diff --git a/proto/safepower_agent.proto b/proto/safepower_agent.proto
index 3ac1091..fb4a05b 100644
--- a/proto/safepower_agent.proto
+++ b/proto/safepower_agent.proto
@@ -1,17 +1,22 @@
-syntax = "proto3";
+edition = "2023";
 
 package safepower_agent_proto;
 
 import "google/protobuf/timestamp.proto";
 
+option features.field_presence = IMPLICIT;
+
 service SafepowerLocalAgent {
   // Get a list of all supported actions
   rpc GetSupportedActions(GetSupportedActionsRequest)
       returns (GetSupportedActionsResponse) {}
+
   // Execute an action when a condition is met
   rpc StartAction(StartActionRequest) returns (StartActionResponse) {}
+
   // Monitor reaction
   rpc MonitorAction(MonitorActionRequest) returns (stream ActionStateLog) {}
+
   // Monitor state.
   rpc MonitorState(MonitorStateRequest) returns (stream SystemState) {}
 }
@@ -25,8 +30,9 @@
 
 // Identifies a component of the system whose state is monitored or acted upon.
 message SystemComponent {
-  optional string node_entity_tag = 1;
-  optional string name = 2;
+  string node_entity_tag = 1 [features.field_presence = EXPLICIT];
+
+  string name = 2 [features.field_presence = EXPLICIT];
 }
 
 enum ActionType {
@@ -45,8 +51,10 @@
 
 // LINT.IfChange(ActionFields)
 message Action {
-  optional ActionType action_type = 1;  // Required
-  optional ActionSeverity action_severity = 2;
+  ActionType action_type = 1 [features.field_presence = EXPLICIT];  // Required
+
+  ActionSeverity action_severity = 2 [features.field_presence = EXPLICIT];
+
   // This may or may not correspond to an entry in SystemStatus reported by
   // this node. For example, it is possible that the actuating node is not the
   // same as the one that can get this status reliably.
@@ -56,13 +64,13 @@
 
 message StartActionRequest {
   // This is an informational string that can be used to identidfy the caller
-  optional string caller_cookie = 1;  // required
+  string caller_cookie = 1 [features.field_presence = EXPLICIT];  // required
+
   // Wait for this condition before running the action. If the matching
   // condition(s) specify that they should abort, the action will not be run. If
   // unspecified, runs the action immediately.
-  optional Condition precondition = 2;
-
-  optional Action action = 3;  // required
+  Condition precondition = 2;
+  Action action = 3;  // required
 
   // Wait until this condition is met. If matching conditions(s) specify that
   // they should abort, the result will be an error.
@@ -70,14 +78,13 @@
 }
 
 message StartActionResponse {
-  optional string response_id = 1;
+  string response_id = 1 [features.field_presence = EXPLICIT];
 }
 
 message Condition {
   oneof condition_type {
     AnyOfCondition any_of = 1;
     AllOfCondition all_of = 2;
-
     StateMatchedCondition state_condition = 3;
     TimeoutCondition timeout = 4;
   }
@@ -99,14 +106,17 @@
   // This matches the keys in SystemState.node_state then
   // NodeState.component_state
   SystemComponent system_component = 1;
+
   // Determine how to compare ComponentStates. Not all types may be applicable
   // to all ComponentState.state types.
-  optional ComparisonType comparison_type = 2;
+  ComparisonType comparison_type = 2 [features.field_presence = EXPLICIT];
+
   // Ignored if matcher is COMPARISON_TYPE_CHANGED. Otherwise, the current state
   // is compared to this state.
   ComponentState component_state = 3;
+
   // If true, the action will be aborted on match.
-  optional bool abort = 4;
+  bool abort = 4 [features.field_presence = EXPLICIT];
 }
 
 enum ComparisonType {
@@ -125,21 +135,24 @@
     uint64 timeout_ms = 1;
     google.protobuf.Timestamp deadline = 2;
   }
+
   // If true, the action will be aborted on match.
-  optional bool abort = 3;
+  bool abort = 3 [features.field_presence = EXPLICIT];
 }
 
 message MonitorActionRequest {
   // This should be an ID returned in StartActionResponse
-  optional string response_id = 1;
+  string response_id = 1 [features.field_presence = EXPLICIT];
 }
 
 message ActionStateLog {
   // Included in all updates. This is a timestamp that is set at service start.
   // This is mostly useful to detect service restarts.
-  optional uint64 epoch_ms = 1;  // required
+  uint64 epoch_ms = 1 [features.field_presence = EXPLICIT];  // required
+
   repeated ActionStateChange history = 2;
-  optional ActionState current_state = 3;  // required
+  ActionState current_state = 3
+      [features.field_presence = EXPLICIT];  // required
 }
 
