diff --git a/CHANGELOG.md b/CHANGELOG.md
index d5f69ec8f..21030ae62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Unreleased changes are available as `avenga/couper:edge` container.
 
 * **Added**
   * Modifier (`set/add/remove_form_params`) for the form parameters ([#223](https://github.com/avenga/couper/pull/223))
+  * Modifier (`set_response_status`) to be able to modify the response HTTP status code ([#250](https://github.com/avenga/couper/pull/250))
 
 * **Changed**
   * Stronger configuration check for `path` and `path_prefix` attributes, possibly resulting in configuration errors ([#232](https://github.com/avenga/couper/pull/232))
diff --git a/config/backend.go b/config/backend.go
index 7bc6d7994..2a5ea9fac 100644
--- a/config/backend.go
+++ b/config/backend.go
@@ -50,11 +50,12 @@ func (b Backend) Schema(inline bool) *hcl.BodySchema {
 
 	type Inline struct {
 		meta.Attributes
-		BasicAuth  string `hcl:"basic_auth,optional"`
-		Hostname   string `hcl:"hostname,optional"`
-		Origin     string `hcl:"origin,optional"`
-		PathPrefix string `hcl:"path_prefix,optional"`
-		ProxyURL   string `hcl:"proxy,optional"`
+		BasicAuth      string `hcl:"basic_auth,optional"`
+		Hostname       string `hcl:"hostname,optional"`
+		Origin         string `hcl:"origin,optional"`
+		PathPrefix     string `hcl:"path_prefix,optional"`
+		ProxyURL       string `hcl:"proxy,optional"`
+		ResponseStatus *uint8 `hcl:"set_response_status,optional"`
 	}
 
 	schema, _ = gohcl.ImpliedBodySchema(&Inline{})
diff --git a/config/endpoint.go b/config/endpoint.go
index 77da46867..60ee1dff4 100644
--- a/config/endpoint.go
+++ b/config/endpoint.go
@@ -40,8 +40,9 @@ func (e Endpoint) Schema(inline bool) *hcl.BodySchema {
 
 	type Inline struct {
 		meta.Attributes
-		Requests Requests `hcl:"request,block"`
-		Proxies  Proxies  `hcl:"proxy,block"`
+		Proxies        Proxies  `hcl:"proxy,block"`
+		Requests       Requests `hcl:"request,block"`
+		ResponseStatus *uint8   `hcl:"set_response_status,optional"`
 	}
 	schema, _ := gohcl.ImpliedBodySchema(&Inline{})
 	return schema
diff --git a/config/error_handler.go b/config/error_handler.go
index e76f46e8f..eede6f83d 100644
--- a/config/error_handler.go
+++ b/config/error_handler.go
@@ -39,8 +39,9 @@ func (e ErrorHandler) Schema(inline bool) *hcl.BodySchema {
 
 	type Inline struct {
 		meta.Attributes
-		Proxies  Proxies  `hcl:"proxy,block"`
-		Requests Requests `hcl:"request,block"`
+		Proxies        Proxies  `hcl:"proxy,block"`
+		Requests       Requests `hcl:"request,block"`
+		ResponseStatus *uint8   `hcl:"set_response_status,optional"`
 	}
 
 	schema, _ := gohcl.ImpliedBodySchema(&Inline{})
diff --git a/docs/README.md b/docs/README.md
index 3aad94dda..944f11d55 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -102,33 +102,33 @@ the gateway. There are a large number of options, but let's focus on the main st
 ```hcl
 server "my_project" {
   files {
-    ...
+    # ...
   }
 
   spa {
-    ...
+    # ...
   }
 
   api {
     access_control = ["foo"]
     endpoint "/bar" {
       proxy {
-        backend {...}
+        backend { }
       }
       request "sub-request" {
-        backend {...}
+        backend { }
       }
-      response {...}
+      response { }
     }
   }
 }
 
 definitions {
-  ...
+  # ...
 }
 
 settings {
-  ...
+  # ...
 }
 ```
 
diff --git a/docs/REFERENCE.md b/docs/REFERENCE.md
index fcc215552..9c7dc8c74 100644
--- a/docs/REFERENCE.md
+++ b/docs/REFERENCE.md
@@ -1,96 +1,97 @@
-* [Reference](#reference)
-   * [Block Reference](#block-reference)
-      * [Server Block](#server-block)
-      * [Files Block](#files-block)
-      * [SPA Block](#spa-block)
-      * [API Block](#api-block)
-      * [Endpoint Block](#endpoint-block)
-      * [Proxy Block](#proxy-block)
-      * [Request Block](#request-block)
-      * [Response Block](#response-block)
-      * [Backend Block](#backend-block)
-         * [Transport Settings Attributes](#transport-settings-attributes)
-         * [Timings](#timings)
-      * [OpenAPI Block](#openapi-block)
-      * [CORS Block](#cors-block)
-      * [OAuth2 Block](#oauth2-block)
-      * [Definitions Block](#definitions-block)
-      * [Basic Auth Block](#basic-auth-block)
-      * [JWT Block](#jwt-block)
-      * [JWT Signing Profile Block](#jwt-signing-profile-block)
-      * [SAML Block](#saml-block)
-      * [Settings Block](#settings-block)
-   * [Access Control](#access-control)
-   * [Health-Check](#health-check)
-   * [Variables](#variables)
-      * [env](#env)
-      * [request](#request)
-      * [backend_requests](#backend_requests)
-      * [backend_responses](#backend_responses)
-   * [Functions](#functions)
-   * [Modifier](#modifier)
-      * [Request Header](#request-header)
-      * [Response Header](#response-header)
-   * [Parameters](#parameters)
-      * [Query Parameter](#query-parameter)
-      * [Form Parameter](#form-parameter)
-      * [Path Parameter](#path-parameter)
+- [Reference](#reference)
+  - [Block Reference](#block-reference)
+    - [Server Block](#server-block)
+    - [Files Block](#files-block)
+    - [SPA Block](#spa-block)
+    - [API Block](#api-block)
+    - [Endpoint Block](#endpoint-block)
+    - [Proxy Block](#proxy-block)
+    - [Request Block](#request-block)
+    - [Response Block](#response-block)
+    - [Backend Block](#backend-block)
+      - [Transport Settings Attributes](#transport-settings-attributes)
+      - [Timings](#timings)
+    - [OpenAPI Block](#openapi-block)
+    - [CORS Block](#cors-block)
+    - [OAuth2 Block](#oauth2-block)
+    - [Definitions Block](#definitions-block)
+    - [Basic Auth Block](#basic-auth-block)
+    - [JWT Block](#jwt-block)
+    - [JWT Signing Profile Block](#jwt-signing-profile-block)
+    - [SAML Block](#saml-block)
+    - [Settings Block](#settings-block)
+  - [Access Control](#access-control)
+  - [Health-Check](#health-check)
+  - [Variables](#variables)
+    - [env](#env)
+    - [request](#request)
+    - [backend_requests](#backend_requests)
+    - [backend_responses](#backend_responses)
+  - [Functions](#functions)
+  - [Modifier](#modifier)
+    - [Request Header](#request-header)
+    - [Response Header](#response-header)
+    - [Set Response Status](#set-response-status)
+  - [Parameters](#parameters)
+    - [Query Parameter](#query-parameter)
+    - [Form Parameter](#form-parameter)
+    - [Path Parameter](#path-parameter)
 
 # Reference
 
-## Block Reference 
+## Block Reference
 
 ### Server Block
 
 The `server` block is the main configuration block of Couper's configuration file.
 
-| Block                                | Description |
-|:-------------------------------------|:------------|
-| *context*                            | Root of the configuration file. |
-| *label*                              | ⚠ Mandatory. |
-| **Nested blocks**                    | **Description** |
-| [CORS Block](#cors-block)            | Configures CORS behavior for [Files Block](#files-block), [SPA Block](#spa-block) and [API Block(s)](#api-block) contexts. |
-| [Files Block](#files-block)          | Configures the file serving. |
-| [SPA Block](#spa-block)              | Configures the Web serving for SPA assets. |
-| [API Block(s)](#api-block)           | Configures routing and communication with backend(s). |
-| [Endpoint Block(s)](#endpoint-block) | Configures specific endpoint(s) for current `Server Block` context. |
-| **Attributes**                       | **Description** |
-| `base_path`                          | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>*Example:* `base_path = "/api"`</li><li>&#9888; Inherited by nested blocks.</li></ul> |
-| `hosts`                              | <ul><li>List.</li><li>&#9888; Mandatory, if there is more than one `Server Block`.</li><li>*Example:* `hosts = ["example.com", "..."]`</li><li>You can add a specific port to your host.</li><li>*Example:* `hosts = ["localhost:9090"]`</li><li>Default port is `8080`.</li><li>Only **one** `hosts` attribute per `Server Block` is allowed.</li><li>Compare the hosts [example](./README.md#hosts-configuration-example) for details.</li></ul> |
-| `error_file`                         | <ul><li>Optional.</li><li>Location of the error file template.</li><li>*Example:* `error_file = "./my_error_page.html"`</li></ul> |
-| `access_control`                     | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Server Block` context.</li><li>*Example:* `access_control = ["foo"]`</li><li>&#9888; Inherited by nested blocks.</li></ul> |
+| Block                                | Description                                                                                                                                                                                                                                                                                                                                                                                                                                        |
+| :----------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                            | Root of the configuration file.                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| _label_                              | &#9888; Mandatory.                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| **Nested blocks**                    | **Description**                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| [CORS Block](#cors-block)            | Configures CORS behavior for [Files Block](#files-block), [SPA Block](#spa-block) and [API Block(s)](#api-block) contexts.                                                                                                                                                                                                                                                                                                                         |
+| [Files Block](#files-block)          | Configures the file serving.                                                                                                                                                                                                                                                                                                                                                                                                                       |
+| [SPA Block](#spa-block)              | Configures the Web serving for SPA assets.                                                                                                                                                                                                                                                                                                                                                                                                         |
+| [API Block(s)](#api-block)           | Configures routing and communication with backend(s).                                                                                                                                                                                                                                                                                                                                                                                              |
+| [Endpoint Block(s)](#endpoint-block) | Configures specific endpoint(s) for current `Server Block` context.                                                                                                                                                                                                                                                                                                                                                                                |
+| **Attributes**                       | **Description**                                                                                                                                                                                                                                                                                                                                                                                                                                    |
+| `base_path`                          | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>_Example:_ `base_path = "/api"`</li><li>&#9888; Inherited by nested blocks.</li></ul>                                                                                                                                                                                                                                                                               |
+| `hosts`                              | <ul><li>List.</li><li>&#9888; Mandatory, if there is more than one `Server Block`.</li><li>_Example:_ `hosts = ["example.com", "..."]`</li><li>You can add a specific port to your host.</li><li>_Example:_ `hosts = ["localhost:9090"]`</li><li>Default port is `8080`.</li><li>Only **one** `hosts` attribute per `Server Block` is allowed.</li><li>Compare the hosts [example](./README.md#hosts-configuration-example) for details.</li></ul> |
+| `error_file`                         | <ul><li>Optional.</li><li>Location of the error file template.</li><li>_Example:_ `error_file = "./my_error_page.html"`</li></ul>                                                                                                                                                                                                                                                                                                                  |
+| `access_control`                     | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Server Block` context.</li><li>_Example:_ `access_control = ["foo"]`</li><li>&#9888; Inherited by nested blocks.</li></ul>                                                                                                                                                                                                                                |
 
