Minter blockchain

Minter is a digital assets marketplace allowing anyone to buy, sell, send, and spend BTC, ETH, BIP, USDC, gold, oil, stocks, and much more within a single decentralized network. Minter is integrated with Ethereum and Binance Smart Chain to provide cross-chain transfers and swaps.

Everything is lightning-fast and cost-efficient: a transaction takes only 5 seconds. Fees are tied to U.S. dollars and can be paid in any liquid coin: $0.03 for trades & $0.01 for transfers. Besides, Minter allows anyone to create tokens and liquidity pools in a couple of clicks.

Install Minter

There are several ways you can install Minter Blockchain Testnet node on your machine.

Using binary

  1. Download Minter Get latest binary build suitable for your architecture and unpack it to desired folder.
  2. Run Minter
    ./minter node

From source

You'll need golang installed https://golang.org/doc/install and the required environment variables set.

  1. Clone Minter source code to your machine

    mkdir -p $GOPATH/src/github.com/MinterTeam
cd $GOPATH/src/github.com/MinterTeam
git clone https://github.com/MinterTeam/minter-go-node.git
cd minter-go-node

  2. Get Tools & Dependencies

    make get_tools
make get_vendor_deps

  3. Compile

    make install

    to put the binary in $GOPATH/bin or use:

    make build

    to put the binary in ./build. The latest minter version is now installed.

  4. Run Minter

    ./build/minter node

    or

    minter node

Blockchain Specification

Tendermint

Minter Blockchain utilizes Tendermint Consensus Engine.

Tendermint is software for securely and consistently replicating an application on many machines.

By 'securely,' we mean that Tendermint works even if up to 1/3 of machines fail in arbitrary ways. By 'consistently,' we mean that every non-faulty machine sees the same transaction log and computes the same state.

Secure and consistent replication is a fundamental problem in distributed systems; it plays a critical role in the fault tolerance of a broad range of applications, from currencies, to elections, to infrastructure orchestration, and beyond.

Tendermint is designed to be easy-to-use, simple-to-understand, highly performant, and useful for a wide variety of distributed applications.

You can read more about Tendermint Consensus in official documentation.

Consensus

In Minter, we implemented Delegated Proof-of-Stake (DPoS) Consensus Protocol.

DPoS is the fastest, most efficient, most decentralized, and most flexible consensus model available. DPoS leverages the power of stakeholder approval voting to resolve consensus issues in a fair and democratic way.

Block speed

Minter Blockchain is configured to produce 1 block per 5 sec. Actual block speed may vary, depending on validators count, their computational power, Internet bandwidth, etc.

Block size

We limit block size to 10 000 transactions. Block size in terms of bytes is not limited.

Coins and tokens

Coins

Minter Blockchain is a multi-coin system.

Base coin on testnet is MNT.
Base coin on mainnet is BIP.

The smallest part of each coin is called pip.
1 pip = 1^-18 of any coin. In Blockchain and API, we only operate with pips.

Note: Each coin has its own pip. You should treat pip like an atomic part of a coin, not as a currency:
1 MNT = 10^18 pip (MNT's pip)
1 ABC = 10^18 pip (ABC's pip)
1 MNT != 1 ABC

Coin issuance

Every user of Minter can issue their own coin. Each coin is backed by a base coin in some proportion. Issuing your own coin is as simple as filling out a form with given fields:

  • Coin name - full name of the coin, up to 64 characters long (you may use spaces, mix upper and lower cases, insert emojis). Doesn't necessarily have to be unique;
  • Coin symbol - short, unique name of the coin (also known as ticker symbol). Must be unique, alphabetic, uppercase, and 3 to 10 letters long;
  • Initial amount - the number of coins to be issued at first (up to 1 000 000 000 000 000 units);
  • Initial reserve - you need to have this amount on your balace. Must be more than or equal to 10 000 BIP;
  • Constant Reserve Ratio (CRR) - uint, should be from 10 to 100. The higher the ratio, the lower the price volatility;
  • Max supply - total supply of your coin will never be more than a number specified here (up to 1 000 000 000 000 000 units).

After the coin has been issued, you can casually send it using regular wallets.

Coin exchange

Any coin can be instantly swapped for any other coin in any volume. This is possible because each coin has 'reserve' in base coin.

'Reserve' refers to a custom coin being backed by the base coin, which is BIP. It can't be lower than 10 000 BIP (neither at the start, nor after the coin has entered circulation). The minimum mandatory reserve approach allows for avoiding the liquidation of coins, which was possible up to Minter version 1.1. This means reduced risks for potential buyers and fewer opportunities for scammers. Transactions (sell, pay fee) causing the coin's reserve to fall below this level will be rejected by the network.

Here are some formulas we're using for coin conversion:

CalculatePurchaseReturn

Given coin supply (s), reserve balance (r), CRR (c), and deposit amount (d), calculates the return for a given conversion (in the base coin):

return s * ((1 + d / r) ^ c - 1);

CalculateSaleReturn

Given coin supply (s), reserve balance (r), CRR (c), and sell amount (a), calculates the return for a given conversion (in the base coin):

return r * (1 - (1 - a / s) ^ (1 / c));

Tokens

Unlike coins, tokens have no BIP reserve.

Token issuance

  • Name - full name of the token, up to 64 characters long (you may use spaces, mix upper and lower cases, insert emojis). Doesn't necessarily have to be unique;
  • Symbol - short, unique name of the token (also known as ticker symbol). Must be unique, alphabetic, uppercase, and 3 to 10 letters long;
  • Initial amount - the number of tokens to be issued at first (up to 1 000 000 000 000 000 units);
  • Max supply - total supply of your token will never be more than a number specified here (up to 1 000 000 000 000 000 units).

Allow owner to edit token supply:

  • Mintable: Ability to gradually increase token supply (cannot exceed Max supply);
  • Burnable: Ability to burn tokens that are freely available in the owner's wallet.

After the token has been created, users can send it via regular wallets similar to ordinary coins.

Token exchange

Since tokens are not backed, their conversion cannot be based on the formulas used with coins. You can swap them for other tokens and coins of the network through liquidity pools they are part of. If no pair has been created with a given token, you won't be able to buy or sell it.

