diff --git a/.changelog/autoload-files-testability.md b/.changelog/autoload-files-testability.md
new file mode 100644
index 000000000..38be71809
--- /dev/null
+++ b/.changelog/autoload-files-testability.md
@@ -0,0 +1,6 @@
+---
+category: fixed
+type: patch
+---
+
+Detect PHP sources declared in Composer `autoload.files` so function-only packages run tests and coverage reporting instead of silently skipping them, without changing API documentation discovery.
diff --git a/src/Project/ProjectCapabilitiesResolver.php b/src/Project/ProjectCapabilitiesResolver.php
index 2481f2a68..793c318a0 100644
--- a/src/Project/ProjectCapabilitiesResolver.php
+++ b/src/Project/ProjectCapabilitiesResolver.php
@@ -157,7 +157,7 @@ private function resolveHasPhpSourceFiles(array $apiDirectories): bool
             }
         }
 
-        foreach (self::API_AUTOLOAD_TYPES as $autoloadType) {
+        foreach ([...self::API_AUTOLOAD_TYPES, 'files'] as $autoloadType) {
             foreach ($this->normalizeAutoloadPaths($this->composer->getAutoload($autoloadType)) as $path) {
                 $absolutePath = $this->filesystem->getAbsolutePath($path);
 
diff --git a/tests/Console/Command/ReportsCommandTest.php b/tests/Console/Command/ReportsCommandTest.php
index 2384798a1..303059141 100644
--- a/tests/Console/Command/ReportsCommandTest.php
+++ b/tests/Console/Command/ReportsCommandTest.php
@@ -20,6 +20,8 @@
 namespace FastForward\DevTools\Tests\Console\Command;
 
 use Symfony\Component\Console\Output\BufferedOutput;
+use FastForward\DevTools\Composer\Json\ComposerJsonInterface;
+use FastForward\DevTools\Filesystem\FilesystemInterface;
 use FastForward\DevTools\Console\Command\Traits\LogsCommandResults;
 use FastForward\DevTools\Console\Command\ReportsCommand;
 use FastForward\DevTools\Console\Output\GithubActionOutput;
@@ -49,6 +51,10 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Process\Process;
+use function Safe\file_put_contents;
+use function Safe\mkdir;
+use function Safe\rmdir;
+use function Safe\unlink;
 
 #[UsesClass(ContainerFactory::class)]
 #[UsesClass(DevToolsServiceProvider::class)]
@@ -253,6 +259,56 @@ public function executeWithNoCacheWillForwardNoCacheOnlyToDocsAndTests(): void
         self::assertSame(ReportsCommand::SUCCESS, $this->executeCommand());
     }
 