 ### Files Block
 
 The `files` block configures the file serving.
 
-| Block                     | Description |
-|:--------------------------|:------------|
-| *context*                 | [Server Block](#server-block). |
-| *label*                   | Not implemented. |
-| **Nested blocks**         | **Description** |
-| [CORS Block](#cors-block) | Configures CORS behavior for the current `Files Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block). |
-| **Attributes**            | **Description** |
-| `base_path`               | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>*Example:* `base_path = "/files"`</li></ul> |
-| `document_root`           | <ul><li>&#9888; Mandatory.</li><li>Location of the document root.</li><li>*Example:* `document_root = "./htdocs"`</li></ul> |
-| `error_file`              | <ul><li>Optional.</li><li>Location of the error file template.</li><li>*Example:* `error_file = "./my_error_page.html"`</li></ul> |
-| `access_control`          | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Files Block` context.</li><li>*Example:* `access_control = ["foo"]`</li></ul>  |
+| Block                     | Description                                                                                                                                                            |
+| :------------------------ | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                 | [Server Block](#server-block).                                                                                                                                         |
+| _label_                   | Not implemented.                                                                                                                                                       |
+| **Nested blocks**         | **Description**                                                                                                                                                        |
+| [CORS Block](#cors-block) | Configures CORS behavior for the current `Files Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block).                               |
+| **Attributes**            | **Description**                                                                                                                                                        |
+| `base_path`               | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>_Example:_ `base_path = "/files"`</li></ul>                                             |
+| `document_root`           | <ul><li>&#9888; Mandatory.</li><li>Location of the document root.</li><li>_Example:_ `document_root = "./htdocs"`</li></ul>                                            |
+| `error_file`              | <ul><li>Optional.</li><li>Location of the error file template.</li><li>_Example:_ `error_file = "./my_error_page.html"`</li></ul>                                      |
+| `access_control`          | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Files Block` context.</li><li>_Example:_ `access_control = ["foo"]`</li></ul> |
 
 ### SPA Block
 
 The `spa` block configures the Web serving for SPA assets.
 
-| Block                     | Description |
-|:--------------------------|:------------|
-| *context*                 | [Server Block](#server-block). |
-| *label*                   | Not implemented. |
-| **Nested blocks**         | **Description** |
-| [CORS Block](#cors-block) | Configures CORS behavior for the current `SPA Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block). |
-| **Attributes**            | **Description** |
-| `base_path`               | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>*Example:* `base_path = "/assets"`</li></ul> |
-| `bootstrap_file`          | <ul><li>&#9888; Mandatory.</li><li>Location of the bootstrap file.</li><li>*Example:* `bootstrap_file = "./htdocs/index.html"`</li></ul>|
-| `paths`                   | <ul><li>&#9888; Mandatory.</li><li>List of SPA paths that need the bootstrap file.</li><li>*Example:* `paths = ["/app/**"]`</li></ul> |
-| `access_control`          | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `SPA Block` context.</li><li>*Example:* `access_control = ["foo"]`</li></ul> |
+| Block                     | Description                                                                                                                                                          |
+| :------------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                 | [Server Block](#server-block).                                                                                                                                       |
+| _label_                   | Not implemented.                                                                                                                                                     |
+| **Nested blocks**         | **Description**                                                                                                                                                      |
+| [CORS Block](#cors-block) | Configures CORS behavior for the current `SPA Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block).                               |
+| **Attributes**            | **Description**                                                                                                                                                      |
+| `base_path`               | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>_Example:_ `base_path = "/assets"`</li></ul>                                          |
+| `bootstrap_file`          | <ul><li>&#9888; Mandatory.</li><li>Location of the bootstrap file.</li><li>_Example:_ `bootstrap_file = "./htdocs/index.html"`</li></ul>                             |
+| `paths`                   | <ul><li>&#9888; Mandatory.</li><li>List of SPA paths that need the bootstrap file.</li><li>_Example:_ `paths = ["/app/**"]`</li></ul>                                |
+| `access_control`          | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `SPA Block` context.</li><li>_Example:_ `access_control = ["foo"]`</li></ul> |
 
 ### API Block
 
@@ -100,39 +101,39 @@ remote/local backend service(s), configured in the nested
 `Server Block`. If an error occurred for api endpoints the response gets processed
 as json error with an error body payload. This can be customized via `error_file`.
 
-| Block                                | Description |
-|:-------------------------------------|:------------|
-| *context*                            | [Server Block](#server-block). |
-| *label*                              | Optional. |
-| **Nested blocks**                    | **Description** |
-| [Endpoint Block(s)](#endpoint-block) | Configures specific endpoint(s) for current `API Block` context. |
-| [CORS Block](#cors-block)            | Configures CORS behavior for the current `API Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block). |
-| **Attributes**                       | **Description** |
-| `base_path`                          | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>Must be unique if multiple API Blocks are defined.</li><li>*Example:* `base_path = "/v1"`</li></ul> |
-| `error_file`                         | <ul><li>Optional.</li><li>Location of the error file template.</li><li>*Example:* `error_file = "./my_error_body.json"`</li></ul> |
-| `access_control`                     | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `API Block` context.</li><li>*Example:* `access_control = ["foo"]`</li><li>&#9888; Inherited by nested blocks.</li></ul> |
+| Block                                | Description                                                                                                                                                                                                      |
+| :----------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                            | [Server Block](#server-block).                                                                                                                                                                                   |
+| _label_                              | Optional.                                                                                                                                                                                                        |
+| **Nested blocks**                    | **Description**                                                                                                                                                                                                  |
+| [Endpoint Block(s)](#endpoint-block) | Configures specific endpoint(s) for current `API Block` context.                                                                                                                                                 |
+| [CORS Block](#cors-block)            | Configures CORS behavior for the current `API Block` context. Overrides the CORS behavior of the parent [Server Block](#server-block).                                                                           |
+| **Attributes**                       | **Description**                                                                                                                                                                                                  |
+| `base_path`                          | <ul><li>Optional.</li><li>Configures the path prefix for all requests.</li><li>Must be unique if multiple API Blocks are defined.</li><li>_Example:_ `base_path = "/v1"`</li></ul>                               |
+| `error_file`                         | <ul><li>Optional.</li><li>Location of the error file template.</li><li>_Example:_ `error_file = "./my_error_body.json"`</li></ul>                                                                                |
+| `access_control`                     | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `API Block` context.</li><li>_Example:_ `access_control = ["foo"]`</li><li>&#9888; Inherited by nested blocks.</li></ul> |
 
 ### Endpoint Block
 
-The `endpoint` blocks define the entry points of Couper. The mandatory *label*
+The `endpoint` blocks define the entry points of Couper. The mandatory _label_
 defines the path suffix for the incoming client request. The `path` attribute
 changes the path for the outgoing request (compare
 [request routing example](./README.md#request-routing-example)). Each `Endpoint Block` must
 produce an explicit or implicit client response.
 
