Andrey Perepelitsyn, Maksim Mironov, Oleg Bakatanov
Depos Foundation Copyright (C) 2019 DEPOS INC. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
Being inspired by the dGoods project we decided to create dBonds standard. dBonds is an open source and free standard for creating virtual debt instruments which may or may not have collateral inside and can represent a traditional (not collateralized bond); a bond, collateralized by an off-chain asset (e.g. real fiat-nominated bond), or a bond collateralized by on-chain collateral locked in dbond smart contract. Here is no liquidation/margin call protocol of any kind and it is built on other incentives. To read more information about the product side of dBonds please visit our page dBonds.org or a Medium page.
Standard consist of smart contract dBonds which helps managing operations with dbond tokens isuued under dBonds contract. We tried to make this standard in the most flexible and intuitive way, though we welcome any questions, discussions and advises on how to make it better.
At this moment only non-fungible dBonds tokens are supported. That means you can buy only the whole debt.
In DEX now you can only sale the dbond initial offer. You can not list a buy-side offer.
Here we show how dBond token is organized and what information has to be provided.
dBond has the following structure:
struct dbond {
dbond_id_class name; // unique name for dbond
name emitent; // account who initiates an issue
asset max_supply; //
int collateral_type; // how is collaterized
extended_asset crypto_collateral; // in case collateral_type is CRYPTO_ASSET,
// this field stores asset
extended_asset issue_price; // unit of account, currency serves as price ex. DUSD
time_point maturity_time; // time until when to be paid off by emitent
extended_asset payoff_price; // price and currency for pay off (face value)
bool fungible; // if fungible or not
int early_payoff_policy; // if available, how is organized
fiat_bond collateral_bond; // if collateral_type != FIAT_BOND then empty
string additional_info;
};
struct fiat_bond {
string ISIN; // main and unique id of fiat bond
string name; // name of the fiat bond (meaningful, any of choice)
string currency; // currency of fiat bond
string country; // country where issued
string bond_description_webpage; // reference for the full fiat bond specification
string proof_of_ownership // info/link for the proof of ownership
};
enum dbond_state: uint8_t {
CREATION = 0, // set dbond configuration. dbond can be modified
INITIAL_SALE_OFFER = 1, // can be bought on built-in DEX. Only issue_price can be changed
CIRCULATING = 2, // is sold, dbond fields are fixed, is traded on secondary market
CIRCULATING_PAIDOFF = 3, // issuer paid off the dbond, received collateral back
// current_time <= maturity time, hence, not expired
EXPIRED_PAIDOFF = 4, // issuer paid off the dbond, current_time > maturity_time
DEFAULTED = 5, // issuer haven't paid of the dbond, current_time > maturity_time
EMPTY = 6, // if there was a collateral or paid off asset, it was exchanged
// in favor of dbond holder
};
enum collateral_type: uint8_t {
CRYPTO_ASSET = 0,
FIAT_BOND = 1,
NONE = 2,
};
enum class early_payoff_policy: int {
FULL_INTEREST_RATE = 0,
TIME_LINEAR_INTEREST_RATE = 1, // not supported yet
First = FULL_INTEREST_RATE,
Last = TIME_LINEAR_INTEREST_RATE
};TRANSFER: standard transfer method
ACTION transfer(name from, name to, asset quantity, const string& memo);CREATE: this action creates an instance of the bond with respect to specification provided wraped up in bond instance.
ACTION create(name from, dbond bond);CHANGE: Only dbond emitent can call this action. With this action created or listed dbond can be updated. Please note, most changes are restricted once dbond is listed for a sale.
ACTION change(name from, dbond_id_class dbond_id);BURN: Can be called either at the beginning (by emitent) or at very end (by holder) of dbond lifecycle. Burns dbond token such that it never existed.
ACTION burn(name from, dbond_id_class dbond_id);LISTSALE: This action is called by emitent for listing a sale of the token in the dBonds contract.
ACTION listsale(name from, dbond_id_class dbond_id);CANCELSALE: Called by emitent, canceles the listed dbond offer if not sold.
ACTION cancelsale(name from, dbond_id_class dbond_id);EXPIRE: When is called, time is checked and if current time exceeds the maturity time, then dbond goes through state change. Can be called by anyone.
ACTION expire(dbond_id_class dbond_id);Here are memos to use
struct MEMOS {
const string put_collateral = "put collateral "; // + bond.bond_name
const string buy_bond = "buy bond "; // + bond.bond_name
const string payoff_bond = "pay off bond "; // + bond.bond_name
const string exchange = "exchange";
} memos;SENDINTOBOND: If created dbond requires crypto collateral, dbond emitent must put it inside before listing a sale by transfering collateral to the smart contract.
void sendintobond(name from, extended_asset collateral, dbond_id_class dbond_id);BUY: Function for buying already listed dbond offer.
void buy(name buyer, dbond_id_class dbond_id, extended_asset price);PAYOFF: Usually is called on transfer from emitent (but generally from anyone) in order to pay off the dbond with the claimed price and asset. It has to be done before expiration date otherwise dbond is claimed defaulted.
void payoff(name from, dbond_id_class dbond_id, extended_asset for_payoff);EXCHANGE: If there is any asset behind the dbond (either collateral or the paid off asset) it is exchanged for dbond token in favor of dbond holder. Can be called only when dbond is paid off or defaulted.
void exchange(name from, dbond_id_class dbond_id);