How to Connect to Hedera Networks Over RPC

The JSON-RPC Relay is the open-source service that bridges EVM-style JSON-RPC clients (MetaMask, ethers.js, web3.js, Hardhat, Foundry, viem, etc.) to the.

The JSON-RPC Relay is the open-source service that bridges EVM-style JSON-RPC clients (MetaMask, ethers.js, web3.js, Hardhat, Foundry, viem, etc.) to the Hedera network. You have three ways to access it: use the free public instance (Hashio), use a managed third-party provider, or run your own instance.

Choose a connection option

Hashio

Free public Hiero JSON-RPC Relay instance hosted by Hashgraph. No sign-up required. Best for prototyping and tutorials. Rate-limited.

Validation Cloud

Freemium managed JSON-RPC and Mirror Node service. Requires an account but no credit card. Scales for production workloads.

QuickNode

Commercial JSON-RPC provider with global edge infrastructure and SLAs. Best for high-throughput production apps.

Self-host the Relay

Run your own instance of the open-source Hiero JSON-RPC Relay for full control over rate limits, caching, and infrastructure.

Network support

Option	Mainnet	Testnet	Previewnet	Sign-up
Hashio (public Hiero Relay)	✅	✅	✅	❌
Validation Cloud	✅	✅	❌	✅
QuickNode	✅	✅	❌	✅
Self-hosted Relay	✅	✅	✅	—

Network reference

Network	Chain ID (decimal)	Chain ID (hex)	Hashio endpoint
Mainnet	295	0x127	https://mainnet.hashio.io/api
Testnet	296	0x128	https://testnet.hashio.io/api
Previewnet	297	0x129	https://previewnet.hashio.io/api

Hashio is for development and testing purposes only. Production use cases are strongly encouraged to use commercial-grade JSON-RPC relays or host their own instance of the Hiero JSON-RPC Relay.

Additional resources

• JSON-RPC Relay overview
• Community-hosted JSON-RPC relays
• Add Hedera to MetaMask
• How to connect MetaMask to Hedera
• Hiero JSON-RPC Relay on GitHub

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Writer: Brendan, DevRel Engineer

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Writer: Aaron, Validation Cloud

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Editor: Krystal, Senior DX Engineer

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