-| Block                              | Description |
-|:-----------------------------------|:------------|
-| *context*                          | [Server Block](#server-block), [API Block](#api-block) |
-| *label*                            | <ul><li>&#9888; Mandatory.</li><li>Defines the path suffix for incoming client requests.</li><li>*Example:* `endpoint "/dashboard" {...}`</li><li>Incoming client request: `http://example.com/api/v1/dashboard`</li><li>See [Path Parameter](#path-parameter), too.</ul> |
-| **Nested blocks**                  | **Description** |
-| [Proxy Block(s)](#proxy-block)     |  |
-| [Request Block(s)](#request-block) |  |
-| [Response Block](#response-block)  |  |
-| **Attributes**                     | **Description** |
-| `request_body_limit`               | <ul><li>Optional.</li><li>Configures the maximum buffer size while accessing `request.form_body` or `request.json_body` content.</li><li>Valid units are: `KiB, MiB, GiB`.</li><li>Default limit is `64MiB`.</li></ul> |
-| `path`                             | <ul><li>Optional.</li><li>Changeable part of the upstream URL.</li><li>Changes the path suffix of the outgoing request.</li></ul> |
-| `access_control`                   | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Endpoint Block` context.</li><li>*Example:* `access_control = ["foo"]`</li></ul> |
-| [Modifier](#modifier)              | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul> |
+| Block                              | Description                                                                                                                                                                                                                                                               |
+| :--------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| _context_                          | [Server Block](#server-block), [API Block](#api-block)                                                                                                                                                                                                                    |
+| _label_                            | <ul><li>&#9888; Mandatory.</li><li>Defines the path suffix for incoming client requests.</li><li>_Example:_ `endpoint "/dashboard" {...}`</li><li>Incoming client request: `http://example.com/api/v1/dashboard`</li><li>See [Path Parameter](#path-parameter), too.</ul> |
+| **Nested blocks**                  | **Description**                                                                                                                                                                                                                                                           |
+| [Proxy Block(s)](#proxy-block)     |                                                                                                                                                                                                                                                                           |
+| [Request Block(s)](#request-block) |                                                                                                                                                                                                                                                                           |
+| [Response Block](#response-block)  |                                                                                                                                                                                                                                                                           |
+| **Attributes**                     | **Description**                                                                                                                                                                                                                                                           |
+| `request_body_limit`               | <ul><li>Optional.</li><li>Configures the maximum buffer size while accessing `request.form_body` or `request.json_body` content.</li><li>Valid units are: `KiB, MiB, GiB`.</li><li>Default limit is `64MiB`.</li></ul>                                                    |
+| `path`                             | <ul><li>Optional.</li><li>Changeable part of the upstream URL.</li><li>Changes the path suffix of the outgoing request.</li></ul>                                                                                                                                         |
+| `access_control`                   | <ul><li>Optional.</li><li>Sets predefined [Access Control](#access-control) for current `Endpoint Block` context.</li><li>_Example:_ `access_control = ["foo"]`</li></ul>                                                                                                 |
+| [Modifier](#modifier)              | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul>                                                                                                                                                                                                            |
 
 ### Proxy Block
 
@@ -140,16 +141,16 @@ The `proxy` block creates and executes a proxy request to a backend service.
 
 &#9888; Multiple `proxy` and `request` blocks are executed in parallel.
 
-| Block                                               | Description |
-|:----------------------------------------------------|:------------|
-| *context*                                           | [Endpoint Block](#endpoint-block). |
-| *label*                                             | <ul><li>Partly optional.</li><li>A `Proxy Block` or [Request Block](#request-block) w/o a label has an implicit label `"default"`.</li><li>Only **one** `Proxy Block` or [Request Block](#request-block) w/ label `"default"` per [Endpoint Block](#endpoint-block) is allowed.</li></ul> |
-| **Nested blocks**                                   | **Description** |
-| [Backend Block](#backend-block)                     | <ul><li>&#9888; Mandatory if no [Backend Block Reference](#backend-block) is defined or no `url` attribute is set.</li><li>Configures the connection to a local/remote backend service.</li></ul> |
-| **Attributes**                                      | **Description** |
-| [Backend Block Reference](#backend-block) | <ul><li>&#9888; Mandatory if no [Backend Block](#backend-block) is defined.</li><li>References or refines a [Backend Block](#backend-block).</li></ul> |
-| `url`                                               | <ul><li>Optional.</li><li>If defined, the host part of the URL must be the same as the `origin` attribute of the used [Backend Block](#backend-block) or [Backend Block Reference](#backend-block) (if defined).</li></ul> |
-| [Modifier](#modifier)                               | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul> |
+| Block                                     | Description                                                                                                                                                                                                                                                                               |
+| :---------------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                                 | [Endpoint Block](#endpoint-block).                                                                                                                                                                                                                                                        |
+| _label_                                   | <ul><li>Partly optional.</li><li>A `Proxy Block` or [Request Block](#request-block) w/o a label has an implicit label `"default"`.</li><li>Only **one** `Proxy Block` or [Request Block](#request-block) w/ label `"default"` per [Endpoint Block](#endpoint-block) is allowed.</li></ul> |
+| **Nested blocks**                         | **Description**                                                                                                                                                                                                                                                                           |
+| [Backend Block](#backend-block)           | <ul><li>&#9888; Mandatory if no [Backend Block Reference](#backend-block) is defined or no `url` attribute is set.</li><li>Configures the connection to a local/remote backend service.</li></ul>                                                                                         |
+| **Attributes**                            | **Description**                                                                                                                                                                                                                                                                           |
+| [Backend Block Reference](#backend-block) | <ul><li>&#9888; Mandatory if no [Backend Block](#backend-block) is defined.</li><li>References or refines a [Backend Block](#backend-block).</li></ul>                                                                                                                                    |
+| `url`                                     | <ul><li>Optional.</li><li>If defined, the host part of the URL must be the same as the `origin` attribute of the used [Backend Block](#backend-block) or [Backend Block Reference](#backend-block) (if defined).</li></ul>                                                                |
+| [Modifier](#modifier)                     | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul>                                                                                                                                                                                                                            |
 
 ### Request Block
 
@@ -157,74 +158,74 @@ The `request` block creates and executes a request to a backend service.
 
 &#9888; Multiple `proxy` and `request` blocks are executed in parallel.
 
-| Block                                               | Description |
-|:----------------------------------------------------|:------------|
-| *context*                                           | [Endpoint Block](#endpoint-block). |
-| *label*                                             | <ul><li>Partly optional.</li><li>A [Proxy Block](#proxy-block) or `Request Block` w/o a label has an implicit label `"default"`.</li><li>Only **one** [Proxy Block](#proxy-block) or `Request Block` w/ label `"default"` per [Endpoint Block](#endpoint-block) is allowed.</li></ul> |
-| **Nested blocks**                                   | **Description** |
-| [Backend Block](#backend-block)                     | <ul><li>&#9888; Mandatory if no [Backend Block Reference](#backend-block) is defined.</li><li>Configures the connection to a local/remote backend service.</li></ul> |
-| **Attributes**                                      | **Description** |
-| [Backend Block Reference](#backend-block) | <ul><li>&#9888; Mandatory if no [Backend Block](#backend-block) is defined.</li><li>References or refines a [Backend Block](#backend-block).</li></ul> |
-| `url`                                               | <ul><li>Optional.</li><li>If defined, the host part of the URL must be the same as the `origin` attribute of the used [Backend Block](#backend-block) or [Backend Block Reference](#backend-block) (if defined).</li></ul> |
-| `body`                                              | <ul><li>String.</li><li>Optional. Creates implicit default `Content-Type: text/plain` header field.</li></ul> |
-| `json_body`                                         | <ul><li>null, Boolean, Number, String, Object, or Tuple.</li><li>Optional. Creates implicit default `Content-Type: application/json` header field.</li></ul> |
-| `form_body`                                         | <ul><li>Object.</li><li>Optional. Creates implicit default `Content-Type: application/x-www-form-urlencoded` header field.</li></ul> |
-| `method`                                            | <ul><li>String.</li><li>Optional.</li><li>Default `GET`.</li></ul> |
-| `headers`                                           | <ul><li>Optional.</li><li>Same as `set_request_headers` in [Request Header](#request-header).</li></ul> |
-| `query_params`                                      | <ul><li>Optional.</li><li>Same as `set_query_params` in [Query Parameter](#query-parameter).</li></ul> |
+| Block                                     | Description                                                                                                                                                                                                                                                                           |
+| :---------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| _context_                                 | [Endpoint Block](#endpoint-block).                                                                                                                                                                                                                                                    |
+| _label_                                   | <ul><li>Partly optional.</li><li>A [Proxy Block](#proxy-block) or `Request Block` w/o a label has an implicit label `"default"`.</li><li>Only **one** [Proxy Block](#proxy-block) or `Request Block` w/ label `"default"` per [Endpoint Block](#endpoint-block) is allowed.</li></ul> |
+| **Nested blocks**                         | **Description**                                                                                                                                                                                                                                                                       |
+| [Backend Block](#backend-block)           | <ul><li>&#9888; Mandatory if no [Backend Block Reference](#backend-block) is defined.</li><li>Configures the connection to a local/remote backend service.</li></ul>                                                                                                                  |
+| **Attributes**                            | **Description**                                                                                                                                                                                                                                                                       |
+| [Backend Block Reference](#backend-block) | <ul><li>&#9888; Mandatory if no [Backend Block](#backend-block) is defined.</li><li>References or refines a [Backend Block](#backend-block).</li></ul>                                                                                                                                |
+| `url`                                     | <ul><li>Optional.</li><li>If defined, the host part of the URL must be the same as the `origin` attribute of the used [Backend Block](#backend-block) or [Backend Block Reference](#backend-block) (if defined).</li></ul>                                                            |
+| `body`                                    | <ul><li>String.</li><li>Optional. Creates implicit default `Content-Type: text/plain` header field.</li></ul>                                                                                                                                                                         |
+| `json_body`                               | <ul><li>null, Boolean, Number, String, Object, or Tuple.</li><li>Optional. Creates implicit default `Content-Type: application/json` header field.</li></ul>                                                                                                                          |
+| `form_body`                               | <ul><li>Object.</li><li>Optional. Creates implicit default `Content-Type: application/x-www-form-urlencoded` header field.</li></ul>                                                                                                                                                  |
+| `method`                                  | <ul><li>String.</li><li>Optional.</li><li>Default `GET`.</li></ul>                                                                                                                                                                                                                    |
+| `headers`                                 | <ul><li>Optional.</li><li>Same as `set_request_headers` in [Request Header](#request-header).</li></ul>                                                                                                                                                                               |
+| `query_params`                            | <ul><li>Optional.</li><li>Same as `set_query_params` in [Query Parameter](#query-parameter).</li></ul>                                                                                                                                                                                |
 
 ### Response Block
 
 The `response` block creates and sends a client response.
 