Issuance fees for coins and tokens

Depending on the length of the ticker Symbol, the creator will be charged a fee that will be then distributed among validators and therefore, their delegators:

3 letters — 100 000 USD
4 letters — 10 000 USD
5 letters — 1 000 USD
6 letters — 100 USD
7–10 letters — 10 USD

Coins and tokens archiving

  1. Starting from version 1.2, coins have unique numerical IDs.
{
   "id": 1,
   "name": "Test Coin",
   ...
}

API responses now return structure (instead of a ticker symbol):

{
   "id": 1,
   "symbol": "TEST"
}

All coin-related transactions are modified so that queries use IDs:

type SendData struct {  
  Coin  types.CoinID  
  To    types.Address  
  Value *big.Int  
}

In the case of JS SDK, you can keep using coin tickers. In most cases, SDK will replace coin tickers with IDs automatically.

In GO SDK v2, we implemented methods of obtaining coin IDs by their tickers from HTTP and gRPC clients:

client, _ := http_client.New("http://localhost:8843/v2") // or client, _ := grpc_client.New("localhost:8842")
id, _ := client.CoinID("BIP")
dataSend := transaction.NewSendData().SetCoin(id) // ...

  1. Each coin now has an owner: owner_address. For new coins, addresses that have created them will be set as owners. For old coins, there may be no owner at all (null value).

  2. The owner can reissue the coin. Suppose there is COIN, and its owner sends a transaction to recreate it. At that point, the old coin is renamed to COIN-1, and the new one is issued under the ticker COIN. If recreating again, the second coin COIN will be renamed to COIN-2, and the third coin will be issued as COIN. See recreate coin and recreate token transactions.

  3. The owner can transfer ticker ownership rights to another address. See edit ticker owner transaction.

Coins and tokens difference

FunctionCoinsTokens
Backingin BIP—
Min. reserve10 000 BIP—
Nameup to 64 letters longup to 64 letters long
Symbol3 to 10 symbols long3 to 10 symbols long
Initial amountYesYes
Max. supplyYesYes
CRR10–100%—
Mintable (by owner)—Yes
Burnable (by any address)—Yes
Swap (reserves)Yes—
Swap (pools)YesYes
Creation of liquidity poolsYesYes
Delegate and receive rewardsYes—
Ticker symbol fees10–100 000 USD10–100 000 USD
Pay feesYesYes
RecreationYesYes

Liquidity pools

Introduction

A liquidity pool is a trading pair of coins/tokens with locked-up funds of liquidity providers that guarantee swappability. Buying or selling a coin through a liquidity pool, a trader uses funds that have been locked into the pool. The process is carried out using Automated Market Maker (AMM).

The AMM mechanism implies that when the coin/token is bought, it’s added to the pool; when sold, it’s removed from it. Hence, with the quantity of both coins/tokens inside the pool being balanced, their price changes as well.

Price for 1 unit of Coin A = Amount of Coin B inside the pool / Amount of Coin A inside the pool

Price for 1 unit of Coin B = Amount of Coin A inside the pool / Amount of Coin B inside the pool

Liquidity providers

For users to be able to buy and sell coins/tokens within the pool, these pools should be liquid. That is ensured by liquidity providers who get 0.2% on each swap transaction as a reward. These fees are automatically added into the pool, thereby increasing it.

To add liquidity, the provider needs to make a corresponding transaction by putting both coins/tokens into the pool in equal amounts (50/50). For that, liquidity providers are accrued additionally minted LP tokens expressing their share of the pool’s total liquidity. To withdraw liquidity, the provider needs to have previously accrued LP tokens on their balance that will now be burned, while the corresponding liquidity share will be returned to the user’s balance.

Transactions

Transactions in Minter are RLP-encoded structures.

Example of a signed transaction:

f873230101aae98a4d4e540000000000000094a93163fdf10724dc4785ff5cbfb9
ac0b5949409f880de0b6b3a764000080801ba06838db4a2197cfd70ede8d8d184d
bf332932ca051a243eb7886791250e545dd3a04b63fb1d1b5ef5f2cbd2ea12530c
da520b3280dcb75bfd45a873629109f24b29

Each transaction has:

  • Nonce - int, unique number for each address, used to prevent transaction replication, starts from 1;
  • ChainID - id of the network (1 = mainnet, 2 = testnet);
  • Gas Price - big int, fee multiplier, should be equal to or greater than current mempool min. gas price;
  • Gas Coin ID - int, coin id to pay fee;
  • Type - type of transaction (see below);
  • Data - data of transaction (depends on transaction type);
  • Payload (arbitrary bytes) - arbitrary user-defined bytes;
  • Service Data - reserved field;
  • Signature Type - single- or multi-sig transaction;
  • Signature Data - digital signature of transaction.
type Transaction struct {
    Nonce         uint64
    ChainID       byte
    GasPrice      *big.Int
    GasCoin       uint32
    Type          byte
    Data          []byte
    Payload       []byte
    ServiceData   []byte
    SignatureType byte
    SignatureData Signature|MultiSignature
}

type Signature struct {
    V           *big.Int
    R           *big.Int
    S           *big.Int
}

type MultiSignature struct {
    MultisigAddress [20]byte
    Signatures      []Signature
}

Signature Types

Type NameByte
TypeSingle0x01
TypeMulti0x02

Types

Type of transaction is determined by a single byte.

Type NameByte
TypeSend0x01
TypeSellCoin0x02
TypeSellAllCoin0x03
TypeBuyCoin0x04
TypeCreateCoin0x05
TypeDeclareCandidacy0x06
TypeDelegate0x07
TypeUnbond0x08
TypeRedeemCheck0x09
TypeSetCandidateOnline0x0A
TypeSetCandidateOffline0x0B
TypeCreateMultisig0x0C
TypeMultisend0x0D
TypeEditCandidate0x0E
TypeSetHaltBlock0x0F
TypeRecreateCoin0x10
TypeEditTickerOwner0x11
TypeEditMultisig0x12
TypePriceVote0x13
TypeEditCandidatePublicKey0x14
TypeAddLiquidity0x15
TypeRemoveLiquidity0x16
TypeSellSwapPool0x17
TypeBuySwapPool0x18
TypeSellAllSwapPool0x19
TypeEditCandidateCommission0x1A
TypeMoveStake0x1B
TypeMintToken0x1C
TypeBurnToken0x1D
TypeCreateToken0x1E
TypeRecreateToken0x1F
TypeVoteCommission0x20
TypeVoteUpdate0x21
TypeCreateSwapPool0x22

Send transaction

Type: 0x01

Transaction for sending an arbitrary coin.

