eth_getUncleByBlockNumberAndIndex

Returns an uncle block by parent block number and uncle index.

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

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

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

Sources

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