eth_sendRawTransaction

eth_sendRawTransaction is how a signed transaction enters Ethereum. You sign and RLP-encode the transaction client-side with a library like ethers, viem, or web3.js, then pass the resulting hex blob to this method; the node validates it, drops it into its mempool, and gossips it to peers so a validator can include it in an upcoming 12-second slot. The call returns the 32-byte transaction hash right away, which is your handle for tracking the transaction, not proof that it has been mined. Broadcast against https://ethereum.therpc.io/YOUR_API_KEY on chain ID 1. Most transactions today are EIP-1559 type-2, carrying maxFeePerGas and maxPriorityFeePerGas so the protocol can burn the base fee in ETH and route the tip to the proposer. Your private key never leaves your machine; only the signed payload is sent.

Use cases

Move ETH between accounts by signing a simple value transfer offline, then broadcasting the serialized result here.
Deploy a contract by leaving to empty and putting the compiled bytecode in data; the receipt's contractAddress then tells you where it landed.
Call a state-changing contract method, such as an ERC-20 transfer or an approve for a DEX, by encoding the call into data and signing it.

Parameters

#	Name	Type	Required	Description
1	`signedTransaction`	string	Yes	The serialized signed transaction. Build and sign it client-side with a library (e.g. ethers, viem, web3.js); never send a private key to the node.

Response

Type	Description
string	32-byte transaction hash (0x-prefixed). The transaction is now in the mempool but not yet confirmed.

Example request

1curl https://ethereum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_sendRawTransaction",
7    "params": ["0x..."],
8    "id": 1
9  }'

Try it live in the Ethereum playground.

Errors & troubleshooting

Code	Message	Cause
`-32000`	`nonce too low`	The nonce in the signed transaction is lower than the sender's current on-chain nonce.
`-32000`	`insufficient funds for gas * price + value`	The sender does not have enough native-token balance to cover gas cost and the transferred value.
`-32000`	`replacement transaction underpriced`	Tried to replace a pending transaction (same nonce) but the new fee is not high enough (typically requires ≥10% bump).

Common pitfalls

The returned hash only means the node accepted the transaction into its mempool. Inclusion is a separate step: poll eth_getTransactionReceipt until it returns non-null to know the transaction was actually mined.
A clean broadcast is not a successful execution. The transaction can still revert on-chain, in which case the receipt comes back with status: "0x0" and the sender still paid for the gas burned up to the revert.
Read a fresh nonce with eth_getTransactionCount right before signing. A stale nonce triggers a nonce-too-low rejection, and to replace a stuck pending transaction you must reuse its nonce with a fee bump of roughly 10% or more, or you will hit replacement-transaction-underpriced.

Supported networks

Mainnet — Chain ID: 1
Sepolia — Chain ID: 11155111