Data field contents:

type SendData struct {
    Coin  uint32
    To    [20]byte
    Value *big.Int
}
  • Coin - id represents a coin;
  • To - recipient's address on the Minter Network;
  • Value - amount of Coin to send.

Sell coin transaction

Type: 0x02

Transaction for selling one coin (owned by sender) for another coin.

Data field contents:

type SellCoinData struct {
    CoinToSell          uint32
    ValueToSell         *big.Int
    CoinToBuy           uint32
    MinimumValueToBuy   *big.Int
}
  • CoinToSell - id of a coin to give.
  • ValueToSell - amount of CoinToSell to give.
  • CoinToBuy - id of a coin to get.
  • MinimumValueToBuy - minimum value of coins to get.

Sell all coin transaction

Type: 0x03

Transaction for selling all existing coins of one type (owned by sender) for another coin.

CoinToSell will be used as GasCoin to pay fee.

Data field contents:

type SellAllCoinData struct {
    CoinToSell          uint32
    CoinToBuy           uint32
    MinimumValueToBuy   *big.Int
}
  • CoinToSell - id of a coin to give.
  • CoinToBuy - id of a coin to get.
  • MinimumValueToBuy - minimum value of coins to get.

Buy coin transaction

Type: 0x04

Transaction for buying a coin paying with another coin (owned by sender).

Data field contents:

type BuyCoinData struct {
    CoinToBuy           uint32
    ValueToBuy          *big.Int
    CoinToSell          uint32
    MaximumValueToSell  *big.Int
}
  • CoinToBuy - id of a coin to get.
  • ValueToBuy - amount of CoinToBuy to get.
  • CoinToSell - id of a coin to give.
  • MaximumValueToSell - maximum value of coins to give.

Create coin transaction

Type: 0x05

Transaction for creating a new coin.

Data field contents:

type CreateCoinData struct {
    Name                 string
    Symbol               [10]byte
    InitialAmount        *big.Int
    InitialReserve       *big.Int
    ConstantReserveRatio uint32
    MaxSupply            *big.Int
}
  • Coin name - full name of the coin, up to 64 characters long (you may use spaces, mix upper and lower cases, insert emojis). Doesn't necessarily have to be unique;
  • Coin symbol - short, unique name of the coin (also known as ticker symbol). Must be unique, alphabetic, uppercase, and 3 to 10 letters long;
  • Initial amount - the number of coins to be issued at first (up to 1 000 000 000 000 000 units);
  • Initial reserve - you need to have this amount on your balace. Must be more than or equal to 10 000 BIP;
  • Constant Reserve Ratio (CRR) - uint, should be from 10 to 100. The higher the ratio, the lower the price volatility;
  • Max supply - total supply of your coin will never be more than a number specified here (up to 1 000 000 000 000 000 units).

Declare candidacy transaction

Type: 0x06

Transaction for declaring new validator candidacy.

Data field contents:

type DeclareCandidacyData struct {
    Address    [20]byte
    PubKey     []byte
    Commission uint
    Coin       uint32
    Stake      *big.Int
}
  • Address - candidate's address on the Minter Network. This address would be able to control candidate. Also, all rewards will be sent to this address;
  • PubKey - public key of the validator;
  • Commission - portion (from 0 to 100%) of rewards that delegators will pay to the validator;
  • Coin - id of coin to stake;
  • Stake - amount of coins to stake.

Delegate transaction

Type: 0x07

Transaction for delegating funds to the validator.

Data field contents:

type DelegateData struct {
    PubKey []byte
    Coin   uint32
    Value  *big.Int
}
  • PubKey - public key of the validator;
  • Coin - id of coin to stake;
  • Value - amount of coins to stake.

Unbond transaction

Type: 0x08

Transaction for unbonding funds from validator's stake.

Data field contents:

type UnbondData struct {
    PubKey []byte
    Coin   uint32
    Value  *big.Int
}
  • PubKey - public key of the validator;
  • Coin - id of coin to unbond;
  • Value - amount of coins to unbond.

Redeem check transaction

Type: 0x09

Transaction for redeeming a check.

Data field contents:

type RedeemCheckData struct {
    Check []byte
    Proof [65]byte
}
  • Check - check received from sender;
  • Proof - proof of owning a check: password signed with recipient's address. Read more

Note that maximum GasPrice is limited to 1 to prevent fraud, because GasPrice is set by redeem tx sender, but the fee is charged to check issuer.

Tx's GasCoin must be the same as that specified in the check.

Set candidate online transaction

Type: 0x0A

Transaction for turning candidate on. This transaction should be sent from the address set in the "Declare candidacy" transaction.

Data field contents:

type SetCandidateOnData struct {
    PubKey []byte
}
  • PubKey - public key of the validator.

Set candidate offline transaction

Type: 0x0B

Transaction for turning candidate off. This transaction should be sent from the address set in the "Declare candidacy" transaction.

Data field contents:

type SetCandidateOffData struct {
    PubKey []byte
}
  • PubKey - public key of the validator.

Create multisig address

Type: 0x0C

Transaction for creating a multi-signature address.

Data field contents:

type CreateMultisigData struct {
    Threshold uint32
    Weights   []uint32
    Addresses [][20]byte
}
  • Threshold - minimum weight of addresses involved in tx signing;
  • Weights - ordered weights array, mapped 1:1 to Addresses: Weights[0] is weight for Addresses[0];
  • Addresses - array of multisig addresses.

Multisend transaction

Type: 0x0D

Transaction for sending coins to multiple addresses. MultisendData can contain only 100 items. Therefore, this type of transaction has a limit of 100 recipent addresses.

Data field contents:

type MultisendData struct {
    List []MultisendDataItem
}

type MultisendDataItem struct {
    Coin  uin32
    To    [20]byte
    Value *big.Int
}

Edit candidate transaction

Type: 0x0E

Transaction for editing existing candidate.

