eth_call

eth_call executes a read-only message call against Polygon's EVM-equivalent state without broadcasting a transaction or spending any MATIC. The node runs your calldata against the target contract at a chosen block and returns the raw return data — nothing is mined, no gas leaves your account. This is the workhorse for reading on-chain state: an ERC-20 balanceOf, a QuickSwap pool's reserves, or an Aave position, all without signing anything. Point it at https://polygon.therpc.io/YOUR_API_KEY (chain ID 137, 0x89) and decode the hex result with the contract ABI.

Use cases

• Read ERC-20 balanceOf, decimals, symbol, or totalSupply — for example query USDT on Polygon at 0xc2132D05D31c914a87C6611C10748AEb04B58e8F.
• Query DEX pool reserves or spot prices from QuickSwap or another Polygon AMM to price a swap.
• Simulate a transaction outcome before signing to catch a revert early and save the user a failed MATIC fee.
• Use the stateOverrides argument to test what-if scenarios — overridden balances or code — without touching live chain state.

Parameters

Response

Example request

1curl https://polygon.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 Polygon playground.

Errors & troubleshooting

Common pitfalls

• State at latest can shift between your call and actual inclusion — at ~2s Polygon blocks the head moves quickly, so never treat a read as a settlement guarantee. For reorg-safe reads use finalized.
• The stateOverrides third argument is not supported by every node; detect the failure and fall back to a plain call rather than assuming it worked.
• A revert comes back 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: 137
• Amoy — Chain ID: 80002

See also

• eth_estimateGas
• eth_sendRawTransaction
• eth_getStorageAt

1curl https://polygon.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"]}'