JSON-RPC overview

Radius exposes a JSON-RPC 2.0 API compatible with standard Ethereum tooling. Use this page to understand compatibility, special behavior, and where to find method-level details.

Compatibility

Radius works with standard Ethereum libraries and tooling:

• viem for TypeScript and Node.js
• WAGMI for React
• Foundry for smart contract development

Most eth_* methods behave as expected. A few return different values or are pseudo-supported.

Key behavior differences

Keep these differences in mind when you build:

• eth_blockNumber returns the current timestamp in milliseconds
• eth_getBalance returns native balance plus the convertible USD balance
• eth_gasPrice returns 0x0 even though fees are required
• eth_feeHistory returns a pseudo-supported response

Read Divergence from Ethereum for detailed explanations.

Gas and fee guidance

Radius uses fixed gas pricing and legacy (type 0) transactions. viem defaults to EIP-1559, so you must set a gasPrice in your chain definition.

• Use the Transaction cost API to fetch gas_price_wei
• Configure fees.estimateFeesPerGas() in viem to return { gasPrice }
• Read Gas pricing for context

WebSocket access

eth_subscribe is supported for logs only and requires an RPC key with elevated privileges. See Network and RPC for access details and rate limits.

Method-level reference

For the full method list, including divergent, pseudo-supported, and unsupported methods, see:

• JSON-RPC API

Related resources

• Network and RPC
• Fees
• Contract addresses