diff --git a/.gitignore b/.gitignore
index c86af6f..fa1d02a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 /node_modules
 
 /.php_cs.cache
+/.php-cs-fixer.cache
 /.phpunit.result.cache
 
 php-cs-fixer.phar
diff --git a/.php_cs.dist b/.php-cs-fixer.dist.php
similarity index 92%
rename from .php_cs.dist
rename to .php-cs-fixer.dist.php
index 704f437..3594ae9 100644
--- a/.php_cs.dist
+++ b/.php-cs-fixer.dist.php
@@ -1,6 +1,6 @@
 <?php
 
-return PhpCsFixer\Config::create()
+return (new PhpCsFixer\Config())
     ->setRules([
         '@PSR2' => true,
         'array_syntax' => ['syntax' => 'short'],
diff --git a/Makefile b/Makefile
index ee99b2a..b4fae49 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,7 @@ check-style: php-cs-fixer.phar
 
 fix-style: php-cs-fixer.phar
 	$(DOCKER_PHP) vendor/bin/indent --tabs composer.json
-	$(DOCKER_PHP) vendor/bin/indent --spaces .php_cs.dist
+	$(DOCKER_PHP) vendor/bin/indent --spaces .php-cs-fixer.dist.php
 	$(DOCKER_PHP) ./php-cs-fixer.phar fix src/ --diff
 
 install: composer.lock yarn.lock
diff --git a/src/Reader.php b/src/Reader.php
index 99ee5c3..2776313 100644
--- a/src/Reader.php
+++ b/src/Reader.php
@@ -23,6 +23,7 @@ class Reader
 {
     /**
      * Populate OpenAPI spec object from JSON data.
+     * Saves reference context for resolving internal references
      * @phpstan-template T of SpecObjectInterface
      * @phpstan-param class-string<T> $baseType
      * @phpstan-return T
@@ -34,7 +35,33 @@ class Reader
      * The type of the returned object depends on the `$baseType` argument.
      * @throws TypeErrorException in case invalid spec data is supplied.
      */
-    public static function readFromJson(string $json, string $baseType = OpenApi::class): SpecObjectInterface
+    public static function readFromJson(string $json, string $baseType = OpenApi::class, bool $resolveReferences = true): SpecObjectInterface
+    {
+        $spec = static::fromJson($json, $baseType);
+        $context = ReferenceContext::readFromString($spec, $json);
+        $context->setDefaultCacheKey($baseType);
+        $context->mode = ReferenceContext::RESOLVE_MODE_INLINE;
+        $spec->setReferenceContext($context);
+        if($resolveReferences && $context->hasComponentsRef()) {
+            $spec->resolveReferences();
+        }
+        return $spec;
+    }
+
+    /**
+     * Populate OpenAPI spec object from JSON data.
+     * @phpstan-template T of SpecObjectInterface
+     * @phpstan-param class-string<T> $baseType
+     * @phpstan-return T
+     * @param string $json the JSON string to decode.
+     * @param string $baseType the base Type to instantiate. This must be an instance of [[SpecObjectInterface]].
+     * The default is [[OpenApi]] which is the base type of a OpenAPI specification file.
+     * You may choose a different type if you instantiate objects from sub sections of a specification.
+     * @return SpecObjectInterface|OpenApi the OpenApi object instance.
+     * The type of the returned object depends on the `$baseType` argument.
+     * @throws TypeErrorException in case invalid spec data is supplied.
+     */
+    protected static function fromJson(string $json, string $baseType = OpenApi::class): SpecObjectInterface
     {
