diff --git a/app/Actions/Post/CreatePost.php b/app/Actions/Post/CreatePost.php
index 7950339d..1462f425 100644
--- a/app/Actions/Post/CreatePost.php
+++ b/app/Actions/Post/CreatePost.php
@@ -12,6 +12,7 @@
 use App\Models\Workspace;
 use Carbon\Carbon;
 use Illuminate\Support\Facades\DB;
+use InvalidArgumentException;
 
 class CreatePost
 {
@@ -39,18 +40,26 @@ class CreatePost
      *     platforms?: array<int, array{social_account_id: string, content_type?: string, meta?: array<string, mixed>}>,
      *     label_ids?: array<int, string>
      * }  $data
+     *
+     * @throws InvalidArgumentException when created_via is missing or not a CreatedVia case
      */
     public static function execute(Workspace $workspace, User $user, array $data): Post
     {
+        $createdVia = data_get($data, 'created_via');
+
+        if (! $createdVia instanceof CreatedVia) {
+            throw new InvalidArgumentException('created_via must be a CreatedVia enum case.');
+        }
+
         $scheduledAt = self::resolveScheduledAt($data);
 
-        $post = DB::transaction(function () use ($workspace, $user, $data, $scheduledAt): Post {
+        $post = DB::transaction(function () use ($workspace, $user, $data, $scheduledAt, $createdVia): Post {
             $post = $workspace->posts()->create([
                 'user_id' => $user->id,
                 'content' => data_get($data, 'content', ''),
                 'media' => data_get($data, 'media', []),
                 'status' => PostStatus::Draft,
-                'created_via' => data_get($data, 'created_via'),
+                'created_via' => $createdVia,
                 'scheduled_at' => $scheduledAt,
             ]);
 
diff --git a/app/Actions/Post/DuplicatePost.php b/app/Actions/Post/DuplicatePost.php
index 3fdd67ec..1e40854e 100644
--- a/app/Actions/Post/DuplicatePost.php
+++ b/app/Actions/Post/DuplicatePost.php
@@ -4,6 +4,7 @@
 
 namespace App\Actions\Post;
 
+use App\Enums\Post\CreatedVia;
 use App\Enums\Post\Status as PostStatus;
 use App\Enums\PostPlatform\Status as PostPlatformStatus;
 use App\Models\Post;
@@ -25,6 +26,7 @@ public static function execute(Post $original, User $user): Post
                 'content' => $original->content,
                 'media' => $original->media,
                 'status' => PostStatus::Draft,
+                'created_via' => CreatedVia::Web,
                 'scheduled_at' => null,
                 'published_at' => null,
             ]);
diff --git a/tests/Feature/Actions/Post/CreatePostTest.php b/tests/Feature/Actions/Post/CreatePostTest.php
index 690f3bb9..e0d2d7f4 100644
--- a/tests/Feature/Actions/Post/CreatePostTest.php
+++ b/tests/Feature/Actions/Post/CreatePostTest.php
@@ -43,3 +43,12 @@
     'api' => CreatedVia::Api,
     'automation' => CreatedVia::Automation,
 ]);
+
+test('execute requires created_via', function () {
+    $user = User::factory()->create();
+    $workspace = Workspace::factory()->create(['user_id' => $user->id]);
+
+    CreatePost::execute($workspace, $user, [
+        'content' => 'Hello world',
+    ]);
+})->throws(InvalidArgumentException::class, 'created_via must be a CreatedVia enum case.');
diff --git a/tests/Feature/Actions/Post/DuplicatePostTest.php b/tests/Feature/Actions/Post/DuplicatePostTest.php
new file mode 100644
index 00000000..628c6943
--- /dev/null
+++ b/tests/Feature/Actions/Post/DuplicatePostTest.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Actions\Post\DuplicatePost;
+use App\Enums\Post\CreatedVia;
+use App\Enums\Post\Status as PostStatus;
+use App\Models\Post;
+use App\Models\User;
+use App\Models\Workspace;
+
+test('execute clones the post as a draft created via web', function () {
+    $user = User::factory()->create();
+    $workspace = Workspace::factory()->create(['user_id' => $user->id]);
+    $original = Post::factory()->create([
+        'workspace_id' => $workspace->id,
+        'user_id' => $user->id,
+        'content' => 'Original content',
+        'created_via' => CreatedVia::Api,
+        'status' => PostStatus::Published,
+    ]);
+
+    $copy = DuplicatePost::execute($original, $user);
+
+    expect($copy->id)->not->toBe($original->id)
+        ->and($copy->content)->toBe('Original content')
+        ->and($copy->status)->toBe(PostStatus::Draft)
+        ->and($copy->created_via)->toBe(CreatedVia::Web)
+        ->and($copy->scheduled_at)->toBeNull()
+        ->and($copy->published_at)->toBeNull();
+});
diff --git a/tests/Feature/Ai/StreamPostCreationTest.php b/tests/Feature/Ai/StreamPostCreationTest.php
index 513da29b..457d1f64 100644
--- a/tests/Feature/Ai/StreamPostCreationTest.php
+++ b/tests/Feature/Ai/StreamPostCreationTest.php
@@ -4,6 +4,7 @@
 
