PIP-10: SBT Governance Token with Delegation per Token ID

• Title: SBT-Based Voting Power Integration
• PIP Number: PIP-10
• Author: pwollemi
• Date of Submission: 2025-05-22
• Status: Draft
• Category: Core

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Motivation

This proposal introduces a governance model based on the ERC-1155 standard, enabling Soulbound Token (SBT)-like functionality by tracking voting delegation on a per-token-ID basis. It allows multiple governance classes, each represented by a different token ID, and supports granular delegation, enhancing DAO tooling and composability.

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Specification / Details

Goals

• Track totalSupply per token ID via ERC1155Supply.
• Enable delegation of voting power per token ID.
• Provide getVotes(account) view function for governance integration.
• Expose token metadata URIs for each token ID.

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Public Interface

FunctionDescriptionmint(address to, uint256 id, uint256 amount, string memory uri)Mint governance tokensburn(address from, uint256 id, uint256 amount)Burn governance tokensdelegate(address to, uint256 tokenId)Delegate voting power of a specific token IDgetVotes(address account)Get full voting power of an accountgetDelegates(address account, uint256 tokenId)Get delegate for an account/token combinationgetGovernanceTokenIds()List all token IDs used for votinguri(uint256 tokenId)Return metadata URI for a token ID

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Storage Layout

mapping(uint256 => string) private _tokenURIs; uint256[] public governanceTokenIds;

mapping(address => mapping(uint256 => address)) public delegates; mapping(uint256 => mapping(address => uint256)) public delegatedVotes;

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Delegation Logic

function delegate(address to, uint256 tokenId) external { address prevDelegate = delegates[msg.sender][tokenId]; uint256 balance = balanceOf(msg.sender, tokenId);

// Revoke previous delegate if (prevDelegate != address(0)) { delegatedVotes[tokenId][prevDelegate] -= balance; }

// Assign new delegate delegates[msg.sender][tokenId] = to;

if (to != address(0)) { delegatedVotes[tokenId][to] += balance; }

emit Delegated(msg.sender, to, tokenId); }

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Voting Power Logic

function getVotes(address account) public view returns (uint256 totalVotes) { for (uint256 i = 0; i < governanceTokenIds.length; i++) { uint256 id = governanceTokenIds[i];

// Own balance (if not delegated) if (delegates[account][id] == address(0)) { totalVotes += balanceOf(account, id); }

// Votes delegated to them totalVotes += delegatedVotes[id][account]; } }

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Transfer Hook for Delegation Tracking

function _afterTokenTransfer( address operator, address from, address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data ) internal override { super._afterTokenTransfer(operator, from, to, ids, amounts, data);

for (uint256 i = 0; i < ids.length; i++) { uint256 id = ids[i]; uint256 amount = amounts[i];

if (from != address(0)) { address fromDelegate = delegates[from][id]; if (fromDelegate != address(0)) { delegatedVotes[id][fromDelegate] -= amount; } }

if (to != address(0)) { address toDelegate = delegates[to][id]; if (toDelegate != address(0)) { delegatedVotes[id][toDelegate] += amount; } } } }

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SBT Evaluation Required?

Yes — delegation is tracked and non-transferable voting logic is advisable for some DAO configurations.

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Scope of Impact / Potential Risks and Mitigation

• Risk: Delegation tracking can become inconsistent if transfer logic is overridden or misused.
• Mitigation: Override _afterTokenTransfer carefully and test edge cases with proxy/multi-delegate scenarios.

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Alternatives and Rationale

• ERC-20 Voting: Simpler, but lacks per-ID granularity.
• ERC-721 Governance: Cannot batch mint or transfer efficiently, less suited for use cases with many token classes.
• Soulbound ERC-1155: Stronger alignment with identity-bound voting, especially with per-ID delegation.

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