diff --git a/hive-c0re/src/agent_server.rs b/hive-c0re/src/agent_server.rs
index 564b150..f77f953 100644
--- a/hive-c0re/src/agent_server.rs
+++ b/hive-c0re/src/agent_server.rs
@@ -188,5 +188,16 @@ async fn dispatch(req: &AgentRequest, agent: &str, coord: &Arc<Coordinator>) ->
                 },
             }
         }
+        AgentRequest::Remind {
+            message,
+            timing,
+            file_path,
+        } => {
+            // TODO: submit to reminder scheduler
+            // For now, return a stub response
+            AgentResponse::Err {
+                message: "remind not yet implemented".to_owned(),
+            }
+        }
     }
 }
diff --git a/hive-sh4re/src/lib.rs b/hive-sh4re/src/lib.rs
index 2035fe4..ed81051 100644
--- a/hive-sh4re/src/lib.rs
+++ b/hive-sh4re/src/lib.rs
@@ -169,6 +169,17 @@ pub struct InboxRow {
     pub at: i64,
 }
 
+/// Reminder timing: either relative (wait N seconds) or absolute (at unix
+/// timestamp).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "timing_type", rename_all = "snake_case")]
+pub enum ReminderTiming {
+    /// Remind after this many seconds from now.
+    InSeconds { seconds: u64 },
+    /// Remind at this unix timestamp (seconds since epoch).
+    At { unix_timestamp: i64 },
+}
+
 /// Requests on a per-agent socket. The agent's identity is the socket
 /// it came in on; `Send.from` is filled in by the server, not the client.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -218,6 +229,18 @@ pub enum AgentRequest {
         #[serde(default)]
         ttl_seconds: Option<u64>,
     },
+    /// Schedule a reminder message to be delivered to this agent at a
+    /// future time. The reminder lands in the agent's inbox as an auto-sent
+    /// message from `"reminder"`. Use for agent follow-ups (e.g. check task
+    /// status, retry failed operation). Message length is limited; pass
+    /// `file_path` to store in a file and get a path-reference message
+    /// instead.
+    Remind {
+        message: String,
+        timing: ReminderTiming,
+        #[serde(default)]
+        file_path: Option<String>,
+    },
 }
 
 /// Responses on a per-agent socket.