From 7b9cd89609b95ae6691481f4bc118954049d9f91 Mon Sep 17 00:00:00 2001
From: maradini77 <140460067+maradini77@users.noreply.github.com>
Date: Mon, 24 Nov 2025 22:17:54 +0100
Subject: [PATCH 1/4] Update service.go

---
 validator/client/service.go | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/validator/client/service.go b/validator/client/service.go
index f4e27254f51d..1484f4e61f8b 100644
--- a/validator/client/service.go
+++ b/validator/client/service.go
@@ -182,7 +182,14 @@ func (v *ValidatorService) Start() {
 	}
 
 	u := strings.ReplaceAll(v.conn.GetBeaconApiUrl(), " ", "")
-	hosts := strings.Split(u, ",")
+	rawHosts := strings.Split(u, ",")
+	hosts := make([]string, 0, len(rawHosts))
+	for _, host := range rawHosts {
+		if host == "" {
+			continue
+		}
+		hosts = append(hosts, host)
+	}
 	if len(hosts) == 0 {
 		log.WithError(err).Error("No API hosts provided")
 		return

From 4f9082234002ab414a17b70235c041907822da21 Mon Sep 17 00:00:00 2001
From: maradini77 <140460067+maradini77@users.noreply.github.com>
Date: Tue, 25 Nov 2025 18:58:10 +0100
Subject: [PATCH 2/4] Create maradini77_patch-2.md

---
 changelog/maradini77_patch-2.md | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 changelog/maradini77_patch-2.md

diff --git a/changelog/maradini77_patch-2.md b/changelog/maradini77_patch-2.md
new file mode 100644
index 000000000000..809755e40a93
--- /dev/null
+++ b/changelog/maradini77_patch-2.md
@@ -0,0 +1,3 @@
+### Fixed
+
+- Fix Beacon API host validation in validator service

From 95d225c0aeead5a53a0436e2184200535c4e93b1 Mon Sep 17 00:00:00 2001
From: maradini77 <140460067+maradini77@users.noreply.github.com>
Date: Tue, 25 Nov 2025 18:59:07 +0100
Subject: [PATCH 3/4] Update maradini77_patch-2.md

---
 changelog/maradini77_patch-2.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changelog/maradini77_patch-2.md b/changelog/maradini77_patch-2.md
index 809755e40a93..8a2c597b7285 100644
--- a/changelog/maradini77_patch-2.md
+++ b/changelog/maradini77_patch-2.md
@@ -1,3 +1,3 @@
 ### Fixed
 
-- Fix Beacon API host validation in validator service
+- Prevent validator service from starting with empty Beacon API host lists by filtering and validating endpoints.

From 69e2c0e4366f10fe173b5969e3155223e3527b93 Mon Sep 17 00:00:00 2001
From: maradini77 <140460067+maradini77@users.noreply.github.com>
Date: Tue, 25 Nov 2025 19:00:10 +0100
Subject: [PATCH 4/4] Update service.go

---
 validator/client/service.go | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/validator/client/service.go b/validator/client/service.go
index 1484f4e61f8b..c3bbf39e28f3 100644
--- a/validator/client/service.go
+++ b/validator/client/service.go
@@ -181,15 +181,7 @@ func (v *ValidatorService) Start() {
 		return
 	}
 
-	u := strings.ReplaceAll(v.conn.GetBeaconApiUrl(), " ", "")
-	rawHosts := strings.Split(u, ",")
-	hosts := make([]string, 0, len(rawHosts))
-	for _, host := range rawHosts {
-		if host == "" {
-			continue
-		}
-		hosts = append(hosts, host)
-	}
+	hosts := sanitizeBeaconAPIHosts(v.conn.GetBeaconApiUrl())
 	if len(hosts) == 0 {
 		log.WithError(err).Error("No API hosts provided")
 		return
@@ -383,6 +375,19 @@ func ConstructDialOptions(
 	return dialOpts
 }
 
+func sanitizeBeaconAPIHosts(raw string) []string {
+	u := strings.ReplaceAll(raw, " ", "")
+	rawHosts := strings.Split(u, ",")
+	hosts := make([]string, 0, len(rawHosts))
+	for _, host := range rawHosts {
+		if host == "" {
+			continue
+		}
+		hosts = append(hosts, host)
+	}
+	return hosts
+}
+
 func (v *ValidatorService) Graffiti(ctx context.Context, pubKey [fieldparams.BLSPubkeyLength]byte) ([]byte, error) {
 	if v.validator == nil {
 		return nil, errors.New("validator is unavailable")