diff --git a/docs/api.md b/docs/api.md
index 41fb622f7..a02a8aae3 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -4,6 +4,22 @@ weight: 75
 ---
 
 Reference API documentation for AsyncAPI Generator library.
+## Classes
+
+<dl>
+<dt><a href="#Generator">Generator</a></dt>
+<dd></dd>
+</dl>
+
+## Typedefs
+
+<dl>
+<dt><a href="#TemplateRenderMetadata">TemplateRenderMetadata</a> : <code>Object</code></dt>
+<dd></dd>
+<dt><a href="#TemplateRenderResult">TemplateRenderResult</a> : <code>Object</code></dt>
+<dd></dd>
+</dl>
+
 
 <a name="Generator"></a>
 
@@ -29,9 +45,9 @@ Reference API documentation for AsyncAPI Generator library.
         * [.originalAsyncAPI](#Generator+originalAsyncAPI) : `String`
         * [.generate(asyncapiDocument)](#Generator+generate) ⇒ `Promise`
         * [.configureTemplate()](#Generator+configureTemplate)
-        * [.generateFromString(asyncapiString, [parseOptions])](#Generator+generateFromString) ⇒ `Promise`
-        * [.generateFromURL(asyncapiURL)](#Generator+generateFromURL) ⇒ `Promise`
-        * [.generateFromFile(asyncapiFile)](#Generator+generateFromFile) ⇒ `Promise`
+        * [.generateFromString(asyncapiString, [parseOptions])](#Generator+generateFromString) ⇒ `Promise.<(TemplateRenderResult|undefined)>`
+        * [.generateFromURL(asyncapiURL)](#Generator+generateFromURL) ⇒ `Promise.<(TemplateRenderResult|undefined)>`
+        * [.generateFromFile(asyncapiFile)](#Generator+generateFromFile) ⇒ `Promise.<(TemplateRenderResult|undefined)>`
         * [.installTemplate([force])](#Generator+installTemplate)
     * _static_
         * [.getTemplateFile(templateName, filePath, [templatesDir])](#Generator.getTemplateFile) ⇒ `Promise`
@@ -342,3 +358,27 @@ const content = await Generator.getTemplateFile('@asyncapi/html-template', 'part
 const Generator = require('@asyncapi/generator');
 const content = await Generator.getTemplateFile('@asyncapi/html-template', 'partials/content.html', '~/my-templates');
 ```
+
+<a name="TemplateRenderMetadata"></a>
+
+* TemplateRenderMetadata : `Object`** :
+**Kind**: global typedef  
+**Properties**
+
+| Name | Type |
+| --- | --- |
+| fileName | `string` | 
+| permissions | `string` | 
+
+
+<a name="TemplateRenderResult"></a>
+
+* TemplateRenderResult : `Object`** :
+**Kind**: global typedef  
+**Properties**
+
+| Name | Type |
+| --- | --- |
+| content | `string` | 
+| metadata | [`TemplateRenderMetadata`](#TemplateRenderMetadata) | 
+
diff --git a/lib/generator.js b/lib/generator.js
index 2caf855ac..1fdd9f5eb 100644
--- a/lib/generator.js
+++ b/lib/generator.js
@@ -213,6 +213,17 @@ class Generator {
       this.nunjucks = configureNunjucks(this.debug, this.templateDir);
     }
   }
+  /**
+ * @typedef {Object} TemplateRenderMetadata
+ * @property {string} fileName
+ * @property {string} permissions
+ */
+
+  /**
+   * @typedef {Object} TemplateRenderResult
+   * @property {string} content
+   * @property {TemplateRenderMetadata} metadata
+   */
 
   /**
    * Generates files from a given template and AsyncAPI string.
@@ -250,7 +261,7 @@ class Generator {
    *
    * @param  {String} asyncapiString AsyncAPI string to use as source.
    * @param  {Object} [parseOptions={}] AsyncAPI Parser parse options. Check out {@link https://www.github.com/asyncapi/parser-js|@asyncapi/parser} for more information.
-   * @return {Promise}
+   * @return {Promise<TemplateRenderResult|undefined>}
    */
   async generateFromString(asyncapiString, parseOptions = {}) {
     if (!asyncapiString || typeof asyncapiString !== 'string') throw new Error('Parameter "asyncapiString" must be a non-empty string.');
@@ -288,7 +299,7 @@ class Generator {
    * }
    *
    * @param  {String} asyncapiURL Link to AsyncAPI file
-   * @return {Promise}
+   * @return {Promise<TemplateRenderResult|undefined>}
    */
   async generateFromURL(asyncapiURL) {
     const doc = await fetchSpec(asyncapiURL);
@@ -315,7 +326,7 @@ class Generator {
    * }
    *
    * @param  {String} asyncapiFile AsyncAPI file to use as source.
-   * @return {Promise}
+   * @return {Promise<TemplateRenderResult|undefined>}
    */
   async generateFromFile(asyncapiFile) {
     const doc = await readFile(asyncapiFile, { encoding: 'utf8' });