Sponsored Gas Transactions

Learn how to implement sponsored gas transactions.

With Openfort you can sponsor transactions to you users, meaning that in-game accounts don't need to have native token to execute transactions.

Note that the absence of a policy will enforce the user to have a native tokens in their account in order to pay for the transaction's gas fee.

What you'll learn:#

How to make a sponsored transaction to mint an NFT.

Select the contract you want to interact with

Import the smart contract if you have not yet
Decide what function of the smart contract you want to use. In our case 'mint'.

command-line

curl https://api.openfort.xyz/v1/contracts \
  -u "$YOUR_SECRET_KEY:" \
  -d 'name=NFT Contract' \
  -d 'chainId=80002' \
  -d 'address=contract address'

Set up a Gas Policy

Create s new policy and select the strategy "pay gas for user"
Select imported contract and the function you want to sponsor

command-line

  curl https://api.openfort.xyz/v1/policies \
  -H "Authorization: Bearer $YOUR_SECRET_KEY" \
  -d chainId=80002 \
  -d name="simple sponsor" \
  -d "strategy[sponsorSchema]=pay_for_user"

command-line

curl https://api.openfort.xyz/v1/policies/:id/policy_rules \
  -H "Authorization: Bearer $YOUR_SECRET_KEY" \
  -d type="contract_functions" \
  -d functionName="All functions" \
  -d contract="con_..."

Create a gasless transaction

Add chainId
Add contract
Add policy
Add function you want to interact with
Add arguments (in the case of mint, '_to' the person who receives the asset)

Note you can make a transaction happen without the need to have a registered user or account. Once you make the transaction a playerId and accountId will be created.

command-line

  curl https://api.openfort.xyz/v1/transaction_intents \
  -u "$YOUR_SECRET_KEY:" \
  -d 'chainId=80002' \
  -d 'policy=pol_...' \
  -d 'optimistic=true' \
  -d 'interactions[0][contract]=con_...' \
  -d 'interactions[0][functionName]=mint' \
  -d 'interactions[0][functionArgs][0]=0x...'

Optional: Add the Account or Player you're using

Add player

command-line

  curl https://api.openfort.xyz/v1/transaction_intents \
  -u "$YOUR_SECRET_KEY:" \
  -d 'chainId=80002' \
  -d 'player=pla...' \
  -d optimistic=true \
  -d 'interactions[0][contract]=con_...' \
  -d 'interactions[0][functionName]=mint' \
  -d 'interactions[0][functionArgs][0]=pla...'