🌀Paymaster

The Bitte Paymaster service lets you create a dedicated wallet that acts as a relayer, covering gas fees for your users. This means your users can interact with your app without needing to hold NEAR.

Creating a Paymaster

Now you can enable your community to interact with your smart contracts freely. They will not need crypto to mint, vote on your DAOs, or receive free airdrops.

1. Go to the Bitte Wallet

2. Head to the APPs tab

3. Click "New Paymaster"

4. Enter the contract you want to sponsor on NEAR

5. Functions will appear below that you can toggle to enable or disable functionalities you want your users to run for free.

6. Fund your paymaster wallet with enough funds to sponsor gas for transactions

The paymaster is now successfully created and will automatically fund the transactions defined before!

Using the paymaster

There are currently 2 ways to use the paymaster, either directly through the wallet or via code.

Using Paymaster Via Wallet

In the previous example I created a sponsorship for the contract blackdragon.tkn.near and selected the method "ft_transfer". Now whenever someone transacts on that contract/method through the wallet their gas fee will be sponsored.

This makes it easy to use, by adding a wallet connection to any application users can be redirected to bitte to sign transactions at which point the sponsorship will take effect.

Currently, the sponsorship will affect all the transactions in the wallet but the plan is for the following versions to allow for passing in certain parameters to only allow certain user bases to take advantage of it.

Using Paymaster with Code

To use the paymaster via code you must have access to accounts from within your application.

Start by copying the relayer URL from the dashboard.

The next step involves buildinng the transaction and sending it to that URL via a post request, you can check the official near docs for more information or use thissimple wrapper library to get started

pnpm i @near-relay/client


import { relayTransaction } from "@near-relay/client";

/**
 * Signs a transaction and sends it to a relayer to get dispatched
 *
 * @param {Action[]} action - The list of actions to include in the transaction.
 * @param {string} receiverId - The ID of the receiver.
 * @param {string} relayerUrl - Url for the relayer to which the tx will be sent
 * @param {Account?} account - Optionally pass in local account
 * @param {string?} network - 'mainnet | testnet'
 * @returns {Promise<any>} - Most likely a receipt (depends on format being returned by relayer).
 */

const receipt = await relayTransaction(action: Action | Action[], receiverId: string, relayerUrl: string, network: string, account: Account)

Managing paymaster

Go to your dashboard to review the account ID, API call URL, and the total sponsored amount. Then, click "Edit" to make any necessary changes.

Editing

Here you can change the smart contract you have selected or change the affected methods

Deleting

At the bottom of the edit page you will find a delete button that will allow you to delete the near account associated with the paymaster automatically giving all of the funds contained in it back to your account.

Managing Balance

When viewing the dashboard hit the manage balance button to to deposit or withdraw funds, here you can toggle the top tab to fund or withdraw from the near account that is associated with the paymaster

FAQ

Can I set spending limits on the gas fees my Paymaster covers?

Not directly, the way you would do that at this point would be to only fund the relayer with the amount you are willing to spend

Is it possible to sponsor specific users or groups using the Paymaster?

This feature is planned, soon TM

What happens if my Paymaster wallet runs out of funds?

When the user tries to submit the transaction they will be prompted to pay gas as normal

Can I sponsor multiple contracts with a single Paymaster?

No. The way you would currently set this up is by managing more than one paymaster

Can I track the transactions that have been sponsored by my Paymaster?

Yes, in the dashboard you can see the amount that has been sponsored, eventually there could be better visualisation tools

Is there a limit to the number of transactions my Paymaster can sponsor?

Not currently but there is a limit for the amount of gas that can be sponsored before KYC is necessary

Can i sponsor account creation?

Account creation is just a function call so technically you could but at this point that would affect all users of the wallet, this will be possible to do in a more conveninent way once you are able to limit usage to certain groups of users