README.md

Chainlink External Adapter for writing to Ethereum-based Blockchains

This external adapter allows you to configure an endpoint and private key to sign and send transactions to external Ethereum-based blockchains.

A typical workflow of a Chainlink job for this external adapter could look like:

• Retrieve a piece of data from some data source
• Parse the desired field from that data source's response
• Utilize this adapter to write the value to ChainB
• Parse the transaction object from ChainB for the transaction hash
• Write the transaction hash from ChainB to ChainA

Environment Variables

Required?	Name	Description	Options	Defaults to
✅	ETHEREUM_RPC_URL	RPC endpoint for that client. For example http://localhost:8545
✅	PRIVATE_KEY	The private key of a funded account, to sign the transactions from.
✅	CONTRACT_ADDRESS	The contract address that the contract is deployed to.

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Input Parameters

Required?	Name	Description	Options	Defaults to
✅	exAddr	The address for sending the transaction to.
	funcId	The setter function to call:	[0xc2b12a73(for bytes32), 0xa53b1c1e(for int256),0xd2282dc5(for uint256)]	0xd2282dc5
	dataType	Pass this only in case you need to encode the data(normally should be already encoded).	[bytes32, int256, uint256]
	result	The result of the previous adapter
	dataToSend	If specified, this value will be sent instead of result.

---

Output Format

{
  "jobRunID": "1",
  "data": {
    "nonce": 1,
    "gasPrice": { "type": "BigNumber", "hex": "0x04a817c800" },
    "gasLimit": { "type": "BigNumber", "hex": "0x53d8" },
    "to": "0xBb5696deFD9005e0CfD8bf40ae4C1f9beB6c109d",
    "value": { "type": "BigNumber", "hex": "0x00" },
    "data": "0xa53b1c1e0000000000000000000000000000000000000000000000000000000000000036",
    "chainId": 1337,
    "v": 2710,
    "r": "0x58389e578005462f7e8d0c980cd4fca9e16ab4141882f56f98deec0b572da0b3",
    "s": "0x17a977f57a88c3dbbab89beac60beb78ae8ab4dffd676831f84d14151c5b03d5",
    "from": "0x78C696E4cA526f17380DAc7b6C5fd54B17F3f637",
    "hash": "0x311b1e57342f61379bc597813c41bfa7c3535cfc2a49e61b2456c602dd07708e"
  },
  "statusCode": 200
}