eth_getTransactionByBlockNumberAndIndex

eth_getTransactionByBlockNumberAndIndex returns a single transaction object selected by two coordinates: the block (by number or block tag) and the transaction's zero-based index within that block. Both the block number and the index are 0x-prefixed hexadecimal strings.

Use it when you already know a transaction's position in a block — for example when iterating a block's transactions one at a time, when you have the index from a prior eth_getBlockByNumber call, or when reconstructing a block body without fetching every transaction at once. If you have the block hash rather than its number, use the sibling method eth_getTransactionByBlockHashAndIndex. If you have the transaction hash directly, use eth_getTransactionByHash.

If the block does not exist, or the index is out of range for that block, the result is null rather than an error.

Pass a two-element positional array.

Response fields

The transaction object contains the standard Ethereum fields:

See errors.md for the full error envelope and handling guidance.

JavaScript (fetch)

const res = await fetch("https://api.triport.io/v1/ethereum", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.TRIPORT_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "eth_getTransactionByBlockNumberAndIndex",
    params: ["latest", "0x0"],
  }),
});


const { result } = await res.json();
console.log(result === null ? "no such transaction" : result.hash);

TypeScript SDK (@triport/sdk)

import { Triport } from "@triport/sdk";


const client = new Triport({ apiKey: process.env.TRIPORT_API_KEY! });


type Transaction = { hash: string; from: string; to: string | null; value: string };


const tx = await client.ethereum.request<Transaction | null>(
  "eth_getTransactionByBlockNumberAndIndex",
  ["0x149e2c1", "0x0"],
);
console.log(tx?.hash ?? "no such transaction");

Python (triport-sdk)

import os
from triport import Triport


client = Triport(api_key=os.environ["TRIPORT_API_KEY"])


tx = client.ethereum.request(
    "eth_getTransactionByBlockNumberAndIndex",
    ["latest", "0x0"],
)
print(tx["hash"] if tx else "no such transaction")

• The index is zero-based: 0x0 is the first transaction in the block.
• An out-of-range index or a non-existent block returns result: null, not an error — check for null before reading fields.
• Numeric fields (value, gas, gasPrice, nonce, …) are hex strings; convert with base 16 before arithmetic.
• eth_getTransactionByBlockNumberAndIndex is available on the free tier (eth_read_rpc category).
• Rate limiting is RPS-per-tier with burst; there is no daily quota. A -32003 rate_limited error means you should back off and retry shortly.
• To select by block hash instead, use eth_getTransactionByBlockHashAndIndex. To look up a transaction by its own hash, use eth_getTransactionByHash. To count a block's transactions first, use eth_getBlockTransactionCountByNumber.