eth_getTransactionByBlockNumberAndIndex — Polygon JSON-RPC

Status: Available

Returns a single Polygon transaction selected by its block (number or tag) and its zero-based position within that block.

POSThttps://triport.io/polygon

Network: Polygon
Scope: polygon_read_rpc
Auth: x-token: $TRIPORT_API_KEY (or Authorization: Bearer) (the x-token: $TRIPORT_API_KEY header is also accepted)
Rate limit: free (and up) — 15 rps (free) · 20 rps (basic) · 100 rps (pro) · 250 rps (business); burst = 2 × the sustained rps

Endpoint and plans: Polygon RPC endpoint.

Request

cURLJavaScriptPython

curl https://triport.io/polygon \
  -H "Authorization: Bearer $TRIPORT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_getTransactionByBlockNumberAndIndex",
    "params": ["latest", "0x0"]
  }'

const res = await fetch("https://triport.io/polygon", {
  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 data = await res.json();
console.log(data);

import os


import requests


resp = requests.post(
    "https://triport.io/polygon",
    headers={
        "Authorization": f"Bearer {os.environ['TRIPORT_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "jsonrpc": "2.0",
        "id": 1,
        "method": "eth_getTransactionByBlockNumberAndIndex",
        "params": [
            "latest",
            "0x0",
        ],
    },
)
data = resp.json()
print(data)

Response

JSON

Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "blockHash": "0x9b83c12c69edb74f6c8dd5d052765c1adf940e320bd1291696e6fa07829eee71",
    "blockNumber": "0x3b9aca00",
    "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
    "gas": "0x5208",
    "gasPrice": "0x6fc23ac00",
    "maxFeePerGas": "0x9502f9000",
    "maxPriorityFeePerGas": "0x77359400",
    "hash": "0x2c0a1b3e4d5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f9",
    "input": "0x",
    "nonce": "0x15",
    "to": "0x53bf833a5d6c4dda888f69c22c88c9f356a41614",
    "transactionIndex": "0x0",
    "value": "0xde0b6b3a7640000",
    "type": "0x2",
    "chainId": "0x89",
    "v": "0x1",
    "r": "0x5e1d3a76fbf824220e68236e2d51cb98f349a5a6e4f1f1c3a0f7d2d0c4d7e8a1",
    "s": "0x3a0f7d2d0c4d7e8a15e1d3a76fbf824220e68236e2d51cb98f349a5a6e4f1f1c"
  }
}

eth_getTransactionByBlockNumberAndIndex returns one transaction identified by two coordinates: the block (given as a hex-encoded block number or one of the tags latest, earliest, pending, safe, finalized) and the transaction's zero-based index within that block. Both parameters are passed as 0x-prefixed hex strings.

Reach for it when you already know a transaction's slot in a block — for example while iterating a Polygon block transaction-by-transaction, or when you have an index from a prior eth_getBlockByNumber call and want only that one body rather than the whole block. This is the by-number counterpart of eth_getTransactionByBlockHashAndIndex; use that sibling when you hold the block hash instead, or eth_getTransactionByHash when you already have the transaction's own hash.

Polygon runs Bor consensus with a ~2.1 s block time, so a typical block carries roughly 50–150 transactions. If the block does not exist, or the index is out of range for that block, result is null rather than an error — check for null before reading fields.

Parameters

Positional params array: [blockNumber, transactionIndex].

blockNumberstringrequired

A hex-encoded block number (e.g. "0x3b9aca00") or a tag: latest, earliest, pending, safe, or finalized.

transactionIndexstringrequired

The zero-based position of the transaction in the block, as a 0x-prefixed hex integer (e.g. "0x0" for the first transaction).

Response

Response fields

Field	Type	Description
`jsonrpc`	string	JSON-RPC version, always `"2.0"`.
`id`	number	Echoes the request `id`.
`result`	object \| null	The transaction object, or `null` if the block was not found or the index is out of range.

The transaction object carries the standard EVM fields:

Field	Type	Description
`blockHash`	string	Hash of the containing block; `null` if pending.
`blockNumber`	string (hex)	Block number; `null` if pending.
`from`	string	Sender address.
`to`	string \| null	Recipient address; `null` for contract-creation transactions.
`gas`	string (hex)	Gas supplied by the sender.
`gasPrice`	string (hex)	Effective gas price, in wei.
`maxFeePerGas`	string (hex)	Max fee per gas — present on EIP-1559 (`type` `0x2`) transactions.
`maxPriorityFeePerGas`	string (hex)	Max priority fee per gas — present on EIP-1559 transactions.
`hash`	string	Transaction hash.
`input`	string	Call data, hex.
`nonce`	string (hex)	Sender nonce.
`transactionIndex`	string (hex)	Index of the transaction in the block.
`value`	string (hex)	Value transferred, in wei.
`type`	string	Transaction type (`0x0` legacy, `0x1` access-list, `0x2` EIP-1559).
`chainId`	string (hex)	Chain ID — `0x89` (137) for Polygon mainnet.
`v`, `r`, `s`	string (hex)	ECDSA signature components.

Errors

Errors arrive in the standard JSON-RPC error object; the extra fields move into error.data.

Code	Meaning	When it happens
`401`	`trial_expired`	The free 7-day trial has ended.
`403`	`tier_insufficient`	Your tier is below what the method requires. (Not expected here — this method is included in the Free trial.)
`429`	`rate_limited`	You exceeded the sustained rps for your tier; respect `Retry-After` / `data.retry_after_sec`.
`401`	`subscription_expired`	A previously active paid subscription has lapsed.
`401`	`unauthorized`	Missing, invalid, or revoked credentials.
HTTP `403`	`method_unknown`	The method name was not recognised on the `polygon` chain.

A missing block or an out-of-range index is not an error — it returns result: null. See the shared Errors reference for the full envelope, the HTTP-status mapping, and error.data field definitions.

Examples

JavaScript (fetch)

JavaScript

const res = await fetch("https://triport.io/polygon", {
  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, error } = await res.json();
if (error) throw new Error(`${error.code}: ${error.message}`);
console.log(result === null ? "no such transaction" : result.hash);

Notes

Zero-based index. 0x0 is the first transaction in the block. Use eth_getBlockTransactionCountByNumber to learn the valid index range first.
Null on miss. An out-of-range index or a non-existent block returns result: null, not an error — guard for null before reading fields.
Hex numerics. value, gas, gasPrice, nonce, … are hex strings; convert with base 16 before doing arithmetic. Values are in wei.
Polygon chain ID. chainId is 0x89 (137) for Polygon mainnet.
No daily cap. Rate limiting is sustained-rps-per-tier with a 2× burst allowance — there is no daily quota. See Rate limits.
Related: eth_getTransactionByBlockHashAndIndex (same lookup, by block hash) · eth_getTransactionByHash (by transaction hash) · eth_getBlockByNumber (the whole block at once).