Zero Cost EthereumTransaction on Success: Hedera's New Fee Model for Relay Operators

By Oliver Thorn

With the implementation of HIP-1084: Zero Cost EthereumTransaction on Success, Hedera is introducing an updated transaction fee model that will eliminate charges for successful EthereumTransactions submitted by relay operators*. This change brings Hedera's fee structure more in line with Ethereum while maintaining network security and improving the network experience for relay operators.*

The Current Landscape: The Relay Fee Framework

Currently, relay operators such as Thirdweb, Arkhia, and HGraph must pay a fee (approximately $0.0001) for every EthereumTransaction they submit on behalf of users, regardless of the transaction's success. This has - in some cases - required operators to implement non-standard business models to cover these costs, creating unnecessary complexity for users and operators alike.

While individual transaction fees are minimal, they accumulate significantly for high-volume relay operators. This forces operators to either absorb costs or develop alternative fee structures for users. For developers building on Hedera, this creates an additional consideration; a requirement to pay fees regardless of transaction outcome may discourages experimentation, particularly from operators accustomed to Ethereum's success-based model.

Success-Based Pricing with HIP-1084

Under the new model, relay operators will only be charged for transactions that fail due diligence checks. Successful transactions and even those that result in contract reverts will incur no relay operator fees. The end users will continue to pay standard gas fees, maintaining alignment with Ethereum's traditional approach.

The success-based model preserves protection against network misuse through targeted fee mechanisms while eliminating costs for legitimate transactions. The approach follows a practical design philosophy where fees apply only when serving a purpose. Relay operators can now design services with greater flexibility while preserving Hedera's performance advantages, knowing successful operations carry no network overhead.

What Qualifies as a Zero-Fee Transaction?

The new model exempts relay operators from fees in several common transaction scenarios, creating significant cost savings for standard operations. These zero-fee transactions include:

• Successful contract executions

• Contract calls that revert

• Successful HBAR transfers

These exemptions cover the vast majority of typical network interactions, allowing relay operators to process most legitimate user transactions without incurring any network charges.

What Transactions Will Incur Relay Operator Charges?

Fees will still apply in specific situations where transactions fail pre-execution checks, serving as a security mechanism against potential network abuse. These chargeable scenarios include:

• Malformed transactions

• Invalid signatures

• Insufficient user funds

• Invalid nonce values

By maintaining fees for these edge cases, Hedera preserves essential network protections while removing costs from successful and legitimate operations.

Benefits for the Ecosystem

The update offers several key advantages:

1. Reduced operational costs for relay operators

2. Simplified business models for relay services

3. Greater alignment with Ethereum's fee structure

4. Zero implementation effort required from operators or users

Implementation Approach

The transition to the new fee model will be seamless, requiring no code changes from relay operators or end users. The update maintains all existing security measures while optimizing the cost structure for legitimate transactions.

Moving Forward

This fee model update represents a significant step forward in Hedera's commitment to providing an efficient and user-friendly network. By eliminating fees for successful transactions, Hedera is removing unnecessary friction while maintaining robust security measures. Relay operators can look forward to reduced operational costs, and users will benefit from a more streamlined experience that better aligns with familiar blockchain standards.

Additional Resources

HIP-1084 Documentation: https://hips.hedera.com/hip/hip-1084
Hedera JSON-RPC Relay Documentation: https://docs.hedera.com/hedera/core-concepts/smart-contracts/json-rpc-relay
Hedera Developer Playground: https://portal.hedera.com/playground