Fixed-Term Teller

The Fixed Term Teller is an implementation of the Bond Base Teller contract specific to handling user bond transactions and tokenizing bond markets where purchases vest in a fixed amount of time (rounded to the day) as ERC1155 tokens.It implements the functions required by the Fixed-Term Teller Interface and the Base Teller Abstract Contract.

It also inherits the ERC1155 standard and is itself the contract which provides information on the Bond Tokens it issues.

Specifically, it implements the _handlePayout function to mint ERC1155 tokens to the user to represent their bond position during a purchase.

Additionally, it implements the deploy (i.e. stores the metadata for a new ERC1155 token if one does not exist for a combination of underlying token and the maturity date), create (allows anyone to mint ERC1155 Bond Tokens for a combination of an underlying token and maturity date by paying a fee to the protocol), and redeem (redeems ERC1155 Bond Tokens that have vested for the underlying token).

By design, the tokenization of the Teller is not permissioned. This allows other market participants to use the same Bond Tokens that Bond Protocol is issuing to create a standard in the market and drive additional liquidity (less likely for ERC1155, but it is an option).

Methods

This section only includes methods not inherited from Base Teller or ERC1155.

batchRedeem

function batchRedeem(uint256[] tokenIds_, uint256[] amounts_) external nonpayable

Redeem multiple fixed-term bond tokens for the underlying tokens (bond tokens must have matured)

Parameters

Name	Type	Description
tokenIds_	uint256[]	Array of bond token ids
amounts_	uint256[]	Array of amounts of bond tokens to redeem

create

function create(contract ERC20 underlying_, uint48 expiry_, uint256 amount_) external nonpayable returns (uint256, uint256)

Deposit an ERC20 token and mint a future-dated ERC1155 bond token

Parameters

Name	Type	Description
underlying_	contract ERC20	ERC20 token redeemable when the bond token vests
expiry_	uint48	Timestamp at which the bond token can be redeemed for the underlying token
amount_	uint256	Amount of underlying tokens to deposit

Returns

Name	Type	Description
tokenId	uint256	ID of the ERC1155 bond token received
amountOut	uint256	Amount of the ERC1155 bond token received

createFeeDiscount

function createFeeDiscount() external view returns (uint48)

'Create' function fee discount. Amount standard fee is reduced by for partners who just want to use the 'create' function to issue bond tokens. Configurable by policy.

Returns

Name	Type	Description
feeDiscount	uint48	undefined

deploy

function deploy(contract ERC20 underlying_, uint48 expiry_) external nonpayable returns (uint256)

"Deploy" a new ERC1155 bond token for an (underlying, expiry) pair and return its ID.

Parameters

Name	Type	Description
underlying_	contract ERC20	ERC20 token redeemable when the bond token vests
expiry_	uint48	Timestamp at which the bond token can be redeemed for the underlying token

Returns

Name	Type	Description
tokenId	uint256	ID of the ERC1155 bond token being created

getTokenId

function getTokenId(contract ERC20 underlying_, uint48 expiry_) external pure returns (uint256)

Get token ID from token and expiry

Parameters

Name	Type	Description
underlying_	contract ERC20	Address of the underlying token
expiry_	uint48	Expiry of the bond

Returns

Name	Type	Description
tokenId	uint256	ID of the bond token

getTokenNameAndSymbol

function getTokenNameAndSymbol(uint256 tokenId_) external view returns (string, string)

Get the token name and symbol for a bond token

Parameters

Name	Type	Description
tokenId_	uint256	ID of the bond token

Returns

Name	Type	Description
name	string	Bond token name
symbol	string	Bond token symbol

redeem

function redeem(uint256 tokenId_, uint256 amount_) external nonpayable

Redeem a fixed-term bond token for the underlying token (bond token must have matured)

Parameters

Name	Type	Description
tokenId_	uint256	ID of the bond token to redeem
amount_	uint256	Amount of bond token to redeem

tokenMetadata

function tokenMetadata(uint256) external view returns (bool active, contract ERC20 payoutToken, uint48 expiry, uint256 supply)

Parameters

Name	Type	Description
tokenId_	uint256	ID of the bond token

Returns

Name	Type	Description
active	bool	Whether the bond token has been created
payoutToken	contract ERC20	Address of the underlying token
expiry	uint48	Timestamp when the bond token can be exchanged for the underlying token
supply	uint256	Total supply of the bond token

Events

ERC1155BondTokenCreated

event ERC1155BondTokenCreated(uint256 tokenId, contract ERC20 indexed payoutToken, uint48 indexed expiry)

Parameters

Name	Type	Description
tokenId	uint256	ID of the ERC1155 bond token
payoutToken indexed	contract ERC20	Address of the underlying token
expiry indexed	uint48	Timestamp when the bond token can be redeemed for the underlying token