PIP-20 : State-Sync Verbosity


Shivam Sharma, Sandeep Sreenath, William Schwab

Type: Core

Table of Contents:

  • Abstract
  • Motivation
  • Specification
  • Backward Compatibility
  • Reference Implementation
  • Copyright


This proposal specifies the addition of event emission in the state-receiver genesis contract on PoS network which can give information on the success of the execution of the stateIDs in a state-sync transaction. It will also enable easier mappings with the Ethereum TxHash <-> Bor-TxHash using heimdall-api as a medium.


Presently, in the event that a stateID encounters failure within the child chain at the execution level owing to inadequate implementation of the recipient contract by a Dapp Developer, no logging or alerts are generated to signal such occurrences. This situation has the potential to impede developers’ progress and lead to the oversight of bugs. The proposed PIP (Protocol Improvement Proposal) addresses this issue by enhancing the observability of state-sync transactions, thereby rectifying the aforementioned challenges.


The event is defined as :

event StateCommitted(uint256 indexed stateId, bool success)

The event is emitted in :

if (isContract(receiver)) {
	uint256 txGas = 5000000;
	bytes memory data = abi.encodeWithSignature("onStateReceive(uint256,bytes)", stateId, stateData);

	assembly {
		success := call(txGas, receiver, 0, add(data, 0x20), mload(data), 0, 0)

	emit StateCommitted(stateId, success);

Genesis changes to upgrade contract on target blockNum :

			"blockAlloc": {
				"<BLOCK_NUMBER>": {
						"balance": "0x0",
						"code": "<NEW_BYTECODE>"

Backward Compatibility

This PIP will not be backward compatible with the current implementation of Bor and will therefore require a Hard Fork.

Reference Implementation


All copyrights and related rights in this work are waived under CC0 1.0 Universal.