IPT

The ERC-20 token that represents fractionalized ownership of an IP-NFT's intellectual property rights

Overview

IPToken is an ERC-20 token that represents a transferable share of intellectual property rights derived from an IP-NFT. Each IP-NFT can be tokenized exactly once, producing a unique IPToken contract. The resulting tokens can be held, transferred, and traded — giving holders economic exposure, governance participation, and token-gated access to the Lab's data room.

IPToken contracts are not deployed individually. They are created as EIP-1167 minimal proxy clones by the Tokenizer contract, which means every IPToken shares the same implementation code but maintains independent state. There is no fixed deployment address for IPTokens — each one is unique and must be discovered through Tokenizer.synthesized(ipnftId) or via the subgraph.

Contract Details

Property	Value
Contract	IPToken v1.3
Standard	ERC-20 (with Burnable)
Type	EIP-1167 Minimal Proxy Clone
Created By	Tokenizer
Owner	Tokenizer contract (enforces IP-NFT holdership)
Solidity	0.8.18
License	MIT

Discovering IPToken Addresses

IPTokens do not have fixed addresses. To find the IPToken for a given IP-NFT:

On-chain:

solidity

IIPToken ipToken = Tokenizer.synthesized(ipnftId);

Via subgraph:

graphql

{
  ipt(where: { ipnftId: "123" }) {
    id
    tokenContract
  }
}

How It Works

Creation

When an IP-NFT owner calls Tokenizer.tokenizeIpnft(), the Tokenizer deploys a new IPToken clone via initialize(). The token is configured with a name, symbol, and a Metadata struct that permanently links it to the originating IP-NFT ID, the original owner's address, and the IPFS CID of the governing legal agreement (FAM agreement).

Supply Control

The IP-NFT controller (the current owner of the underlying IP-NFT, resolved through the Tokenizer) can issue additional tokens at any time by calling issue() through the Tokenizer. Once cap() is called, the supply is permanently frozen — no new tokens can ever be minted. Capping is irreversible.

The totalIssued counter tracks all tokens ever minted and may differ from totalSupply() if tokens have been burned.

Controller Model

The IPToken's owner is always the Tokenizer contract, not the IP-NFT holder directly. Write operations (issue and cap) are gated by the onlyTokenizerOrIPNFTController modifier, which allows calls from either the Tokenizer itself or the current controller of the associated IP-NFT (as resolved by Tokenizer.controllerOf(ipnftId)). This means IPToken control automatically transfers when the IP-NFT changes hands — there is no separate ownership transfer needed.

Burning

IPToken inherits from ERC20BurnableUpgradeable. Any holder can burn their own tokens via burn(amount) or burnFrom(account, amount) with approval. Burning permanently removes tokens from circulation and reduces totalSupply(), but totalIssued remains unchanged.

Functions

Write Functions

issue Mints new tokens to a specified address. Only callable by the Tokenizer or the current IP-NFT controller. Reverts if the token has been capped.

solidity

function issue(address receiver, uint256 amount) external

Parameters:

• receiver (address): The address to receive newly minted tokens.

• amount (uint256): The number of tokens to mint (18 decimals).

cap Permanently freezes the token supply. After calling, no new tokens can ever be issued. Irreversible.

solidity

function cap() external

Emits: Capped(uint256 atSupply)

burn (inherited from ERC20Burnable) Burns tokens from the caller's balance.

solidity

function burn(uint256 amount) public

burnFrom (inherited from ERC20Burnable) Burns tokens from another account (requires approval).

solidity

function burnFrom(address account, uint256 amount) public

transfer / transferFrom / approve (standard ERC-20) Standard ERC-20 transfer and approval functions. No restrictions — IPTokens are freely transferable.

Read Functions

metadata Returns the Metadata struct linking this token to its originating IP-NFT.

solidity

function metadata() external view returns (Metadata memory)

Returns:

• ipnftId (uint256): The ID of the parent IP-NFT.

• originalOwner (address): The IP-NFT owner at the time of tokenization.

• agreementCid (string): IPFS CID of the legal agreement governing this token.

totalIssued Returns the total number of tokens ever minted. This may exceed totalSupply() if tokens have been burned.

solidity

function totalIssued() external view returns (uint256)

capped Returns whether the token supply has been permanently frozen.

solidity

function capped() external view returns (bool)

uri Returns a base64-encoded data URL containing ERC-1155-compatible JSON metadata, including the IP-NFT ID, agreement CID, original owner, token contract address, and current supply.

solidity

function uri() external view returns (string memory)

totalSupply / balanceOf / allowance / name / symbol / decimals (standard ERC-20) Standard ERC-20 read functions. Decimals is always 18.

Metadata Struct

solidity

struct Metadata {
    uint256 ipnftId;       // The ID of the parent IP-NFT
    address originalOwner; // The IP-NFT owner at tokenization time
    string agreementCid;   // IPFS CID of the governing legal agreement
}

Events

Event	Description
Capped(uint256 atSupply)	Emitted when the token supply is permanently frozen. atSupply is the final totalIssued value.
Transfer(address from, address to, uint256 value)	Standard ERC-20 transfer event (includes mints from address(0) and burns to address(0)).
Approval(address owner, address spender, uint256 value)	Standard ERC-20 approval event.

Errors

Error	Description
TokenCapped()	Attempted to call issue() after the token has been capped.
MustControlIpnft()	Caller is not the Tokenizer contract or the current IP-NFT controller.

Security Considerations

Controller-gated supply. Only the Tokenizer or the current IP-NFT holder can issue or cap tokens. This is enforced on-chain by the onlyTokenizerOrIPNFTController modifier.

Irreversible capping. Once cap() is called, the supply is permanently frozen. There is no mechanism to uncap a token. This protects holders from unexpected dilution.

Automatic controller transfer. IPToken control follows IP-NFT ownership. Transferring the IP-NFT to a new address immediately grants that address the ability to issue and cap tokens. No separate IPToken ownership transfer is needed.

Clone architecture. IPTokens are EIP-1167 minimal proxy clones. The implementation is shared, reducing deployment gas, but each clone has independent storage. The implementation contract cannot be called directly (initializers are disabled in the constructor).

Freely transferable. IPTokens have no transfer restrictions. They can be sent to any address, traded on DEXes, or used in DeFi protocols.

Audited. IPToken is covered by the Pashov security review.

Related Contracts

Contract	Relationship
Tokenizer	Creates IPToken clones and enforces IP-NFT holdership rules for issue and cap.
IPNFT	The ERC-721 token that IPTokens are derived from. IP-NFT ownership determines who controls the IPToken.
AccessResolver	Uses IP-NFT ownership to resolve file access permissions for IPToken holders.
TimelockedToken	Can lock IPTokens for a configurable duration (used in vesting and crowdsales).

Resources

Resource	Link
Source Code	IPToken.sol
Interface	IIPToken.sol
ABI	Available in @moleculexyz/common/abis
Audit	Pashov Security Review
Subgraph	Query IPTokens via the Molecule Subgraph