX_ATTEMPTS times
- *
- * @param $client
- * @param $uploadClient
- * @param $owner
- * @param $repo
- * @param $releaseBody
- * @param $uploadUrl
- * @param $filename
- * @return bool|int
- */
-function retryUpload($client, $uploadClient, $owner, $repo, $releaseBody, $uploadUrl, $filename)
-{
-    $isSuccessful = false;
-    $attempts = 0;
-    $filetype = substr($filename, strpos($filename, '.') + 1);
-
-    while (!$isSuccessful && $attempts < MAX_ATTEMPTS) {
-        try {
-            $attempts++;
-            $response = $uploadClient->post("{$uploadUrl}/assets?name={$filename}", [
-                'headers' => ['Content-Type' => "application/{$filetype}"],
-                'body'    => Psr7\Utils::tryFopen(__DIR__ . "/artifacts/{$filename}", 'r')
-            ]);
-            echo "{$filename} uploaded to: " . json_decode($response->getBody(), true)['browser_download_url'] . "\n";
-            $isSuccessful = true;
-        } catch (\GuzzleHttp\Exception\ServerException $e) {
-            echo "{$filename} failed to upload:\n";
-            var_dump($e->getMessage());
-
-            // Fetch and inspect assets for failed downloads
-            $response = $client->get("/repos/{$owner}/{$repo}/releases/{$releaseBody['id']}/assets", []);
-            $assets = json_decode($response->getBody(), true);
-
-            foreach ($assets as $asset) {
-
-                // Only successful uploads have a state of 'uploaded'
-                if ($asset['state'] !== 'uploaded') {
-                    try {
-
-                        // Failed uploads leave behind a corrupted artifact that must be deleted
-                        $response = $uploadClient->delete("/repos/{$owner}/{$repo}/releases/assets/{$asset['id']}", []);
-
-                        // Currently the successful 204 will trigger an exception due to response formatting,
-                        // but keeping this in case Github changes their API response
-                        if ($response->getStatusCode() == 204) {
-                            echo "Failed upload of {$asset['name']} at {$asset['browser_download_url']} has successfully been deleted.\n";
-                        } else {
-                            echo "Failed upload of {$asset['name']} at {$asset['browser_download_url']} was unable to be deleted.\n";
-                        }
-                    } catch (\GuzzleHttp\Exception\ClientException $e) {
-
-                        // Currently expected to generate an exception every time, even for success
-                        $response = $e->getResponse();
-                        if ($response->getStatusCode() == 204) {
-                            echo "Failed upload of {$asset['name']} at {$asset['browser_download_url']} has successfully been deleted.\n";
-                        } else {
-                            echo "Failed upload of {$asset['name']} at {$asset['browser_download_url']} was unable to be deleted.\n";
-                            var_dump($e);
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    if ($isSuccessful) {
-        return $attempts;
-    }
-
-    return false;
-}
diff --git a/build/normalize-docs-files.php b/build/normalize-docs-files.php
deleted file mode 100644
index 320a8a3078..0000000000
--- a/build/normalize-docs-files.php
+++ /dev/null
@@ -1,273 +0,0 @@
-<?php
-
-// Function to normalize and move files
-function normalizeAndMoveFiles($directory, $prefix) {
-    $files = glob($directory . '/*');
-    foreach ($files as $file) {
-        if (is_file($file)) {
-            // Extract the basename and apply transformations
-            $basename = ucfirst(basename($file));
-
-            // Replace all dashes in the basename with dots
-            $modifiedBasename = str_replace("-", ".", $basename);
-
-            // Construct the new filename by prepending the prefix (which includes the dash)
-            $newFilename = $prefix . $modifiedBasename;