+    /**
+     * @return void
+     */
+    #[Test]
+    public function executeWillGenerateCoverageForFilesOnlyPackage(): void
+    {
+        $workspace = sys_get_temp_dir() . '/dev-tools-files-reports-' . uniqid('', true);
+        mkdir($workspace);
+        mkdir($workspace . '/tests');
+        file_put_contents($workspace . '/functions.php', "<?php\nfunction fixtureFunction(): bool { return true; }\n");
+
+        try {
+            $composer = $this->prophesize(ComposerJsonInterface::class);
+            $filesystem = $this->prophesize(FilesystemInterface::class);
+            foreach (['psr-4', 'psr-0', 'classmap'] as $autoloadType) {
+                $composer->getAutoload($autoloadType)->willReturn([]);
+            }
+            $composer->getAutoload('files')->willReturn(['functions.php']);
+            $filesystem->getAbsolutePath('functions.php')->willReturn($workspace . '/functions.php');
+            $filesystem->exists('./tests')->willReturn(true);
+            $filesystem->exists('docs')->willReturn(false);
+            $filesystem->exists('.github/wiki')->willReturn(false);
+            $resolver = new ProjectCapabilitiesResolver($composer->reveal(), $filesystem->reveal());
+            $capabilities = $resolver->resolve();
+            self::assertSame([], $capabilities->getApiDirectories());
+            self::assertTrue($capabilities->canRunTests());
+            $this->projectCapabilitiesResolver->resolve()->willReturn($capabilities);
+            $this->processBuilder->build([DevToolsPathResolver::getBinaryPath(), 'tests'])
+                ->willReturn($this->process->reveal())->shouldBeCalledOnce();
+            $this->processQueue->add($this->process->reveal(), false, false, 'Generating Coverage Report')
+                ->shouldBeCalledOnce();
+            $this->processQueue->add($this->process->reveal(), false, true, 'Generating API Docs Report')
+                ->shouldBeCalledOnce();
+            $this->processQueue->add($this->process->reveal(), false, false, 'Generating Metrics Report')
+                ->shouldBeCalledOnce();
+            $this->processQueue->run($this->output->reveal())
+                ->willReturn(ReportsCommand::SUCCESS)->shouldBeCalledOnce();
+            $this->logger->log('info', 'Generating frontpage for Fast Forward documentation...', Argument::type('array'))
+                ->shouldBeCalledOnce();
+            $this->logger->log('info', 'Documentation reports generated successfully.', Argument::type('array'))
+                ->shouldBeCalledOnce();
+
+            self::assertSame(ReportsCommand::SUCCESS, $this->executeCommand());
+        } finally {
+            unlink($workspace . '/functions.php');
+            rmdir($workspace . '/tests');
+            rmdir($workspace);
+        }
+    }
+
     /**
      * @return void
      */
diff --git a/tests/Console/Command/TestsCommandTest.php b/tests/Console/Command/TestsCommandTest.php
index d1d24a806..e397be7c9 100644
--- a/tests/Console/Command/TestsCommandTest.php
+++ b/tests/Console/Command/TestsCommandTest.php
@@ -36,6 +36,7 @@
 use FastForward\DevTools\Path\DevToolsPathResolver;
 use FastForward\DevTools\Project\ProjectCapabilities;
 use FastForward\DevTools\Project\ProjectCapabilitiesResolverInterface;
+use FastForward\DevTools\Project\ProjectCapabilitiesResolver;
 use FastForward\DevTools\Path\WorkingProjectPathResolver;
 use FastForward\DevTools\Environment\Environment as DevToolsEnvironment;
 use FastForward\DevTools\Environment\RuntimeEnvironment;
@@ -54,6 +55,8 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Process\Process;
+use function Safe\file_put_contents;
+use function Safe\unlink;
 use function Safe\mkdir;
 use function Safe\rmdir;
 use function Safe\getcwd;
@@ -69,6 +72,7 @@
 #[UsesClass(ProcessBuilder::class)]
 #[UsesClass(ManagedWorkspace::class)]
 #[UsesClass(ProjectCapabilities::class)]
+#[UsesClass(ProjectCapabilitiesResolver::class)]
 #[UsesClass(WorkingProjectPathResolver::class)]
 #[UsesTrait(LogsCommandResults::class)]
 final class TestsCommandTest extends TestCase
@@ -572,6 +576,57 @@ public function executeWithInvalidMinCoverageWillReturnFailure(): void
         self::assertSame(TestsCommand::FAILURE, $this->invokeExecute());
     }
 
