Jester

Jester is a sidecar application designed to be run by the Noble validator set. It facilitates the implementation of the Noble Dollar, powered by M0.

Note

Jester is not needed by node operators. Only validators need to run Jester.

What does Jester do?

Jester acts as a relayer listening for $USDN transfers between Ethereum and Noble.

As events are observed, Jester accumulates Wormhole VAA's (Verified Action Approvals). These VAA's are handed off to Noble validators and submitted on-chain.

Installation 💾

To install from source, clone the repository and install:

git clone https://github.com/noble-assets/jester.git
cd jester
make install

Jester is also available via releases and Docker.

To ensure is Jester is properly installed, try printing out version info:

jesterd version

Setup ⚙

Initialize config:

jesterd config init

By default, Jester's config will be placed in $HOME/.jester/

Example Config

# log level format (info, debug, warn, error)
log-level = "debug"
# log style format (text, json, pretty)
log-style = "pretty"
testnet = false
# jester's gRPC server
server-address = "localhost:9091"

[ethereum]
  websocket-url = "wss://MY-ENDPOINT"
  rpc-url = "https://MY-ENDPOINT"

# Prometheus Metrics
[metrics]
  enabled = true
  address = "localhost:2112"

Jesters config is simple and mostly auto generated via the init command. Please ensure all values are filled out.

You will need a reliable Ethereum websocket-url and Ethereum rpc-url.

Make sure you toggle the testnet boolean accordingly.

By default, Jesters gRPC server address is localhost:9091. This endpoint should not be publicly exposed and only accessed by the Noble binary.

Are you are a validator updating from a Noble version < v9?

You will need to add the following to Nobles app.toml file. By default this file lives at $HOME/.noble/config/app.toml

###############################################################################
###                             Jester (sidecar)                            ###
###############################################################################

[jester]

# Jester's gRPC server address. 
# This should not conflict with the CometBFT gRPC server.
grpc-address = "localhost:9091"

New versions of Noble will automatically have this field when initialized.

Make sure that Jesters gRPC server matches the configuration set in Noble's app.toml ($HOME/.noble/config/app.toml). You do not need need to worry about this if you are using defaults.

Run 🃏

To run:

jesterd start

Prometheus

Jester includes a Prometheus server to monitor its status. We HIGHLY encourage all operators to scrape the up metric to ensure that Jester is up and running.

By default, the Prometheus server listens on localhost:2112.

The default metrics are available at /metrics.

Custom metrics can be accessed at /jester/metrics.

More details for the Prometheus server are available here

Important

The only way Jester is expected to quit is if the Ethereum Websocket becomes disconnect. Jester will make several attempts to reconnect. If all attempts fails, Jester quits.

Flags and Configuration

Users have three options to configure Jester:

1. Flags: Use the --help flag to see available flags per command.
2. Environment Variables: These must match either a config file setting or a flag. Must be UPPERCASE. If a flag uses "-", the ENV var equivalent is "_". There is one unique variable: JESTER_HOME that mimics the --home flag.
3. Config File

Note that configuration precedence takes place in the above order. Flags are prioritized, then ENV variables then the config file.

TIP: Use flags when running jesterd config init to automatically fill out the config file.

More Questions?

Please visit our FAQ.