-
-            // Move file to parent directory
-            $newPath = dirname($directory) . '/' . $newFilename;
-            rename($file, $newPath);
-            echo "Moved and renamed $file to $newPath\n";
-        }
-    }
-}
-
-// Function to update hrefs in HTML files
-function updateHtmlHrefs($directory) {
-    $htmlFiles = glob($directory . '/*.html');
-    foreach ($htmlFiles as $file) {
-        $doc = new DOMDocument();
-        @$doc->loadHTMLFile($file); // Suppress warnings for invalid HTML
-
-        // Remove <base> tags
-        while (($baseTags = $doc->getElementsByTagName('base')) && $baseTags->length) {
-            $baseTag = $baseTags->item(0);
-            $baseTag->parentNode->removeChild($baseTag);
-        }
-
-        $links = $doc->getElementsByTagName('a');
-
-        foreach ($links as $link) {
-            if ($link->hasAttribute('href')) {
-                $href = $link->getAttribute('href');
-                // Replace and capitalize as needed
-                $href = preg_replace_callback(
-                    '/(namespaces|classes|packages)\/([a-zA-Z])/',
-                    function ($matches) {
-                        // Capitalize the first letter after the prefix and replace / with -
-                        if ($matches[1] === 'classes') {
-                            $prefix = 'class'; // Directly set to 'class' for 'classes'
-                        } else {
-                            // For 'namespaces' and 'packages', simply remove the last character
-                            $prefix = substr($matches[1], 0, -1);
-                        }
-
-                        return $prefix . '-' . strtoupper($matches[2]);
-                    },
-                    $href
-                );
-                // Replace dashes with dots after the specific prefixes
-                $href = preg_replace_callback(
-                    '/(namespace-|class-|package-)([\w-]+)\.html/',
-                    function ($matches) {
-                        // Replace all dashes in the suffix part with dots
-                        $suffix = str_replace("-", ".", $matches[2]);
-                        return $matches[1] . $suffix . '.html';
-                    },
-                    $href
-                );
-                $link->setAttribute('href', $href);
-            }
-        }
-
-        // Remove <aside> tags with class "phpdocumentor-element-found-in"
-        $asides = $doc->getElementsByTagName('aside');
-        $asidesToRemove = [];
-
-        foreach ($asides as $aside) {
-            if ($aside->getAttribute('class') === 'phpdocumentor-element-found-in') {
-                $asidesToRemove[] = $aside;
-            }
-        }
-
-        // Remove the selected <aside> tags
-        foreach ($asidesToRemove as $asideToRemove) {
-            $asideToRemove->parentNode->removeChild($asideToRemove);
-        }
-
-        $divs = $doc->getElementsByTagName('div');
-
-        foreach ($divs as $div) {
-            // Check if the div has the class 'phpdocumentor-modal-content'
-            if ($div->getAttribute('class') === 'phpdocumentor-modal-content') {
-                $preTags = $div->getElementsByTagName('pre');
-
-                // Check each pre tag in the current div
-                foreach ($preTags as $pre) {
-                    if ($pre->hasAttribute('data-src') && strpos($pre->getAttribute('data-src'), 'files/') === 0) {
-                        // If condition is met, remove the div from its parent
-                        $div->parentNode->removeChild($div);
-                        break; // Stop checking other pre tags if one meets the criteria
-                    }
-                }
-            }
-        }
-
-        // Save the changes
-        $doc->saveHTMLFile($file);
-        echo "Updated hrefs in $file\n";
-    }
-}
-
-function updateSearchIndex($filePath) {
-    // Read the content of the file
