---
title: Director backend
summary: Maps and relates backends as belonging to directors. Backends can belong to any number of directors but directors can only hold one reference to a specific backend.
url: https://www.fastly.com/documentation/reference/api/load-balancing/directors/backend
---

Maps and relates backends as belonging to directors. Backends can belong to any number of directors but directors can only hold one reference to a specific backend.

## Data model

| Field | Type | Description |
|-------|------|-------------|
| `backend_name` | string | The name of the backend. |
| `created_at` | string | Date and time in ISO 8601 format. (Read-only) |
| `deleted_at` | string | Date and time in ISO 8601 format. (Read-only) |
| `director` | string | Name for the Director. |
| `service_id` | string | Alphanumeric string identifying the service. (Read-only) |
| `updated_at` | string | Date and time in ISO 8601 format. (Read-only) |
| `version` | integer | Integer identifying a service version. (Read-only) |

## API endpoints

### Get a director-backend relationship

**GET** `/service/{service_id}/version/{version_id}/director/{director_name}/backend/{backend_name}`

Returns the relationship between a Backend and a Director. If the Backend has been associated with the Director, it returns a simple record indicating this. Otherwise, returns a 404.

**Parameters:**

| Name | Type | In | Required | Description |
|------|------|----|---------|--------------|
| `backend_name` | string | path | Yes | The name of the backend. |
| `director_name` | string | path | Yes | Name for the Director. |
| `service_id` | string | path | Yes | Alphanumeric string identifying the service. |
| `version_id` | integer | path | Yes | Integer identifying a service version. |

### Create a director-backend relationship

**POST** `/service/{service_id}/version/{version_id}/director/{director_name}/backend/{backend_name}`

Establishes a relationship between a Backend and a Director. The Backend is then considered a member of the Director and can be used to balance traffic onto.

**Parameters:**

| Name | Type | In | Required | Description |
|------|------|----|---------|--------------|
| `backend_name` | string | path | Yes | The name of the backend. |
| `director_name` | string | path | Yes | Name for the Director. |
| `service_id` | string | path | Yes | Alphanumeric string identifying the service. |
| `version_id` | integer | path | Yes | Integer identifying a service version. |

### Delete a director-backend relationship

**DELETE** `/service/{service_id}/version/{version_id}/director/{director_name}/backend/{backend_name}`

Deletes the relationship between a Backend and a Director. The Backend is no longer considered a member of the Director and thus will not have traffic balanced onto it from this Director.

**Parameters:**

| Name | Type | In | Required | Description |
|------|------|----|---------|--------------|
| `backend_name` | string | path | Yes | The name of the backend. |
| `director_name` | string | path | Yes | Name for the Director. |
| `service_id` | string | path | Yes | Alphanumeric string identifying the service. |
| `version_id` | integer | path | Yes | Integer identifying a service version. |