diff --git a/signal-gateway-bin/src/main.rs b/signal-gateway-bin/src/main.rs
index ca66332..f658f2a 100644
--- a/signal-gateway-bin/src/main.rs
+++ b/signal-gateway-bin/src/main.rs
@@ -244,7 +244,7 @@ limits = [
             Duration::from_secs(10)
         );
         assert_eq!(config.gateway.admin_signal_uuids.len(), 2);
-        assert!(config.gateway.admin_signal_uuids.contains_key("abc-123-uuid"));
+        assert!(config.gateway.admin_signal_uuids.contains("abc-123-uuid"));
 
         let syslog = config.syslog.expect("syslog should be present");
         assert_eq!(syslog.listen_addr, "0.0.0.0:1514".parse().unwrap());
diff --git a/signal-gateway/src/gateway/admin_uuids.rs b/signal-gateway/src/gateway/admin_uuids.rs
new file mode 100644
index 0000000..ee0f36a
--- /dev/null
+++ b/signal-gateway/src/gateway/admin_uuids.rs
@@ -0,0 +1,169 @@
+//! Admin Signal UUIDs container with flexible deserialization.
+//!
+//! Supports two formats:
+//! - Map: `{"uuid1": ["safety1", "safety2"], "uuid2": []}`
+//! - Sequence: `["uuid1", "uuid2"]` (treated as UUIDs with no safety numbers)
+
+use serde::de::{MapAccess, SeqAccess, Visitor};
+use serde::{Deserialize, Deserializer};
+use std::collections::HashMap;
+use std::fmt;
+
+/// Container for admin Signal UUIDs mapped to their optional safety numbers.
+///
+/// Can be deserialized from either:
+/// - A map of UUID -> safety numbers: `{"uuid1": ["12345..."], "uuid2": []}`
+/// - A sequence of UUIDs (no safety numbers): `["uuid1", "uuid2"]`
+#[derive(Clone, Debug, Default)]
+pub struct AdminSignalUuids {
+    map: HashMap<String, Vec<String>>,
+}
+
+impl AdminSignalUuids {
+    /// Create an empty container.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Check if a UUID is a registered admin.
+    pub fn contains(&self, uuid: &str) -> bool {
+        self.map.contains_key(uuid)
+    }
+
+    /// Get all admin UUIDs.
+    pub fn uuids(&self) -> impl Iterator<Item = &String> {
+        self.map.keys()
+    }
+
+    /// Get the number of admin UUIDs.
+    pub fn len(&self) -> usize {
+        self.map.len()
+    }
+
+    /// Check if empty.
+    pub fn is_empty(&self) -> bool {
+        self.map.is_empty()
+    }
+
+    /// Iterate over UUID and safety number pairs.
+    pub fn iter(&self) -> impl Iterator<Item = (&String, &Vec<String>)> {
+        self.map.iter()
+    }
+
+    /// Get safety numbers for a specific UUID.
+    pub fn get(&self, uuid: &str) -> Option<&Vec<String>> {
+        self.map.get(uuid)
+    }
+}
+
+impl<'de> Deserialize<'de> for AdminSignalUuids {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_any(AdminSignalUuidsVisitor)
+    }
+}
+
+struct AdminSignalUuidsVisitor;
+
+impl<'de> Visitor<'de> for AdminSignalUuidsVisitor {
+    type Value = AdminSignalUuids;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a map of UUIDs to safety numbers, or a sequence of UUIDs")
+    }
+
+    fn visit_map<M>(self, mut access: M) -> Result<Self::Value, M::Error>
+    where
+        M: MapAccess<'de>,
+    {
+        let mut map = HashMap::with_capacity(access.size_hint().unwrap_or(0));
+        while let Some((key, value)) = access.next_entry::<String, Vec<String>>()? {
+            map.insert(key, value);
+        }
+        Ok(AdminSignalUuids { map })
+    }
+
+    fn visit_seq<S>(self, mut access: S) -> Result<Self::Value, S::Error>
+    where
+        S: SeqAccess<'de>,
+    {
+        let mut map = HashMap::with_capacity(access.size_hint().unwrap_or(0));
+        while let Some(uuid) = access.next_element::<String>()? {
+            map.insert(uuid, Vec::new());
+        }
+        Ok(AdminSignalUuids { map })
+    }
+}
+
+impl FromIterator<String> for AdminSignalUuids {
+    fn from_iter<I: IntoIterator<Item = String>>(iter: I) -> Self {
+        Self {
+            map: iter.into_iter().map(|uuid| (uuid, Vec::new())).collect(),
+        }
+    }
+}
+
+impl FromIterator<(String, Vec<String>)> for AdminSignalUuids {
+    fn from_iter<I: IntoIterator<Item = (String, Vec<String>)>>(iter: I) -> Self {
+        Self {
+            map: iter.into_iter().collect(),
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a AdminSignalUuids {
+    type Item = (&'a String, &'a Vec<String>);
+    type IntoIter = std::collections::hash_map::Iter<'a, String, Vec<String>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.map.iter()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_deserialize_map() {
+        let json = r#"{"uuid1": ["safety1", "safety2"], "uuid2": []}"#;
+        let uuids: AdminSignalUuids = serde_json::from_str(json).unwrap();
+
+        assert_eq!(uuids.len(), 2);
+        assert!(uuids.contains("uuid1"));
+        assert!(uuids.contains("uuid2"));
+        assert_eq!(uuids.get("uuid1").unwrap(), &vec!["safety1", "safety2"]);
+        assert_eq!(uuids.get("uuid2").unwrap(), &Vec::<String>::new());
+    }
+
+    #[test]
+    fn test_deserialize_seq() {
+        let json = r#"["uuid1", "uuid2", "uuid3"]"#;
+        let uuids: AdminSignalUuids = serde_json::from_str(json).unwrap();
+
+        assert_eq!(uuids.len(), 3);
+        assert!(uuids.contains("uuid1"));
+        assert!(uuids.contains("uuid2"));
+        assert!(uuids.contains("uuid3"));
+        // All should have empty safety numbers
+        assert!(uuids.get("uuid1").unwrap().is_empty());
+        assert!(uuids.get("uuid2").unwrap().is_empty());
+        assert!(uuids.get("uuid3").unwrap().is_empty());
+    }
+
+    #[test]
+    fn test_empty_map() {
+        let json = r#"{}"#;
+        let uuids: AdminSignalUuids = serde_json::from_str(json).unwrap();
+        assert!(uuids.is_empty());
+    }
+
+    #[test]
+    fn test_empty_seq() {
+        let json = r#"[]"#;
+        let uuids: AdminSignalUuids = serde_json::from_str(json).unwrap();
+        assert!(uuids.is_empty());
+    }
+}
diff --git a/signal-gateway/src/gateway/mod.rs b/signal-gateway/src/gateway/mod.rs
index 470670b..d58ce2a 100644
--- a/signal-gateway/src/gateway/mod.rs
+++ b/signal-gateway/src/gateway/mod.rs
@@ -20,14 +20,7 @@ use http::{Method, Request, Response, StatusCode};
 use http_body::Body;
 use http_body_util::BodyExt;
 use prometheus_http_client::{AlertStatus, ExtractLabels};
-use std::{
-    collections::HashMap,
-    fmt::Write,
-    net::SocketAddr,
-    path::PathBuf,
-    sync::Mutex,
-    time::Duration,
-};
+use std::{fmt::Write, net::SocketAddr, path::PathBuf, sync::Mutex, time::Duration};
 use tokio::{
     join,
     sync::mpsc::{UnboundedReceiver, UnboundedSender, unbounded_channel},
@@ -35,6 +28,9 @@ use tokio::{
 use tokio_util::{bytes::Buf, sync::CancellationToken};
 use tracing::{debug, error, info, warn};
 
