Minting Subscriptions

Minting a subscription purchases time with tokens. The amount of time alloted depends on tokensPerSecond and the amount of tokens transfered. Additionally, minimumPurchaseSeconds is assigned at creation, which sets the floor duration/price for a given purchase.

Upon minting, the calling account is assigned an NFT and several variables representing subscription state. If the account already has an NFT, the subscriptions expiration date is simply extended.

Simple Mint / Renew

The most basic minting operation is to simply mint or renew a subscription with network native tokens. This will mint a new NFT if the account doesn't already have one, or renew the existing NFT if it does.

import {
  prepareMint,
} from '@withfabric/protocol-sdks/stpv1';
 
const mint = await prepareMint({
  contractAddress: '0x...',
  amount: 100_000n,
})
 
const receipt = await mint();

Minting with ERC20 Tokens

Minting will revert on preparation if the balance is too low, or an ERC20 approval isn't sufficient. Driving the user to approve tokens before mint will ensure a smooth experience.

Note: The code below doesn't factor in UX logic and flows. It's a procedural example of the steps required to mint a ERC20 denominated subscription.

import {
  prepareMint,
  fetchContext,
} from '@withfabric/protocol-sdks/stpv1';
 
import {
  prepareTokenApproval,
} from '@withfabricxyz/protocol-sdks/erc20';
 
const context = fetchContext(
  contractAddress: '0x...',
  account: '0x...',
);
 
// Minimum purchase
const amount = context.collection.minimumPurchaseSeconds * context.collection.tokensPerSecond;
 
if(context.holdings.balance < amount) {
  throw new Error('Insufficient balance');
}
 
// Approve if necessary (holdings approved = balance for native tokens such as ether)
if(context.holdings.approved < amount) {
  const approve = await prepareTokenApproval({
    address: '0x...',
    spender: context.collection.address,
    amount,
  });
 
  await approve();
}
 
// Now we can mint
const mint = await prepareMint({
  contractAddress: '0x...',
  amount: config.amount,
  erc20: context.collection.erc20Address != zeroAddress,
})
 
const receipt = await mint();

Sponsored Minting

The mintFor function allows any caller to mint or renew a subscription for another account. This is useful for sponsored calls, automating renewals with credit cards, etc.

Note: For ERC20, the caller must have an approved balance for the amount of tokens to be transfered. See the example above.

import {
  prepareMintFor
} from '@withfabric/protocol-sdks/stpv1';
 
const mint = await prepareMintFor({
  contractAddress: '0x...',
  amount: 1_000_000_000n,
  account: '0x...', // <-- Receives the nft, rewards, time, etc
})
 
const receipt = await mint();

Reading State Withdraws