BIP-4: Trail of Bits Audit and Fundraisers

Proposed: November 27, 2021

Status: Passed

Link: GitHub PR




Beanstalk is unaudited at the moment. A high quality audit will facilitate further growth and adoption.

In addition, there are regular updates to the code through BIPs. It is important to have an auditor that will continue working with Beanstalk after the initial audit to facilitate timely and efficient code reviews for BIPs.

Paying for the Audit

Until Beanstalk has sufficiently established Beans as a reliable stablecoin such that Beanstalk can make all payments in Beans, Beanstalk needs a way to pay for things (including this audit) in other stablecoins. Thus, Beanstalk needs a way to convert Beans to a traditional stablecoin without having to sell a large amount of Beans in the Uniswap pool.

Proposed Solution


Publius has connected with Trail of Bits. Trail of Bits is a world class computer security firm and the gold standard for smart contract audits. They have audited many of the top DeFi projects, which are viewable here: Publius was incredibly impressed by them and the audit they have offered to perform on Beanstalk.

Trail of Bits has also expressed interest in maintaining a continuous relationship with Beanstalk.

Upon passage of this BIP and payment of 347,440 USDC, Trail of Bits will perform an initial audit for Beanstalk and retain a continuous relationship with Beanstalk to review future versions of the code.

Paying for the Audit

This BIP proposes a "Fundraiser" standard that will allow Beanstalk to raise money to pay for things in other stablecoins, without requiring sales on Uniswap. Instead, Fundraisers will first mint a pre-defined number of Beans, to be bought 1:1 for a pre-defined stablecoin. Each Bean purchased in exchange for 1 of the stablecoin will be sown at the current Weather, and the Pods received in exchange will be sent to the wallet that bought the Beans. Beacause all the Beans being Sown were minted as part of the Fundraiser, no Soil will be used to mint Pods by the FundraiserFacet.

Fundraisers will be created by a BIP and will require:

  1. The number of dollars required for the Fundraiser (X);
  2. The address of the stablecoin that will be used for the Fundraiser (Y); and
  3. The address that the Fundraiser will make the payment to (Z).

Fundraisers allow any farmer to convert the desired stablecoin for Beans at a 1:1 rate. The Beans will then be immediately sown. Once the fundraiser has reached its goal, the funds will be forwarded to the payment address.

Anyone can participate in a Fundraiser by sending up to X of Y to the FundraiserFacet. No other contributions to the Fundraiser other than the first X of Y will receive Pods.


The cost of the contract (initial audit, and then reviewal of BIPs for a period of time) is 320,000 USDC, paid upfront. 24,000 USDC are paid in the future, after the first 8 engineer-weeks have been used. There is a 1% payment fee added on top, because Trail of Bits requires payment through BitPay.

Upon approval, this BIP will mint 347,440 Beans to fund the Trail of Bits audit. Upon deployment of the Fundraiser, anyone can sell USDC to Beanstalk in exchange for sown Beans. For each of the first 347,440 USDC sent to the FundraiserFacet, 1 Bean will be sown and the corresponding Pods returned to the sender based on the Weather at the time of the sow.

Upon completion of the sale of all 347,440 Beans for 347,440 USDC, Publius will submit the initial 320,000 USDC payment to Trail of Bits. Publius will make the final payment when appropriate.

Fundraiser Rationale

347,440 Beans may seem like a lot of money for an audit, but we have been told explicitly from larger potential investors that a Trail of Bits audit goes a long way. Furthermore, the Bean farmer that connected us with Trail of Bits have stated they are willing to fill the entire Fundraiser for 347,440 USDC. However, given that we want Beanstalk to operate in the most decentralized way possible, we do not want to give any particular investor priority in supplying funds. Therefore, anyone can supply USDC to the Fundraiser in exchange for a sown Bean.

User Interface

The website will feature a new "Fundraiser" page that will allow users to participate in active Fundraisers.