The System Contract on V Systems is quite unique in that it is directly included in the protocol and not registered by users. Since Contract variables and VSYS tokens use different databases, it is normally not possible for them to interact. However, the System Contract handles the mixing of these two databases, and allows users to do things such as deposit and withdraw VSYS token from contracts.
import * as jv from '@virtualeconomy/js-vsys';
// acnt: Account
// ch: Chain
// initial a new system contract on mainnet
const nc = new jv.SysCtrt('CCL1QGBqPAaFjYiA8NMGVhzkd3nJkGeKYBq');
// initial a new system contract on testnet
const nc = new jv.SysCtrt('CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt', ch);
console.log(nc.ctrtId); // print the id of the system contract
Example output
CtrtID { data: 'CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt' }
Send VSYS tokens to another user.
import * as jv from '@virtualeconomy/js-vsys';
// acnt0: Account
// acnt1: Account
// amount: number
const resp = await nc.send(
acnt0, // acnt0
acnt1.addr.data, // acnt1
10 // amount
);
console.log(resp);
Example output
{
type: 9,
id: 'Frn5wW8QrVP15amwBUvYKU2v17xczMJhEbwy2mpLZz3k',
fee: 30000000,
feeScale: 100,
timestamp: 1655112977675000000,
proofs: [
{
proofType: 'Curve25519',
publicKey: 'FwuW4LhiBFn6uu5id9nZGtp9o1RUG3DoX5MhyZibrjkE',
address: 'ATse3RcjEzwc5JHDPcduPYe4qA2mWhSNZaV',
signature: '62f1ScywBJwmeMZNEC2D7Hnhnd5rE7MHrj8MSGvbmrawwAnnfPLXpexKJYMBm5vkDo6eBmoV4C7asCKs32rdM3oP'
}
],
contractId: 'CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt',
functionIndex: 0,
functionData: '14uNyPNLz6igvdRLtuP8E7K8eVTNvW9mniVqpF3TCPRmFGpWH7D',
attachment: ''
}
Deposit VSYS tokens to a token-holding contract instance(e.g. lock contract).
Note that only the token defined in the token-holding contract instance can be deposited into it.
import * as jv from '@virtualeconomy/js-vsys';
// acnt0: Account
// nc: jv.SysCtrt
// lc: jv.LockCtrt
// amount: number
const lcId = lc.ctrtId.data;
const resp = await nc.deposit(
acnt0, // by
lcId, // ctrtId
10 // amount
);
console.log(resp);
Example output
{
type:9,
id:'7DxP86FzXEDxNqiNhQkehL51GXSyoeRGYH5YSHshh1ga',
fee:30000000,
feeScale:100,
timestamp:1646663600529510912,
proofs:[
{
proofType:'Curve25519',
publicKey:'AGy4ASY2CmVPSjQX4rNHrSHmcYAL4DNBawdyKT7p8vot',
address:'AU8h6YH5iJuwFzcUdGugUwKo2E8tbEHdtqu',
signature:'3uaoJmeUdoPGuyqAbVjt3ASbcknNMfz15XKR4ZW3UH9Hds3hj7vygsdiYVMRoYp3orp3ptvVFepX2wcisgLtZHeS'
}
],
contractId:'CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt',
functionIndex:1,
functionData:'14VJY1ZP9F8AxnTMyoWJiGRvyvgT7cKTmLDrGJJp1VtHTAWRFTDHsGqz5YaSHFiE33y1QtrPZwSTz5PKzi6xyv7Z',
attachment:'
}
Withdraw VSYS tokens from a token-holding contract instance(e.g. lock contract).
Note that only the one who deposits the token can withdraw.
import * as jv from '@virtualeconomy/js-vsys';
// acnt0: Account
// nc: jv.SysCtrt
// lc: jv.LockCtrt
// amount: number
const lcId = lc.ctrtId.data;
const resp = await nc.withdraw(
acnt0, // by
lcId, // ctrtId
10 // amount
);
console.log(resp);
Example output
{
type:9,
id:'EF6Brq21Wi1Hv3N4z2BuVNRNfeXjb9uzv2HBVS8voRqG',
fee:30000000,
feeScale:100,
timestamp:1646295771726907904,
proofs:[
{
proofType:'Curve25519',
publicKey:'6gmM7UxzUyRJXidy2DpXXMvrPqEF9hR1eAqsmh33J6eL',
address:'AU6BNRK34SLuc27evpzJbAswB6ntHV2hmjD',
signature:'4bEfdwPrwNzGkdLjP7JSvg2xdDnbPabtGK3fdGampaF9LySUHtsMJrD3V35F7C9zwgBrvMhEZfTfEB7iyY7SGquM'
}
],
contractId:'CEu8AuKJS2Pr67RPV9dFjPAb8TL151weQsi',
functionIndex:5,
functionData:'1Y5SeLwhk5NvqLEeqZuAFHiVY6k713zijrRcTwsgJDd7gGwi9dxZpZCyGMqUWZJovQUcDw6MBsnz1AKygj',
attachment:'
}
Transfer the VSYS token to another account(e.g. user or contract).
transfer
is the underlying action of send
, deposit
, and withdraw
. It is not recommended to use transfer directly. Use send
, deposit
, withdraw
instead when possible.
import * as jv from '@virtualeconomy/js-vsys';
// acnt0: Account
// acnt1: Account
// nc: jv.SysCtrt
// amount: number
const resp = await nc.transfer(
acnt1, // by
acnt1.addr.data, // sender
acnt0.addr.data, // recipient
10 // amount
);
console.log(resp);
Example output
{ type: 9, id: 'Gfwdba3CVwKbYkj4ApowajmQfDmzzLPiRoB6VKT23dFm', fee: 30000000, feeScale: 100, timestamp: 1655114346074000000, proofs: [ { proofType: 'Curve25519', publicKey: 'FwuW4LhiBFn6uu5id9nZGtp9o1RUG3DoX5MhyZibrjkE', address: 'ATse3RcjEzwc5JHDPcduPYe4qA2mWhSNZaV', signature: '4P4MEXGLh1b43gdSRrfbBT5Sf6xNNKkj3AXdK1QU5vw7ySjRmts42tQE64SxYHCsPhB2TUe4F7jaRgMUuntTZbj2' } ], contractId: 'CF9Nd9wvQ8qVsGk8jYHbj6sf8TK7MJ2GYgt', functionIndex: 3, functionData: '14VJY1483JwCJVMajdB5ZaWwLWpHK3XV2ArryugxyB9sCGPgWBURtLLbQnCunuE97bAULDv7cWyEU2q1R3cUZTQK', attachment: '' }