diff --git a/schema/functions.json b/schema/functions.json
index 08f3b345..a29bd2d7 100644
--- a/schema/functions.json
+++ b/schema/functions.json
@@ -54,9 +54,32 @@
           "default": "rest"
         },
         "authRef": {
-          "type": "string",
-          "description": "References an auth definition name to be used to access to resource defined in the operation parameter",
-          "minLength": 1
+          "oneOf": [
+            {
+              "type": "string",
+              "description": "References the auth definition to be used to invoke the operation",
+              "minLength": 1
+            },
+            {
+              "type": "object",
+              "description": "Configures both the auth definition used to retrieve the operation's resource and the auth definition used to invoke said operation",
+              "properties":{
+                "resource":{
+                  "type": "string",
+                  "description": "References an auth definition to be used to access the resource defined in the operation parameter",
+                  "minLength": 1
+                },
+                "invocation":{
+                  "type": "string",
+                  "description": "References an auth definition to be used to invoke the operation"
+                }
+              },
+              "additionalProperties": false,
+              "required": [
+                "resource"
+              ]
+            }
+          ]
         },
         "metadata": {
           "$ref": "common.json#/definitions/metadata"
diff --git a/specification.md b/specification.md
index 159ef389..2627a6f0 100644
--- a/specification.md
+++ b/specification.md
@@ -1986,8 +1986,7 @@ If we have the following function definition:
 ```
 
 The `authRef` property is used to reference an authentication definition in
-the `auth` property and should be applied to access the `https://secure.resources.com/myapi.json`
-OpenApi definition file.
+the `auth` property and should be applied when invoking the `helloWorld` function. An [AuthRef](#AuthRef-Definition) object can alternatively be used to configure the authentication definition to use when accessing the function's resource and/or when invoking the function.
 
 The `functions` property can be either an in-line [function](#Function-Definition) definition array, or an URI reference to
 a resource containing an array of [functions](#Function-Definition) definition.
@@ -3248,7 +3247,7 @@ Depending on the function `type`, the `operation` property can be:
 Defining custom function types is possible, for more information on that refer to the [Defining custom function types](#defining-custom-function-types) section.
 
 The `authRef` property references a name of a defined workflow [auth definition](#Auth-Definition).
-It is used to provide authentication info to access the resource defined in the `operation` property.
+It is used to provide authentication info to access the resource defined in the `operation` property and/or to invoke the function.
 
 The [`metadata`](#Workflow-Metadata) property allows users to define custom information to function definitions.
 This allows you for example to define functions that describe of a command executions on a Docker image:
@@ -3266,6 +3265,55 @@ Note that using metadata for cases such as above heavily reduces the portability
 Function definitions themselves do not define data input parameters. Parameters can be
 defined via the `parameters` property in [function definitions](#FunctionRef-Definition) inside [actions](#Action-Definition).
 
+###### AuthRef Definition
+
+| Parameter | Description | Type | Required |
+| --- | --- | --- | --- |
+| resource | References an auth definition to be used to access the resource defined in the operation parameter | string | yes |
+| invocation | References an auth definition to be used to invoke the operation | string | no |
+
+The `authRef` property references a name of a defined workflow [auth definition](#Auth-Definition). It can be a string or an object.
+
+If it's a string, the referenced [auth definition](#Auth-Definition) is used solely for the function's invocation.
+
+If it's an object, it is possible to specify an [auth definition](#Auth-Definition) to use for the function's resource retrieval (as defined by the `operation` property) and another for its invocation.
+
+Example of a function definition configured to use an [auth definition](#Auth-Definition) called "My Basic Auth" upon invocation:
+
+```yaml
+functions:
+- name: SecuredFunctionInvocation
+  operation: https://test.com/swagger.json#HelloWorld
+  authRef: My Basic Auth
+```
+
+Example of a function definition configured to use an [auth definition](#Auth-Definition) called "My Basic Auth" to retrieve the resource defined by the `operation` property, and an [auth definition](#Auth-Definition) called "My OIDC Auth" upon invocation:
+
+```yaml
+functions:
+- name: SecuredFunctionInvocation
+  operation: https://test.com/swagger.json#HelloWorld
+  authRef:
+    resource: My Basic Auth
+    invocation: My OIDC Auth
+```
+
+Note that if multiple functions share the same `operation` path (*which is the first component of the operation value, located before the first '#' character*), and if one of them defines an [auth definition](#Auth-Definition) for resource access, then it should always be used to access said resource.
+In other words, when retrieving the resource of the function "MySecuredFunction2" defined in the following example, the "My Api Key Auth" [auth definition](#Auth-Definition) should be used, because the "MySecuredFunction1" has defined it for resource access. 
+This is done to avoid unnecessary repetitions of [auth definition](#Auth-Definition) configuration when using the same resource for multiple defined functions.
+
+```yaml
+functions:
+  - name: MySecuredFunction1
+    operation: https://secure.resources.com/myapi.json#helloWorld
+    authRef:
+      resource: My ApiKey Auth 
+  - name: MySecuredFunction2
+    operation: https://secure.resources.com/myapi.json#holaMundo
+```
+
+It's worth noting that if an [auth definition](#Auth-Definition) has been defined for an OpenAPI function which's resource declare an authentication mechanism, the later should be used instead, thus ignoring entirely the [auth definition](#Auth-Definition).
+
 ##### Event Definition
 
 | Parameter | Description | Type | Required |
@@ -3483,10 +3531,8 @@ If `false`, both Event payload and context attributes should be accessible.
 
 ##### Auth Definition
 
-Auth definitions can be used to define authentication information that should be applied
-to resources defined in the operation property of [function definitions](#Function-Definition).
-It is not used as authentication information for the function invocation, but just to access
-the resource containing the function invocation information.
+Auth definitions can be used to define authentication information that should be applied to [function definitions](#Function-Definition).
+It can be used for both the retrieval of the function's resource (as defined by the `operation` property) and for the function's invocation.
 
 | Parameter | Description | Type | Required |
 | --- | --- | --- | --- |