Cosmovisor supports custom pre-upgrade handling. Use pre-upgrade handling when you need to implement application config changes that are required in the newer version before you perform the upgrade.
Using Cosmovisor pre-upgrade handling is optional. If pre-upgrade handling is not implemented, the upgrade continues.
For example, make the required new-version changes to `app.toml` settings during the pre-upgrade handling. The pre-upgrade handling process means that the file does not have to be manually updated after the upgrade.
Before the application binary is upgraded, Cosmovisor calls a `pre-upgrade` command that can be implemented by the application.
The `pre-upgrade` command does not take in any command-line arguments and is expected to terminate with the following exit codes:
| Exit status code | How it is handled in Cosmosvisor |