+mod admin_uuids;
+pub use admin_uuids::AdminSignalUuids;
+
 mod log_buffer;
 mod log_handler;
 use log_handler::{LogHandler, LogHandlerConfig};
@@ -67,9 +63,9 @@ pub struct GatewayConfig {
     #[conf(long, env, default_value = "5s", value_parser = conf_extra::parse_duration, serde(use_value_parser))]
     pub signal_cli_retry_delay: Duration,
     /// Admin UUIDs mapped to their safety numbers (can be empty).
-    /// Example: `{"uuid1": ["12345...", "67890..."], "uuid2": []}`
+    /// Accepts either a map `{"uuid1": ["12345..."], "uuid2": []}` or a list `["uuid1", "uuid2"]`.
     #[conf(long, env, value_parser = serde_json::from_str)]
-    pub admin_signal_uuids: HashMap<String, Vec<String>>,
+    pub admin_signal_uuids: AdminSignalUuids,
     /// If set, alerts are sent to this group instead of individual admins.
     #[conf(long, env)]
     pub alert_group_id: Option<String>,
@@ -84,12 +80,12 @@ pub struct GatewayConfig {
 impl GatewayConfig {
     /// Check if a UUID is a registered admin
     pub fn is_admin(&self, uuid: &str) -> bool {
-        self.admin_signal_uuids.contains_key(uuid)
+        self.admin_signal_uuids.contains(uuid)
     }
 
     /// Get all admin UUIDs
     pub fn admin_uuids(&self) -> Vec<String> {
-        self.admin_signal_uuids.keys().cloned().collect()
+        self.admin_signal_uuids.uuids().cloned().collect()
     }
 }