-    $content = file_get_contents($filePath);
-    if ($content === false) {
-        echo "Failed to read file: $filePath\n";
-        return;
-    }
-
-    // Regular expression to find and replace the URLs
-    $pattern = '/("url":\s*")((?:classes|namespaces)\/)([^"]+)(")/';
-    $replacement = function ($matches) {
-        // Replace 'classes/' with 'class-' and 'namespaces/' with 'namespace-'
-        $newPrefix = str_replace(['classes/', 'namespaces/'], ['class-', 'namespace-'], $matches[2]);
-
-        // Capitalize the first letter after the prefix and replace dashes with dots in the rest of the string
-        $remainder = ucfirst($matches[3]);
-        $remainder = preg_replace('/-/', '.', $remainder);
-
-        return $matches[1] . $newPrefix . $remainder . $matches[4];
-    };
-
-    // Perform the replacement
-    $updatedContent = preg_replace_callback($pattern, $replacement, $content);
-
-    // Write the updated content back to the file
-    $result = file_put_contents($filePath, $updatedContent);
-    if ($result === false) {
-        echo "Failed to write updated content to file: $filePath\n";
-    } else {
-        echo "File updated successfully: $filePath\n";
-    }
-}
-
-function insertSnsValidatorNotice($directory)
-{
-    $targetFile = $directory . '/class-Aws.Sns.MessageValidator.html';
-
-    if (!file_exists($targetFile)) {
-        echo "SNS MessageValidator class file not found\n";
-        return;
-    }
-
-    $doc = new DOMDocument();
-    @$doc->loadHTMLFile($targetFile);
-
-    $titleElement = null;
-    $h2Elements = $doc->getElementsByTagName('h2');
-    foreach ($h2Elements as $h2) {
-        if ($h2->getAttribute('class') === 'phpdocumentor-content__title') {
-            $titleElement = $h2;
-            break;
-        }
-    }
-
-    if (!$titleElement) {
-        echo "Could not find title element in MessageValidator documentation\n";
-        return;
-    }
-
-    $noticeDiv = $doc->createElement('div');
-    $noticeDiv->setAttribute('class', 'phpdocumentor-admonition');
-
-    // Create header paragraph with icon and Info text
-    $headerParagraph = $doc->createElement('p');
-    $icon = $doc->createElement('i');
-    $icon->setAttribute('class', 'fas fa-question-circle phpdocumentor-admonition__icon');
-    $headerParagraph->appendChild($icon);
-
-    // Create the main content paragraph
-    $contentParagraph = $doc->createElement('p');
-    $textBefore = $doc->createTextNode('This class is maintained in ');
-    $link = $doc->createElement('a', 'aws-php-sns-message-validator');
-    $link->setAttribute('href', 'https://github.com/aws/aws-php-sns-message-validator');
-
-    $contentParagraph->appendChild($textBefore);
-    $contentParagraph->appendChild($link);
-
-    // Append both paragraphs to the notice div
-    $noticeDiv->appendChild($headerParagraph);
-    $noticeDiv->appendChild($contentParagraph);
-
-    $titleElement->parentNode->insertBefore($noticeDiv, $titleElement->nextSibling);
-
-    $doc->saveHTMLFile($targetFile);
-    echo "Added SNS validator notice to MessageValidator documentation\n";
-}
-
-function copyDirectory($src, $dst) {
-    if (!file_exists($dst)) {
-        mkdir($dst, 0777, true);
-    }
-
-    $dir = opendir($src);
-    while (false !== ($file = readdir($dir))) {
-        if ($file != '.' && $file != '..') {
-            if (is_dir($src . '/' . $file)) {
-                copyDirectory($src . '/' . $file, $dst . '/' . $file);
-            } else {
-                copy($src . '/' . $file, $dst . '/' . $file);
-            }
-        }
-    }
-
-    closedir($dir);
-}
-
-function deleteDirectory($dir) {
-    if (!is_dir($dir)) {
-        return false;
-    }
-
-    $handle = opendir($dir);
-
-    while (false !== ($file = readdir($handle))) {
-        if ($file != '.' && $file != '..') {
-            $path = $dir . '/' . $file;
-            if (is_dir($path)) {