-| Block          | Description |
-|:---------------|:------------|
-| *context*      | [Endpoint Block](#endpoint-block). |
-| *label*        | Not implemented. |
-| **Attributes** | **Description** |
-| `body`         | <ul><li>String.</li><li>Optional. Creates implicit default `Content-Type: text/plain` header field.</li></ul> |
+| Block          | Description                                                                                                                                                  |
+| :------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_      | [Endpoint Block](#endpoint-block).                                                                                                                           |
+| _label_        | Not implemented.                                                                                                                                             |
+| **Attributes** | **Description**                                                                                                                                              |
+| `body`         | <ul><li>String.</li><li>Optional. Creates implicit default `Content-Type: text/plain` header field.</li></ul>                                                |
 | `json_body`    | <ul><li>null, Boolean, Number, String, Object, or Tuple.</li><li>Optional. Creates implicit default `Content-Type: application/json` header field.</li></ul> |
-| `status`       | <ul><li>HTTP status code.</li><li>Optional.</li><li>Default `200`.</li></ul> |
-| `headers`      | <ul><li>Optional.</li><li>Same as `set_response_headers` in [Request Header](#response-header).</li></ul> |
+| `status`       | <ul><li>HTTP status code.</li><li>Optional.</li><li>Default `200`.</li></ul>                                                                                 |
+| `headers`      | <ul><li>Optional.</li><li>Same as `set_response_headers` in [Request Header](#response-header).</li></ul>                                                    |
 
 ### Backend Block
 
 A `backend` defines the connection to a local/remote backend service. Backends
-can be defined in the [Definitions Block](#definitions-block) and use the *label*
+can be defined in the [Definitions Block](#definitions-block) and use the _label_
 as reference.
 
-| Block                           | Description |
-|:--------------------------------|:------------|
-| *context*                       | [Definitions Block](#definitions-block), [Proxy Block](#proxy-block), [Request Block](#request-block). |
-| *label*                         | &#9888; Mandatory in the [Definitions Block](#definitions-block). |
-| **Nested blocks**               | **Description** |
-| [OpenAPI Block](#openapi-block) | <ul><li>Optional.</li><li>Definition for validating outgoing requests to the origin and incoming responses from the origin.</li></ul> |
-| [OAuth2 Block](#oauth2-block)   | <ul><li>Optional.</li><li>OAuth2 configuration block.</li></ul>
-| **Attributes**                  | **Description** |
-| `basic_auth`                    | <ul><li>Optional.</li><li>Basic auth for the upstream request in format `username:password`.</li></ul> |
+| Block                           | Description                                                                                                                                                                                                                                |
+| :------------------------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                       | [Definitions Block](#definitions-block), [Proxy Block](#proxy-block), [Request Block](#request-block).                                                                                                                                     |
+| _label_                         | &#9888; Mandatory in the [Definitions Block](#definitions-block).                                                                                                                                                                          |
+| **Nested blocks**               | **Description**                                                                                                                                                                                                                            |
+| [OpenAPI Block](#openapi-block) | <ul><li>Optional.</li><li>Definition for validating outgoing requests to the origin and incoming responses from the origin.</li></ul>                                                                                                      |
+| [OAuth2 Block](#oauth2-block)   | <ul><li>Optional.</li><li>OAuth2 configuration block.</li></ul>                                                                                                                                                                            |
+| **Attributes**                  | **Description**                                                                                                                                                                                                                            |
+| `basic_auth`                    | <ul><li>Optional.</li><li>Basic auth for the upstream request in format `username:password`.</li></ul>                                                                                                                                     |
 | `hostname`                      | <ul><li>Optional.</li><li>Value of the HTTP host header field for the origin request. Since `hostname` replaces the request host the value will also be used for a server identity check during a TLS handshake with the origin.</li></ul> |
-| `origin`                        | <ul><li>&#9888; Mandatory.</li><li>URL to connect to for backend requests.</li><li>&#9888; Must start with the scheme `http://...`.</li></ul> |
-| `path`                          | <ul><li>Optional.</li><li>Changeable part of upstream URL.</li></ul> |
-| `path_prefix`                   | <ul><li>Optional.</li><li>Prefixes all backend request paths with the given prefix.</li><li>Relative prefixes are prefixed with a slash `/`.</li></ul>
-| [Modifier](#modifier)           | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul> |
+| `origin`                        | <ul><li>&#9888; Mandatory.</li><li>URL to connect to for backend requests.</li><li>&#9888; Must start with the scheme `http://...`.</li></ul>                                                                                              |
+| `path`                          | <ul><li>Optional.</li><li>Changeable part of upstream URL.</li></ul>                                                                                                                                                                       |
+| `path_prefix`                   | <ul><li>Optional.</li><li>Prefixes all backend request paths with the given prefix.</li><li>Relative prefixes are prefixed with a slash `/`.</li></ul>                                                                                     |
+| [Modifier](#modifier)           | <ul><li>Optional.</li><li>All [Modifier](#modifier).</li></ul>                                                                                                                                                                             |
 
 #### Transport Settings Attributes
 
-| Name                             | Type               | Default         | Description |
-|:---------------------------------|:-------------------|:----------------|:------------|
-| `connect_timeout`                | [Timing](#timings) | `10s`           | The total timeout for dialing and connect to the origin. |
-| `disable_certificate_validation` | bool               | `false`         | Disables the peer certificate validation. |
-| `disable_connection_reuse`       | bool               | `false`         | Disables reusage of connections to the origin. |
-| `http2`                          | bool               | `false`         | Enables the HTTP2 support. |
-| `max_connections`                | int                | `0` (unlimited) | The maximum number of concurrent connections in any state (*active* or *idle*) to the origin. |
-| `proxy`                          | string             | (no default)    | A proxy URL for the related origin request. Example: `http://SERVER-IP_OR_NAME:PORT`. |
-| `timeout`                        | [Timing](#timings) | `300s`          | The total deadline duration a backend request has for write and read/pipe. |
-| `ttfb_timeout`                   | [Timing](#timings) | `60s`           | The duration from writing the full request to the origin and receiving the answer. |
+| Name                             | Type               | Default         | Description                                                                                   |
+| :------------------------------- | :----------------- | :-------------- | :-------------------------------------------------------------------------------------------- |
+| `connect_timeout`                | [Timing](#timings) | `10s`           | The total timeout for dialing and connect to the origin.                                      |
+| `disable_certificate_validation` | bool               | `false`         | Disables the peer certificate validation.                                                     |
+| `disable_connection_reuse`       | bool               | `false`         | Disables reusage of connections to the origin.                                                |
+| `http2`                          | bool               | `false`         | Enables the HTTP2 support.                                                                    |
+| `max_connections`                | int                | `0` (unlimited) | The maximum number of concurrent connections in any state (_active_ or _idle_) to the origin. |
+| `proxy`                          | string             | (no default)    | A proxy URL for the related origin request. Example: `http://SERVER-IP_OR_NAME:PORT`.         |
+| `timeout`                        | [Timing](#timings) | `300s`          | The total deadline duration a backend request has for write and read/pipe.                    |
+| `ttfb_timeout`                   | [Timing](#timings) | `60s`           | The duration from writing the full request to the origin and receiving the answer.            |
 
 #### Timings
 
 | Valid time unit | Description  |
-|:----------------|:-------------|
+| :-------------- | :----------- |
 | `ns`            | nanoseconds  |
 | `us` (or `µs`)  | microseconds |
 | `ms`            | milliseconds |
@@ -241,88 +242,87 @@ requests, and the Couper client from invalid answers. An example can be found
 To do so Couper uses the [OpenAPI 3 standard](https://www.openapis.org/) to load
 the definitions from a given document defined with the `file` attribute.
 
-| Block                        | Description |
-|:-----------------------------|:------------|
-| *context*                    | [Backend Block](#backend-block). |
-| *label*                      | Not implemented. |
-| **Attributes**               | **Description** |
-| `file`                       | <ul><li>&#9888; Mandatory.</li><li>OpenAPI yaml definition file.</li></ul> |
-| `ignore_request_violations`  | <ul><li>Optional.</li><li>Log request validation results, skip err handling.</li><li>Default `false`.</li></ul> |
+| Block                        | Description                                                                                                      |
+| :--------------------------- | :--------------------------------------------------------------------------------------------------------------- |
+| _context_                    | [Backend Block](#backend-block).                                                                                 |
+| _label_                      | Not implemented.                                                                                                 |
+| **Attributes**               | **Description**                                                                                                  |
+| `file`                       | <ul><li>&#9888; Mandatory.</li><li>OpenAPI yaml definition file.</li></ul>                                       |
+| `ignore_request_violations`  | <ul><li>Optional.</li><li>Log request validation results, skip err handling.</li><li>Default `false`.</li></ul>  |
 | `ignore_response_violations` | <ul><li>Optional.</li><li>Log response validation results, skip err handling.</li><li>Default `false`.</li></ul> |
 
 **Caveats**: While ignoring request violations an invalid method or path would
-lead to a non-matching *route* which is still required for response validations.
+lead to a non-matching _route_ which is still required for response validations.
 In this case the response validation will fail if not ignored too.
 
 ### CORS Block
 
 The CORS block configures the CORS (Cross-Origin Resource Sharing) behavior in Couper.
 
