Tracer Perpetual Pools

Tracer Perpetual Pools V2 is the second major release of Tracer's Perpetual Pools product.

Tracer Perpetual Pools is a system that provides leveraged, tokenised exposure to arbitrary assets via a simple and elegant model where settlement is locked within the system in exchange for pool tokens (via minting) and pool tokens are returned to the protocol in exchange for (some of) the underlying settlement tokens (via burning).

For additional information on the higher-level economics of how Pools works, please consult the whitepaper.

Prior Audit Work

Sigma Prime

Sigma Prime have performed an audit of the previous version of the codebase — i.e., Perpetual Pools v1. Both the audit report and the team's response to the audit's findings are available here.

Code Arena

A crowdsourced audit was also undertaken via Code 423n4. The results are available here.

Changes Since V1

The most accurate version of this list is the set of all PRs merged in since 16 September 2021 until today (inclusive): https://github.com/tracer-protocol/perpetual-pools-contracts/pulls?q=is%3Apr+is%3Aclosed+merged%3A2021-09-16..2021-11-01

Regardless, an abridged list is provided for convenience:

• SMA pricing is now available via SMAOracle.sol (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/172)
• The frontrunning interval is now able to be (and likely will be) much longer than the update interval (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/190)
• Commitments now occur in aggregate (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/176)
• Deployments of new instances of the Perpetual Pools system are now deterministic (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/181)
• Deployments are now permissionless (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/186)
• There is now an automatic claiming facility for users to have the results of their commitments occurring on their behalf (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/256)
• Minting and burning (both forms of commitments) now incur independent fees (https://github.com/tracer-protocol/perpetual-pools-contracts/pull/211)

Known Issues

Any issues in the public repository that were opened prior to the start of CARE are considered known and thus out-of-scope.

Security Assumptions

Any given pool will be upkept (that is to say PoolCommitter::performUpkeepSinglePool, PoolCommitter::performUpkeepMultiplePools, or their packed variants are called with the LeveragedPool's address as a parameter) within a reasonable time after an update interval finishes (~15 minutes maximum)).

Update Interval

The update interval (LeveragedPool::updateInterval) is typically 1 hour (3600 seconds).

Contributing

Install

$ git clone [email protected]:tracer-protocol/perpetual-pools-contracts.git
$ cd perpetual-pools-contracts
perpetual-pools-contracts$ yarn install

Compile

$ yarn run compile

Test

$ yarn run test

Lint

$ yarn run lint # to check
$ yarn run lint:fix # to fix

Miscellaneous

Slither

Requires Slither to both be installed and on current PATH.

$ yarn run slither

UML Diagrams

Via sol2uml:

$ yarn run uml

Coverage

Note that this can take a while and also both gas usage and contract code size metrics will be incorrect (this is due to added overhead due to instrumentation).

$ yarn run coverage

Deploy to Ethereum

Create/modify network config in hardhat.config.ts and add API key and private key, then run:

Deploy on Arbitrum Mainnet

npx hardhat deploy --network arb --tags ArbDeploy --reset

Deploy on Arbitrum Rinkeby

npx hardhat deploy --network arbRinkeby --tags ArbRinkebyDeploy --reset

Note: As of this commit, deploys are out of sync with the current contract set-up and therefore will not work.

Verify on Etherscan

Using the hardhat-etherscan plugin, add Etherscan API key to hardhat.config.ts, then run:

npx hardhat verify --network rinkeby <DEPLOYED ADDRESS>

PRs and feedback welcome!

Frequently Asked Questions

How are pool keepers to be chosen? How many keepers are there?

The Pool Keeper is simply a contract that enforces the correct keeper behaviour. Anyone may be a keeper by calling the keeper function on that contract with a pool that is valid for upkeep. We will initially be adding wrappers for Chainlink keepers as well as having custom keepers.

The leveraged pool fee is represented as a bytes16 value. Why is this chosen over something like uint? What denomination does this represent?

The leveraged pool fee is a bytes16 value simply due to the maths library used. We often represent values in WAD values (popularised by the Maker DAO team). WAD values are the integer value multiplied by 10^18 (e.g. 1 = 1*10^18). The maths library we currently use represents values in IEEE quad precision numbers and uses bytes as way of storing this. A good primer on the above can be found here and WAD / RAY maths is introduced here.

How many different type of tests are there? There are unit tests in the test suite. Are there also end to end tests?

Most tests are unit tests. There is a single E2E test in e2e.spec.ts right now. We plan to add more.

Whats the deployments/kovan folder for? They seem to be different from the ABIs I get from artifacts folder when I compile.

We use a plugin for hardhat called hardhat deploy that helps with deployment. They recommend you commit the deployments folder to have consistent data across deploys. The deploys you find there will be deploys that have been run from old versions of the contract, hence the ABI difference.