From 5060f863a735f4ecb966cb68dcf5e65986034458 Mon Sep 17 00:00:00 2001
From: Chris Hager <chris@linuxuser.at>
Date: Fri, 4 Jul 2025 14:45:56 +0200
Subject: [PATCH] new receiver flag: builder-ready-endpoint

---
 cmd/receiver-proxy/main.go |  8 ++++++++
 proxy/receiver_api.go      | 11 ++++++++---
 proxy/receiver_proxy.go    |  4 ++++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/cmd/receiver-proxy/main.go b/cmd/receiver-proxy/main.go
index d4b0644..bfbe510 100644
--- a/cmd/receiver-proxy/main.go
+++ b/cmd/receiver-proxy/main.go
@@ -46,6 +46,12 @@ var flags = []cli.Flag{
 		Usage:   "address to send local ordeflow to",
 		EnvVars: []string{"BUILDER_ENDPOINT"},
 	},
+	&cli.StringFlag{
+		Name:    "builder-ready-endpoint",
+		Value:   "http://127.0.0.1:6070",
+		Usage:   "address to send /readyz to",
+		EnvVars: []string{"BUILDER_READY_ENDPOINT"},
+	},
 	&cli.StringFlag{
 		Name:    "rpc-endpoint",
 		Value:   "http://127.0.0.1:8545",
@@ -201,6 +207,7 @@ func runMain(cCtx *cli.Context) error {
 
 	builderEndpoint := cCtx.String("builder-endpoint")
 	rpcEndpoint := cCtx.String("rpc-endpoint")
+	builderReadyEndpoint := cCtx.String("builder-ready-endpoint")
 
 	builderConfigHubEndpoint := cCtx.String("builder-confighub-endpoint")
 	archiveEndpoint := cCtx.String("orderflow-archive-endpoint")
@@ -220,6 +227,7 @@ func runMain(cCtx *cli.Context) error {
 		BuilderConfigHubEndpoint: builderConfigHubEndpoint,
 		ArchiveEndpoint:          archiveEndpoint,
 		ArchiveConnections:       connectionsPerPeer,
+		BuilderReadyEndpoint:     builderReadyEndpoint,
 		EthRPC:                   rpcEndpoint,
 		MaxRequestBodySizeBytes:  maxRequestBodySizeBytes,
 		ConnectionsPerPeer:       connectionsPerPeer,
diff --git a/proxy/receiver_api.go b/proxy/receiver_api.go
index 6b6a198..dfe8397 100644
--- a/proxy/receiver_api.go
+++ b/proxy/receiver_api.go
@@ -80,14 +80,19 @@ func (prx *ReceiverProxy) UserJSONRPCHandler(maxRequestBodySizeBytes int64) (*rp
 
 // readyHandler calls /readyz on rbuilder
 func (prx *ReceiverProxy) readyHandler(w http.ResponseWriter, r *http.Request) error {
-	resp, err := http.Get(prx.LocalBuilderEndpoint + "/readyz")
+	if prx.builderReadyEndpoint == "" {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("ready"))
+		return nil
+	}
+
+	resp, err := http.Get(prx.builderReadyEndpoint + "/readyz")
 	if err != nil {
 		prx.Log.Warn("Failed to check builder readiness", slog.Any("error", err))
 		http.Error(w, "not ready", http.StatusServiceUnavailable)
 		return nil
 	}
 	defer resp.Body.Close()
-
 	if resp.StatusCode != http.StatusOK {
 		http.Error(w, "not ready", http.StatusServiceUnavailable)
 		return nil
@@ -95,7 +100,7 @@ func (prx *ReceiverProxy) readyHandler(w http.ResponseWriter, r *http.Request) e
 
 	// If the builder is ready, return 200 OK
 	w.WriteHeader(http.StatusOK)
-	_, _ = w.Write([]byte("ready"))
+	_, _ = w.Write([]byte("OK"))
 	return nil
 }
 
diff --git a/proxy/receiver_proxy.go b/proxy/receiver_proxy.go
index 54d3ddc..89c3813 100644
--- a/proxy/receiver_proxy.go
+++ b/proxy/receiver_proxy.go
@@ -60,6 +60,8 @@ type ReceiverProxy struct {
 	userAPIRateLimiter *rate.Limiter
 
 	localBuilderSender LocalBuilderSender
+
+	builderReadyEndpoint string
 }
 
 type ReceiverProxyConstantConfig struct {
@@ -76,6 +78,7 @@ type ReceiverProxyConfig struct {
 	BuilderConfigHubEndpoint string
 	ArchiveEndpoint          string
 	ArchiveConnections       int
+	BuilderReadyEndpoint     string
 
 	// EthRPC should support eth_blockNumber API
 	EthRPC string
@@ -110,6 +113,7 @@ func NewReceiverProxy(config ReceiverProxyConfig) (*ReceiverProxy, error) {
 		replacementNonceRLU:         expirable.NewLRU[replacementNonceKey, int](replacementNonceSize, nil, replacementNonceTTL),
 		userAPIRateLimiter:          userAPIRateLimiter,
 		localBuilderSender:          localBuilderSender,
+		builderReadyEndpoint:        config.BuilderReadyEndpoint,
 	}
 	maxRequestBodySizeBytes := DefaultMaxRequestBodySizeBytes
 	if config.MaxRequestBodySizeBytes != 0 {