Data field contents:

type EditCandidateData struct {
    PubKey           []byte
    RewardAddress    [20]byte
    OwnerAddress     [20]byte
    ControlAddress   [20]byte
}
  • RewardAddress - address for accumulating rewards;
  • OwnerAddress - address with full control of the validator;
  • ControlAddress - its functionality is strictly limited to switching masternode on and off (SetCandidateOnline/SetCandidateOffline transactions).

Set halt block transaction

Type: 0x0F

Since Minter 1.2 release, validators can vote for a particular block to stop the blockchain for update. For this purpose, a new transaction SetHaltBlock was introduced. If +2/3 of the voting power votes for halt on a given height, the blockchain will stop producing new blocks and wait for update.

Data field contents:

type SetHaltBlockData struct {
    PubKey [32]byte
    Height uint64
}
  • PubKey - node's public key;
  • Height - block number.

Recreate coin transaction

Type: 0x10

Data field contents:

type RecreateCoinData struct {
    Name                 string
    Symbol               [10]byte
    InitialAmount        *big.Int
    InitialReserve       *big.Int
    ConstantReserveRatio uint32
    MaxSupply            *big.Int
}
  • Coin name - full name of the coin, up to 64 characters long (you may use spaces, mix upper and lower cases, insert emojis). Doesn't necessarily have to be unique;
  • Coin symbol - short, unique name of the coin (also known as ticker symbol). Must be unique, alphabetic, uppercase, and 3 to 10 letters long;
  • Initial amount - the number of coins to be issued at first (up to 1 000 000 000 000 000 units);
  • Initial reserve - you need to have this amount on your balace. Must be more than or equal to 10 000 BIP;
  • Constant Reserve Ratio (CRR) - uint, should be from 10 to 100. The higher the ratio, the lower the price volatility;
  • Max supply - total supply of your coin will never be more than a number specified here (up to 1 000 000 000 000 000 units).

Edit ticker owner transaction

Type: 0x11

Transaction to change ticker owner's address.

Data field contents:

type EditTickerOwnerData struct {
    Symbol   [10]byte
    NewOwner [20]byte
}
  • Symbol - ticker Symbol of a coin/token;
  • NewOwner - address of the new owner.

Edit multisig transaction

Type: 0x12

Transaction for changing a multi-signature address. Allows one to make changes to the list of MultiSig owners and threshold without changing the address itself. Must be sent from the MultiSig address and signed by the required number of owners.

Data field contents:

type EditMultisigData struct {
    Threshold uint32
    Weights   []uint32
    Addresses [][20]byte
}

Data is the same as in create multisig address transaction.

Price vote transaction

Type: 0x13

Disabled transaction, not used anymore

To be able to run complex smart contracts and services, we need a way to discover the price of BIP on-chain. We will start with introducing a new tx type: PriceVote.

Data field contents:

type PriceVoteData struct {
    Price uint
}

Edit candidate public key transaction

Type: 0x14

Transaction to change candidate's public key. To improve validator security, it was proposed to add the public key change feature. The transaction must be sent from the validator (OwnerAddress). Once changed, the old public key is blacklisted and cannot be declared again.

Data field contents:

type EditCandidatePublicKeyData struct {
    PubKey    [32]byte
    NewPubKey [32]byte
}
  • PubKey - current public key;
  • NewPubKey - new public key.

With Minter 2.0 released, there are a few new transactions:

Add liquidity to swap pool transaction

Type: 0x15

Transaction to add reserves of a pair of coins to the pool and create liquidity through this pool.

Data field contents:

type AddLiquidityData struct {
    Coin0          uin32
    Coin1          uin32
    Volume0        *big.Int
    MaximumVolume1 *big.Int
}
  • Coin0 - id of the first coin in a pair;
  • Coin1 - id of the second coin in a pair;
  • Volume0 - volume of the first coin to add to reserve of the swap pool;
  • MaximumVolume1 - maximum volume of the second coin to add to reserve of the swap pool.

When a new liquidity provider deposits tokens into an existing pair, the number of liquidity tokens minted is computed based on the existing quantity of tokens:

To see the total supply and balance of the provider, check out SwapPool and SwapPoolProvider API v2 endpoints.

Remove liquidity from swap pool transaction

Type: 0x16

Transaction to withdraw the reserves of a pair from the pool.

Data field contents:

type RemoveLiquidityData struct {
    Coin0          uin32
    Coin1          uin32
    Liquidity      *big.Int
    MinimumVolume0 *big.Int
    MinimumVolume1 *big.Int
}
  • Coin0 - id of the first coin in a pair
  • Coin1 - id of the second coin in a pair
  • Liquidity - volume of shares to be withdrawn from the pool
  • MinimumVolume0 - minimum expected volume of coin0 to be returned to the account
  • MinimumVolume1 - minimum expected volume of coin1 to be returned to the account

Sell from swap pool transaction

Type: 0x17

Transaction for selling from the swap pool of the pair.

Data field contents:

type SellSwapPoolData struct {
    Coins               []uint32
    ValueToSell         *big.Int
    MinimumValueToBuy   *big.Int
}
  • Coins - list of coin IDs from given to received;
  • ValueToSell - amount of coin to spend (the first coin in Coins list);
  • MinimumValueToBuy - minimum value of coin to get.

Use EstimateCoinSell API v2 endpoint with swap_from=pool parameter to calculate sale price from swap pool.

Buy from swap pool transaction

Type: 0x18

Transaction for buying from the swap pool of the pair.

Data field contents:

type BuySwapPoolData struct {
    Coins               []uint32
    ValueToBuy          *big.Int
    MaximumValueToSell  *big.Int
}
  • Coins - list of coin IDs from given to received;
  • ValueToBuy - amount of coin to get (the last coin in Coins list);
  • MaximumValueToSell - xaximum value of coin to spend.

Use API v2 endpoint to calculate purchase price:

Use EstimateCoinBuy API v2 endpoint with swap_from=pool parameter to calculate purchase price from swap pool.

Sell all from swap pool transaction

Type: 0x19

Transaction for selling all existing coins from the swap pool of the pair.

Coin to spend (Coins[0]) will be used as GasCoin to pay fee.

Data field contents:

type SellAllSwapPoolData struct {
    Coins               []uint32
    MinimumValueToBuy   *big.Int
}
  • Coins - list of coin IDs from given to received.
  • MinimumValueToBuy - minimum value of coin to get.

