From 917baceda86a971ac4c27c22ddb18635e63169d7 Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Thu, 21 Aug 2025 13:40:35 +0800
Subject: [PATCH] ethclient, internal/ethapi: add support for EIP-695
 (eth_chainId) #19694 #23778 (#1362)

* ethclient, internal/ethapi: add support for EIP-695 (eth_chainId) #19694

* ethclient: fix typo #23778
---
 ethclient/ethclient.go | 10 ++++++++++
 internal/ethapi/api.go |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/ethclient/ethclient.go b/ethclient/ethclient.go
index 0d1b86d04d..19e15c77a2 100644
--- a/ethclient/ethclient.go
+++ b/ethclient/ethclient.go
@@ -63,6 +63,16 @@ func (ec *Client) Close() {
 
 // Blockchain Access
 
+// ChainID retrieves the current chain ID for transaction replay protection.
+func (ec *Client) ChainID(ctx context.Context) (*big.Int, error) {
+	var result hexutil.Big
+	err := ec.c.CallContext(ctx, &result, "eth_chainId")
+	if err != nil {
+		return nil, err
+	}
+	return (*big.Int)(&result), err
+}
+
 // BlockByHash returns the given full block.
 //
 // Note that loading full blocks requires two requests. Use HeaderByHash
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index acac735cbf..432d5a4306 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -306,6 +306,11 @@ func NewBlockChainAPI(b Backend, chainReader consensus.ChainReader) *BlockChainA
 	}
 }
 
+// ChainId returns the chainID value for transaction replay protection.
+func (s *BlockChainAPI) ChainId() *hexutil.Big {
+	return (*hexutil.Big)(s.b.ChainConfig().ChainId)
+}
+
 // BlockNumber returns the block number of the chain head.
 func (s *BlockChainAPI) BlockNumber() hexutil.Uint64 {
 	header, _ := s.b.HeaderByNumber(context.Background(), rpc.LatestBlockNumber) // latest header should always be available