Sun

The Beanstalk peg maintenance mechanism requires a protocol-native timekeeping mechanism and regular code execution on Arbitrum. The Sun keeps time on the Farm in Seasons and incentivizes cost-efficient and timely calling of the gm function.

Beanstalk adjusts itself to return the Bean price to its value peg at the beginning of every Season. Each Season is ~1 hour long. The first Season began when Beanstalk was deployed on August 6, 2021 (initially on Ethereum).

The exact beginning of each Season may vary as Seasons do not begin until the gm function has been called through an Arbitrum transaction. The first transaction that successfully calls the gm function after the top of each hour UTC begins a new Season. Beanstalk only accepts one gm function call per Season.

Beanstalk covers the cost of calling the gm function by awarding the sender of an accepted gm function call with newly minted Beans. To encourage regular gm function calls even during periods of congestion on Arbitrum while minimizing cost, the award for successfully calling the gm function starts at 1 Bean and compounds 1.0201% every additional 2 seconds for 300 seconds.

Upon acceptance of the gm call, the Sun:

1. Increments the Season number;

2. Calculates deltaB, the sum of the time-weighted average shortages or excesses Beans across liquidity pools on the Minting Whitelist;

3. Changes the Maximum Temperature if necessary and checks for Flood;

4. Changes the Crop Ratio (and updates the Gauge Points of each whitelisted asset);

5. Sets the initial Soil supply;

6. Mints Beans if necessary; and

7. Awards Beans to the address that successfully called the gm function.

Minting Whitelist

To be included in the calculation of deltaB, a liquidity pool must be on the Minting Whitelist.

Additional liquidity pools may be added to the Minting Whitelist via Beanstalk governance. In order for a liquidity pool to be added to the Minting Whitelist, Beanstalk requires:

1. The pool address; and

2. A function to calculate the liquidity and time weighted average shortage or excess of Beans in the pool.

Current Minting Whitelist

Name	Address
BEAN:WETH Well	0xBeA00Aa8130aCaD047E137ec68693C005f8736Ce
BEAN:wstETH Well	0xBEa00BbE8b5da39a3F57824a1a13Ec2a8848D74F
BEAN:weETH Well	0xBeA00Cc9F93E9a8aC0DFdfF2D64Ba38eb9C2e48c
BEAN:WBTC Well	0xBea00DDe4b34ACDcB1a30442bD2B39CA8Be1b09c
BEAN:USDC Well	0xBea00ee04D8289aEd04f92EA122a96dC76A91bd7
BEAN:USDT Well	0xbEA00fF437ca7E8354B174339643B4d1814bED33