Steward is a side-car process that connects the Sommelier chain to the outside world. It provides an API for Strategy Providers to update Cellars through the Sommelier validator set based on off-chain calculations. Additionally, it subsumes the functionality of gorc for managing the Gravity bridge Orchestrator, and provides developer tools and features for developing and testing Cellars.

Steward runs on every Validator in the Sommelier Validator set. It runs a server to which Strategy Providers (SPs) send requests whenever they determine that the market has changed enough to warrant an update to the Cellar position. The request payload contains everything needed to make a cork: a signed combination of a chain ID, cellar ID (contract address), and an ABI encoded contract call. When Steward receives a request, it attempts to establish two-way trust via TLS 1.3 to verify that it is from an SP. It then validates that the SP is the trusted Publisher for updates to the target cellar address. Finally, steward builds a cork, signs it with the configured delegate key, and submits it to the either the x/cork module or x/axelarcork module on chain depending on whether the Cellar is on Ethereum or another EVM chain respectively, where it will then be relayed to the target Cellar contract if a consensus of validators submit the same cork.

💡 Steward authenticates via TLS 1.3 and authorizes via the (x/pubsub module)[https://github.com/peggyjv/sommelier/tree/main/x/pubsub] all requests to prevent malicious actors from controlling Cellars. Additionally, the Steward API limits the capabilities SPs have to functionality related to managing Cellar funds. They cannot execute withdrawals.

To start Steward, simply run

steward -c <config_toml_path> start

A few of the necessary fields required in this config TOML file are covered in this document. See the Configuration document for an example config file and field reference.

⚠️ If this is production and your node is running, don't forget to make sure the Orchestrator is also running! If you don't, you can be jailed and your submitted corks will not be processed. See the Orchestrator Quickstart section of the docs.

• Domain name for Strategy Providers to use for requests to Steward
• Firewall configured to allow requests to hit the Steward port over the internet
• Connectivity between Steward and your Sommelier node's gRPC endpoint
• On-disk key store containing a delegate key in this key store for Steward and Orchestrator to share. This can be generated with Steward, or you may have already done this step with gorc in the past. If that's the case you can just use the delegate key you’ve already created.
• TLS 1.3 server CA and certificate signed with said CA
• TOML config file containing the above values
• Create a Subscriber on chain representing your steward's identity. If your steward was in the Steward Registry before the v7 upgrade, it has already been included as a subscriber in the migration.

Before SPs can establish a connection with your steward server, you will need to generate a CA, a TLS certificate signed by this CA, and the SP's client CA. These certificates must be TLS 1.3 compliant. For detailed steps please see the Generating Certificates document.

The paths to the generated certificates and the key used to create your signed server certificate must be configured in the [server] table of your config file.

Steward signs corks with the same key that the Orchestrator uses to sign Ethereum -> Cosmos transactions. Therefore, if you have already generated a delegate key for the Orchestrator in the past, you do not need to do it again for Steward. Simply set the path to this key in your Steward config.

If you are a new validator, we recommend following the Sommelier installation steps to generate all the keys you need and set them as the delegate keys for your validator. It is ok to use gorc for key generation as that document recommends, however you can also generate them using Steward. Examples of the commands used to do this can be found in the Orchestrator Setup section.

The Cosmos delegate key generated (called "orchestrator" in the Sommelier docs) should be set as the delegate_key field under the [server] table of your configuration file.

⚠️ Remember to set this key as a delegate key in your validator node. The steps to do this are covered in the Sommelier documentaion linked above.

Other important configuration fields like your Sommelier node's endpoint are also required so that Steward knows where to send corks. Here is an example configuration you can use to get your config file started. Most of the fields have sensible defaults; you can use the configuration reference to determine which fields you don't need to explicity set if you wish.

Once your keys, certs, and config file are ready, you have created a Subscriber on the x/pubsub module, and your Sommelier node is running, refer to the Quickstart section above to start Steward!