---
title: "Add a backend to a load balancer."
method: POST
path: "/v1/lb/{id}/backends"
tags: ["Load Balancer"]
---

# Add a backend to a load balancer.

`POST /v1/lb/{id}/backends`

## Request

- Base URL: `https://api.scalix.world`
- URL: `https://api.scalix.world/v1/lb/{id}/backends`
- Auth: HTTP bearer

Registers a backend target on the load balancer and returns its details.

## Path parameters

- `id` string, required

## Request body

- AddBackendRequest
  - `url` string, required
  - `weight` integer

## Response `200`

Backend added

- BackendInfo
  - `id` string, uuid, required
  - `url` string, required
  - `weight` integer, required
  - `healthy` boolean, required
  - `active_conns` integer, required

## Other responses

- `400`: Load balancer not found or invalid backend
- `401`: Missing or invalid credentials
- `403`: Token lacks the lb:write scope
- `500`: Internal error

---

[API](https://skmtc.dev/scalix/apis/scalix-cloud-api.md) · [All operations](https://skmtc.dev/scalix/apis/scalix-cloud-api/llms.txt) · [OpenAPI document](https://skmtc.dev/scalix/apis/scalix-cloud-api/revisions/2c04ca0a90bb?raw)