Ethereum
Ethereum
¿Listo para usar esto en producción?
El plan gratuito cubre proyectos personales. El pago por uso escala sin necesidad de tarjeta.
Ethereum
El plan gratuito cubre proyectos personales. El pago por uso escala sin necesidad de tarjeta.
These are the operations almost every Ethereum integration needs on day one: read an account's ETH balance, look up a transaction and its receipt, fetch a block, call a contract's view function, and pull the gas price and nonce you need before sending. Each one is a plain JSON-RPC POST to https://ethereum.therpc.io/YOUR_API_KEY. The examples below run unmodified against chain 1.
Start with two reads that everything else builds on. eth_blockNumber returns the height of the current chain head as a hex string — handy for confirming your endpoint is live and tracking how far behind you are. eth_getBalance returns an account's balance, but mind the units: the value comes back in wei, the smallest denomination, so you divide by 10^18 (ETH has 18 decimals) to read it as ETH. A balance of 0xde0b6b3a7640000 is one whole ETH.
There are two ways to look at a transaction. eth_getTransactionByHash returns the transaction itself — sender, recipient, value, gas settings, and whether it is still pending or already mined. eth_getTransactionReceipt returns the outcome after it lands in a block: the status field (0x1 success, 0x0 revert), the block it was included in, gas actually used, and the full array of event logs the transaction emitted. A null receipt means the transaction has not been mined yet, so receipts are what you poll while waiting for confirmation.
You can fetch a block either by its number with eth_getBlockByNumber or by its hash with eth_getBlockByHash. By-number also accepts the named tags — latest, safe, finalized, pending, earliest — which is how you read at proof-of-stake finality instead of at the head. Both take a boolean second parameter: pass false to get just the list of transaction hashes (smaller, faster), or true to get every transaction expanded into a full object inline.
Two methods cover reading from contracts. eth_call executes a function against the current state without sending a transaction or spending gas — this is how you read an ERC-20 balanceOf, a Uniswap pool's reserves, or any view function. The data field carries the ABI-encoded selector and arguments. eth_getCode returns the deployed bytecode at an address; a non-empty result confirms the address is a contract rather than an externally owned account, and 0x means there is no code there.
Two checks tell you about the node and the network. net_version returns the network ID as a string — 1 for Ethereum mainnet — which is a quick way to confirm you have not accidentally pointed at Sepolia or Holesky. eth_syncing reports whether the node is still catching up: it returns false once fully synced, or an object with current and highest block numbers while it is still importing. Reads served while a node is mid-sync can be stale, so this is worth checking if results look behind.
Before you broadcast a transaction you need two values. eth_gasPrice returns a single suggested price in wei — the legacy path; for EIP-1559 type-2 transactions you would instead build maxFeePerGas and maxPriorityFeePerGas from eth_feeHistory and eth_maxPriorityFeePerGas. eth_getTransactionCount returns the account's nonce, the count of transactions it has already sent. The nonce sequences transactions from an address: each one must use the next integer in order, and a gap leaves later transactions stuck in the queued pool until the missing nonce arrives.