Crate varro

varro is a persistent, robust, and composable proposal service for rollup stacks written in pure rust.

Note

Varro is primarily tested against the op-stack.

Quickstart

Varro provides an easy to use installer called varrup.

To install varro, run: curl https://raw.githubusercontent.com/refcell/varro/main/varrup/install | bash.

Additionally, you can run varro for ethereum-optimism using the provided scripts in the scripts directory.

Architecture

At it’s core, varro is a client. In ./src/client.rs, there is an Varro struct that is the core client/driver of the batcher.

The Varro struct first builds “stages” and then executes them as asynchronous threads. These stages split up the transformation of data types and handles channel transitions and metrics.

The primary entrypoint for varro is ./src/client/rs which is the Varro struct. Varro exposes methods for constructing proposals.

Configuration

The varro cli maintains a verbose menu for running a proposal service. To see a list of all available commands, run varro --help. This will print output similar to the following:

Environment Variables

The following environment variables are the default values for varro’s configuration.

They can be overridden by setting the environment variable in the shell before running varro, or setting the associated flags when running the varro cli.

Specifications

// TODO:

Why “Varro”?

The term “varro” comes from Marcus Terentius Varro, an ancient Roman polymath and prolific author. Referred to the “great third light of Rome”, Varro mirrors the role of the varro service in the rollup stack, handling the “inscription” of outputs to the settlement layer (eg, posting L2 output proposals to Ethereum).

FAQ

// TODO:

Contributing

All contributions are welcome. Before opening a PR, please submit an issue detailing the bug or feature. When opening a PR, please ensure that your contribution builds on the nightly rust toolchain, has been linted with cargo fmt, and contains tests when applicable.

Disclaimer

This code is being provided as is. No guarantee, representation or warranty is being made, express or implied, as to the safety or correctness of the code. It has not been audited and as such there can be no assurance it will work as intended, and users may experience delays, failures, errors, omissions or loss of transmitted information. Nothing in this repo should be construed as investment advice or legal advice for any particular facts or circumstances and is not meant to replace competent counsel. It is strongly advised for you to contact a reputable attorney in your jurisdiction for any questions or concerns with respect thereto. The authors is not liable for any use of the foregoing, and users should proceed with caution and use at their own risk.

Re-exports

• pub use telemetry::*;

Modules

• builder
  A Builder for the [Varro] client
• cli
  CLI parsing
• client
  The core [Varro] client
• config
  Configuration
• errors
  Common Errors
• metrics
  The metrics server
• prelude
  Re-export Archon Types
• rollup
  The Rollup Node Rollup
• telemetry
  Telemetry module

Macros

• extract_env
  This macro is used to read the value of an environment variable. If the environment variable is not set, the macro will panic.

Structs

• Http
  A low-level JSON-RPC Client over HTTP.
• OutputOracle
  An OutputOracle is a contract that provides the next block number to use for the next proposal.
• Provider
  An abstract provider for interacting with the Ethereum JSON RPC API. Must be instantiated with a data transport which implements the JsonRpcClient trait (e.g. HTTP, Websockets etc.)

Traits

• Middleware
  A middleware allows customizing requests send and received from an ethereum node.

Type Definitions

• L1Client
  An L1Client is an Http Provider for Ethereum Mainnet.