-| Block               | Description |
-|:--------------------|:------------|
-| *context*           | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block). |
-| *label*             | Not implemented. |
-| **Attributes**      | **Description** |
+| Block               | Description                                                                                                                                                                                                                                                                                                                                              |
+| :------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_           | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block).                                                                                                                                                                                                                                            |
+| _label_             | Not implemented.                                                                                                                                                                                                                                                                                                                                         |
+| **Attributes**      | **Description**                                                                                                                                                                                                                                                                                                                                          |
 | `allowed_origins`   | <ul><li>&#9888; Mandatory.</li><li>A list of allowed origin(s).</li><li>Can be either of:<br/><ul><li>a string with a single specific origin (e.g. `"https://www.example.com"`).</li><li>`"*"` (all origins are allowed).</li><li>an array of specific origins (e.g. `["https://www.example.com", "https://www.another.host.org"]`).</li></ul></li></ul> |
-| `allow_credentials` | <ul><li>Optional.</li><li>Set to `true` if the response can be shared with credentialed requests (containing `Cookie` or `Authorization` HTTP header fields).</li><li>Default `false`.</li></ul> |
-| `disable`           | <ul><li>Optional.</li><li>Set to `true` to disable the inheritance of CORS from the [Server Block](#server-block) in [Files Block](#files-block), [SPA Block](#spa-block) and [API Block](#api-block) contexts.</li><li>Default `false`.</li></ul> |
-| `max_age`           | <ul><li>Optional.</li><li>Indicates the time the information provided by the `Access-Control-Allow-Methods` and `Access-Control-Allow-Headers` response HTTP header fields.</li><li>Can be cached (string with time unit, e.g. `"1h"`).</li></li></ul> |
+| `allow_credentials` | <ul><li>Optional.</li><li>Set to `true` if the response can be shared with credentialed requests (containing `Cookie` or `Authorization` HTTP header fields).</li><li>Default `false`.</li></ul>                                                                                                                                                         |
+| `disable`           | <ul><li>Optional.</li><li>Set to `true` to disable the inheritance of CORS from the [Server Block](#server-block) in [Files Block](#files-block), [SPA Block](#spa-block) and [API Block](#api-block) contexts.</li><li>Default `false`.</li></ul>                                                                                                       |
+| `max_age`           | <ul><li>Optional.</li><li>Indicates the time the information provided by the `Access-Control-Allow-Methods` and `Access-Control-Allow-Headers` response HTTP header fields.</li><li>Can be cached (string with time unit, e.g. `"1h"`).</li></li></ul>                                                                                                   |
 
 ### OAuth2 Block
 
-| Block                           | Description |
-|:--------------------------------|:------------|
-| *context*                       | [Backend Block](#backend-block). |
-| *label*                         | Not implemented. |
-| **Nested blocks**               | **Description** |
-| [Backend Block](#backend-block) | Optional. |
-| **Attributes**                  | **Description** |
-| `backend`                       | <ul><li>Optional.</li><li>[Backend Block Reference](#backend-block).</li></ul> |
-| `grant_type`                    | <ul><li>&#9888; Mandatory.</li><li>Available values: `client_credentials`.</li></ul> |
-| `token_endpoint`                | <ul><li>&#9888; Mandatory.</li><li>URL of the token endpoint at the authorization server.</li></ul> |
-| `client_id`                     | <ul><li>&#9888; Mandatory.</li><li>The client identifier.</li></ul> |
-| `client_secret`                 | <ul><li>&#9888; Mandatory.</li><li>The client password.</li></ul> |
-| `retries`                       | <ul><li>Optional.</li><li>The number of retries to get the token and resource, if the resource-request responds with `401 Unauthorized` HTTP status code.</li><li>Default: `1`.</li></ul> |
+| Block                           | Description                                                                                                                                                                                                                                                                                                                                                    |
+| :------------------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                       | [Backend Block](#backend-block).                                                                                                                                                                                                                                                                                                                               |
+| _label_                         | Not implemented.                                                                                                                                                                                                                                                                                                                                               |
+| **Nested blocks**               | **Description**                                                                                                                                                                                                                                                                                                                                                |
+| [Backend Block](#backend-block) | Optional.                                                                                                                                                                                                                                                                                                                                                      |
+| **Attributes**                  | **Description**                                                                                                                                                                                                                                                                                                                                                |
+| `backend`                       | <ul><li>Optional.</li><li>[Backend Block Reference](#backend-block).</li></ul>                                                                                                                                                                                                                                                                                 |
+| `grant_type`                    | <ul><li>&#9888; Mandatory.</li><li>Available values: `client_credentials`.</li></ul>                                                                                                                                                                                                                                                                           |
+| `token_endpoint`                | <ul><li>&#9888; Mandatory.</li><li>URL of the token endpoint at the authorization server.</li></ul>                                                                                                                                                                                                                                                            |
+| `client_id`                     | <ul><li>&#9888; Mandatory.</li><li>The client identifier.</li></ul>                                                                                                                                                                                                                                                                                            |
+| `client_secret`                 | <ul><li>&#9888; Mandatory.</li><li>The client password.</li></ul>                                                                                                                                                                                                                                                                                              |
+| `retries`                       | <ul><li>Optional.</li><li>The number of retries to get the token and resource, if the resource-request responds with `401 Unauthorized` HTTP status code.</li><li>Default: `1`.</li></ul>                                                                                                                                                                      |
 | `token_endpoint_auth_method`    | <ul><li>Optional.</li><li>Defines the method to authenticate the client at the token endpoint.</li><li>If set to `client_secret_post`, the client credentials are transported in the request body.</li><li>If set to `client_secret_basic`, the client credentials are transported via Basic Authentication.</li><li>Default: `client_secret_basic`.</li></ul> |
-| `scope`                         | <ul><li>Optional.</li><li>A space separated list of requested scopes for the access token.</li></ul> |
-
+| `scope`                         | <ul><li>Optional.</li><li>A space separated list of requested scopes for the access token.</li></ul>                                                                                                                                                                                                                                                           |
 
 ### Definitions Block
 
 Use the `definitions` block to define configurations you want to reuse.
 [Access Control](#access-control) is **always** defined in the `Definitions Block`.
 
-| Block                                    | Description |
-|:-----------------------------------------|:------------|
-| *context*                                | Root of the configuration file. |
-| *label*                                  | Not implemented. |
-| **Nested blocks**                        | **Description** |
-| [Backend Block(s)](#backend-block)       | Defines `Backend Block(s)`. |
-| [Basic Auth Block(s)](#basic-auth-block) | Defines `Basic Auth Block(s)`. |
-| [JWT Block(s)](#jwt-block)               | Defines `JWT Block(s)`. |
+| Block                                                      | Description                             |
+| :--------------------------------------------------------- | :-------------------------------------- |
+| _context_                                                  | Root of the configuration file.         |
+| _label_                                                    | Not implemented.                        |
+| **Nested blocks**                                          | **Description**                         |
+| [Backend Block(s)](#backend-block)                         | Defines `Backend Block(s)`.             |
+| [Basic Auth Block(s)](#basic-auth-block)                   | Defines `Basic Auth Block(s)`.          |
+| [JWT Block(s)](#jwt-block)                                 | Defines `JWT Block(s)`.                 |
 | [JWT Signing Profile Block(s)](#jwt-signing-profile-block) | Defines `JWT Signing Profile Block(s)`. |
-| [SAML Block(s)](#saml-block)             | Defines `SAML Block(s)`. |
+| [SAML Block(s)](#saml-block)                               | Defines `SAML Block(s)`.                |
 
 ### Basic Auth Block
 
 The `basic_auth` block lets you configure basic auth for your gateway. Like all
 [Access Control](#access-control) types, the `Basic Auth` block is defined in the
 [Definitions Block](#definitions-block) and can be referenced in all configuration
-blocks by its mandatory *label*.
+blocks by its mandatory _label_.
 
 If both `user`/`password` and `htpasswd_file` are configured, the incoming
 credentials from the `Authorization` request HTTP header field are checked against
 `user`/`password` if the user matches, and against the data in the file referenced
 by `htpasswd_file` otherwise.
 
-| Block           | Description |
-|:----------------|:------------|
-| *context*       | [Definitions Block](#definitions-block). |
-| *label*         | &#9888; Mandatory. |
-| **Attributes**  | **Description** |
-| `user`          | <ul><li>Optional.</li><li>The user name.</li></ul> |
-| `password`      | <ul><li>Optional.</li><li>The corresponding password.</li></ul> |
-| `htpasswd_file` | <ul><li>Optional.</li><li>The htpasswd file.</li></ul> |
+| Block           | Description                                                                                                  |
+| :-------------- | :----------------------------------------------------------------------------------------------------------- |
+| _context_       | [Definitions Block](#definitions-block).                                                                     |
+| _label_         | &#9888; Mandatory.                                                                                           |
+| **Attributes**  | **Description**                                                                                              |
+| `user`          | <ul><li>Optional.</li><li>The user name.</li></ul>                                                           |
+| `password`      | <ul><li>Optional.</li><li>The corresponding password.</li></ul>                                              |
+| `htpasswd_file` | <ul><li>Optional.</li><li>The htpasswd file.</li></ul>                                                       |
 | `realm`         | <ul><li>Optional.</li><li>The realm to be sent in a `WWW-Authenticate` response HTTP header field.</li></ul> |
 