Use EstimateCoinSellAll API v2 endpoint with swap_from=pool parameter to calculate sale price from swap pool.

Edit candidate commission transaction

Type: 0x1A

This transaction changes the validator's fee. Only validator owner is allowed to send. The fee cannot be increased by more than 10 units at once and cannot be changed sooner than once in every three UnbondPeriod's. UnbondPeriod = 518400 blocks (177 on testnet).

Data field contents:

type EditCandidateCommissionData struct {
    PubKey    [32]byte
    Commission uint32
}
  • PubKey - public key of a validator.
  • Commission - portion (from 0 to 100%) of rewards that delegators will pay to the validator.

Move stake transaction

Type: 0x1B

Reserved transaction, disabled in current version.

Data field contents:

type MoveStakeData struct {
    From     [32]byte
    To       [32]byte
    Coin     uint32
    Stake    *big.Int
}

const TypeStakeMoveEvent = "minter/StakeMoveEvent"

type StakeMoveEvent struct {
    Address         string `json:"address"`
    Amount          string `json:"amount"`
    Coin            string `json:"coin"`
    ValidatorPubKey string `json:"validator_pub_key"`
    WaitList        bool   `json:"waitlist"`
}

Mint token transaction

Type: 0x1C

This transaction increases the token's supply. Can be applied to tokens only and is executed from the coin owner address. The new supply must not exceed the MaxSupply value.

Data field contents:

type MintTokenData struct {
    Coin     uint32
    Value    *big.Int
}
  • Coin - the token's id;
  • Value - the quantity of coins to be issued.

Burn token transaction

Type: 0x1D

This transaction decreases the token's supply. Can be applied to tokens only and is executed from the address of the user who has the necessary amount of this coin. The new supply must be more than or equal to 0.

Data field contents:

type BurnTokenData struct {
    Coin     uint32
    Value    *big.Int
}

Create token transaction

Type: 0x1E

Creation of a token (non-reserve coin).

Data field contents:

type CreateTokenData struct {
    Name          string
    Symbol        [10]byte
    InitialAmount *big.Int
    MaxSupply     *big.Int
    Mintable      bool
    Burnable      bool
}
  • InitialAmount - the number of tokens to be created at the start;
  • MaxSupply - the upper limit of the total number of tokens;
  • Mintable - allow new tokens to be issued additionally;
  • Burnable - allow all tokens to be burned.

Recreate token transaction

Type: 0x1F

This transaction re-creates the coins (both backed and non-reserve).

Data field contents:

type RecreateTokenData struct {
    Name          string
    Symbol        [10]byte
    InitialAmount *big.Int
    MaxSupply     *big.Int
    Mintable      bool
    Burnable      bool
}
  • InitialAmount - the number of tokens to be created at the start;
  • MaxSupply - the upper limit of the total number of tokens;
  • Mintable - allow new tokens to be issued additionally;
  • Burnable - allow all tokens to be burned.

Vote for commission price transaction

Type: 0x20

This transaction enables validators to vote for the fees to be changed. The change comes into force once a two-thirds majority is reached. The vote can be sent from the validator owner address.

Data field contents:

type VoteCommissionData struct {
    PubKey                  types.Pubkey
    Height                  uint64
    Coin                    types.CoinID
    PayloadByte             *big.Int
    Send                    *big.Int
    BuyBancor               *big.Int
    SellBancor              *big.Int
    SellAllBancor           *big.Int
    BuyPoolBase             *big.Int
    BuyPoolDelta            *big.Int
    SellPoolBase            *big.Int
    SellPoolDelta           *big.Int
    SellAllPoolBase         *big.Int
    SellAllPoolDelta        *big.Int
    CreateTicker3           *big.Int
    CreateTicker4           *big.Int
    CreateTicker5           *big.Int
    CreateTicker6           *big.Int
    CreateTicker7to10       *big.Int
    CreateCoin              *big.Int
    CreateToken             *big.Int
    RecreateCoin            *big.Int
    RecreateToken           *big.Int
    DeclareCandidacy        *big.Int
    Delegate                *big.Int
    Unbond                  *big.Int
    RedeemCheck             *big.Int
    SetCandidateOn          *big.Int
    SetCandidateOff         *big.Int
    CreateMultisig          *big.Int
    MultisendBase           *big.Int
    MultisendDelta          *big.Int
    EditCandidate           *big.Int
    SetHaltBlock            *big.Int
    EditTickerOwner         *big.Int
    EditMultisig            *big.Int
    EditCandidatePublicKey  *big.Int
    CreateSwapPool          *big.Int
    AddLiquidity            *big.Int
    RemoveLiquidity         *big.Int
    EditCandidateCommission *big.Int
    MintToken               *big.Int
    BurnToken               *big.Int
    VoteCommission          *big.Int
    VoteUpdate              *big.Int
}

Once there is a consensus, the event with the information about the new fees will occur at the corresponding block height.

const TypeUpdateCommissionsEvent = "minter/UpdateCommissionsEvent"
type UpdateCommissionsEvent struct {
    Coin                    uint64 `json:"coin"`
    PayloadByte             string `json:"payload_byte"`
    Send                    string `json:"send"`
    BuyBancor               string `json:"buy_bancor"`
    SellBancor              string `json:"sell_bancor"`
    SellAllBancor           string `json:"sell_all_bancor"`
    BuyPoolBase             string `json:"buy_pool_base"`
    BuyPoolDelta            string `json:"buy_pool_delta"`
    SellPoolBase            string `json:"sell_pool_base"`
    SellPoolDelta           string `json:"sell_pool_delta"`
    SellAllPoolBase         string `json:"sell_all_pool_base"`
    SellAllPoolDelta        string `json:"sell_all_pool_delta"`
    CreateTicker3           string `json:"create_ticker3"`
    CreateTicker4           string `json:"create_ticker4"`
    CreateTicker5           string `json:"create_ticker5"`
    CreateTicker6           string `json:"create_ticker6"`
    CreateTicker7_10        string `json:"create_ticker7_10"`
    CreateCoin              string `json:"create_coin"`
    CreateToken             string `json:"create_token"`
    RecreateCoin            string `json:"recreate_coin"`
    RecreateToken           string `json:"recreate_token"`
    DeclareCandidacy        string `json:"declare_candidacy"`
    Delegate                string `json:"delegate"`
    Unbond                  string `json:"unbond"`
    RedeemCheck             string `json:"redeem_check"`
    SetCandidateOn          string `json:"set_candidate_on"`
    SetCandidateOff         string `json:"set_candidate_off"`
    CreateMultisig          string `json:"create_multisig"`
    MultisendBase           string `json:"multisend_base"`
    MultisendDelta          string `json:"multisend_delta"`
    EditCandidate           string `json:"edit_candidate"`
    SetHaltBlock            string `json:"set_halt_block"`
    EditTickerOwner         string `json:"edit_ticker_owner"`
    EditMultisig            string `json:"edit_multisig"`
    EditCandidatePublicKey  string `json:"edit_candidate_public_key"`
    CreateSwapPool          string `json:"create_swap_pool"`
    AddLiquidity            string `json:"add_liquidity"`
    RemoveLiquidity         string `json:"remove_liquidity"`
    EditCandidateCommission string `json:"edit_candidate_commission"`
    MintToken               string `json:"mint_token"`
    BurnToken               string `json:"burn_token"`
    VoteCommission          string `json:"vote_commission"`
    VoteUpdate              string `json:"vote_update"`
}

