diff --git a/entrypoint.sh b/entrypoint.sh
index ef3c3be..7b8c1b2 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -12,18 +12,28 @@ USER_ID="${INPUT_USER_ID}"
 MESSAGE="${INPUT_MESSAGE}"
 CHANNEL="${INPUT_CHANNEL}"
 
-RESPONSE=$(curl -s -X POST \
+HTTP_CODE=$(curl -s -o /tmp/rc_response -w "%{http_code}" -X POST \
   -H "Content-Type: application/json" \
   -H "X-Auth-Token: ${AUTH_TOKEN}" \
   -H "X-User-Id: ${USER_ID}" \
   -d "$(jq -n --arg channel "$CHANNEL" --arg text "$MESSAGE" '{"channel": $channel, "text": $text}')" \
-  "${SERVER}/api/v1/chat.postMessage")
+  "${SERVER}/api/v1/chat.postMessage") || {
+  echo -e "${RED}${BOLD}✗ Connection failed${RESET} — could not reach ${SERVER}"
+  exit 1
+}
+RESPONSE=$(cat /tmp/rc_response)
 
-mapfile -t response_data < <(jq -r '.success, .channel, .message.u.username, .message._id' <<< "$RESPONSE")
-SUCCESS="${response_data[0]}"
-CHANNEL_NAME="${response_data[1]}"
-SENDER="${response_data[2]}"
-MSG_ID="${response_data[3]}"
+if [ "$HTTP_CODE" = "401" ]; then
+  echo -e "${RED}${BOLD}✗ Authentication failed${RESET} — invalid auth-token or user-id"
+  exit 1
+fi
+
+if ! jq -e '.success' <<< "$RESPONSE" > /dev/null 2>&1; then
+  echo -e "${RED}${BOLD}✗ Unexpected response${RESET} (HTTP ${HTTP_CODE})"
+  exit 1
+fi
+
+SUCCESS=$(jq -r '.success' <<< "$RESPONSE")
 
 if [ "$SUCCESS" != "true" ]; then
   ERROR=$(jq -r '.error // .message // "unknown error"' <<< "$RESPONSE")
@@ -31,4 +41,9 @@ if [ "$SUCCESS" != "true" ]; then
   exit 1
 fi
 
+mapfile -t response_data < <(jq -r '.channel, .message.u.username, .message._id' <<< "$RESPONSE")
+CHANNEL_NAME="${response_data[0]}"
+SENDER="${response_data[1]}"
+MSG_ID="${response_data[2]}"
+
 echo -e "${GREEN}${BOLD}✓ Message sent${RESET} — channel: ${BOLD}${CHANNEL_NAME}${RESET}, sender: ${SENDER}, id: ${MSG_ID}"