         return new $baseType(json_decode($json, true));
     }
@@ -52,7 +79,33 @@ public static function readFromJson(string $json, string $baseType = OpenApi::cl
      * The type of the returned object depends on the `$baseType` argument.
      * @throws TypeErrorException in case invalid spec data is supplied.
      */
-    public static function readFromYaml(string $yaml, string $baseType = OpenApi::class): SpecObjectInterface
+    public static function readFromYaml(string $yaml, string $baseType = OpenApi::class, bool $resolveReferences = true): SpecObjectInterface
+    {
+        $spec = static::fromYaml($yaml, $baseType);
+        $context = ReferenceContext::readFromString($spec, $yaml);
+        $context->setDefaultCacheKey($baseType);
+        $context->mode = ReferenceContext::RESOLVE_MODE_INLINE;
+        $spec->setReferenceContext($context);
+        if($resolveReferences && $context->hasComponentsRef()) {
+            $spec->resolveReferences();
+        }
+        return $spec;
+    }
+
+    /**
+     * Populate OpenAPI spec object from YAML data.
+     * @phpstan-template T of SpecObjectInterface
+     * @phpstan-param class-string<T> $baseType
+     * @phpstan-return T
+     * @param string $yaml the YAML string to decode.
+     * @param string $baseType the base Type to instantiate. This must be an instance of [[SpecObjectInterface]].
+     * The default is [[OpenApi]] which is the base type of a OpenAPI specification file.
+     * You may choose a different type if you instantiate objects from sub sections of a specification.
+     * @return SpecObjectInterface|OpenApi the OpenApi object instance.
+     * The type of the returned object depends on the `$baseType` argument.
+     * @throws TypeErrorException in case invalid spec data is supplied.
+     */
+    public static function fromYaml(string $yaml, string $baseType = OpenApi::class): SpecObjectInterface
     {
         return new $baseType(Yaml::parse($yaml));
     }
@@ -89,7 +142,7 @@ public static function readFromJsonFile(string $fileName, string $baseType = Ope
             $e->fileName = $fileName;
             throw $e;
         }
-        $spec = static::readFromJson($fileContent, $baseType);
+        $spec = static::fromJson($fileContent, $baseType);
         $context = new ReferenceContext($spec, $fileName);
         $spec->setReferenceContext($context);
         if ($resolveReferences !== false) {
@@ -135,7 +188,7 @@ public static function readFromYamlFile(string $fileName, string $baseType = Ope
             $e->fileName = $fileName;
             throw $e;
         }
-        $spec = static::readFromYaml($fileContent, $baseType);
+        $spec = static::fromYaml($fileContent, $baseType);
         $context = new ReferenceContext($spec, $fileName);
         $spec->setReferenceContext($context);
         if ($resolveReferences !== false) {
diff --git a/src/ReferenceContext.php b/src/ReferenceContext.php
index bde0a96..4fba238 100644
--- a/src/ReferenceContext.php
+++ b/src/ReferenceContext.php
@@ -10,6 +10,7 @@
 use cebe\openapi\exceptions\IOException;
 use cebe\openapi\exceptions\UnresolvableReferenceException;
 use cebe\openapi\json\JsonPointer;
+use cebe\openapi\spec\OpenApi;
 use cebe\openapi\spec\Reference;
 use Symfony\Component\Yaml\Yaml;
 
