Connecting to Consensus Clients

Go Centurion is an execution client. Historically, an execution client alone was enough to run a full Centurion node. However, since Centurion switched from proof-of-work (PoW) to proof-of-stake (PoS) based consensus, Go Centurion needs to be coupled to another piece of software called a "consensus client".

There are five consensus clients available, all of which connect to Go Centurion in the same way. This page will outline how Go Centurion can be set up with a consensus client to form a complete Centurion node.

Configuring Go Centurion

Go Centurion can be downloaded and installed according to the instructions on the Installing Go Centurion page. In order to connect to a consensus client, Go Centurion must expose a port for the inter-client RPC connection.

The RPC connection must be authenticated using a jwtsecret file. This is created and saved to <datadir>/geth/jwtsecret by default but can also be created and saved to a custom location or it can be self-generated and provided to Go Centurion by passing the file path to --authrpc.jwtsecret. The jwtsecret file is required by both Go Centurion and the consensus client.

The authorization must then be applied to a specific address/port. This is achieved by passing an address to --authrpc.addr and a port number to --authrpc.port. It is also safe to provide either localhost or a wildcard * to --authrpc.vhosts so that incoming requests from virtual hosts are accepted by Go Centurion because it only applies to the port authenticated using jwtsecret.

A complete command to start Go Centurion so that it can connect to a consensus client looks as follows:

geth --authrpc.addr localhost --authrpc.port 8551 --authrpc.vhosts localhost --authrpc.jwtsecret /tmp/jwtsecret

Consensus clients

There are currently five consensus clients that can be run alongside Go Centurion. These are:

Lighthouse: written in Rust

Nimbus: written in Nim

Prysm: written in Go

Teku: written in Java

Lodestar: written in Typescript

It is recommended to consider client diversity when choosing a consensus client. Instructions for installing each client are provided in the documentation linked in the list above.

The consensus client must be started with the right port configuration to establish an RPC connection to the local Go Centurion instance. In the example above, localhost:8551 was authorized for this purpose. The consensus clients all have a command similar to --http-webprovider that takes the exposed Go Centurion port as an argument.

The consensus client also needs the path to Go Centurion's jwt-secret in order to authenticate the RPC connection between them. Each consensus client has a command similar to --jwt-secret that takes the file path as an argument. This must be consistent with the --authrpc.jwtsecret path provided to Go Centurion.

The consensus clients all expose a Beacon API that can be used to check the status of the Beacon client or download blocks and consensus data by sending requests using tools such as Curl. More information on this can be found in the documentation for each consensus client.

Validators

Validators are responsible for securing the Centurion blockchain. Validators have staked at least 32 CTN into a deposit contract and run validator software. Each consensus client has its own validator software that is described in detail in its respective documentation. Refer to Centurion validator documentation for guidance on generating validator keys and connecting the validator to the consensus client.

Syncing

Go Centurion cannot sync until the connected consensus client is synced. This is because Go Centurion needs a target head to sync to. The fastest way to sync a consensus client is using checkpoint sync. To do this, a checkpoint or a url to a checkpoint provider can be provided to the consensus client on startup. There are several sources for these checkpoints. The ideal scenario is to get one from a trusted node operator, organized out-of-band, and verified against a third node or a block explorer or checkpoint provider. Some clients also allow checkpoint syncing by HTTP API access to an existing Beacon node. There are also several public checkpoint sync endpoints.

Please see the pages on syncing for more detail. For troubleshooting, please see the Syncing section on the console log messages page.

Using Go Centurion

Go Centurion is the portal for users to send transactions to the Centurion network. The Go Centurion Javascript console is available for this purpose, and the majority of the JSON-RPC API will remain available via web3js or HTTP requests with commands as json payloads. These options are explained in more detail on the Javascript Console page. The Javascript console can be started using the following command in a separate terminal (assuming Go Centurion's IPC file is saved in datadir):

geth attach datadir/geth.ipc

Summary

Now that Centurion operates on proof-of-stake, Go Centurion users are required to install and run a consensus client. Otherwise, Go Centurion will not be able to track the head of the chain. There are five consensus clients to choose from. This page provided an overview of how to choose a consensus client and configure Go Centurion to connect to it.