-                // Recursively delete subdirectories
-                deleteDirectory($path);
-            } else {
-                // Delete files
-                unlink($path);
-            }
-        }
-    }
-    closedir($handle);
-
-    return rmdir($dir);
-}
-
-$parentDirectory = __DIR__ . '/artifacts/docs';
-$classesDirectory = "$parentDirectory/classes";
-$namespacesDirectory = "$parentDirectory/namespaces";
-$packagesDirectory = "$parentDirectory/packages";
-
-// Process classes and namespaces directories
-normalizeAndMoveFiles($namespacesDirectory, "namespace-");
-normalizeAndMoveFiles($classesDirectory, "class-");
-normalizeAndMoveFiles($packagesDirectory, "package-");
-
-// Update hrefs in HTML files
-updateHtmlHrefs($parentDirectory);
-
-// Updates search index urls with generated api pages
-updateSearchIndex($parentDirectory . '/js/searchIndex.js');
-
-// Add the SNS validator notice
-insertSnsValidatorNotice($parentDirectory);
-
-//move static assets
-copyDirectory(__DIR__ . '/docs/static', $parentDirectory . '/static');
-copyDirectory(__DIR__ . '/docs/js', $parentDirectory . '/js');
-copyDirectory(__DIR__ . '/docs/css', $parentDirectory . '/css');
-
-//remove unnecessary files/directories
-$removableDirs = ['classes', 'files', 'graphs', 'indices', 'namespaces', 'packages', 'reports'];
-
-foreach ($removableDirs as $dir) {
-    deleteDirectory("{$parentDirectory}/{$dir}");
-}
-
-echo "All tasks completed.\n";
diff --git a/build/option-docs.php b/build/option-docs.php
deleted file mode 100644
index 0dba0124e8..0000000000
--- a/build/option-docs.php
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-require __DIR__  . '/../vendor/autoload.php';
-
-function generateDocblock(array $args)
-{
-    foreach ($args as $name => $value) {
-        if (!isset($value['doc']) || !empty($value['internal'])) {
-            continue;
-        }
-
-        $docs = $value['doc'];
-        $modifiers = [];
-
-        if (isset($value['valid'])) {
-            $modifiers[] = implode('|', $value['valid']);
-        }
-
-        if (!empty($value['required'])) {
-            $modifiers[] = 'required';
-        }
-
-        if (isset($value['default']) && !is_callable($value['default'])) {
-            $modifiers[] = 'default=' . \Aws\describe_type($value['default']);
-        }
-
-        if ($modifiers) {
-            $docs = '(' . implode(', ', $modifiers) . ') ' . $docs;
-        }
-
-        $docs = '* - ' . $name . ': ' . $docs;
-        echo wordwrap($docs, 70, "\n*   ") . "\n";
-    }
-}
-
-$clientName = isset($argv[1]) ? $argv[1] : 'Aws\AwsClient';
-$args = call_user_func([$clientName, 'getArguments']);
-ksort($args);
-
-$type = isset($argv[2]) ? $argv[2] : 'docblock';
-
-switch ($type) {
-    case 'docblock':
-        generateDocblock($args);
-        break;
-    default:
-        die('Unknown type: ' . $type);
-}
diff --git a/build/packager.php b/build/packager.php
deleted file mode 100644
index 1050a2e4c7..0000000000
--- a/build/packager.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-require __DIR__ . '/../vendor/autoload.php';
-
-$stageDirectory = __DIR__ . '/artifacts/staging';
-$projectRoot = __DIR__ . '/../';
-$burgomaster = new \Burgomaster($stageDirectory, $projectRoot);
-$autoloaderFilename = 'aws-autoloader.php';
-
-$metaFiles = ['README.md', 'LICENSE', 'NOTICE', 'CHANGELOG.md'];
-foreach ($metaFiles as $file) {
-    $burgomaster->deepCopy($file, $file);
-}
-
-$sdkFiles = new \RecursiveIteratorIterator(
-    new \RecursiveDirectoryIterator(realpath('src'))
-);
-$sdkFiles = new CallbackFilterIterator($sdkFiles, function (SplFileInfo $file) {
-    return !in_array($file->getBasename('.php'), [
-        'docs-2.json',
-        'examples-1.json',
-    ]);
-});
-
-$burgomaster->recursiveCopy('src', 'Aws', ['php', 'php.gz'], $sdkFiles);
-$burgomaster->recursiveCopy('vendor/aws/aws-php-sns-message-validator/src', 'Aws/Sns');
-$burgomaster->recursiveCopy('vendor/mtdowling/jmespath.php/src', 'JmesPath');