@@ -51,6 +52,21 @@ class ReferenceContext
      */
     private $_cache;
 
+    /**
+     * @var bool checks if content is read from string or file
+     */
+    private $_read_from_string = false;
+
+    /**
+     * @var string Default cache key for data read from string
+     */
+    private $_string_cache_key = OpenApi::class;
+
+    /**
+     * @var bool checks if read string contains components
+     */
+    private $_content_has_components = false;
+
 
     /**
      * ReferenceContext constructor.
@@ -62,7 +78,7 @@ class ReferenceContext
     public function __construct(?SpecObjectInterface $base, string $uri, $cache = null)
     {
         $this->_baseSpec = $base;
-        $this->_uri = $this->normalizeUri($uri);
+        $this->_uri = empty($uri) ? static::class : $this->normalizeUri($uri);
         $this->_cache = $cache ?? new ReferenceContextCache();
         if ($cache === null && $base !== null) {
             $this->_cache->set($this->_uri, null, $base);
@@ -210,6 +226,7 @@ public function resolveRelativeUri(string $uri): string
      */
     public function fetchReferencedFile($uri)
     {
+        $uri = $this->resolveCacheUri($uri);
         if ($this->_cache->has('FILE_CONTENT://' . $uri, 'FILE_CONTENT')) {
             return $this->_cache->get('FILE_CONTENT://' . $uri, 'FILE_CONTENT');
         }
@@ -221,6 +238,15 @@ public function fetchReferencedFile($uri)
             throw $e;
         }
         // TODO lazy content detection, should be improved
+        $parsedContent = $this->parseAndCacheContent($content, $uri);
+        return $parsedContent;
+    }
+
+    /**
+     * Parse content from string to either Yaml or Json
+     */
+    protected function parseAndCacheContent($content, $uri): array
+    {
         if (strpos(ltrim($content), '{') === 0) {
             $parsedContent = json_decode($content, true);
         } else {
@@ -229,6 +255,43 @@ public function fetchReferencedFile($uri)
         $this->_cache->set('FILE_CONTENT://' . $uri, 'FILE_CONTENT', $parsedContent);
         return $parsedContent;
     }
+    
+    /**
+     * Prepare content read and cache from JSON or YAML string
+     */
+    public function prepareDataFromString($content)
+    {
+        $this->_read_from_string = true;
+        $parsedContent  = $this->parseAndCacheContent($content, $this->resolveCacheUri(''));
+
+        if(array_key_exists('components', $parsedContent) && str_contains($content, '#/components')) {
+            $this->_content_has_components = true;
+        }
+    }
+    
+    /**
+     * Is content from string or file
+     */
+    public function isFromFile(): bool
+    {
+        return !$this->_read_from_string;
+    }
+
+    /**
+     * Uses default base classname to cache what ever is read
+     */
+    public function setDefaultCacheKey($key = OpenApi::class)
+    {
+        $this->_string_cache_key = $key;
+    }
+
+    /**
+     * Return result indicating if components and ref is present in read string
+     */
+    public function hasComponentsRef(): bool
+    {
+        return $this->_content_has_components;
+    }
 
     /**
      * Retrieve the referenced data via JSON pointer.
@@ -267,4 +330,19 @@ public function resolveReferenceData($uri, JsonPointer $pointer, $data, $toType)
 
         return $referencedObject;
     }
+
+    protected function resolveCacheUri($uri)
+    {
+        return empty($uri) ? $this->_string_cache_key : $uri;
+    }
+
+    /**
+     * Static function that reads from string and initialises base class
+     */
+    public static function readFromString($base, $content): static
+    {
+        $context = new static($base, '');
+        $context->prepareDataFromString($content);
+        return $context;
+    }
 }
diff --git a/src/json/JsonPointer.php b/src/json/JsonPointer.php
index 0e1f75e..3121e08 100644
--- a/src/json/JsonPointer.php
+++ b/src/json/JsonPointer.php
@@ -107,11 +107,11 @@ public function evaluate($jsonDocument)
 
