> For the complete documentation index, see [llms.txt](https://docs.megaeth.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.megaeth.com/developer-docs/rpc/reference/eth_getunclebyblocknumberandindex.md).

# eth\_getUncleByBlockNumberAndIndex

## Summary

Returns an uncle block selected by its parent block number or tag and index. MegaETH blocks do not contain proof-of-work uncles, so the method returns `null` for valid MegaETH blocks.

## Parameters

| Position | Name    | Type                    | Required | Description                                                              |
| -------- | ------- | ----------------------- | -------- | ------------------------------------------------------------------------ |
| `0`      | `block` | `QUANTITY` or block tag | Yes      | Block number or `latest`, `safe`, `finalized`, `earliest`, or `pending`. |
| `1`      | `index` | `QUANTITY`              | Yes      | Zero-based uncle index.                                                  |

## Result

The result is a block object or `null` when no uncle exists at the selected index. On MegaETH, `null` is expected and does not mean that the parent block itself is missing.

## Comparison with Ethereum Standard JSON-RPC

### Ethereum Standard

The method returns the uncle header at the selected index as a block object without transactions.

### MegaETH Node Behavior

MegaETH inherits the compatibility method, but its proof-of-stake L2 blocks do not contain proof-of-work uncles.

### MegaETH Public Gateway

The gateway may cache immutable selections and treats head tags as dynamic. A lookup at index zero for the `latest` block returned `null` on July 24, 2026.

## Errors

The `| Scope |` column distinguishes method failures from gateway policy errors.

| Code     | Scope            | Message           | When it happens                                      |
| -------- | ---------------- | ----------------- | ---------------------------------------------------- |
| `-32602` | Method           | Invalid params    | The block selector or index is missing or malformed. |
| `-32099` | Transport/policy | Payload too large | The request exceeds the public endpoint body limit.  |

No method-specific errors were observed for a canonical lookup.

## Examples

Endpoint: `https://mainnet.megaeth.com/rpc`

Capture date: July 24, 2026

Outcome: null

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getUncleByBlockNumberAndIndex",
  "params": ["latest", "0x0"]
}
```

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": null
}
```

## Sources

* Probe: MegaETH Mainnet public endpoint, July 24, 2026


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