API for current prices PriceCommission and votes for updating fees PriceVotes.

Vote for network update transaction

Type: 0x21

This transaction allows to vote whether to proceed with the network's upgrade to a new version. Can only be sent by a node owner and from the owner address. The upgrade is approved if the two-thirds of the voting power is in favor.

Data field contents:

type VoteUpdateData struct {
    Version string
    PubKey  [32]byte
    Height  uint64
}
  • Version - the codename of the upgrade;
  • PubKey - the public key of the validator that's casting a vote;
  • Height - the block in which the upgrade is to take place.

Once there is a consensus, the event will occur at the corresponding block height.

const TypeUpdateNetworkEvent = "minter/UpdateNetworkEvent"
type UpdateNetworkEvent struct {
    Version string `json:"version"`
}

Create swap pool transaction

Type: 0x22

This transaction creates a liquidity pool for two coins, in volumes specified within this transaction. The volumes will be withdrawn from your balance according to the figure you've specified in the transaction. When a pool is established, a P-number coin (example: P-123) is created and issued in the amount equal to the amount of pool liquidity. The calculations related to that liquidity are described below.

Data field contents:

type CreateSwapPoolData struct {
    Coin0          uin32
    Coin1          uin32
    Volume0        *big.Int
    Volume1        *big.Int
}

Number of liquidity tokens is equal to the geometric mean of the amounts deposited:

The above formula ensures that a liquidity pool share will never be worth less than the geometric mean of the reserves in that pool. It is possible, however, for the value of a liquidity pool share to grow over time, either by accumulating trading fees or through “donations” to the liquidity pool. In theory, this could result in a situation where the value of the minimum quantity of liquidity pool shares (1e-18 pool shares) is worth so much that it becomes infeasible for small liquidity providers to provide any liquidity.

To mitigate this, we burn the first 1e-15 (0.000000000000001) pool shares that are minted (1 000 times the minimum quantity of pool shares), sending them to the zeroth address instead of to the minter. This should be a negligible cost for almost any token pair. But it dramatically increases the cost of the above attack. In order to raise the value of a liquidity pool share to $100, the attacker would need to donate $100,000 to the pool, which would be permanently locked up as liquidity.

To see the total supply and balance of the provider, check out SwapPool and SwapPoolProvider API v2 endpoints.

Minter Check

Minter Check is like an ordinary bank check. Each user of the network can issue a check with any amount of coins and pass it to another person. The receiver will be able to redeem that check from an arbitrary account.

Introduction

Checks are prefixed with Mc. Here is an example of a Minter Check:

Mcf89b01830f423f8a4d4e5400000000000000843b9aca00b8419b3beac2c6ad88a8bd54d24912754bb820e58345731cb1b9bc0885ee74f9e50a58a80aa990a29c98b05541b266af99d3825bb1e5ed4e540c6e2f7c9b40af9ecc011ca0387fd67ec41be0f1cf92c7d0181368b4c67ab07df2d2384192520d74ff77ace6a04ba0e7ad7b34c64223fe59584bc464d53fcdc7091faaee5df0451254062cfb37

Each Minter Check has:

  • Nonce - unique "id" of the check;
  • ChainID - id of the network (1 = mainnet, 2 = testnet);
  • Coin - id of a coin to redeem;
  • Value - amount;
  • GasCoin - id of a coin to pay fee;
  • Due Block - the last block height at which the check can be used;
  • Lock - secret to prevent hijacking;
  • Signature - signature of issuer.

Check hijacking protection

Minter Checks are issued off-line and do not exist on blockchain until redemption. So we've decided to use a special passphrase to protect checks from hijacking by another person at the moment of activation. The hash of this passphrase is used as a private key in ECDSA to prove that the sender is the one who owns the check.

TODO: describe algo

How to issue a Minter Check

To issue a Minter Check, you can use our Console.

You will need to fill out a form:

  • Nonce - unique "id" of the check;
  • Coin ID - id of coin;
  • Gas coin - id of a coin to pay fee;
  • Value - amount;
  • Passphrase - secret phrase that you will pass to receiver of the check.

How to redeem a Minter Check

To redeem a check, the user should send a redeem check transaction with the following data:

  • Check itself
  • Secret passphrase

After redeeming, the user's balance will increase instantly.

Commission

There is no fee for issuing a check, because it's done off-line. The issuer pays the fee at the time of redemption.

Multi-signatures

Minter has built-in support for multi-signature wallets. Multi-signatures, or technically Accountable Subgroup Multi-signatures (ASM), are signature schemes which enable any subgroup of a set of signers to sign any message, and reveal to the verifier exactly who the signers were.

Suppose the set of signers is of size n. If we validate a signature if any subgroup of size k signs a message, this becomes what is commonly reffered to as a k of n multisig in Bitcoin.