-$burgomaster->recursiveCopy('vendor/guzzlehttp/guzzle/src', 'GuzzleHttp');
-$burgomaster->recursiveCopy('vendor/guzzlehttp/psr7/src', 'GuzzleHttp/Psr7');
-$burgomaster->recursiveCopy('vendor/guzzlehttp/promises/src', 'GuzzleHttp/Promise');
-$burgomaster->recursiveCopy('vendor/psr/http-message/src', 'Psr/Http/Message');
-
-$autoloaderContents = [
-    'Aws/functions.php',
-    'GuzzleHttp/functions_include.php',
-    'JmesPath/JmesPath.php',
-];
-
-if (file_exists($projectRoot . 'vendor/symfony/polyfill-intl-idn')) {
-    $burgomaster->recursiveCopy($projectRoot . 'vendor/symfony/polyfill-intl-idn', 'Symfony/Polyfill/Intl/Idn');
-    array_push($autoloaderContents, 'Symfony/Polyfill/Intl/Idn/bootstrap.php');
-}
-
-if (file_exists($projectRoot . 'vendor/psr/http-client/src')) {
-    $burgomaster->recursiveCopy($projectRoot . 'vendor/psr/http-client/src', 'Psr/Http/Client');
-}
-
-$burgomaster->createAutoloader($autoloaderContents, $autoloaderFilename);
-
-$burgomaster->createZip(__DIR__ . "/artifacts/aws.zip");
-$burgomaster->createPhar(
-    __DIR__ . "/artifacts/aws.phar",
-    null,
-    $autoloaderFilename,
-    'aws-' . \Aws\Sdk::VERSION . '.phar'
-);
-
-$burgomaster->startSection('test-phar');
-$burgomaster->exec('php ' . __DIR__ . '/test-phar.php');
-$burgomaster->endSection();
diff --git a/build/phar-test-runner.php b/build/phar-test-runner.php
deleted file mode 100644
index 5d5044b7ac..0000000000
--- a/build/phar-test-runner.php
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/usr/bin/env php
-<?php
-
-require __DIR__ . '/artifacts/aws.phar';
-require __DIR__ . '/artifacts/phpunit.phar';
-require __DIR__ . '/artifacts/behat.phar';
diff --git a/build/remove-method-annotations.php b/build/remove-method-annotations.php
deleted file mode 100644
index 92027835a0..0000000000
--- a/build/remove-method-annotations.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-/**
- *   This script removes `@method` annotations on service client classes prior to doc generation.
- *   Removing these annotations prevents phpDocumentor from generating documentation for service methods
- *   on the client class.
- */
-
-function removeMethodAnnotations($dir, $fileSuffix) {
-    $iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir));
-
-    foreach ($iterator as $file) {
-        if ($file->isDir()) {
-            continue;
-        }
-
-        if (str_ends_with($file->getPathname(), $fileSuffix)) {
-            $filePath = $file->getRealPath();
-            $content = file_get_contents($filePath);
-
-            // Regular expression to match @method annotations
-            // This pattern assumes @method annotations may span multiple lines and are within comment blocks
-            $pattern = '/^\s*\*\s+@method\s+[^\n]+\n/m';
-
-            if (preg_match($pattern, $content)) {
-                // Remove @method annotations
-                $newContent = preg_replace($pattern, '', $content);
-
-                // Write the clean content back to the file
-                file_put_contents($filePath, $newContent);
-                echo "Method annotations removed from: $filePath\n";
-            }
-        }
-    }
-}
-
-$directoryPath = __DIR__ . '/artifacts/staging/Aws';
-$fileSuffix = 'Client.php';
-removeMethodAnnotations($directoryPath, $fileSuffix);
\ No newline at end of file
diff --git a/build/test-phar.php b/build/test-phar.php
deleted file mode 100644
index 48e66efced..0000000000
--- a/build/test-phar.php
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-require __DIR__ . '/artifacts/aws.phar';
-
-$conf = [
-    'credentials' => ['key' => 'foo', 'secret' => 'bar'],
-    'region'      => 'us-west-2',
-    'version'     => 'latest'
-];
-
-// Ensure that a client can be created.
-$s3 = new Aws\S3\S3Client($conf);
-// Ensure that waiters can be found.
-$s3->getPaginator('ListObjects');
-
-// Legacy factory instantiation.
