Rolling Smart Contract Hedera API Fees into Gas Fees
Jun 14, 2022
by Atul Mahamuni
Senior Vice President of Product at Swirlds Labs

Since the launch of Smart Contracts 2.0 on the Hedera network in February 2022, core contributors have continued to improve the user experience. As explained in this blog posting announcing the JSON-RPC Relay, it is now easy to integrate existing Ethereum ecosystem libraries, tools, and wallets with the Hedera Smart Contract service.

Core contributors are now focused on an important pricing update for the Hedera Smart Contract service, recently approved by the Coin Committee of the Hedera Governing Council. This update rolls Smart Contract Hedera API (HAPI) fees into gas fees and removes the cover charge for HAPI fees when making a ContractCall transaction.

Please read on to learn how this update might affect fees for your application. As always, you can visit for the most up-to-date Hedera fee estimates.

Rolling Smart Contract HAPI Fees into Gas Fees

​​Today, when an end-user makes a ContractCall API call, they pay two fees:

  1. HAPI fees (i.e. the “cover charge”): All Hedera transactions submitted using the HAPI require users to pay fees for processing those transactions in HBAR. Currently, the fee for the ContractCall is approximately $0.03.

  2. Gas for smart contract execution: The amount of gas consumed depends on the number of executed EVM instructions and their complexity.

Ethereum application developers are accustomed to only paying gas fees, and there is no logical equivalent to a “cover charge” for HAPI calls.

For compatibility reasons, the Hedera network will now roll the cover charge into Smart Contract execution-related transactions and the gas cost will be updated to approximately $0.000_000_0852 per unit of gas. All other smart contract transactions will continue to charge HAPI fees (ContractDelete, ContractCreate, etc).

A majority of Smart Contract execution calls today use less than 1,000,000 gas and will cost less than what they’re paying on Hedera today. Larger contract calls that use over 1,000,000 gas will pay slightly higher fees. Fee estimates for all transactions and queries on Hedera can be calculated at