SIMD-0232: Custom Fee Collector Account

Author: jstarry

proposals/0232-custom-fee-collector.md

@@ -0,0 +1,71 @@
+---
+simd: '0232'
+title: Custom Fee Collector Account
+authors: Justin Starry (Anza)
+category: Standard
+type: Core
+status: Review
+created: 2025-01-24
+feature: (fill in with feature tracking issues once accepted)
+---
+
+## Summary
+
+Allow validators to specify a custom fee collector account where all earned
+block fees will be deposited.
+
+## Motivation
+
+Validator fee collector accounts must currently be the same as their identity
+hot wallet account. This means that program derived addresses are unable to be
+used for fee collection adding friction to validators distributing their revenue
+in custom ways. By allowing validators to specify a separate custom fee
+collector address, they can use onchain programs to customize how their block
+revenue is distributed.
+
+## Alternatives Considered
+
+NA
+
+## New Terminology
+
+NA
+
+## Detailed Design
+
+This proposal requires the adoption of SIMD-0180 and SIMD-0185. SIMD-0180
+adjusts the leader schedule algorithm to make it possible to designate a
+specific vote account for a given leader slot. SIMD-0185 adds a new fee
+collector address field to the vote account state.
+
+After adoption of SIMD-0180 and SIMD-0185, a given block's fee collector address
+can be looked up via the designated vote account for the leader schedule slot
+that the block was produced in.
+
+In order to eliminate the overhead of tracking the latest fee collector address
+of each vote account, the fee collector address should be fetched from the state
+of the vote account at the beginning of the previous epoch. This is the same
+vote account state used to build the leader schedule for the current epoch.
+
+Note that the fee-collector constraints defined in SIMD-0085 still hold. The
+designated fee collector must be a system program owned account that is
+rent-exempt after receiving collected block fee rewards. If either of these
+constraints is violated, the fees collected for that block will be burned. 
+
+## Impact
+
+Validator identity and fee collector accounts no longer need to be the same
+account. This opens up the ability to use PDA accounts for fee collection.
+
+## Security Considerations
+
+NA
+
+## Drawbacks *(Optional)*
+
+NA
+
+## Backwards Compatibility *(Optional)*
+
+This change will require the use of a new feature gate which will enable
+collecting fees into custom fee collector addresses if specified by a validator.