eth_call

eth_call executes a read-only message call against the Base EVM without broadcasting a transaction or spending any ETH on gas — the node runs your calldata against current state and hands back the return value. Base is Coinbase's OP Stack rollup that settles to Ethereum L1 and uses ETH as its gas token, so this is the method you reach for whenever you need to read contract state rather than mutate it. Send the request to https://base.therpc.io/YOUR_API_KEY (chain ID 8453); because nothing is mined, it costs no gas and never appears on-chain.

Use cases

• Read ERC-20 state such as balanceOf, decimals, symbol, or totalSupply for the many USDC and token contracts deployed on Base.
• Query DEX state directly — Aerodrome or Uniswap pool reserves and spot prices — to price a swap before you route it.
• Simulate a transaction's outcome before signing so you can catch a revert early instead of paying for a failed on-chain attempt.
• Apply state overrides (third argument) to test what-if scenarios — a fake balance or patched code — without touching live Base state.

Parameters

Response

Example request

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_call",
7    "params": [
8        {
9          "to": "0x0000000000000000000000000000000000000000",
10          "data": "0x"
11        },
12        "latest",
13        {}
14      ],
15    "id": 1
16  }'

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• State read at latest can shift before your transaction is actually included — with ~2s Base blocks the gap is short, but a price or reserve read is still a snapshot, not a guarantee.
• State overrides are not supported by every provider; detect the unsupported case and fall back to a plain call rather than assuming the override took effect.
• A revert surfaces as a JSON-RPC error (code 3 or -32000), not as a special success field — always handle the error path and decode the revert reason from the error data.

Supported networks

• Mainnet — Chain ID: 8453
• Sepolia — Chain ID: 84532

See also

• eth_estimateGas
• eth_sendRawTransaction
• eth_getStorageAt

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_call","params":[{"to":"0x0000000000000000000000000000000000000000","data":"0x"},"latest"]}'