eth_chainId

eth_chainId JSON-RPC reference for MegaETH.

Summary

Returns the chain ID of the connected network.

The public MegaETH endpoint supports this method. The standard, node, and gateway layers below identify behavior that differs from a generic Ethereum endpoint.

Parameters

None.

Result

result Quantity

The chain ID for the connected network.

Comparison with Ethereum Standard JSON-RPC

Ethereum Standard

The canonical Ethereum method uses the parameter and result contract documented above, including the stated null, false, or zero-value semantics where applicable.

MegaETH Node Behavior

The node derives this value from its chain specification. MegaETH Mainnet uses chain ID 4326; callers should read the value rather than hardcode it across environments.

MegaETH Public Gateway

The gateway uses the instant read tier and caches the immutable result for 30 minutes. MegaETH Mainnet returned chain ID 4326 in the captured example.

Errors

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

No method-specific errors were observed.

Code	Scope	Message	When it happens
-32005	Transport/policy	Rate limit exceeded	The caller exceeds the public gateway's instant read budget.
-32099	Transport/policy	Payload too large	The request body exceeds the 128 KiB public endpoint limit.

See also Error Codes.

Examples

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

Capture date: July 24, 2026

Outcome: success

{
  "jsonrpc": "2.0",
  "id": 31,
  "method": "eth_chainId",
  "params": []
}

{
  "jsonrpc": "2.0",
  "id": 31,
  "result": "0x10e6"
}

Sources

• Spec: [email protected]:ethereum/execution-apis.git @ d24f58b56dcd16ab0f0c70ec609bcc1c42750b51: src/eth/client.yaml
• Code: [email protected]:megaeth-labs/mega-reth.git @ ab60376631228edab3a6df180f295280bad26e93: crates/rpc/rpc-eth-api/src/core.rs
• Code: [email protected]:megaeth-labs/mega-rpc.git @ 06aa35aa95d569c227cc25d2aa12834eb0458aa0: workers/src/spec/methods.ts
• Probe: MegaETH Mainnet public endpoint, July 24, 2026