diff --git a/app/Models/Project.php b/app/Models/Project.php
index 62900d4e986f..e3669bc3ad7b 100644
--- a/app/Models/Project.php
+++ b/app/Models/Project.php
@@ -61,6 +61,11 @@ class Project extends BaseModel
         return $this->belongsTo(Client::class)->withTrashed();
     }
 
+    public function documents()
+    {
+        return $this->morphMany(Document::class, 'documentable');
+    }
+
     // /**
     //  * @return \Illuminate\Database\Eloquent\Relations\HasMany
     //  */
diff --git a/app/Transformers/ExpenseTransformer.php b/app/Transformers/ExpenseTransformer.php
index 7a78910a0b6a..8dcde2bfd23d 100644
--- a/app/Transformers/ExpenseTransformer.php
+++ b/app/Transformers/ExpenseTransformer.php
@@ -11,6 +11,7 @@
 
 namespace App\Transformers;
 
+use App\Models\Document;
 use App\Models\Expense;
 use App\Utils\Traits\MakesHash;
 use Illuminate\Database\Eloquent\SoftDeletes;
@@ -23,15 +24,23 @@ class ExpenseTransformer extends EntityTransformer
     use MakesHash;
     use SoftDeletes;
     protected $defaultIncludes = [
+        'documents',
     ];
 
     /**
      * @var array
      */
     protected $availableIncludes = [
-
+        'documents',
     ];
 
+    public function includeDocuments(Expense $expense)
+    {
+        $transformer = new DocumentTransformer($this->serializer);
+
+        return $this->includeCollection($expense->documents, $transformer, Document::class);
+    }
+
     /**
      * @param Expense $expense
      *
diff --git a/app/Transformers/ProjectTransformer.php b/app/Transformers/ProjectTransformer.php
index 8232603d14e3..6ba7d0749b97 100644
--- a/app/Transformers/ProjectTransformer.php
+++ b/app/Transformers/ProjectTransformer.php
@@ -11,6 +11,7 @@
 
 namespace App\Transformers;
 
+use App\Models\Document;
 use App\Models\Project;
 use App\Utils\Traits\MakesHash;
 
@@ -22,14 +23,23 @@ class ProjectTransformer extends EntityTransformer
     use MakesHash;
 
     protected $defaultIncludes = [
+        'documents',
     ];
 
     /**
      * @var array
      */
     protected $availableIncludes = [
+        'documents'
     ];
 
+    public function includeDocuments(Project $project)
+    {
+        $transformer = new DocumentTransformer($this->serializer);
+
+        return $this->includeCollection($project->documents, $transformer, Document::class);
+    }
+
     public function transform(Project $project)
     {
         return [
diff --git a/app/Transformers/VendorTransformer.php b/app/Transformers/VendorTransformer.php
index a85e76a5af8d..e6a4c7799c03 100644
--- a/app/Transformers/VendorTransformer.php
+++ b/app/Transformers/VendorTransformer.php
@@ -12,6 +12,7 @@
 namespace App\Transformers;
 
 use App\Models\Activity;
+use App\Models\Document;
 use App\Models\Vendor;
 use App\Models\VendorContact;
 use App\Models\VendorGatewayToken;
@@ -29,6 +30,7 @@ class VendorTransformer extends EntityTransformer
 
     protected $defaultIncludes = [
         'contacts',
+        'documents'
     ];
 
     /**
@@ -36,6 +38,7 @@ class VendorTransformer extends EntityTransformer
      */
     protected $availableIncludes = [
         'activities',
+        'documents',
     ];
 
     /**
@@ -62,6 +65,13 @@ class VendorTransformer extends EntityTransformer
         return $this->includeCollection($vendor->contacts, $transformer, VendorContact::class);
     }
 
+    public function includeDocuments(Vendor $vendor)
+    {
+        $transformer = new DocumentTransformer($this->serializer);
+
+        return $this->includeCollection($vendor->documents, $transformer, Document::class);
+    }
+
     /**
      * @param Vendor $vendor
      *
diff --git a/tests/Feature/DocumentsApiTest.php b/tests/Feature/DocumentsApiTest.php
new file mode 100644
index 000000000000..512c918cb8f7
--- /dev/null
+++ b/tests/Feature/DocumentsApiTest.php
@@ -0,0 +1,143 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2020. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://opensource.org/licenses/AAL
+ */
+namespace Tests\Feature;
+
+use App\DataMapper\DefaultSettings;
+use App\Models\Account;
+use App\Models\Client;
+use App\Models\ClientContact;
+use App\Models\Company;
+use App\Models\User;
+use App\Utils\Traits\MakesHash;
+use Faker\Factory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Foundation\Testing\WithFaker;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Facades\Session;
+use Tests\MockAccountData;
+use Tests\TestCase;
+
+/**
+ * @test
+ * @covers App\Http\Controllers\DocumentController
+ */
+class DocumentsApiTest extends TestCase
+{
+    use MakesHash;
+    use DatabaseTransactions;
+    use MockAccountData;
+
+    public function setUp() :void
+    {
+        parent::setUp();
+
+        $this->makeTestData();
+
+        Session::start();
+
+        $this->faker = \Faker\Factory::create();
+
+        Model::reguard();
+    }
+
+    public function testClientDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/clients');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+
+    public function testInvoiceDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/invoices');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+
+    public function testProjectsDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/projects');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+
+    public function testExpenseDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/expenses');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+
+    public function testVendorDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/vendors');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+
+    public function testProductDocuments()
+    {
+
+        $response = $this->withHeaders([
+                'X-API-SECRET' => config('ninja.api_secret'),
+                'X-API-TOKEN' => $this->token,
+            ])->get('/api/v1/products');
+
+        $response->assertStatus(200);
+        $arr = $response->json();
+        $this->assertArrayHasKey('documents', $arr['data'][0]);
+
+    }
+
+}
diff --git a/tests/MockAccountData.php b/tests/MockAccountData.php
index 31c88f16fd76..27acbaf2b934 100644
--- a/tests/MockAccountData.php
+++ b/tests/MockAccountData.php
@@ -35,6 +35,7 @@ use App\Models\Expense;
 use App\Models\GroupSetting;
 use App\Models\Invoice;
 use App\Models\InvoiceInvitation;
+use App\Models\Product;
 use App\Models\Project;
 use App\Models\Quote;
 use App\Models\QuoteInvitation;
@@ -159,6 +160,11 @@ trait MockAccountData
 
         $company_token->save();
 
+        Product::factory()->create([
+                'user_id' => $this->user->id,
+                'company_id' => $this->company->id,
+        ]);
+        
         $this->client = Client::factory()->create([
                 'user_id' => $this->user->id,
                 'company_id' => $this->company->id,