slinky

A general purpose price oracle leveraging ABCI++. Please visit our docs page for more information!

Slinky uses Vote Extensions to create an hyperperformant, extremely secure mechanism for aggregating off-chain data onto a blockchain. It is used by many of the highest-performance decentralized applications today. If you would like to integrate Slinky to power your use case, please contact us on our Discord.

Note

Slinky is business-licensed software under BSL, meaning it requires a license to use or reference. It is source viewable, but reach out to us on Discord if you are interested in integrating! We are limiting the number of chains we work with to seven in 2024. We apologize if we run out of capacity.

Install

$ go install github.com/dydxprotocol/slinky

Overview

The slinky repository is composed of the following core packages:

• abci - This package contains the vote extension, proposal, and preblock handlers that are used to broadcast oracle data to the network and to store it in the blockchain.
• oracle - This package contains the main oracle that aggregates external data sources before broadcasting it to the network. You can reference the provider documentation here to get a high level overview of how the oracle works.
• providers - This package contains a collection of websocket and API based data providers that are used by the oracle to collect external data.
• x/oracle - This package contains a Cosmos SDK module that allows you to store oracle data on a blockchain.
• x/marketmap - This package contains a Cosmos SDK module that allows for market configuration to be stored and updated on a blockchain.

Validator Usage

To read how to run the oracle as a validator based on the chain, please reference the validator documentation.

Developer Usage

To run the oracle, run the following command.

$ make start-all-dev

This will:

1. Start a blockchain with a single validator node. It may take a few minutes to build and reach a point where vote extensions can be submitted.
2. Start the oracle side-car that will aggregate prices from external data providers and broadcast them to the network. To check the current aggregated prices on the side-car, you can run curl localhost:8080/slinky/oracle/v1/prices.
3. Host a prometheus instance that will scrape metrics from the oracle sidecar. Navigate to http://localhost:9091 to see all network traffic and metrics pertaining to the oracle sidecar. Navigate to http://localhost:8002 to see all application-side oracle metrics.
4. Host a profiler that will allow you to profile the oracle side-car. Navigate to http://localhost:6060 to see the profiler.
5. Host a grafana instance that will allow you to visualize the metrics scraped by prometheus. Navigate to http://localhost:3000 to see the grafana dashboard. The default username and password are admin and admin, respectively.

After a few minutes, run the following commands to see the prices written to the blockchain:

# access the blockchain container
$ docker exec -it compose-blockchain-1 bash

# query the price of bitcoin in USD on the node
$ (compose-blockchain-1) ./build/slinkyd q oracle price BTC USD

Result:

decimals: "8"
id: "0"
nonce: "44"
price:
  block_height: "46"
  block_timestamp: "2024-01-29T01:43:48.735542Z"
  price: "4221100000000"

To stop the oracle, run the following command:

$ make stop-all-dev

Metrics

Oracle Service Metrics

We have an extensive suite of metrics available to validators and chain operators. Please join our discord if you want help setting them up!

• metrics relevant to the oracle service's health + operation are here

Oracle Application / Network Metrics

• metrics relevant to the network's (that is running the instance of slinky) performance are here

---

dYdX Fork

Slinky vs. Connect Rename

• Skip renamed their repo (and code refs) from Slinky --> Connect for branding purposes.
• Unfortunately it is impossible to update V4 protocol to use the renamed version, as message names etc. were changed. This would cause downtime during the interval when validators have updated v4-chain to use the rename but have not yet updated sidecar (or vice-versa).
• As a result, the dYdX fork of skip-mev/connect has chosen to roll back to the pre-rename state, slinky, as the base for future development (along with backporting any essential post-rename changes to functionality).

Publishing a Release

To publish a new release of the dydxprotocol/slinky codebase, follow the official Go docs for Publishing A Module.

TODO: Sidecar Deploys

• The GitHub workflows in this repo can build + deploy new images of the Slinky sidecar (along with other images for E2E testing, local testing, etc.)
• However, these workflows have not yet been updated for dYdX's use case. (Ex. ECR + GHCR URLs still point to Skip's accounts, still rely on Skip secrets, etc.)
• This is not an urgent issue, unless the sidecar code itself is updated, or breaking changes are made to the format of the Market Map.
  • Note: Adding new fields to ex. the metadata_json string in Market Map, is not a breaking change (assuming these new fields are not required by the sidecar for price-fetching).
• Next Steps to enable deploys for dYdX's fork of sidecar:
  • Update the URLs and secrets in build-docker.yml to deploy to dYdX's ECR / GHCR repos.
  • Update v4-chain's docker-compose.yml to pull from dYdX's repos when building the slinky0 (sidecar) image.