# 80000: Connection failed

Identifier: `connection_failed`



The connection moved to the failed state, a terminal condition from which the SDK does not automatically reconnect. It differs from a temporary disconnection, where the SDK keeps retrying to restore the connection on its own.

## What you should do

Start from the error attached to the failed state, which explains why the connection failed. Because the [failed state](https://ably.com/docs/connect/states.md) is terminal, the SDK will not reconnect on its own, so once the underlying cause is resolved you need to call `connect()` to try again.

## Why it happens

The connection entered the failed state, usually because of an error the SDK treats as non-recoverable rather than a passing network problem. A fatal authentication error is a common cause. This is distinct from a temporary disconnection, where the SDK keeps retrying by itself.

## What you'll see

The error is reported with code 80000. The message is typically `Connection failed or disconnected by server`, though the failure that caused it carries its own, more specific error.