 ### JWT Block
@@ -330,37 +330,37 @@ by `htpasswd_file` otherwise.
 The `jwt` block lets you configure JSON Web Token access control for your gateway.
 Like all [Access Control](#access-control) types, the `jwt` block is defined in
 the `definitions` block and can be referenced in all configuration blocks by its
-mandatory *label*.
-
-| Block                      | Description |
-|:---------------------------|:------------|
-| *context*                  | [Definitions Block](#definitions-block). |
-| *label*                    | &#9888; Mandatory. |
-| **Attributes**             | **Description** |
-| `cookie = "AccessToken"`   | <ul><li>Optional.</li><li>Read `AccessToken` key to gain the token value from a cookie.</li></ul> |
+mandatory _label_.
+
+| Block                      | Description                                                                                                                                              |
+| :------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _context_                  | [Definitions Block](#definitions-block).                                                                                                                 |
+| _label_                    | &#9888; Mandatory.                                                                                                                                       |
+| **Attributes**             | **Description**                                                                                                                                          |
+| `cookie = "AccessToken"`   | <ul><li>Optional.</li><li>Read `AccessToken` key to gain the token value from a cookie.</li></ul>                                                        |
 | `header = "Authorization"` | <ul><li>Optional.</li><li>&#9888; Implies `Bearer` if `Authorization` (case-insensitive) is used, otherwise any other header name can be used.</li></ul> |
-| `key`                      | <ul><li>Optional.</li><li>Public key (in PEM format) for `RS*` variants or the secret for `HS*` algorithm.</li></ul> |
-| `key_file`                 | <ul><li>Optional.</li><li>Optional file reference instead of `key` usage.</li></ul> |
-| `signature_algorithm`      | <ul><li>&#9888; Mandatory.</li><li>Valid values are: `RS256` `RS384` `RS512` `HS256` `HS384` `HS512`.</li></ul> |
-| **`claims`**               | <ul><li>Optional.</li><li>Equals/in comparison with JWT payload.</li></ul> |
-| **`required_claims`**      | <ul><li>Optional.</li><li>List of claims that must be given for a valid token</li></ul> |
+| `key`                      | <ul><li>Optional.</li><li>Public key (in PEM format) for `RS*` variants or the secret for `HS*` algorithm.</li></ul>                                     |
+| `key_file`                 | <ul><li>Optional.</li><li>Optional file reference instead of `key` usage.</li></ul>                                                                      |
+| `signature_algorithm`      | <ul><li>&#9888; Mandatory.</li><li>Valid values are: `RS256` `RS384` `RS512` `HS256` `HS384` `HS512`.</li></ul>                                          |
+| **`claims`**               | <ul><li>Optional.</li><li>Equals/in comparison with JWT payload.</li></ul>                                                                               |
+| **`required_claims`**      | <ul><li>Optional.</li><li>List of claims that must be given for a valid token</li></ul>                                                                  |
 
 ### JWT Signing Profile Block
 
 The `jwt_signing_profile` block lets you configure a JSON Web Token signing
 profile for your gateway. It is referenced in the [`jwt_sign()` function](#functions)
-by its mandatory *label*.
-
-| Name                      | Description |
-|:--------------------------|:------------|
-| *context*                 | [Definitions Block](#definitions-block). |
-| *label*                   | &#9888; Mandatory. |
-| **Attributes**            | **Description** |
-| `key`                     | <ul><li>Optional.</li><li>Private key (in PEM format) for `RS*` variants or the secret for `HS*` algorithm.</li></ul> |
-| `key_file`                | <ul><li>Optional.</li><li>Optional file reference instead of `key` usage.</li></ul> |
-| `signature_algorithm`     | <ul><li>&#9888; Mandatory.</li><li>Valid values are: `RS256` `RS384` `RS512` `HS256` `HS384` `HS512`.</li></ul> |
-| `ttl`                     | <ul><li>Optional.</li><li>The token's time-to-live (creates the `exp` claim).</li></ul> |
-| **`claims`**              | <ul><li>Optional.</li><li>Default claims for the JWT payload.</li></ul> |
+by its mandatory _label_.
+
+| Name                  | Description                                                                                                           |
+| :-------------------- | :-------------------------------------------------------------------------------------------------------------------- |
+| _context_             | [Definitions Block](#definitions-block).                                                                              |
+| _label_               | &#9888; Mandatory.                                                                                                    |
+| **Attributes**        | **Description**                                                                                                       |
+| `key`                 | <ul><li>Optional.</li><li>Private key (in PEM format) for `RS*` variants or the secret for `HS*` algorithm.</li></ul> |
+| `key_file`            | <ul><li>Optional.</li><li>Optional file reference instead of `key` usage.</li></ul>                                   |
+| `signature_algorithm` | <ul><li>&#9888; Mandatory.</li><li>Valid values are: `RS256` `RS384` `RS512` `HS256` `HS384` `HS512`.</li></ul>       |
+| `ttl`                 | <ul><li>Optional.</li><li>The token's time-to-live (creates the `exp` claim).</li></ul>                               |
+| **`claims`**          | <ul><li>Optional.</li><li>Default claims for the JWT payload.</li></ul>                                               |
 
 ### SAML Block
 
@@ -368,42 +368,42 @@ The `saml` block lets you configure the `saml_sso_url()` [function](#functions)
 control for a SAML Assertion Consumer Service (ACS) endpoint.
 Like all [Access Control](#access-control) types, the `saml` block is defined in
 the `definitions` block and can be referenced in all configuration blocks by its
-mandatory *label*.
-
-| Block                      | Description |
-|:---------------------------|:------------|
-| *context*                  | [Definitions Block](#definitions-block). |
-| *label*                    | &#9888; Mandatory. |
-| **Attributes**             | **Description** |
-| `idp_metadata_file`        | <ul><li>&#9888; Mandatory.</li><li>File reference to the Identity Provider metadata XML file.</li></ul> |
-| `sp_acs_url`               | <ul><li>&#9888; Mandatory.</li><li>The URL of the Service Provider's ACS endpoint.</li></ul> |
-| `sp_entity_id`             | <ul><li>&#9888; Mandatory.</li><li>The Service Provider's entity ID.</li></ul> |
-| `array_attributes`         | <ul><li>Optional.</li><li>A list of assertion attributes that may have several values.</li></ul> |
+mandatory _label_.
+
+| Block               | Description                                                                                             |
+| :------------------ | :------------------------------------------------------------------------------------------------------ |
+| _context_           | [Definitions Block](#definitions-block).                                                                |
+| _label_             | &#9888; Mandatory.                                                                                      |
+| **Attributes**      | **Description**                                                                                         |
+| `idp_metadata_file` | <ul><li>&#9888; Mandatory.</li><li>File reference to the Identity Provider metadata XML file.</li></ul> |
+| `sp_acs_url`        | <ul><li>&#9888; Mandatory.</li><li>The URL of the Service Provider's ACS endpoint.</li></ul>            |
+| `sp_entity_id`      | <ul><li>&#9888; Mandatory.</li><li>The Service Provider's entity ID.</li></ul>                          |
+| `array_attributes`  | <ul><li>Optional.</li><li>A list of assertion attributes that may have several values.</li></ul>        |
 
 Some information from the assertion consumed at the ACS endpoint is provided in the context at `request.context.<label>`:
 
-* the `NameID` of the assertion's `Subject` (`request.context.<label>.sub`)
-* the session expiry date `SessionNotOnOrAfter` (as UNIX timestamp: `request.context.<label>.exp`)
-* the attributes (`request.context.<label>.attributes.<name>`)
+- the `NameID` of the assertion's `Subject` (`request.context.<label>.sub`)
+- the session expiry date `SessionNotOnOrAfter` (as UNIX timestamp: `request.context.<label>.exp`)
+- the attributes (`request.context.<label>.attributes.<name>`)
 
 ### Settings Block
 
 The `settings` block let you configure the more basic and global behavior of your
 gateway instance.
 
-| Block               | Description |  |
-|:--------------------|:------------|:--------|
-| *context*           | Root of the configuration file. | |
-| *label*             | Not impplemented. | |
-| **Attributes**      | **Description** | **Default** |
-| `health_path`       | Health path which is available for all configured server and ports | `/healthz` |
-| `no_proxy_from_env` | Disables the connect hop to configured [proxy via environment](https://godoc.org/golang.org/x/net/http/httpproxy). | `false` |
-| `default_port`      | Port which will be used if not explicitly specified per host within the [`hosts`](#server-block) list | `8080` |
-| `log_format`        | Switch for tab/field based colored view or json log lines | `common` |
-| `log_pretty`        | Global option for `json` log format which pretty prints with basic key coloring | `false` |
-| `xfh`               | Option to use the `X-Forwarded-Host` header as the request host | `false` |
-| `request_id_format` | If set to `uuid4` a rfc4122 uuid is used for `request.id` and related log fields | `common` |
-| `secure_cookies`    | If set to `"strip"`, the `Secure` flag is removed from all `Set-Cookie` HTTP header fields. | `""` |
+| Block               | Description                                                                                                        |             |
+| :------------------ | :----------------------------------------------------------------------------------------------------------------- | :---------- |
+| _context_           | Root of the configuration file.                                                                                    |             |
+| _label_             | Not impplemented.                                                                                                  |             |
+| **Attributes**      | **Description**                                                                                                    | **Default** |
+| `health_path`       | Health path which is available for all configured server and ports                                                 | `/healthz`  |
+| `no_proxy_from_env` | Disables the connect hop to configured [proxy via environment](https://godoc.org/golang.org/x/net/http/httpproxy). | `false`     |
+| `default_port`      | Port which will be used if not explicitly specified per host within the [`hosts`](#server-block) list              | `8080`      |
+| `log_format`        | Switch for tab/field based colored view or json log lines                                                          | `common`    |
+| `log_pretty`        | Global option for `json` log format which pretty prints with basic key coloring                                    | `false`     |
+| `xfh`               | Option to use the `X-Forwarded-Host` header as the request host                                                    | `false`     |
+| `request_id_format` | If set to `uuid4` a rfc4122 uuid is used for `request.id` and related log fields                                   | `common`    |
+| `secure_cookies`    | If set to `"strip"`, the `Secure` flag is removed from all `Set-Cookie` HTTP header fields.                        | `""`        |
 
 ## Access Control
 
@@ -416,8 +416,6 @@ the `access_control` type `bar` will be disabled for the corresponding block con
 
 All access controls have an option to handle related errors. Please refer to [Errors](ERRORS.md).
 
-
-
 ## Health-Check
 
 The health check will answer a status `200 OK` on every port with the configured
@@ -429,7 +427,6 @@ shutdown mode with a deadline of `5s` and no new requests will be accepted.
 The shutdown timings defaults to `0` which means no delaying with development setups.
 Both durations can be configured via environment variable. Please refer to the [docker document](./../DOCKER.md).
 
-
 ## Variables
 
 ### `env`
@@ -437,21 +434,21 @@ Both durations can be configured via environment variable. Please refer to the [
 Environment variables can be accessed everywhere within the configuration file
 since these references get evaluated at start.
 
