🟪 Polygon

Polygon API Documentation

eth_chainId JSON-RPC method

eth_chainId is used to retrieve the current chain ID. The chain ID is a unique identifier for each Blockchain network that is used to differentiate between them.


Polygon network chain ID is 137

This method can be used to verify that your node is connected to the correct Blockchain network. Each Blockchain network has a unique chain ID, so you can compare the returned value to the known chain ID of the network you want to connect to.


Chain id - Hexadecimal value in string format which represents an integer of the chain ID




POST https://<network>.chainnodes.org/YOUR-API-KEY


  • HTTPS POST Request with a JSON RPC call in the body
  • Replace YOUR-API-KEY with the API key from your CHAINNODES.ORG Dashboard
  • You can use a different supported network by replacing polygon-mainnet
curl https://polygon-mainnet.chainnodes.org/YOUR-API-KEY \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'

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  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1"

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JSON-RPC API Documentation by CHAINNODES is based on Erigon node client. Contact us if you are interested in specific methods that are only available on geth, besu, Nethermind or reth