-Aws\DynamoDb\DynamoDbClient::factory($conf);
-
-// JMESPath autoloader
-\JmesPath\search('foo', ['foo' => 'bar']);
-
-// React autoloader
-$checks = [
-    'JmesPath\\search',
-    'Aws\\dir_iterator',
-];
-
-foreach ($checks as $check) {
-    if (!function_exists($check)) {
-        echo $check . ' not found';
-        exit(1);
-    }
-}
-
-$classMethodChecks = [
-    'GuzzleHttp\\Promise\\Utils' => 'inspect',
-    'GuzzleHttp\\Psr7\\Utils' => 'streamFor',
-];
-
-foreach ($classMethodChecks as $class => $method) {
-    if (!method_exists($class, $method)
-    ) {
-        echo $class . '::' . $method . ' not found';
-        exit(1);
-    }
-}
-
-echo 'Version=' . Aws\Sdk::VERSION;
diff --git a/composer.json b/composer.json
index d9698ea05d..96ecad7670 100644
--- a/composer.json
+++ b/composer.json
@@ -61,7 +61,8 @@
     },
     "autoload-dev": {
         "psr-4": {
-            "Aws\\Test\\": "tests/"
+            "Aws\\Test\\": "tests/",
+            "AwsBuild\\Command\\": "build/Command"
         },
         "classmap": ["build/"]
     },
diff --git a/tests/Build/Command/RemoveServiceCommandTest.php b/tests/Build/Command/RemoveServiceCommandTest.php
new file mode 100644
index 0000000000..2f36070c47
--- /dev/null
+++ b/tests/Build/Command/RemoveServiceCommandTest.php
@@ -0,0 +1,324 @@
+<?php
+
+namespace Aws\Test\Build\Command;
+
+use Aws\Test\TestsUtility;
+use AwsBuild\Command\RemoveServiceCommand;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(RemoveServiceCommand::class)]
+final class RemoveServiceCommandTest extends TestCase
+{
+    private string $projectDir;
+
+    protected function setUp(): void
+    {
+        $this->projectDir = sys_get_temp_dir() . '/' . uniqid('rsc_test_');
+        mkdir($this->projectDir, 0755, true);
+        mkdir($this->projectDir . '/src', 0755, true);
+        mkdir($this->projectDir . '/src/data', 0755, true);
+        mkdir($this->projectDir . '/.changes', 0755, true);
+
+        $manifest = [
+            'test-service' => [
+                'namespace' => 'TestService',
+                'serviceIdentifier' => 'Test Service',
+            ],
+            'other-service' => [
+                'namespace' => 'OtherService',
+                'serviceIdentifier' => 'Other Service',
+            ],
+        ];
+
+        $this->createManifest($manifest);
+        $this->createSdkPhp(['TestService', 'OtherService']);
+        $this->createGrandfatheredJson(['TestService', 'OtherService']);
+        $this->createGrandfatheredPhp(['TestService', 'OtherService']);
+        $this->createClientFolder('TestService');
+        $this->createClientFolder('OtherService');
+        $this->createDataFolder('test-service');
+        $this->createDataFolder('other-service');
+    }
+
+    protected function tearDown(): void
+    {
+        TestsUtility::cleanUpDir($this->projectDir);
+    }
+
+    public function testRemoveServiceByServiceKey(): void
+    {
+        $result = $this->executeCommand(['--service-id=test-service', '--commit=false']);
+
+        $this->assertSame(0, $result['exitCode'], 'Exit code should be 0. stderr: ' . $result['stderr']);
+        $this->assertServiceRemoved('test-service', 'TestService');
+        $this->assertServicePreserved('other-service', 'OtherService');
+    }
+
+    public function testRemoveServiceByNamespace(): void
+    {
+        $result = $this->executeCommand(['--service-id=TestService', '--commit=false']);
+
+        $this->assertSame(0, $result['exitCode'], 'Exit code should be 0. stderr: ' . $result['stderr']);
+        $this->assertServiceRemoved('test-service', 'TestService');
+        $this->assertServicePreserved('other-service', 'OtherService');
+    }
+
+    public function testRemoveServiceByServiceIdentifier(): void
+    {
+        $result = $this->executeCommand(['--service-id=Test Service', '--commit=false']);
+
+        $this->assertSame(0, $result['exitCode'], 'Exit code should be 0. stderr: ' . $result['stderr']);
+        $this->assertServiceRemoved('test-service', 'TestService');
+        $this->assertServicePreserved('other-service', 'OtherService');
+    }
+
+    public function testDryRunDoesNotModifyFilesystem(): void
+    {
+        $before = $this->snapshotFilesystem();
+
+        $result = $this->executeCommand(['--service-id=test-service', '--dry-run', '--commit=false']);
+
+        $this->assertSame(0, $result['exitCode'], 'Exit code should be 0. stderr: ' . $result['stderr']);
