Base RPC Overview

Complete reference for all JSON-RPC methods available on Base nodes.

Base exposes a single, fully EVM-compatible JSON-RPC API. Base produces a canonical block every 200ms, each with its own hash, receipts, and state root.

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Networks

For network details, RPC endpoints, and wallet setup, see Connecting to Base.

The public Base endpoints are HTTP only. WebSocket RPC connections (eth_subscribe, newHeads, logs) are not available on public Base endpoints — choose a WebSocket-capable provider from the Builder Stack.

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API Reference

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Ethereum JSON-RPC API

Core Ethereum protocol methods for account queries, block and transaction data, gas estimation, and log filtering.

Method	Description
eth_blockNumber	Current block number
eth_getBalance	Account ETH balance
eth_getTransactionCount	Account nonce / tx count
eth_getCode	Deployed contract bytecode
eth_getStorageAt	Contract storage slot value
eth_call	Execute read-only call
eth_getBlockByNumber	Block data by number
eth_getBlockByHash	Block data by hash
eth_getBlockReceipts	All receipts for a block
eth_getBlockTransactionCountByNumber	Tx count by block number
eth_getBlockTransactionCountByHash	Tx count by block hash
eth_getTransactionByHash	Transaction data by hash
eth_getTransactionByBlockHashAndIndex	Tx by block hash and index
eth_getTransactionByBlockNumberAndIndex	Tx by block number and index
eth_getTransactionReceipt	Receipt for a mined tx
eth_sendRawTransaction	Submit signed transaction
eth_simulateV1	Simulate transaction bundles against canonical state
eth_gasPrice	Current gas price
eth_maxPriorityFeePerGas	Max priority fee estimate
eth_feeHistory	Historical base fee and rewards
eth_estimateGas	Estimate gas for a tx
eth_getLogs	Query event logs by filter
eth_chainId	Network chain ID
eth_syncing	Node sync status
net_version	Network version ID
web3_clientVersion	Client version string
eth_subscribe	Subscribe to events (WSS)
eth_unsubscribe	Cancel a subscription (WSS)

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Base API

Base-specific methods served by Base nodes.

Method	Description
base_transactionStatus	Check whether a transaction is in the node mempool. Not available on the public endpoints.

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Debug API

Development and debugging utilities for deep transaction inspection and block replay. The public endpoints (https://mainnet.base.org and https://sepolia.base.org) do not serve debug methods or the trace and txpool namespaces. See Connect to Base for public endpoint limits. Debug methods replay transactions and are computationally expensive, so availability and rate limits vary among providers in the Builder Stack.

Method	Description
debug_traceTransaction	Full EVM execution trace for a transaction
debug_traceBlockByHash	EVM traces for all transactions in a block by hash
debug_traceBlockByNumber	EVM traces for all transactions in a block by number

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Request & Response Format

All requests are HTTP POST with Content-Type: application/json.

Field	Type	Description
jsonrpc	string	Always "2.0"
method	string	The RPC method name
params	array	Method parameters in order
id	number | string	Identifier echoed back in the response

Request:

Request

{
  "jsonrpc": "2.0",
  "method": "eth_getBalance",
  "params": ["0x742d35Cc6634C0532925a3b8D4C9dD0b4f3BaEa", "latest"],
  "id": 1
}

Success response:

Success Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1a055690d9db80000"
}

Error response:

Error Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "error": {
    "code": -32602,
    "message": "Invalid params"
  }
}

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Error Codes

Code	Name	Description
-32700	Parse error	Invalid JSON
-32600	Invalid request	Not a valid JSON-RPC 2.0 object
-32601	Method not found	Method does not exist or is unavailable
-32602	Invalid params	Invalid method parameters
-32603	Internal error	Internal JSON-RPC error
-32000	Server error	Node-specific error (see message)

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Block Parameters

Value	Description
"latest"	Most recently sealed block
"pending"	Accepted and resolves to the latest canonical block. Use "latest" instead.
"safe"	Latest safe block
"finalized"	Latest finalized block
"earliest"	Genesis block
"0x<n>"	Specific block by number