-### `request` 
-
-| Variable                  | Description |
-|:--------------------------|:------------|
-| `id`                      | Unique request id |
-| `method`                  | HTTP method |
-| `path`                    | URL path |
-| `endpoint`                | Matched endpoint pattern |
-| `headers.<name>`          | HTTP request header value for requested lower-case key |
-| `cookies.<name>`          | Value from `Cookie` request header for requested key (&#9888; last wins!) |
-| `query.<name>`            | Query parameter values (&#9888; last wins!) |
-| `path_params.<name>`      | Value from a named path parameter defined within an endpoint path label |
-| `body`                    | The request message body |
-| `form_body.<name>`        | Parameter in a `application/x-www-form-urlencoded` body |
-| `json_body.<name>`        | Access json decoded object properties. Media type must be `application/json` or `application/*+json`. |
+### `request`
+
+| Variable                         | Description                                                                                                                                                                                                                                                                         |
+| :------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `id`                             | Unique request id                                                                                                                                                                                                                                                                   |
+| `method`                         | HTTP method                                                                                                                                                                                                                                                                         |
+| `path`                           | URL path                                                                                                                                                                                                                                                                            |
+| `endpoint`                       | Matched endpoint pattern                                                                                                                                                                                                                                                            |
+| `headers.<name>`                 | HTTP request header value for requested lower-case key                                                                                                                                                                                                                              |
+| `cookies.<name>`                 | Value from `Cookie` request header for requested key (&#9888; last wins!)                                                                                                                                                                                                           |
+| `query.<name>`                   | Query parameter values (&#9888; last wins!)                                                                                                                                                                                                                                         |
+| `path_params.<name>`             | Value from a named path parameter defined within an endpoint path label                                                                                                                                                                                                             |
+| `body`                           | The request message body                                                                                                                                                                                                                                                            |
+| `form_body.<name>`               | Parameter in a `application/x-www-form-urlencoded` body                                                                                                                                                                                                                             |
+| `json_body.<name>`               | Access json decoded object properties. Media type must be `application/json` or `application/*+json`.                                                                                                                                                                               |
 | `context.<name>.<property_name>` | Request context containing claims from JWT used for [Access Control](#access-control) or information from a SAML assertion, `<name>` being the [JWT Block's](#jwt-block) or [SAML Block's](#saml-block) label and `property_name` being the claim's or assertion information's name |
 
 ### `backend_requests`
@@ -461,17 +458,17 @@ To access a specific request use the related label. [Request](#request-block) an
 [Proxy](#proxy-block) blocks without a label will be available as `default`.
 To access the HTTP method of the `default` request use `backend_requests.default.method` .
 
-| Variable                  | Description |
-|:--------------------------|:------------|
-| `id`                      | Unique request id |
-| `method`                  | HTTP method |
-| `path`                    | URL path |
-| `headers.<name>`          | HTTP request header value for requested lower-case key |
-| `cookies.<name>`          | Value from `Cookie` request header for requested key (&#9888; last wins!) |
-| `query.<name>`            | Query parameter values (&#9888; last wins!) |
-| `form_body.<name>`        | Parameter in a `application/x-www-form-urlencoded` body |
+| Variable                         | Description                                                                                                                                                                                                                                                                         |
+| :------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `id`                             | Unique request id                                                                                                                                                                                                                                                                   |
+| `method`                         | HTTP method                                                                                                                                                                                                                                                                         |
+| `path`                           | URL path                                                                                                                                                                                                                                                                            |
+| `headers.<name>`                 | HTTP request header value for requested lower-case key                                                                                                                                                                                                                              |
+| `cookies.<name>`                 | Value from `Cookie` request header for requested key (&#9888; last wins!)                                                                                                                                                                                                           |
+| `query.<name>`                   | Query parameter values (&#9888; last wins!)                                                                                                                                                                                                                                         |
+| `form_body.<name>`               | Parameter in a `application/x-www-form-urlencoded` body                                                                                                                                                                                                                             |
 | `context.<name>.<property_name>` | Request context containing claims from JWT used for [Access Control](#access-control) or information from a SAML assertion, `<name>` being the [JWT Block's](#jwt-block) or [SAML Block's](#saml-block) label and `property_name` being the claim's or assertion information's name |
-| `url`                     | Backend origin URL |
+| `url`                            | Backend origin URL                                                                                                                                                                                                                                                                  |
 
 ### `backend_responses`
 
@@ -480,37 +477,38 @@ Use the related label to access a specific response.
 [Request](#request-block) and [Proxy](#proxy-block) blocks without a label will be available as `default`.
 To access the HTTP status code of the `default` response use `backend_responses.default.status` .
 
-| Variable           | Description |
-|:-------------------|:------------|
-| `status`           | HTTP status code |
-| `headers.<name>`   | HTTP response header value for requested lower-case key |
-| `cookies.<name>`   | Value from `Set-Cookie` response header for requested key (&#9888; last wins!) |
-| `body`             | The response message body |
+| Variable           | Description                                                                                           |
+| :----------------- | :---------------------------------------------------------------------------------------------------- |
+| `status`           | HTTP status code                                                                                      |
+| `headers.<name>`   | HTTP response header value for requested lower-case key                                               |
+| `cookies.<name>`   | Value from `Set-Cookie` response header for requested key (&#9888; last wins!)                        |
+| `body`             | The response message body                                                                             |
 | `json_body.<name>` | Access json decoded object properties. Media type must be `application/json` or `application/*+json`. |
 
 ## Functions
 
-| Name               | Description |
-|:-------------------|:------------|
-| `base64_decode`    | Decodes Base64 data, as specified in RFC 4648. |
-| `base64_encode`    | Encodes Base64 data, as specified in RFC 4648. |
-| `coalesce`         | Returns the first of the given arguments that is not null. |
-| `json_decode`      | Parses the given JSON string and, if it is valid, returns the value it represents. |
-| `json_encode`      | Returns a JSON serialization of the given value. |
-| `jwt_sign`         | jwt_sign creates and signs a JSON Web Token (JWT) from information from a referenced [JWT Signing Profile Block](#jwt-signing-profile-block) and additional claims provided as a function parameter. |
-| `merge`            | Deep-merges two or more of either objects or tuples. `null` arguments are ignored. A `null` attribute value in an object removes the previous attribute value. An attribute value with a different type than the current value is set as the new value. `merge()` with no parameters returns `null`. |
-| `saml_sso_url`     | Creates a SAML SingleSignOn URL (including the `SAMLRequest` parameter) from a referenced [SAML Block](#saml-block). |
-| `to_lower`         | Converts a given string to lowercase. |
-| `to_upper`         | Converts a given string to uppercase. |
-| `unixtime`         | Retrieves the current UNIX timestamp in seconds. |
-| `url_encode`       | URL-encodes a given string according to RFC 3986. |
+| Name            | Description                                                                                                                                                                                                                                                                                          |
+| :-------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `base64_decode` | Decodes Base64 data, as specified in RFC 4648.                                                                                                                                                                                                                                                       |
+| `base64_encode` | Encodes Base64 data, as specified in RFC 4648.                                                                                                                                                                                                                                                       |
+| `coalesce`      | Returns the first of the given arguments that is not null.                                                                                                                                                                                                                                           |
+| `json_decode`   | Parses the given JSON string and, if it is valid, returns the value it represents.                                                                                                                                                                                                                   |
+| `json_encode`   | Returns a JSON serialization of the given value.                                                                                                                                                                                                                                                     |
+| `jwt_sign`      | jwt_sign creates and signs a JSON Web Token (JWT) from information from a referenced [JWT Signing Profile Block](#jwt-signing-profile-block) and additional claims provided as a function parameter.                                                                                                 |
+| `merge`         | Deep-merges two or more of either objects or tuples. `null` arguments are ignored. A `null` attribute value in an object removes the previous attribute value. An attribute value with a different type than the current value is set as the new value. `merge()` with no parameters returns `null`. |
+| `saml_sso_url`  | Creates a SAML SingleSignOn URL (including the `SAMLRequest` parameter) from a referenced [SAML Block](#saml-block).                                                                                                                                                                                 |
+| `to_lower`      | Converts a given string to lowercase.                                                                                                                                                                                                                                                                |
+| `to_upper`      | Converts a given string to uppercase.                                                                                                                                                                                                                                                                |
+| `unixtime`      | Retrieves the current UNIX timestamp in seconds.                                                                                                                                                                                                                                                     |
+| `url_encode`    | URL-encodes a given string according to RFC 3986.                                                                                                                                                                                                                                                    |
 
 ## Modifier
 
-* [Request Header](#request-header)
-* [Response Header](#response-header)
-* [Query Parameter](#query-parameter)
-* [Form Parameter](#form-parameter)
+- [Request Header](#request-header)
+- [Response Header](#response-header)
+- [Set Response Status](#set-response-status)
+- [Query Parameter](#query-parameter)
+- [Form Parameter](#form-parameter)
 
 ### Request Header
 
@@ -518,9 +516,9 @@ Couper offers three attributes to manipulate the request header fields. The head
 attributes can be defined unordered within the configuration file but will be
 executed ordered as follows:
 
-| Modifier                 | Contexts                                                                                        | Description |
-|:-------------------------|:------------------------------------------------------------------------------------------------|:------------|
-| `remove_request_headers` | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of request header to be removed from the upstream request. |
+| Modifier                 | Contexts                                                                                                                                                | Description                                                       |
+| :----------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------ | :---------------------------------------------------------------- |
+| `remove_request_headers` | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of request header to be removed from the upstream request.   |
 | `set_request_headers`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to set request header in the upstream request. |
 | `add_request_headers`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to add request header to the upstream request. |
 
@@ -532,15 +530,27 @@ Couper offers three attributes to manipulate the response header fields. The hea
 attributes can be defined unordered within the configuration file but will be
 executed ordered as follows:
 
-| Modifier                  | Contexts                                                                                        | Description |
-|:--------------------------|:------------------------------------------------------------------------------------------------|:------------|
-| `remove_response_headers` | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block), [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of response header to be removed from the client response. |
+| Modifier                  | Contexts                                                                                                                                                                                                                                                              | Description                                                       |
+| :------------------------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------- |
+| `remove_response_headers` | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block), [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of response header to be removed from the client response.   |
 | `set_response_headers`    | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block), [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to set response header in the client response. |
 | `add_response_headers`    | [Server Block](#server-block), [Files Block](#files-block), [SPA Block](#spa-block), [API Block](#api-block), [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to add response header to the client response. |
 
 All `*_response_headers` are executed from: `server`, `files`, `spa`, `api`, `endpoint`, `proxy`, `backend` and `error_handler`.
 
