# 40171: Token renewal not configured

Identifier: `token_renewal_not_configured`



The auth token expired and could not be renewed because no renewal mechanism was configured. Without an authCallback, authUrl, or API key, the Ably SDK has no way to obtain a replacement token.

## What you should do

Configure the client so it can [renew tokens](https://ably.com/docs/auth/token.md). Set an `authUrl`, `authCallback`, or API `key` in the client options, and the SDK will obtain a fresh token automatically when the current one expires. A bare token literal can't be renewed once it expires.

## Why it happens

The client was given only a token literal, with no `authUrl`, `authCallback`, or API key alongside it. When that token expired, the SDK had no configured way to obtain a replacement, so it couldn't continue.

## What you'll see

The error is reported with code 40171 and HTTP status 403. The message is typically `library initialized with a token literal without any way to renew the token when it expires (no authUrl, authCallback, or key)`.