+    /**
+     * @return void
+     */
+    #[Test]
+    public function executeWillPropagateTestFailureForFilesOnlyPackage(): void
+    {
+        $workspace = sys_get_temp_dir() . '/dev-tools-files-tests-' . uniqid('', true);
+        mkdir($workspace);
+        mkdir($workspace . '/tests');
+        file_put_contents($workspace . '/functions.php', "<?php\nfunction fixtureFunction(): bool { return true; }\n");
+
+        try {
+            $composer = $this->prophesize(ComposerJsonInterface::class);
+            $filesystem = $this->prophesize(FilesystemInterface::class);
+            foreach (['psr-4', 'psr-0', 'classmap'] as $autoloadType) {
+                $composer->getAutoload($autoloadType)->willReturn([]);
+            }
+            $composer->getAutoload('files')->willReturn(['functions.php']);
+            $filesystem->getAbsolutePath('functions.php')->willReturn($workspace . '/functions.php');
+            $filesystem->exists('./tests')->willReturn(true);
+            $filesystem->exists('docs')->willReturn(false);
+            $filesystem->exists('.github/wiki')->willReturn(false);
+            $resolver = new ProjectCapabilitiesResolver($composer->reveal(), $filesystem->reveal());
+            $capabilities = $resolver->resolve();
+            self::assertSame([], $capabilities->getApiDirectories());
+            self::assertTrue($capabilities->canRunTests());
+            $this->projectCapabilitiesResolver->resolve(Argument::any())->willReturn($capabilities);
+            $this->processQueue->add(
+                Argument::that(static fn(Process $process): bool => str_contains(
+                    $process->getCommandLine(),
+                    DevToolsPathResolver::getPreferredToolBinaryPath('phpunit'),
+                )),
+                false,
+                false,
+                'Running PHPUnit Tests',
+            )->shouldBeCalledOnce();
+            $this->processQueue->run($this->output->reveal())
+                ->willReturn(TestsCommand::FAILURE)->shouldBeCalledOnce();
+            $this->logger->log('info', 'Running PHPUnit tests...', Argument::type('array'))
+                ->shouldBeCalledOnce();
+            $this->logger->error('PHPUnit tests failed.', Argument::type('array'))
+                ->shouldBeCalledOnce();
+
+            self::assertSame(TestsCommand::FAILURE, $this->invokeExecute());
+        } finally {
+            unlink($workspace . '/functions.php');
+            rmdir($workspace . '/tests');
+            rmdir($workspace);
+        }
+    }
+
     /**
      * @return void
      */
diff --git a/tests/Project/ProjectCapabilitiesResolverTest.php b/tests/Project/ProjectCapabilitiesResolverTest.php
index a8d025631..68e271dc1 100644
--- a/tests/Project/ProjectCapabilitiesResolverTest.php
+++ b/tests/Project/ProjectCapabilitiesResolverTest.php
@@ -60,6 +60,7 @@ final class ProjectCapabilitiesResolverTest extends TestCase
     protected function setUp(): void
     {
         $this->composer = $this->prophesize(ComposerJsonInterface::class);
+        $this->composer->getAutoload('files')->willReturn([]);
         $this->filesystem = new SymfonyFilesystem();
         $this->workingDirectory = getcwd();
         $this->workspace = sys_get_temp_dir() . '/dev-tools-project-capabilities-' . uniqid('', true);
@@ -178,6 +179,48 @@ public function resolveWillDetectPhpSourceFromFileBasedClassmapEntries(): void
         self::assertFalse($capabilities->canGenerateApiDocumentation());
     }
 
+    /**
+     * @return void
+     */
+    #[Test]
+    public function resolveWillDetectFilesOnlySourceWithoutInventingApiDirectories(): void
+    {
+        mkdir($this->workspace . '/tests');
+        file_put_contents($this->workspace . '/functions.php', "<?php\nfunction example(): void {}\n");
+
+        foreach (['psr-4', 'psr-0', 'classmap'] as $type) {
+            $this->composer->getAutoload($type)->willReturn([]);
+        }
+
+        $this->composer->getAutoload('files')->willReturn(['missing.php', 'functions.php']);
+
+        $capabilities = $this->resolver->resolve();
+
+        self::assertTrue($capabilities->hasTestsPath());
+        self::assertTrue($capabilities->hasPhpSourceFiles());
+        self::assertTrue($capabilities->canRunTests());
+        self::assertSame([], $capabilities->getApiDirectories());
+        self::assertFalse($capabilities->canGenerateApiDocumentation());
+        self::assertFalse($capabilities->canGenerateWiki());
+    }
+
+    /**
+     * @return void
+     */
+    #[Test]
+    public function resolveWillIgnoreMissingAndNonPhpAutoloadFiles(): void
+    {
+        file_put_contents($this->workspace . '/README.md', 'Guide');
+
+        foreach (['psr-4', 'psr-0', 'classmap'] as $type) {
+            $this->composer->getAutoload($type)->willReturn([]);
+        }
+
+        $this->composer->getAutoload('files')->willReturn(['missing.php', 'README.md']);
+
+        self::assertFalse($this->resolver->resolve()->canRunTests());
+    }
+
     /**
      * @return void
      */