         foreach ($this->getPath() as $part) {
             if (is_array($currentReference)) {
-//                if (!preg_match('~^([1-9]*[0-9]|-)$~', $part)) {
-//                    throw new NonexistentJsonPointerReferenceException(
-//                        "Failed to evaluate pointer '$this->_pointer'. Invalid pointer path '$part' for Array at path '$currentPath'."
-//                    );
-//                }
+                //                if (!preg_match('~^([1-9]*[0-9]|-)$~', $part)) {
+                //                    throw new NonexistentJsonPointerReferenceException(
+                //                        "Failed to evaluate pointer '$this->_pointer'. Invalid pointer path '$part' for Array at path '$currentPath'."
+                //                    );
+                //                }
                 if ($part === '-' || !array_key_exists($part, $currentReference)) {
                     throw new NonexistentJsonPointerReferenceException(
                         "Failed to evaluate pointer '$this->_pointer'. Array has no member $part at path '$currentPath'."
diff --git a/src/spec/Reference.php b/src/spec/Reference.php
index cda612a..f3191bc 100644
--- a/src/spec/Reference.php
+++ b/src/spec/Reference.php
@@ -154,7 +154,7 @@ public function setContext(ReferenceContext $context)
     /**
      * @return ReferenceContext
      */
-    public function getContext() : ?ReferenceContext
+    public function getContext(): ?ReferenceContext
     {
         return $this->_context;
     }
@@ -186,53 +186,58 @@ public function resolve(ReferenceContext $context = null)
             return $this;
         }
         try {
-            if ($jsonReference->getDocumentUri() === '') {
-                if ($context->mode === ReferenceContext::RESOLVE_MODE_INLINE) {
-                    return $this;
-                }
-
-                // resolve in current document
-                $baseSpec = $context->getBaseSpec();
-                if ($baseSpec !== null) {
-                    // TODO type error if resolved object does not match $this->_to ?
-                    /** @var SpecObjectInterface $referencedObject */
-                    $referencedObject = $jsonReference->getJsonPointer()->evaluate($baseSpec);
-                    // transitive reference
-                    if ($referencedObject instanceof Reference) {
-                        $referencedObject = $this->resolveTransitiveReference($referencedObject, $context);
+            if ($context->isFromFile()) {
+                if ($jsonReference->getDocumentUri() === '') {
+                    if ($context->mode === ReferenceContext::RESOLVE_MODE_INLINE) {
+                        return $this;
                     }
-                    if ($referencedObject instanceof SpecObjectInterface) {
-                        $referencedObject->setReferenceContext($context);
+
+                    // resolve in current document
+                    $baseSpec = $context->getBaseSpec();
+                    if ($baseSpec !== null) {
+                        // TODO type error if resolved object does not match $this->_to ?
+                        /** @var SpecObjectInterface $referencedObject */
+                        $referencedObject = $jsonReference->getJsonPointer()->evaluate($baseSpec);
+                        // transitive reference
+                        if ($referencedObject instanceof Reference) {
+                            $referencedObject = $this->resolveTransitiveReference($referencedObject, $context);
+                        }
+                        if ($referencedObject instanceof SpecObjectInterface) {
+                            $referencedObject->setReferenceContext($context);
+                        }
+                        return $referencedObject;
+                    } else {
+                        // if current document was loaded via reference, it may be null,
+                        // so we load current document by URI instead.
+                        $jsonReference = JsonReference::createFromUri($context->getUri(), $jsonReference->getJsonPointer());
                     }
-                    return $referencedObject;
-                } else {
-                    // if current document was loaded via reference, it may be null,
-                    // so we load current document by URI instead.
-                    $jsonReference = JsonReference::createFromUri($context->getUri(), $jsonReference->getJsonPointer());
                 }
-            }
 
-            // resolve in external document
-            $file = $context->resolveRelativeUri($jsonReference->getDocumentUri());
-            try {
-                $referencedDocument = $context->fetchReferencedFile($file);
-            } catch (\Throwable $e) {
-                $exception = new UnresolvableReferenceException(
-                    "Failed to resolve Reference '$this->_ref' to $this->_to Object: " . $e->getMessage(),
-                    $e->getCode(),
-                    $e
-                );
-                $exception->context = $this->getDocumentPosition();
-                throw $exception;
-            }
+                // resolve in external document
+                $file = $context->resolveRelativeUri($jsonReference->getDocumentUri());
+                try {
+                    $referencedDocument = $context->fetchReferencedFile($file);
+                } catch (\Throwable $e) {
+                    $exception = new UnresolvableReferenceException(
+                        "Failed to resolve Reference '$this->_ref' to $this->_to Object: " . $e->getMessage(),
+                        $e->getCode(),
+                        $e
+                    );
+                    $exception->context = $this->getDocumentPosition();
+                    throw $exception;
+                }
 
-            $referencedDocument = $this->adjustRelativeReferences($referencedDocument, $file, null, $context);
-            $referencedObject = $context->resolveReferenceData($file, $jsonReference->getJsonPointer(), $referencedDocument, $this->_to);
+                $referencedDocument = $this->adjustRelativeReferences($referencedDocument, $file, null, $context);
+                $referencedObject = $context->resolveReferenceData($file, $jsonReference->getJsonPointer(), $referencedDocument, $this->_to);
 
-            if ($referencedObject instanceof DocumentContextInterface) {
-                if ($referencedObject->getDocumentPosition() === null && $this->getDocumentPosition() !== null) {
-                    $referencedObject->setDocumentContext($context->getBaseSpec(), $this->getDocumentPosition());
+                if ($referencedObject instanceof DocumentContextInterface) {
+                    if ($referencedObject->getDocumentPosition() === null && $this->getDocumentPosition() !== null) {
+                        $referencedObject->setDocumentContext($context->getBaseSpec(), $this->getDocumentPosition());
+                    }
                 }
+            } else {
+                $referencedDocument = $context->fetchReferencedFile('');
+                $referencedObject = $context->resolveReferenceData('', $jsonReference->getJsonPointer(), $referencedDocument, $this->_to);
             }
 
