eth_getUncleCountByBlockNumber — Ethereum JSON-RPC

Status: Available

Returns the number of uncles (ommers) in the block identified by its number or a block tag.

POSThttps://triport.io/eth

Network: Ethereum
Scope: eth_read_rpc
Auth: x-token: $TRIPORT_API_KEY (or Authorization: Bearer)
Rate limit: free 10 RPS sustained · up to 20 burst · basic 20 RPS sustained · up to 40 burst · pro 100 RPS sustained · up to 200 burst · business 250 RPS sustained · up to 500 burst; Burst capacity

Endpoint and plans: Ethereum RPC endpoint.

Request

cURLJavaScriptPython

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

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

import os


import requests


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

Response

JSON

Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x0"
}

eth_getUncleCountByBlockNumber returns how many uncle blocks (also called ommers) are referenced by a given block, selected by block number (a 0x-prefixed hex integer) or by one of the named block tags. The count is returned as a 0x-prefixed hexadecimal string.

Uncles were a feature of Ethereum's proof-of-work consensus, where a valid block that lost the race to be canonical could still be referenced by a later block. Since the Merge (proof-of-stake), Ethereum no longer produces uncles, so this method always returns 0x0 for any post-Merge block. It is retained for compatibility with tools and clients that still inspect the uncle list. To read historical uncle counts, query a pre-Merge block number.

If you already have a block hash instead of a number, use the sibling method eth_getUncleCountByBlockHash. A request for a block that does not exist (e.g. a height beyond the current chain head) returns a result of null rather than an error.

Parameters

Pass a single-element positional array.

blockParameterstringrequired

Either a 0x-prefixed hex block number (e.g. 0x149e2c1) or a block tag: latest, earliest, pending, safe, or finalized.

Response

"0x0" decodes to 0 uncles — the expected value for any post-Merge block.

jsonrpcstring

JSON-RPC version, always "2.0".

idnumber

Echoes the request id.

resultstring | null

Number of uncles in the block as a 0x-prefixed hex string (0x0 for post-Merge blocks), or null if the block was not found.

Errors

Code	Meaning	When it happens
`401`	`trial_expired`	The account's trial period has ended.
`429`	`rate_limited`	The per-tier RPS limit was exceeded. Back off and retry.

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

Examples

JavaScript (fetch)

JavaScript

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


const { result } = await res.json();
console.log("uncle count:", result === null ? null : parseInt(result, 16)); // 0

Notes

The result is a hex string — convert with base 16 before arithmetic.
Post-Merge (proof-of-stake) Ethereum produces no uncles, so latest and any recent block return 0x0. Non-zero counts only appear for historical pre-Merge block numbers.
A non-existent block returns result: null, not an error; check for null before parsing.
eth_getUncleCountByBlockNumber is available on the Free trial (eth_read_rpc category).
Rate limiting is RPS-per-tier with burst; there is no daily quota. An HTTP 429 rate_limited error means you should back off and retry shortly.
To look up the uncle count by block hash instead, use eth_getUncleCountByBlockHash. To fetch the full block, use eth_getBlockByNumber.