 use App\Ai\Agents\PostContentGenerator;
 use App\Ai\Agents\PostContentHumanizer;
+use App\Enums\Post\CreatedVia;
 use App\Enums\PostPlatform\ContentType;
 use App\Enums\UserWorkspace\Role;
 use App\Jobs\Ai\StreamPostCreation;
@@ -111,7 +112,8 @@ function runStreamPostCreation(string $format, SocialAccount $account, int $imag
     $post = $this->user->currentWorkspace->posts()->latest()->first();
 
     expect($post->content)->toBe('Hello world\n\nSecond para.')
-        ->and($post->media)->toHaveCount(1);
+        ->and($post->media)->toHaveCount(1)
+        ->and($post->created_via)->toBe(CreatedVia::Web);
 
     $platform = PostPlatform::where('social_account_id', $this->account->id)->firstOrFail();
 
diff --git a/tests/Feature/Api/PostApiTest.php b/tests/Feature/Api/PostApiTest.php
index 444bcbfd..567607a6 100644
--- a/tests/Feature/Api/PostApiTest.php
+++ b/tests/Feature/Api/PostApiTest.php
@@ -78,6 +78,23 @@
     expect($post->created_via)->toBe(CreatedVia::Api);
 });
 
+it('ignores a client-supplied created_via and always records api', function () {
+    $this->withHeaders(['Authorization' => 'Bearer '.$this->plainToken])
+        ->postJson(route('api.posts.store'), [
+            'created_via' => 'web',
+            'platforms' => [
+                [
+                    'social_account_id' => $this->socialAccount->id,
+                    'content_type' => 'linkedin_post',
+                ],
+            ],
+        ])
+        ->assertCreated();
+
+    $post = Post::where('workspace_id', $this->workspace->id)->first();
+    expect($post->created_via)->toBe(CreatedVia::Api);
+});
+
 it('creates a post with content, media, and labels', function () {
     $label = WorkspaceLabel::factory()->create(['workspace_id' => $this->workspace->id]);
 
diff --git a/tests/Feature/Automation/Node/GenerateNodeTest.php b/tests/Feature/Automation/Node/GenerateNodeTest.php
index f8fa5673..368a99de 100644
--- a/tests/Feature/Automation/Node/GenerateNodeTest.php
+++ b/tests/Feature/Automation/Node/GenerateNodeTest.php
@@ -7,6 +7,7 @@
 use App\Ai\Agents\PostContentHumanizer;
 use App\Enums\Ai\ContentStyle;
 use App\Enums\Ai\GeneratorFormat;
+use App\Enums\Post\CreatedVia;
 use App\Enums\Post\Status as PostStatus;
 use App\Enums\PostPlatform\ContentType;
 use App\Models\Automation;
@@ -47,6 +48,7 @@
     $post = Post::find($run->generated_post_id);
     expect($post)->not->toBeNull();
     expect($post->status)->toBe(PostStatus::Draft);
+    expect($post->created_via)->toBe(CreatedVia::Automation);
 });
 
 it('applies brand voice by default', function () {
diff --git a/tests/Feature/PostTemplateControllerTest.php b/tests/Feature/PostTemplateControllerTest.php
index be4b34bd..7e20d520 100644
--- a/tests/Feature/PostTemplateControllerTest.php
+++ b/tests/Feature/PostTemplateControllerTest.php
@@ -2,6 +2,7 @@
 
 declare(strict_types=1);
 
+use App\Enums\Post\CreatedVia;
 use App\Enums\UserWorkspace\Role;
 use App\Models\Account;
 use App\Models\SocialAccount;
@@ -72,6 +73,9 @@
 
     expect($response->json('post_id'))->toBeString();
     expect($response->json('redirect_url'))->toContain('edit');
+
+    $post = $this->workspace->posts()->find($response->json('post_id'));
+    expect($post->created_via)->toBe(CreatedVia::Web);
 });
 
 test('apply interpolates brand_name in content', function () {