             // transitive reference
diff --git a/tests/spec/OpenApiTest.php b/tests/spec/OpenApiTest.php
index 20b568e..178d759 100644
--- a/tests/spec/OpenApiTest.php
+++ b/tests/spec/OpenApiTest.php
@@ -1,5 +1,6 @@
 <?php
 
+use cebe\openapi\Reader;
 use cebe\openapi\spec\OpenApi;
 use Symfony\Component\Yaml\Yaml;
 
@@ -232,4 +233,199 @@ public function testSpecs($openApiFile)
         }
 
     }
+
+
+    public function testDeepValidationOfApiOperationsJSON()
+    {
+        $openapi = Reader::readFromJson(<<<JSON
+        {
+          "openapi": "3.0.0",
+          "info": {
+            "title": "Test API",
+            "version": "1.0.0"
+          },
+          "paths": {
+            "/path": {
+              "get": {
+                "responses": {
+                  "200": {
+                    "\$ref": "#/components/schemas/notAResponse"
+                  }
+                }
+              }
+            }
+          },
+          "components": {
+            "schemas": {
+              "notAResponse": {
+                "type": "integer"
+              }
+            }
+          }
+        }
+        JSON);
+        $this->assertFalse($openapi->validate()); 
+
+        //PASS - Contains Description
+        $openapi = Reader::readFromJson(<<<JSON
+        {
+          "openapi": "3.0.0",
+          "info": {
+            "title": "Test API",
+            "version": "1.0.0"
+          },
+          "paths": {
+            "/path": {
+              "get": {
+                "responses": {
+                  "200": {
+                    "\$ref": "#/components/schemas/notAResponse"
+                  }
+                }
+              }
+            }
+          },
+          "components": {
+            "schemas": {
+              "notAResponse": {
+                "type": "integer",
+                "description": "Test Description"
+              }
+            }
+          }
+        }
+        JSON);
+        $this->assertTrue($openapi->validate()); 
+
+
+        //FAILS - Does not contain required description
+        $openapi = Reader::readFromJson(<<<JSON
+        {
+          "openapi": "3.0.0",
+          "info": {
+            "title": "Test API",
+            "version": "1.0.0"
+          },
+          "paths": {
+            "/path": {
+              "get": {
+                "responses": {
+                  "200": {
+                    "content": "A simple response"
+                  }
+                }
+              }
+            }
+          }
+        }
+        JSON);
+        $this->assertFalse($openapi->validate());         
+
+        //PASSES - Contains Description
+        $openapi = Reader::readFromJson(<<<JSON
+        {
+          "openapi": "3.0.0",
+          "info": {
+            "title": "Test API",
+            "version": "1.0.0"
+          },
+          "paths": {
+            "/path": {
+              "get": {
+                "responses": {
+                  "200": {
+                    "description": "A simple response"
+                  }
+                }
+              }
+            }
+          }
+        }
+        JSON);
+        $this->assertTrue($openapi->validate());              
+    }   
+    
+    public function testDeepValidationOfApiOperationsYAML()
+    {
+        $openapi = Reader::readFromYaml(<<<'YAML'
+openapi: 3.0.2
+info:
+  title: My API
+  version: "1.0.0"
+paths:
+  '/path':
+    get:
+      responses:
+        200:
+          $ref: '#/components/schemas/notAResponse'
+components:
+  schemas:
+    notAResponse:
+      type: "integer"                  
+YAML);
+        $this->assertFalse($openapi->validate()); 
+
+        //PASS - Contains Description
+        $openapi = Reader::readFromYaml(<<<'YAML'
+openapi: 3.0.2
+info:
+  title: My API
+  version: "1.0.0"
+paths:
+  '/path':
+    get:
+      responses:
+        200:
+          $ref: '#/components/schemas/notAResponse'
+components:
+  schemas:
+    notAResponse:
+      type: "integer" 
+      description: "Test Description"                 
+YAML);
+
+        $this->assertTrue($openapi->validate());  
+        
+        //FAILS - Contains Description
+        $openapi = Reader::readFromYaml(<<<'YAML'
+openapi: 3.0.2
+info:
+  title: My API
+  version: "1.0.0"
+paths:
+  '/path':
+    get:
+      responses:
+        200:
+          content: "A simple response"
+components:
+  schemas:
+    notAResponse:
+      type: "integer" 
+      description: "Test Description"                 
+YAML);
+
+        $this->assertFalse($openapi->validate());    
+        
+        //FAILS - Contains Description
+        $openapi = Reader::readFromYaml(<<<'YAML'
+openapi: 3.0.2
+info:
+  title: My API
+  version: "1.0.0"
+paths:
+  '/path':
+    get:
+      responses:
+        200:
+          description: "Test Description" 
+components:
+  schemas:
+    notAResponse:
+      type: "integer" 
+      description: "Test Description"                 
+YAML);
+
+        $this->assertTrue($openapi->validate());         
+    }     
 }
diff --git a/tests/spec/ReferenceTest.php b/tests/spec/ReferenceTest.php
index b94c946..30a552f 100644
--- a/tests/spec/ReferenceTest.php
+++ b/tests/spec/ReferenceTest.php
@@ -54,7 +54,7 @@ public function testResolveInDocument()
         200:
           $ref: "#/components/responses/Pet"
 YAML
-            , OpenApi::class);
+            , OpenApi::class, false);
 