Minter Multisig Wallets have 2 main goals:

  • Atomic swaps with sidechains
  • Basic usage to manage funds within Minter Blockchain

Structure of multisig wallet

Each multisig wallet has:

  • Set of signers with corresponding weights
  • Threshold

Transactions from multisig wallets are proceeded with identically to the K of N multisig in Bitcoin, except the multisig fails if the sum of the weights of signatures is less than the threshold.

How to create a multisig wallet

TO BE DESCRIBED

How to use a multisig wallet

TO BE DESCRIBED

Fee

For each transaction, the sender should pay a fee. They are measured in the pip value of commission price coin. It can be either the base coin or a reserveless token. If the price coin differs from the base one, then the needed base coin value is calculated as "how much of the base coin would be received if a certain amount of the price coin were sold to the swap pool." The swap will actually not occur, it will only calculate the needed base coin amount.

User also has option to pay the fee in any coin or reservless token that can be converted into the base coin. In such case, this custom coin will be converted into the base coin automatically. When a transaction changes the blockchain state, it first applies changes from the fee coin converted into the base coin; secondly, it applies changes from transaction data. E.g., if the user makes a "buy from swap pool" transaction and pays the fee with one of the tokens in this pool pair, the fee conversion will affect pool parameters and the received amount for swap will be calculated based on the modified pool parameters.

So in the most complicated case, there can be three fee values:

  • commission coin price value: how validators assess transaction costs
  • base coin value: how much of the base coin will be spent for validating rewards
  • custom coin value: how much of the custom coin the sender will spend

You can estimate fee value required for transaction in /v2/estimate_tx_commission/{tx} API method.

Since Minter 2.0, there are no standard fees.
Commission price may change after the validators vote on it. See list of available fields to change by vote.

Current fee values can be found in /v2/price_commissions API method.

How fees are calculated

Needed commission price coin amount consist of several parts:

1. Base

Depends on transaction type, each type has its own base amount field.

2. Delta

Some transaction types have delta amount field based on count of something. In this case, the fee will be calculated as follows: fee = base_value + (count - 1) * delta_value.
For multi-send transaction, count is the number of recepients.
For swap within pool transaction, count is the number of pools participating in a swap chain route.

3. Ticker length

To create a coin or token, the Coiner should reserve a ticker for it for an extra fee. The shorter the ticker's length, the bigger the fee's amount. A 3-letter ticker is the most expensive, and 7–10-letter, the cheapest.

4. Payload length

The sender should pay an extra fee per each byte in the Payload fields.

Validators

Introduction

The Minter Blockchain is based on Tendermint, which relies on a set of validators that are responsible for committing new blocks in the blockchain. These validators participate in the consensus protocol by broadcasting votes which contain cryptographic signatures signed by each validator's private key.

Validator candidates can bond their own coins and have coins "delegated," or staked, to them by token holders. Those who have the biggest stakes delegated to them become validators.

Validators and their delegators earn base coin BIP as block rewards and fees. Validators can also share some of their own reward with delegators (think of cashback) as an additional incentive.

There are two types of penalty for validators:

  • If validators double-sign, their staked coins will be slashed for 5% (including coins of users that delegated to them);
  • If validators skip signing 12 of the last 24 blocks, they will be banned for 24 hours.

Requirements

Minimal requirements for running Validator's Node on testnet are:

  • 4GB RAM
  • 200GB SSD
  • x64 2.0 GHz 4 vCPUs

SSD disks are preferable for high transaction throughput.

Recommended:

  • 4GB RAM
  • 200GB SSD
  • x64 3.4 GHz 8 vCPUs
  • HSM

Validators limitations

The Minter Network has a limited number of available slots for validators.

At launch, there were 16 slots. 4 slots were added once in every 518 400 blocks. The maximum number of validators is 64.

Rewards

Block rewards and fees are accumulated and proportionally (based on stake value) paid out once per 720 blocks (approx. 1 hour) to all active validators (and their delegators).

Block rewards are configured to decrease from 333 to 0 BIP (MNT) in ~7 years.

Delegators receive their rewards at the same time after paying the fee to their validator automatically (this value is based on validator's settings).

10% from reward goes to DAO address.

10% from reward goes to Developers.

Rules and fines

Validators have one main responsibility: being able to constantly run a correct version of the software. Validators need to make sure that their servers are always on-line and their private keys are not compromised. If the validator misbehaves, its bonded stake will be slashed along with its delegators' stakes. The severity of the punishment depends on the type of fault.

There are 2 main faults that can result in the slashing of funds of a validator and its delegators:

  • Double-signing: If someone on chain A reports that a validator has signed two blocks at the same height on chain A and chain B, this validator will get slashed on chain A for 5% of stake;
  • Unavailability: If a validator's signature has not been included in 12 of the last 24 blocks, this validator will be turned off and banned for 24 hours.

Note that even if a validator does not misbehave intentionally, it can still be slashed if its node crashes, looses connectivity, gets DDoSed, or if its private key is compromised.

Becoming a validator on testnet

  1. Install and run Minter Full Node;

  2. Get your validator's public key (minter show_validator);

  3. Go to Minter Console and send 2 transactions:

    Fill out and send Declare candidacy and Set candidate online forms.

  4. Declare candidacy Validators should declare their candidacy, after which users can delegate and, if they so wish, unbond:

    • Address - you will receive rewards to this address and will be able to turn your validator on/off.
    • Public Key - paste the public key from step 2 (Mp...);
    • Commission - set the fee you'll be charging to your delegators;
    • Coin - enter the coin of your stake (i.e., MNT);
    • Stake - enter the value of your stake in a given coin.

  5. Set candidate online Validators are off-line by default. When off-line, validators are not included in the list of Minter Blockchain validators, so they are not receiving any rewards and cannot be punished for low availability. To turn your validator on, you should provide Public Key (from step 2, (Mp...)). Note: You should send transaction from address you choose in Address field in step 3.1;

  6. Done. Now you will be receiving rewards as long as your node is running and available.

DDoS protection. Sentry node architecture

Denial-of-Service attacks occur when an attacker sends a flood of Internet traffic to an IP address to prevent the server at the IP address from connecting to the Internet.

An attacker scans the network and tries to learn the IP addresses of various validator nodes to disconnect them from communication by flooding them with traffic.

One recommended way to mitigate these risks is for validators to carefully structure their network topology in a so-called sentry node architecture.

