Enable gasless transactions by sponsoring transaction fees for your users. Tempo's native fee sponsorship allows applications to pay fees on behalf of users, improving UX and removing friction from payment flows.
Fee sponsorship demo
Sponsor User Fees
demo
1
Create an account, or use an existing one.
2
Add testnet funds to your account.
Fee sponsorship implementation steps
Build your own fee payer service
Instead of using the hosted fee payer service, you can build your own.
The sender must indicate sponsorship before signing, because the transaction's signing hash differs based on whether it will be sponsored:
Sponsored transactions: The fee_token field is omitted from the sender's signing payload, and a 0x00 marker is used. This allows the fee payer to choose the fee token.
Non-sponsored transactions: The fee_token is included in the sender's signing payload.
The SDKs handle this automatically. Here's how each SDK manages the dual-signing flow:
Fee sponsorship best practices
Set sponsorship limits: Implement daily or per-user limits to control costs
Monitor expenses: Track sponsorship costs regularly to stay within budget
Consider selective sponsorship: Only sponsor fees for specific operations or user segments
Educate users: Clearly communicate when fees are being sponsored
Fee sponsorship security considerations
Transaction-specific: Fee payer signatures are tied to specific transactions
No delegation risk: Fee payer can't execute arbitrary transactions
Balance checks: Network verifies fee payer has sufficient balance
Signature validation: Both signatures must be valid
To sponsor transactions with your own infrastructure, run a JSON-RPC relay that validates incoming requests, fills Tempo Transactions, signs the fee payer payload, and broadcasts approved transactions. The fee payer account must be funded with the stablecoin it will use for fees.
Your relay should expose the same core JSON-RPC methods described in the Hosted Fee Payer API reference, then apply your own sponsorship policy before signing.
Configure your client to use the fee payer service
Sponsor your user's transactions
Now transactions will be sponsored by your relay. For more details on how to send a transaction, see the Send a payment guide.
Next steps for fee sponsorship
Now that you've implemented fee sponsorship, you can:
Learn more about the Tempo Transaction type and fee payer signature details
Use Tempo Transactions to sponsor multiple calls in a single signed operation
