Hiero JSON-RPC Relay
Visit the Hedera status page for the latest versions supported on each network. The Hiero JSON-RPC Relay is an open-source implementation of Ethereum JSON-RPC APIs for Hedera. It allows developers to interact with Hedera nodes using familiar EVM-compatible tools such as Hardhat, MetaMask, and ethers.js.Latest Releases
v0.77.0
Release v0.77.0 updates several default configuration values to better align the Relay’s behavior with what developers expect from standard Ethereum JSON-RPC implementations. Operators running their own relay instances should review these changes carefully before upgrading.Breaking Changes
The following default configuration values have changed:| Configuration | Old Default | New Default |
|---|---|---|
ENABLE_TX_POOL | false | true |
REDIS_ENABLED | true | false |
USE_ASYNC_TX_PROCESSING | true | false |
RATE_LIMIT_DISABLED | false | true |
SUBSCRIPTIONS_ENABLED | false | true |
HBAR_RATE_LIMIT_TINYBAR | 25000000000 | 0 |
v0.76.2
Patch release with bug fixes and stability improvements. Full GitHub Release Notes: v0.76.2v0.76.1
Patch release with bug fixes and stability improvements. Full GitHub Release Notes: v0.76.1v0.76.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.76.0v0.75.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.75.0v0.74.0
Release v0.74.0 introduces a significant experimental feature for Nonce Ordering with Locks (#4635), designed to drastically reduceWRONG_NONCE errors by ensuring transactions are processed in the correct sequence even during asynchronous operations. This release also continues the extensive enhancement of the Transaction Pool service, adding RLP hex transaction storage (#4521), encapsulating the ENABLE_TX_POOL flag for better configuration management (#4581), and introducing new txpool_* related RPC methods (#4544) to expand relay capabilities.
Operational observability and debugging have been improved with updates to the /liveness and /readiness endpoints (#4622) and a review of 200/400 HTTP response codes (#4650). To improve accuracy, the relay now removes the fallback predefined gas value for eth_estimateGas when the Mirror Node fails to retrieve an estimate (#4678). Additionally, developers can now leverage synthetic HTS transaction support in debug_traceTransaction and debug_traceBlockByNumber (#4694) for deeper insights into token operations, while internal error handling has been tightened to stop silently swallowing errors (#4758/#4775).
Other notable changes include CORS configuration aligned with other JSON-RPC providers (#4710), IPRateLimiter rework with Redis integration (#4662), a configurable SDK_LOG_LEVEL for enhanced SDK logging (#4578), the addition of JSON logging via environment variable (#4474), and migration of API testing from Postman to Hoppscotch (#4687). Dependency updates include pino 9.7.0 to 10.1.0, pino-pretty 7.6.1 to 13.1.2, @hashgraph/sdk 2.75.0 to 2.78.0, and Koa v2 to v3 migration.
Full GitHub Release Notes: v0.74.0
v0.73.1
Patch release with bug fixes and stability improvements. Full GitHub Release Notes: v0.73.1v0.73.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.73.0v0.72.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.72.0v0.71.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.71.0v0.70.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.70.0v0.69.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.69.0v0.68.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.68.0v0.67.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.67.0v0.66.0
See the full release notes on GitHub for a complete list of changes in this release. Full GitHub Release Notes: v0.66.0v0.65.0
Release v0.65.0 introduces critical improvements to transaction handling and log retrieval. A key fix resolves an issue whereeth_getBlockByNumber failed when encountering transactions with CONTRACT_NEGATIVE_VALUE (#3387). With this update, blocks containing transactions that failed due to negative values are now correctly processed and returned, ensuring better reliability and consistency in block retrieval. Additionally, eth_getLogs has been enhanced with timestamp range validation and improved error handling (#3431), providing more accurate and reliable log retrieval while reducing potential inconsistencies in event filtering.
Other improvements include enhanced logging upon receiving responses from the Mirror Node server (#3422), a new Blockscout example project (#3386), and the addition of a DEPENDENT_SERVICE_IMMATURE_RECORDS predefined error. Dependency updates include @hashgraph/sdk 2.53.0 to 2.56.0.
Full GitHub Release Notes: v0.65.0