> ## Documentation Index
> Fetch the complete documentation index at: https://thrackle.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Upgrading A Handler Diamond Facet

Upgrading an asset-handler facet must be done following the next steps:

1. Set the environment variables in the `.env` file for the upgrade. Specifically set the variables:

```shell
DEPLOYMENT_OWNER_KEY=<YOUR_DEPLOYMENT_OWNER_KEY>
FACET_TO_UPGRADE=<THE_NAME_OF_THE_FACET_CONTRACT_TO_UPGRADE>
FACET_ADDRESS_TO_UPGRADE=<THE_ADDRESS_OF_THE_FACET_CONTRACT_TO_UPGRADE>
DIAMOND_TO_UPGRADE=<THE_NAME_OF_THE_DIAMOND_AS_IT_IS_RECORDED_IN_THE_DEPLOYMENTS>
RECORD_DEPLOYMENTS_FOR_ALL_CHAINS=<true/false> #true if testing in 31337 and recorded values are needed
```

2. Run the following script:

```shell
forge script --ffi script/clientScripts/UpgradeAHandlerFacet.s.sol --broadcast --rpc-url <YOUR_RPC_URL>
```

Notice that the environment variables are automatically cleaned by the script. This is to prevent accidental faulty upgrades. Also, the script makes sure that the upgrade was successful by checking that the old selectors are first removed, and that the new ones are in the diamond pointing to the new facet address.

## Trouble Shooting

If an upgrade needs to be reverted, see [Revert a Diamond Upgrade](/v1/architecture/common/diamond-upgrade-reversion).