BIP-30: Generalized Pipeline and ERC-20 and ERC-721 Permit Support

Proposed: December 1, 2022

Status: Passed

Link: Snapshot

Proposer

Beanstalk Farms

Proposer Wallet: 0xB77c0dBA1186483E9cc284a950564Fe886c12dB8

Summary

Problem

The farm function allows Farmers to perform a series of function calls in a single transaction defined by static calldata. Static calldata is limiting as on-chain outputs can change between transaction creation and settlement.

Currently, adding Pipeline functionality requires new Pipelines to be added to the Depot via Beanstalk governance, which results in very high development overhead for enabling Farmers to use other protocols through Beanstalk.

Farmers have to approve transfers of ERC-20 and ERC-721 tokens in their Circulating balance through a separate transaction, which creates a suboptimal user experience.

Beanstalk is currently overpaying for the sunrise incentive reward due to the high base incentive.

Proposed Solution

Clipboard

We propose upgrading the Farm Facet to support Clipboard functionality from Pipeline, allowing Farmers to copy return values from any function call into the function calldata of subsequent functions.

Specification

AdvancedFarmCall is a farm call that can use a version of Clipboard. With Clipboard, Farmers can copy return values stored as returnData from any AdvancedFarmCalls already executed and paste them into the callData of the next AdvancedFarmCall, in a customizable manner.

Each AdvancedPipeCall includes a version of Clipboard to encode:

  1. How many paste operations to perform;
  2. Which returnData from previous AdvancedFarmCalls to copy (i.e., returnDataIndex);
  3. Where to copy from within (2) (i.e., copyIndex); and
  4. Where to paste it in the callData of the next AdvancedFarmCall (i.e., pasteIndex).

Bytes are pasted 32 bytes at a time.

The only difference between the Clipboard implemented on the Farm and the one implemented in Pipeline is that the Farm version always uses padding in the second byte, whereas the Pipeline version includes a Use Ether Flag in the second byte, which specifies whether to include Ether in the Clipboard. Because the farm call already is able to include Ether, the second byte does not need to be used in the Farm version of Clipboard.

Depot V2

We propose adding new Depot Facet that wraps the standalone Pipeline contract, providing access to Pipeline from Beanstalk through the use of the farm function.

ERC-20 and ERC-721 Token Permits

We propose adding EIP-2612 support for ERC-20 tokens and EIP-4494 support for ERC-721 tokens from Circulating balances, which allows Farmers to perform approvals through permits without the need for a separate transaction.

Sunrise Incentive Adjustment

We propose reducing the base sunrise incentive from 100 Beans to 25 Beans such that the new formula for is:

Technical Rationale

Allowing Farmers to copy return values from any function call into the function calldata of subsequent functions significantly improves the composability supported by the farm function.

A new Depot that allows Farmers to access the standalone Pipeline contract from Beanstalk significantly reduces the development time necessary to enable Farmers to interact with new protocols via Beanstalk.

The ability for Farmers to approve transfers of ERC-20 and ERC-721 tokens in their Circulating balance without the need for a separate transaction reduces the friction of interacting with Beanstalk.

The majority of the transaction fee from sunrise calls is the priority fee. Until a more sophisticated update to the sunrise function has been audited, reducing the base reward is likely to reduce the Beans Beanstalk issues each month to pay for the sunrise call by up to 75%.

Economic Rationale

Improving the composability of, and reducing the number of separate transactions required to interact with, Beanstalk should improve the user experience and utility of Beanstalk and Beans.

Reducing unnecessary Bean issuance in the sunrise incentive reward can reduce sell pressure on Beans by 60,000 per month.

Contract Changes

Farm Facet

The following FarmFacet is being removed from Beanstalk:

The following FarmFacet is being added to Beanstalk:

FarmFacet Function Changes

Function Name Selector Action Type New Functionality
advancedFarm 0x36bfafbd Add Call ✓
farm 0x300dd6cf Replace Call ✓

FarmFacet Event Changes

None.

Depot Facet

The following DepotFacet is being added to Beanstalk:

DepotFacet Function Changes

Name Selector Action Type New Functionality
pipe 0x08e1a0ab Add Call ✓
multiPipe 0xcabec62b Add Call ✓
advancedPipe 0xb452c7ae Add Call ✓
etherPipe 0x6e47d07b Add Call ✓
readPipe 0xdd756c4f Add View ✓

DepotFacet Event Changes

None.

Token Support Facet

The following TokenSupportFacet is being added to Beanstalk:

TokenSupportFacet Function Changes

Name Selector Action Type New Functionality
permitERC20 0xb442b398 Add Call ✓
transferERC721 0x1aca6376 Add Call ✓
permitERC721 0x4935ed43 Add Call ✓
transferERC1155 0x0a7e880c Add Call ✓
batchTransferERC1155 0xa9412a59 Add Call ✓

TokenSupportFacet Event Changes

None.

Season Facet

The following SeasonFacet is being removed from Beanstalk:

The following SeasonFacet is being added to Beanstalk:

SeasonFacet Function Changes

Function Name Selector Action Type New Functionality
sunrise 0xfc06d2a6 Replace Call
paused 0x5c975abb Replace View
plentyPerRoot 0xe60d7a83 Replace View
poolDeltaB 0x471bcdbe Replace View
rain 0x43def26e Replace View
season 0xc50b0fb0 Replace View
seasonTime 0xca7b7d7b Replace View
time 0x16ada547 Replace View
totalDeltaB 0x06c499d8 Replace View
weather 0x686b6159 Replace View
yield 0x28593984 Replace View

SeasonFacet Event Changes

None.

Beans Minted

None.

Audit

The commit hash of this BIP is 9029875262f83cf394b0ed048704133e16e969d4.

Halborn has performed an audit of this BIP up until the commit hash that reduces the base sunrise incentive reward. You can view the Halborn audit report of this commit hash on Arweave here:

Effective

Effective immediately upon commit.