+
+        // Stdout should contain service info
+        $this->assertStringContainsString('test-service', $result['stdout']);
+        $this->assertStringContainsString('TestService', $result['stdout']);
+        $this->assertStringContainsString('Test Service', $result['stdout']);
+
+        // Filesystem should be unchanged
+        $after = $this->snapshotFilesystem();
+        $this->assertSame($before, $after, 'Dry run should not modify any files');
+    }
+
+    private function createManifest(array $entries): void
+    {
+        $jsonPath = $this->projectDir . '/src/data/manifest.json';
+        file_put_contents(
+            $jsonPath,
+            json_encode($entries, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n"
+        );
+
+        $phpPath = $this->projectDir . '/src/data/manifest.json.php';
+        file_put_contents(
+            $phpPath,
+            "<?php\nreturn " . var_export($entries, true) . ";\n"
+        );
+    }
+
+    private function createSdkPhp(array $namespaces): void
+    {
+        $lines = ["<?php", "/**"];
+        foreach ($namespaces as $ns) {
+            $lines[] = " * @method \\Aws\\{$ns}\\{$ns}Client create{$ns}(array \$args = [])";
+            $lines[] = " * @method \\Aws\\MultiRegionClient createMultiRegion{$ns}(array \$args = [])";
+        }
+        $lines[] = " */";
+        $lines[] = "class Sdk { }";
+        file_put_contents(
+            $this->projectDir . '/src/Sdk.php',
+            implode("\n", $lines) . "\n"
+        );
+    }
+
+    private function createGrandfatheredJson(array $namespaces): void
+    {
+        $data = ['grandfathered-services' => $namespaces];
+        file_put_contents(
+            $this->projectDir . '/src/data/grandfathered-services.json',
+            json_encode($data, JSON_PRETTY_PRINT) . "\n"
+        );
+    }
+
+    private function createGrandfatheredPhp(array $namespaces): void
+    {
+        $items = implode(', ', array_map(fn($s) => "'" . $s . "'", $namespaces));
+        $content = "<?php\n"
+            . "// This file was auto-generated from sdk-root/src/data/grandfathered-services.json\n"
+            . "return [ 'grandfathered-services' => [ " . $items . ", ],];\n";
+        file_put_contents(
+            $this->projectDir . '/src/data/grandfathered-services.json.php',
+            $content
+        );
+    }
+
+    private function createClientFolder(string $namespace): void
+    {
+        $dir = $this->projectDir . '/src/' . $namespace;
+        if (!is_dir($dir)) {
+            mkdir($dir, 0755, true);
+        }
+        file_put_contents(
+            $dir . '/' . $namespace . 'Client.php',
+            "<?php\n// {$namespace} client stub\n"
+        );
+    }
+
+    private function createDataFolder(string $serviceKey): void
+    {
+        $dir = $this->projectDir . '/src/data/' . $serviceKey;
+        if (!is_dir($dir)) {
+            mkdir($dir, 0755, true);
+        }
+        file_put_contents(
+            $dir . '/api-2.json',
+            json_encode(['version' => '2.0'], JSON_PRETTY_PRINT) . "\n"
+        );
+    }
+
+    private function executeCommand(array $args): array
+    {
+        $runnerPath = dirname(__DIR__, 3) . '/build/WorkflowCommandRunner.php';
+        $allArgs = array_merge(
+            [PHP_BINARY, $runnerPath, 'remove-service', '--project-root=' . $this->projectDir],
+            $args
+        );
+        $cmdLine = implode(' ', array_map('escapeshellarg', $allArgs));
+
+        $process = proc_open($cmdLine, [
+            0 => ['pipe', 'r'],
+            1 => ['pipe', 'w'],
+            2 => ['pipe', 'w'],
+        ], $pipes);
+
+        fclose($pipes[0]);
+        $stdout = stream_get_contents($pipes[1]);
+        fclose($pipes[1]);
+        $stderr = stream_get_contents($pipes[2]);
+        fclose($pipes[2]);
+        $exitCode = proc_close($process);
+
+        return ['exitCode' => $exitCode, 'stdout' => $stdout, 'stderr' => $stderr];
+    }
+
+    private function assertServiceRemoved(string $serviceKey, string $namespace): void
+    {
+        // Client folder deleted
+        $this->assertDirectoryDoesNotExist(
+            $this->projectDir . '/src/' . $namespace,
+            "Client folder src/{$namespace}/ should have been deleted"
+        );
+
+        // Data folder deleted
+        $this->assertDirectoryDoesNotExist(
+            $this->projectDir . '/src/data/' . $serviceKey,