 enum ActionState {
@@ -153,20 +166,25 @@
 }
 
 message ActionStateChange {
-  optional ActionState previous_state =
-      1;  // Required except for transition to Init
+  ActionState previous_state = 1
+      [features.field_presence =
+           EXPLICIT];  // Required except for transition to Init
+
   // Time when the state changed to the next state
   google.protobuf.Timestamp changed_at = 2;
+
   // Status of the operation that caused the state change
   Status status = 3;
+
   // Optional conditions that matched resulting in the state change. This is
   // only present if the state change was because of a condition match.
   repeated Condition matching_conditions = 4;
 }
 
 message Status {
-  optional int64 code = 1;
-  optional string message = 2;
+  int64 code = 1 [features.field_presence = EXPLICIT];
+
+  string message = 2 [features.field_presence = EXPLICIT];
 }
 
 message MonitorStateRequest {}
@@ -174,13 +192,15 @@
 message SystemState {
   // Included in all updates. This is a timestamp that is set at service start.
   // This is mostly useful to detect service restarts.
-  optional uint64 epoch_ms = 1;  // required
+  uint64 epoch_ms = 1 [features.field_presence = EXPLICIT];  // required
+
   // The contents are platform and node specific. Keys are node entity tags and
   // values are state information for the corresponding node. This includes all
   // nodes for which this node can obtain status. For example, an arena
   // controller may have power state information for other nodes in the arena.
   map<string, NodeState> node_state = 2;
 }
+
 message NodeState {
   // The contents are platform and node specific. Keys are component names
   // (service, subsystem, or other property like power state), values are the
@@ -197,13 +217,15 @@
     BootState boot_state = 65;
     ConnectionState connection_state = 66;
     PowerState power_state = 67;
+
     // add specific types for component types here
   }
 }
 
 message DaemonState {
-  optional uint32 restart_counter = 1;
-  optional bool healthy = 2;
+  uint32 restart_counter = 1 [features.field_presence = EXPLICIT];
+
+  bool healthy = 2 [features.field_presence = EXPLICIT];
 }
 
 enum BootStateSpecifier {
@@ -214,13 +236,15 @@
 }
 
 message BootState {
-  optional uint32 boot_counter = 1;
-  optional uint64 uptime_ms = 2;
-  optional BootStateSpecifier state = 3;
+  uint32 boot_counter = 1 [features.field_presence = EXPLICIT];
+
+  uint64 uptime_ms = 2 [features.field_presence = EXPLICIT];
+
+  BootStateSpecifier state = 3 [features.field_presence = EXPLICIT];
 }
 
 message ConnectionState {
-  optional uint32 reconnect_counter = 1;
+  uint32 reconnect_counter = 1 [features.field_presence = EXPLICIT];
 }
 
 // Based on Redfish PowerState
@@ -234,7 +258,8 @@
 }
 
 message PowerState {
-  optional PowerStateSpecifier state = 1;
-  optional uint32 power_cycle_counter = 2;
+  PowerStateSpecifier state = 1 [features.field_presence = EXPLICIT];
+
+  uint32 power_cycle_counter = 2 [features.field_presence = EXPLICIT];
 }
 // LINT.ThenChange(//depot/state_fields.h:ComponentStateFields)
diff --git a/proto/safepower_agent_config.proto b/proto/safepower_agent_config.proto
index ff620ce..1325416 100644
--- a/proto/safepower_agent_config.proto
+++ b/proto/safepower_agent_config.proto
@@ -1,9 +1,11 @@
-syntax = "proto3";
+edition = "2023";
 
 package safepower_agent_config;
 
 import "safepower_agent.proto";
 
+option features.field_presence = IMPLICIT;
+
 // shared configs
 message SafePowerAgentConfig {
   GpowerdConfig gpowerd_config = 1;
@@ -25,6 +27,7 @@
     RedfishInfo redfish = 1;
     DbusInfo dbus = 2;
   }
+
   uint32 collection_interval_ms = 3;
   safepower_agent_proto.ComponentState prototype = 4;
 }
@@ -44,6 +47,7 @@
 message ActionConfig {
   string action_name = 1;
   safepower_agent_proto.Action action = 2;
+
   oneof info {
     RedfishAction redfish = 4;
     DbusAction dbus = 5;
diff --git a/proto/state_persistence.proto b/proto/state_persistence.proto
index 5ad09c8..164cec2 100644
--- a/proto/state_persistence.proto
+++ b/proto/state_persistence.proto
@@ -1,9 +1,11 @@
-syntax = "proto3";
+edition = "2023";
 
 package safepower_agent_persistence_proto;
 
 import "safepower_agent.proto";
 
+option features.field_presence = IMPLICIT;
+
 message SavedAction {
   safepower_agent_proto.StartActionRequest original_request = 1;
   safepower_agent_proto.ActionStateLog action_state_log = 2;