feat: add sendBackrunBundle

pkg/mev/bundle_sender.go

@@ -55,6 +55,56 @@ func (s *Client) SendBundle(
 	return s.sendBundle(ctx, ETHSendBundleMethod, uuid, blockNumber, txs...)
 }
 
+func (s *Client) SendBackrunBundle(
+	ctx context.Context,
+	uuid *string,
+	blockNumber uint64,
+	pendingTxHash common.Hash,
+	txs ...*types.Transaction,
+) (SendBundleResponse, error) {
+	req := SendBundleRequest{
+		ID:      SendBundleID,
+		JSONRPC: JSONRPC2,
+		Method:  ETHSendBundleMethod,
+	}
+	p := new(SendBundleParams).SetBlockNumber(blockNumber).SetTransactions(txs...).SetPendingTxHash(pendingTxHash)
+	if uuid != nil {
+		p.SetUUID(*uuid, s.senderType)
+	}
+	req.Params = append(req.Params, p)
+
+	reqBody, err := json.Marshal(req)
+	if err != nil {
+		return SendBundleResponse{}, fmt.Errorf("marshal json error: %w", err)
+	}
+
+	var headers [][2]string
+	if s.flashbotKey != nil {
+		signature, err := requestSignature(s.flashbotKey, reqBody)
+		if err != nil {
+			return SendBundleResponse{}, fmt.Errorf("sign flashbot request error: %w", err)
+		}
+		headers = append(headers, [2]string{"X-Flashbots-Signature", signature})
+	}
+
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, s.endpoint, bytes.NewBuffer(reqBody))
+	if err != nil {
+		return SendBundleResponse{}, fmt.Errorf("new http request error: %w", err)
+	}
+
+	resp, err := doRequest[SendBundleResponse](s.c, httpReq, headers...)
+	if err != nil {
+		return SendBundleResponse{}, err
+	}
+
+	if len(resp.Error.Messange) != 0 {
+		return SendBundleResponse{}, fmt.Errorf("response error, code: [%d], message: [%s]",
+			resp.Error.Code, resp.Error.Messange)
+	}
+
+	return resp, nil
+}
+
 func (s *Client) CancelBundle(
 	ctx context.Context, bundleUUID string,
 ) error {

pkg/mev/pkg.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net/http"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
@@ -40,6 +41,13 @@ type IBundleSender interface {
 		blockNumber uint64,
 		tx ...*types.Transaction,
 	) (SendBundleResponse, error)
+	SendBackrunBundle(
+		ctx context.Context,
+		uuid *string,
+		blockNumber uint64,
+		pendingTxHash common.Hash,
+		tx ...*types.Transaction,
+	) (SendBundleResponse, error)
 	CancelBundle(
 		ctx context.Context, bundleUUID string,
 	) error