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Ethereum

Smart Router serves Ethereum mainnet over JSON-RPC. This page covers the supported methods, the example config, and how to connect a client.

Endpoint
Default port 3360 (override per endpoints[] entry)
Calling convention POST / with a JSON-RPC body
Spec specs/ethereum.json

Supported method families

Family Examples
Standard eth_blockNumber, eth_call, eth_getBalance, eth_getBlockByNumber, eth_getLogs, eth_estimateGas, eth_gasPrice, eth_feeHistory, eth_sendRawTransaction
Tracing (debug add-on) debug_traceTransaction, debug_traceCall, debug_traceBlockByNumber, debug_storageRangeAt, debug_getRawBlock, debug_getRawReceipts
Tracing (trace add-on) trace_call, trace_block, trace_transaction, trace_get
Account abstraction (ERC-4337) eth_estimateUserOperationGas, eth_sendUserOperation, etc. (node-dependent)
Network / client web3_*, net_*

The spec file linked above has the full method list.

Upstream capabilities

Some methods only work on upstreams with specific capabilities. Mark these capabilities as add-ons in your config. The router then routes matching methods only to capable upstreams. If no upstream declares an add-on, the upstreams you have serve the matching requests. If a request explicitly asked for the extension, it gets a Lava-Extension-Unavailable response header that says so.

Add-on Required for
debug debug_* tracing methods
trace trace_* methods (trace_call, trace_block, …)
archive deep eth_getLogs and historical state (also extends the debug / trace collections for old blocks)
bundler ERC-4337 user-operation methods

Connect a client

import { createPublicClient, http } from 'viem';
import { mainnet } from 'viem/chains';

const client = createPublicClient({
  chain: mainnet,
  transport: http('http://127.0.0.1:3360'),
});

const block = await client.getBlockNumber();

import { JsonRpcProvider } from 'ethers';
const provider = new JsonRpcProvider('http://127.0.0.1:3360');
const block = await provider.getBlockNumber();

from web3 import Web3
w3 = Web3(Web3.HTTPProvider('http://127.0.0.1:3360'))
print(w3.eth.block_number)

curl -X POST http://127.0.0.1:3360 \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Migrating from Alchemy / Infura / QuickNode

Replace the node URL with your Smart Router URL. The JSON-RPC protocol is the same, so your existing client code does not change.

If you used vendor-specific extensions (Alchemy enhanced APIs, QuickNode add-ons, etc.), check whether your upstream nodes expose the equivalent methods. The chain spec decides which methods are covered, and the spec is maintained in the catalog. If a method you need is not covered, request it.

Run this example

The repo has a ready-to-run config at config/smartrouter_examples/smartrouter_eth.yml. It uses two public upstreams (PublicNode, Tenderly) over HTTP + WS and needs no API key:

SR_CONFIG=config/smartrouter_examples/smartrouter_eth.yml \
  docker compose -f docker/docker-compose.yml up --build

smartrouter config/smartrouter_examples/smartrouter_eth.yml --use-static-spec specs/

It listens on port 3360. Send it a request with any of the client snippets above.