Validator nodes should only connect to full nodes they trust because they operate them themselves or they are run by other validators they know socially. A validator node will typically run in a data center. Most data centers provide direct links to the networks of major cloud providers. The validator can use those links to connect to sentry nodes in the cloud. This shifts the burden of denial-of-service from the validator's node directly to its sentry nodes, and may require new sentry nodes to be spun up or activated to mitigate attacks on the existing ones.

Sentry nodes can be quickly spun up or change their IP addresses. Because the links to the sentry nodes are in private IP space, an Internet-based attack cannot disturb them directly. This will ensure validator block proposals and votes always make it to the rest of the network.

It is expected that good operating procedures on that part of validators will completely mitigate these threats.

Practical instructions

To set up your sentry node architecture, you can follow the instructions below:

Validators nodes should edit their config.toml:

# Comma separated list of nodes to keep persistent connections to
# Do not add private peers to this list if you don't want them advertised
persistent_peers = ["list of sentry nodes"]
# Set true to enable the peer-exchange reactor
pex = false

Sentry Nodes should edit their config.toml:

# Comma separated list of peer IDs to keep private (will not be gossiped to other peers)
private_peer_ids = "ipaddress of validator nodes"

Delegator FAQ

Who's a delegator?

People that cannot or do not want to run validator operations can still participate in the staking process as delegators. Indeed, validators are not chosen based on their own stake but based on their total stake, which is the sum of their own stake and the stakes that are delegated to them. This is an important property, as it makes delegators a safeguard against validators that exhibit bad behavior. If a validator misbehaves, its delegators will unbond and move their staked coins away from it, thereby reducing its stake. Eventually, if a validator's stake falls below that of the last top address, it will be excluded from the validators set.

Delegators share the rewards of their validators, but they also share the risks. In terms of rewards, validators and delegators differ in that validators can apply a fee on the reward that goes to their delegators before it is distributed. This fee is known to delegators beforehand and can be changed since Minter 2.0. In terms of risks, delegators' coins can be slashed if their validator misbehaves. For more, see Risks section.

To become a delegator, the coin holder needs to send a "Delegate" transaction where they specify how many coins they want to bond and to which validator. Later, if a delegator wants to unbond part or all of their stake, they need to send an "Unbond" transaction. From there, the delegator will have to wait for 30 days to get their coins back.

Directives of delegators

Being a delegator is not a passive task. Here are the main directives of a delegator:

  • Perform careful due diligence on validators before delegating. If a validator misbehaves, part of its total stake, which includes the stakes of its delegators, can be slashed. Delegators should therefore carefully select validators they think will behave correctly.
  • Actively monitor their validator after having delegated. Delegators should ensure that the validators they're delegating to behave properly, meaning they have good uptime, do not get hacked, and participate in governance. If a delegator is not satisfied with their validator, they can unbond and switch to another validator.

Rewards

Validators and delegators earn rewards in exchange for their services. These rewards are given in two forms:

  • Block rewards;
  • Transaction fees: each transaction on the Minter Network comes with transactions fees. Fees are distributed to validators and delegators in proportion to their stake.

Validator commission

Each validator's staking pool receives rewards in proportion to its total stake. Before these rewards are distributed to delegators inside the staking pool, however, the validator can apply a fee. In other words, delegators have to pay a fee to their validators on the rewards they earn.

10% from reward goes to DAO address.

10% from reward goes to Developers.

Let us consider a validator whose stake (i.e., self-bonded stake + delegated stake) is 10% of the total stake of all validators. This validator has a 20% self-bonded stake and applies a fee of 10%. Now, let's suppose there's a block with the following rewards:

  • 111 BIP as block reward (after subtracting 20%)
  • 10 BIP as transaction fees (after subtracting 20%)

This amounts to a total of 121 BIP to be distributed among all staking pools.

Our validator's staking pool represents 10% of the total stake, which means the pool obtains 12.1 BIP. Now, let us look at the internal distribution of rewards:

  • Fee = 10% 80% 12.1 BIP = 0.69696 BIP
  • Validator's rewards = 20% * 12.1 BIP + Fee = 3.11696 BIP
  • Delegators' total rewards = 80% * 12.1 BIP - Fee = 8.98304 BIP

Then, each delegator in the staking pool can claim their portion of the delegators' total rewards.

Risks

Staking coins is not free of risk. First, staked coins are locked up, and getting them back requires a 30-day wait called unbonding period. Additionally, if a validator misbehaves, a portion of its total stake can be slashed (i.e., destroyed). This includes the stakes of their delegators.

There are 2 main slashing conditions:

  • Double-signing: If someone on chain A reports that a validator has signed two blocks at the same height on chain A and chain B, this validator will get slashed on chain A for 5% of stake;
  • Unavailability: If a validator's signature has not been included in 12 of the last 24 blocks, this validator will be turned off and banned for 24 hours.

This is why delegators should do their own research on validators before delegating. It is also important that delegators actively monitor the activity of their validators. If a validator behaves suspiciously or is off-line too often, delegators can choose to unbond from it or switch to another validator. Delegators can also mitigate risk by distributing their stake across multiple validators ('don't put all your eggs in one basket').

Minter SDKs

GO SDK

  • minter-go-sdk – a pure GO SDK for working with Minter blockchain

JavaScript SDK

  • minter-js-sdk – work with transactions, checks, and deeplinks
  • minterjs-wallet – work with mnemonics, private/public keys, and addresses
  • minterjs-tx – low-level TX implementation (only for advanced users; otherwise, use SDK instead)
  • minterjs-util – a collection of utility functions for Minter

iOS SDK

PHP SDK

Android SDK

C++ SDK

Node API

v2 (latest)

  • Documentation
  • Testnet base url: https://node-api.testnet.minter.network/v2/

v1 (deprecated)

Other public services

Explorer API

  • Documentation
  • Testnet base url: https://explorer-api.testnet.minter.network/api/v2/
  • Mainnet base url: https://explorer-api.minter.network/api/v2/

Gate API (v2)

Minter Gate is a service to publish prepared transactions to the Minter Network. Preferable to be used instead of node, because it provides load balancing and automatical check of transaction success.

  • Documentation
  • Testnet base url: https://gate-api.testnet.minter.network/api/v2/
  • Mainnet base url: https://gate-api.minter.network/api/v2/