-## Parameters 
+### Set Response Status
+
+The `set_response_status` attribute allows to modify the HTTP status code to the
+given value.
+
+| Modifier              | Contexts                                                                                            | Description                                        |
+| :-------------------- | :-------------------------------------------------------------------------------------------------- | :------------------------------------------------- |
+| `set_response_status` | [Endpoint Block](#endpoint-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | HTTP status code to be set to the client response. |
+
+If the HTTP status code ist set to `204`, the reponse body and the HTTP header
+field `Content-Length` is removed from the client response, and a warning is logged.
+
+## Parameters
 
 ### Query Parameter
 
@@ -548,9 +558,9 @@ Couper offers three attributes to manipulate the query parameter. The query
 attributes can be defined unordered within the configuration file but will be
 executed ordered as follows:
 
-| Modifier              | Contexts                                                                                        | Description |
-|:----------------------|:------------------------------------------------------------------------------------------------|:------------|
-| `remove_query_params` | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of query parameters to be removed from the upstream request URL. |
+| Modifier              | Contexts                                                                                                                                                | Description                                                             |
+| :-------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------ | :---------------------------------------------------------------------- |
+| `remove_query_params` | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of query parameters to be removed from the upstream request URL.   |
 | `set_query_params`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to set query parameters in the upstream request URL. |
 | `add_query_params`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to add query parameters to the upstream request URL. |
 
@@ -594,11 +604,11 @@ Couper offers three attributes to manipulate the form parameter. The form
 attributes can be defined unordered within the configuration file but will be
 executed ordered as follows:
 
-| Modifier              | Contexts                                                                                        | Description |
-|:----------------------|:------------------------------------------------------------------------------------------------|:------------|
-| `remove_form_params`  | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of form parameters to be removed from the upstream request body. |
-| `set_form_params`     | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to set form parameters in the upstream request body. |
-| `add_form_params`     | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to add form parameters to the upstream request body. |
+| Modifier             | Contexts                                                                                                                                                | Description                                                             |
+| :------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------ | :---------------------------------------------------------------------- |
+| `remove_form_params` | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | List of form parameters to be removed from the upstream request body.   |
+| `set_form_params`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to set form parameters in the upstream request body. |
+| `add_form_params`    | [Endpoint Block](#endpoint-block), [Proxy Block](#proxy-block), [Backend Block](#backend-block), [Error Handler](ERRORS.md#error_handler-specification) | Key/value(s) pairs to add form parameters to the upstream request body. |
 
 All `*_form_params` are executed from: `endpoint`, `proxy`, `backend` and `error_handler`.
 
@@ -643,8 +653,7 @@ An endpoint label could be defined as `endpoint "/app/{section}/{project}/view"
 to access the named path parameter `section` and `project` via `request.path_params.*`.
 The values would map as following for the request path: `/app/nature/plant-a-tree/view`:
 
-| Variable                  | Value          |
-|:--------------------------|:---------------|
+| Variable                      | Value          |
+| :---------------------------- | :------------- |
 | `request.path_params.section` | `nature`       |
 | `request.path_params.project` | `plant-a-tree` |
-
diff --git a/eval/http.go b/eval/http.go
index b3c62ef7d..84bacf647 100644
--- a/eval/http.go
+++ b/eval/http.go
@@ -16,6 +16,7 @@ import (
 	"github.com/zclconf/go-cty/cty"
 	"github.com/zclconf/go-cty/cty/function/stdlib"
 
+	"github.com/avenga/couper/config"
 	"github.com/avenga/couper/config/meta"
 	"github.com/avenga/couper/config/request"
 	"github.com/avenga/couper/errors"
@@ -290,7 +291,41 @@ func ApplyResponseContext(ctx context.Context, body hcl.Body, beresp *http.Respo
 		return nil
 	}
 
-	return ApplyResponseHeaderOps(ctx, body, beresp.Header)
+	if err := ApplyResponseHeaderOps(ctx, body, beresp.Header); err != nil {
+		return err
+	}
+
+	content, _, _ := body.PartialContent(config.BackendInlineSchema)
+	if attr, ok := content.Attributes["set_response_status"]; ok {
+		var httpCtx *hcl.EvalContext
+		if c, ok := ctx.Value(ContextType).(*Context); ok {
+			httpCtx = c.eval
+		}
+
+		val, attrDiags := attr.Expr.Value(httpCtx)
+		if seetie.SetSeverityLevel(attrDiags).HasErrors() {
+			return attrDiags
+		}
+
+		status := seetie.ValueToInt(val)
+		if status < 100 || status > 599 {
+			return errors.Configuration.Label("set_response_status").Messagef("invalid http status code: %d", status)
+		}
+
+		if status == 204 {
+			beresp.Request.Context().
+				Value(request.LogEntry).(*logrus.Entry).
+				Warn("set_response_status: removing body, if any due to status-code 204")
+
+			beresp.Body = io.NopCloser(bytes.NewBuffer([]byte{}))
+			beresp.ContentLength = -1
+			beresp.Header.Del("Content-Length")
+		}
+
+		beresp.StatusCode = int(status)
+	}
+
+	return nil
 }
 
 func ApplyResponseHeaderOps(ctx context.Context, body hcl.Body, headers ...http.Header) error {
diff --git a/handler/endpoint.go b/handler/endpoint.go
index 352b86c9d..32aa8801f 100644
--- a/handler/endpoint.go
+++ b/handler/endpoint.go
@@ -169,7 +169,8 @@ func (e *Endpoint) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 
 	// always apply before write: redirect, response
 	if err = eval.ApplyResponseContext(evalContext, e.opts.Context, clientres); err != nil {
-		log.WithError(err).Error()
+		e.opts.Error.ServeError(err).ServeHTTP(rw, req)
+		return
 	}
 
 	select {
diff --git a/server/modifier_test.go b/server/modifier_test.go
index fc8e82cd5..1d357625f 100644
--- a/server/modifier_test.go
+++ b/server/modifier_test.go
@@ -10,6 +10,9 @@ import (
 func TestIntegration_ResponseHeaders(t *testing.T) {
 	const confFile = "testdata/integration/modifier/01_couper.hcl"
 
+	shutdown, _ := newCouper(confFile, test.New(t))
+	defer shutdown()
+
 	client := newClient()
 
 	type testCase struct {
@@ -46,10 +49,7 @@ func TestIntegration_ResponseHeaders(t *testing.T) {
 		},
 	} {
 		t.Run(tc.path, func(subT *testing.T) {
-			helper := test.New(t)
-
-			shutdown, _ := newCouper(confFile, helper)
-			defer shutdown()
+			helper := test.New(subT)
 
 			req, err := http.NewRequest(http.MethodGet, "http://example.com:8080"+tc.path, nil)
 			helper.Must(err)
@@ -65,3 +65,55 @@ func TestIntegration_ResponseHeaders(t *testing.T) {
 		})
 	}
 }
+
+func TestIntegration_SetResponseStatus(t *testing.T) {
+	const confFile = "testdata/integration/modifier/02_couper.hcl"
+
+	shutdown, hook := newCouper(confFile, test.New(t))
+	defer shutdown()
+
+	client := newClient()
+
+	type testCase struct {
+		path       string
+		expMessage string
+		expStatus  int
+	}
+
+	for _, tc := range []testCase{
+		{
+			path:       "/204",
+			expMessage: "set_response_status: removing body, if any due to status-code 204",
+			expStatus:  204,
+		},
+		{
+			path:       "/201",
+			expMessage: "",
+			expStatus:  201,
+		},
+		{
+			path:       "/600",
+			expMessage: "configuration error: set_response_status: invalid http status code: 600",
+			expStatus:  500,
+		},
+	} {
+		t.Run(tc.path, func(subT *testing.T) {
+			helper := test.New(subT)
+
+			req, err := http.NewRequest(http.MethodGet, "http://example.com:8080"+tc.path, nil)
+			helper.Must(err)
+
+			hook.Reset()
+			res, err := client.Do(req)
+			helper.Must(err)
+
+			if res.StatusCode != tc.expStatus {
+				t.Errorf("Expected status code %d, given: %d", tc.expStatus, res.StatusCode)
+			}
+
+			if hook.Entries[0].Message != tc.expMessage {
+				t.Errorf("Unexpected message given: %s", hook.Entries[0].Message)
+			}
+		})
+	}
+}
diff --git a/server/testdata/integration/modifier/02_couper.hcl b/server/testdata/integration/modifier/02_couper.hcl
new file mode 100644
index 000000000..fa4827939
--- /dev/null
+++ b/server/testdata/integration/modifier/02_couper.hcl
@@ -0,0 +1,26 @@
+server "set-response-status" {
+  endpoint "/204" {
+    proxy {
+      url = "${env.COUPER_TEST_BACKEND_ADDR}/anything"
+      backend {
+        set_response_status = 204
+      }
+    }
+  }
+  endpoint "/201" {
+    proxy {
+      url = "${env.COUPER_TEST_BACKEND_ADDR}/anything"
+      backend {
+        set_response_status = 201
+      }
+    }
+  }
+  endpoint "/600" {
+    proxy {
+      url = "${env.COUPER_TEST_BACKEND_ADDR}/anything"
+      backend {
+        set_response_status = 600
+      }
+    }
+  }
+}