         $result = $openapi->validate();
         $this->assertEquals([], $openapi->getErrors());
@@ -113,7 +113,7 @@ public function testResolveCyclicReferenceInDocument()
                 frog:
                   $ref: "#/components/examples/frog-example"
 YAML
-            , OpenApi::class);
+            , OpenApi::class, false);
 
         $result = $openapi->validate();
         $this->assertEquals([], $openapi->getErrors());
@@ -311,7 +311,7 @@ enum:
             - "Six"
 
 YAML;
-        $openapi = Reader::readFromYaml($schema);
+        $openapi = Reader::readFromYaml($schema, OpenApi::class, false);
         $openapi->resolveReferences(new \cebe\openapi\ReferenceContext($openapi, $this->createFileUri(__DIR__ . '/data/reference/definitions.yaml')));
 
         $this->assertTrue(isset($openapi->components->schemas['Pet']));
@@ -392,7 +392,7 @@ public function testTransitiveReferenceToFile()
 
 YAML;
 
-        $openapi = Reader::readFromYaml($schema);
+        $openapi = Reader::readFromYaml($schema, OpenApi::class, false);
         $openapi->resolveReferences(new \cebe\openapi\ReferenceContext($openapi, $this->createFileUri(__DIR__ . '/data/reference/definitions.yaml')));
 
         $this->assertTrue(isset($openapi->components->schemas['Dog']));
diff --git a/tests/spec/SchemaTest.php b/tests/spec/SchemaTest.php
index 1600b3b..fc0ffdc 100644
--- a/tests/spec/SchemaTest.php
+++ b/tests/spec/SchemaTest.php
@@ -3,6 +3,7 @@
 use cebe\openapi\Reader;
 use cebe\openapi\ReferenceContext;
 use cebe\openapi\spec\Discriminator;
+use cebe\openapi\spec\OpenApi;
 use cebe\openapi\spec\Reference;
 use cebe\openapi\spec\Schema;
 use cebe\openapi\spec\Type;
@@ -278,7 +279,7 @@ public function testAllOf()
   }
 }
 JSON;
-        $openApi = Reader::readFromJson($json);
+        $openApi = Reader::readFromJson($json, OpenApi::class, false);
         $this->assertInstanceOf(Schema::class, $identifier = $openApi->components->schemas['identifier']);
         $this->assertInstanceOf(Schema::class, $person = $openApi->components->schemas['person']);
 
@@ -371,7 +372,7 @@ public function testRefAdditionalProperties()
   }
 }
 JSON;
-        $openApi = Reader::readFromJson($json);
+        $openApi = Reader::readFromJson($json, OpenApi::class, false);
         $this->assertInstanceOf(Schema::class, $booleanProperties = $openApi->components->schemas['booleanProperties']);
         $this->assertInstanceOf(Schema::class, $person = $openApi->components->schemas['person']);