+            "Data folder src/data/{$serviceKey}/ should have been deleted"
+        );
+
+        // Sdk.php annotations removed
+        $sdkContent = file_get_contents($this->projectDir . '/src/Sdk.php');
+        $this->assertStringNotContainsString(
+            'create' . $namespace . '(',
+            $sdkContent,
+            "Sdk.php should not contain create{$namespace}( annotation"
+        );
+        $this->assertStringNotContainsString(
+            'createMultiRegion' . $namespace . '(',
+            $sdkContent,
+            "Sdk.php should not contain createMultiRegion{$namespace}( annotation"
+        );
+
+        // Grandfathered JSON entry removed
+        $gfJson = json_decode(
+            file_get_contents($this->projectDir . '/src/data/grandfathered-services.json'),
+            true
+        );
+        $this->assertNotContains(
+            $namespace,
+            $gfJson['grandfathered-services'],
+            "grandfathered-services.json should not contain {$namespace}"
+        );
+
+        // Grandfathered PHP entry removed
+        $gfPhp = include $this->projectDir . '/src/data/grandfathered-services.json.php';
+        $this->assertNotContains(
+            $namespace,
+            $gfPhp['grandfathered-services'],
+            "grandfathered-services.json.php should not contain {$namespace}"
+        );
+
+        // Manifest entry removed
+        $manifest = json_decode(
+            file_get_contents($this->projectDir . '/src/data/manifest.json'),
+            true
+        );
+        $this->assertArrayNotHasKey(
+            $serviceKey,
+            $manifest,
+            "manifest.json should not contain key {$serviceKey}"
+        );
+
+        // Changelog entry created
+        $changelogPath = $this->projectDir . '/.changes/nextrelease/remove-' . $serviceKey . '.json';
+        $this->assertFileExists($changelogPath, "Changelog entry should exist");
+        $changelog = json_decode(file_get_contents($changelogPath), true);
+        $this->assertSame('api-change', $changelog[0]['type']);
+        $this->assertSame($namespace, $changelog[0]['category']);
+        $this->assertStringContainsString($namespace, $changelog[0]['description']);
+    }
+
+    private function assertServicePreserved(string $serviceKey, string $namespace): void
+    {
+        // Client folder exists
+        $this->assertDirectoryExists(
+            $this->projectDir . '/src/' . $namespace,
+            "Client folder src/{$namespace}/ should still exist"
+        );
+
+        // Data folder exists
+        $this->assertDirectoryExists(
+            $this->projectDir . '/src/data/' . $serviceKey,
+            "Data folder src/data/{$serviceKey}/ should still exist"
+        );
+
+        // Sdk.php annotations present
+        $sdkContent = file_get_contents($this->projectDir . '/src/Sdk.php');
+        $this->assertStringContainsString(
+            'create' . $namespace . '(',
+            $sdkContent,
+            "Sdk.php should still contain create{$namespace}( annotation"
+        );
+
+        // Grandfathered JSON entry present
+        $gfJson = json_decode(
+            file_get_contents($this->projectDir . '/src/data/grandfathered-services.json'),
+            true
+        );
+        $this->assertContains(
+            $namespace,
+            $gfJson['grandfathered-services'],
+            "grandfathered-services.json should still contain {$namespace}"
+        );
+
+        // Manifest entry present
+        $manifest = json_decode(
+            file_get_contents($this->projectDir . '/src/data/manifest.json'),
+            true
+        );
+        $this->assertArrayHasKey(
+            $serviceKey,
+            $manifest,
+            "manifest.json should still contain key {$serviceKey}"
+        );
+    }
+
+    private function snapshotFilesystem(): array
+    {
+        $snapshot = [];
+        $iterator = new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator($this->projectDir, \FilesystemIterator::SKIP_DOTS),
+            \RecursiveIteratorIterator::SELF_FIRST
+        );
+        foreach ($iterator as $item) {
+            $relativePath = substr($item->getPathname(), strlen($this->projectDir));
+            if ($item->isDir()) {
+                $snapshot[$relativePath] = 'DIR';
+            } else {
+                $snapshot[$relativePath] = md5_file($item->getPathname());
+            }
+        }
+        ksort($snapshot);
+
+        return $snapshot;
+    }
+}