diff --git a/app/api-token-vault/src/rotation.rs b/app/api-token-vault/src/rotation.rs
new file mode 100644
index 0000000..1115d3b
--- /dev/null
+++ b/app/api-token-vault/src/rotation.rs
@@ -0,0 +1,215 @@
+use crate::vault::Vault;
+use crate::token::TokenData;
+use chrono::{DateTime, Utc, Duration};
+use std::collections::HashMap;
+
+#[derive(Debug, Clone)]
+pub struct RotationSchedule {
+    pub token_name: String,
+    pub rotation_days: u32,
+    pub last_rotated: Option<DateTime<Utc>>,
+    pub next_rotation: Option<DateTime<Utc>>,
+}
+
+impl RotationSchedule {
+    pub fn from_token(token_name: &str, token_data: &TokenData) -> Option<Self> {
+        if !token_data.auto_rotate {
+            return None;
+        }
+        
+        let last_rotated = token_data.last_rotated.unwrap_or(token_data.created_at);
+        let next_rotation = Some(last_rotated + Duration::days(token_data.rotation_days.unwrap_or(30) as i64));
+        
+        Some(RotationSchedule {
+            token_name: token_name.to_string(),
+            rotation_days: token_data.rotation_days.unwrap_or(30),
+            last_rotated: Some(last_rotated),
+            next_rotation,
+        })
+    }
+    
+    pub fn is_due(&self) -> bool {
+        if let Some(next) = self.next_rotation {
+            Utc::now() >= next
+        } else {
+            false
+        }
+    }
+    
+    pub fn days_until_rotation(&self) -> Option<i64> {
+        self.next_rotation.map(|next| {
+            let diff = next - Utc::now();
+            diff.num_days()
+        })
+    }
+}
+
+pub struct RotationEngine;
+
+impl RotationEngine {
+    pub fn check_schedules(vault: &Vault) -> Vec<RotationSchedule> {
+        let mut schedules = Vec::new();
+        
+        for (name, token_data) in &vault.tokens {
+            if let Some(schedule) = RotationSchedule::from_token(name, token_data) {
+                schedules.push(schedule);
+            }
+        }
+        
+        schedules
+    }
+    
+    pub fn get_due_rotations(vault: &Vault) -> Vec<RotationSchedule> {
+        Self::check_schedules(vault)
+            .into_iter()
+            .filter(|s| s.is_due())
+            .collect()
+    }
+    
+    pub fn get_upcoming_rotations(vault: &Vault, days: i64) -> Vec<RotationSchedule> {
+        let now = Utc::now();
+        let threshold = now + Duration::days(days);
+        
+        Self::check_schedules(vault)
+            .into_iter()
+            .filter(|s| {
+                if let Some(next) = s.next_rotation {
+                    next >= now && next <= threshold
+                } else {
+                    false
+                }
+            })
+            .collect()
+    }
+    
+    pub fn rotate_due_tokens(vault: &mut Vault) -> HashMap<String, String> {
+        let due_names: Vec<String> = vault.tokens.iter()
+            .filter(|(_, token)| token.should_rotate())
+            .map(|(name, _)| name.clone())
+            .collect();
+        
+        let mut results = HashMap::new();
+        
+        for name in due_names {
+            if let Ok(new_value) = vault.rotate_token(&name, true) {
+                results.insert(name, new_value);
+            }
+        }
+        
+        results
+    }
+    
+    pub fn calculate_next_rotation(token_data: &TokenData) -> Option<DateTime<Utc>> {
+        let base_time = token_data.last_rotated.unwrap_or(token_data.created_at);
+        let days = token_data.rotation_days.unwrap_or(30);
+        Some(base_time + Duration::days(days as i64))
+    }
+    
+    pub fn format_schedule_report(schedules: &[RotationSchedule]) -> String {
+        if schedules.is_empty() {
+            return "No scheduled rotations".to_string();
+        }
+        
+        let mut report = String::from("Rotation Schedule:\n");
+        report.push_str(&"=".repeat(50));
+        report.push('\n');
+        
+        let mut due_count = 0;
+        let mut upcoming_count = 0;
+        
+        for schedule in schedules {
+            let status = if schedule.is_due() {
+                due_count += 1;
+                "DUE NOW"
+            } else if let Some(days) = schedule.days_until_rotation() {
+                upcoming_count += 1;
+                format!("in {} days", days)
+            } else {
+                "unknown".to_string()
+            };
+            
+            report.push_str(&format!(
+                "  {}: every {} days - {}\n",
+                schedule.token_name,
+                schedule.rotation_days,
+                status
+            ));
+        }
+        
+        report.push_str(&"-".repeat(50));
+        report.push('\n');
+        report.push_str(&format!("Due now: {}, Upcoming: {}\n", due_count, upcoming_count));
+        
+        report
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::vault::Vault;
+    
+    #[test]
+    fn test_rotation_schedule_creation() {
+        let password = "test";
+        let project = "test_schedule";
+        
+        let mut vault = Vault::initialize(password, project).unwrap();
+        vault.generate_token("auto_rotate", 32).unwrap();
+        vault.set_rotation("auto_rotate", 30).unwrap();
+        
+        let schedules = RotationEngine::check_schedules(&vault);
+        assert_eq!(schedules.len(), 1);
+        assert_eq!(schedules[0].token_name, "auto_rotate");
+        assert_eq!(schedules[0].rotation_days, 30);
+        
+        let vault_path = Vault::get_vault_path(project).unwrap();
+        if vault_path.exists() {
+            std::fs::remove_file(&vault_path).unwrap();
+        }
+    }
+    
+    #[test]
+    fn test_manual_rotation_not_scheduled() {
+        let password = "test";
+        let project = "test_manual";
+        
+        let mut vault = Vault::initialize(password, project).unwrap();
+        vault.generate_token("manual", 32).unwrap();
+        
+        let schedules = RotationEngine::check_schedules(&vault);
+        assert!(schedules.is_empty());
+        
+        let vault_path = Vault::get_vault_path(project).unwrap();
+        if vault_path.exists() {
+            std::fs::remove_file(&vault_path).unwrap();
+        }
+    }
+    
+    #[test]
+    fn test_schedule_report() {
+        let schedules = vec![
+            RotationSchedule {
+                token_name: "token1".to_string(),
+                rotation_days: 30,
+                last_rotated: Some(Utc::now() - Duration::days(35)),
+                next_rotation: Some(Utc::now() - Duration::days(5)),
+            },
+            RotationSchedule {
+                token_name: "token2".to_string(),
+                rotation_days: 60,
+                last_rotated: Some(Utc::now()),
+                next_rotation: Some(Utc::now() + Duration::days(60)),
+            },
+        ];
+        
+        let report = RotationEngine::format_schedule_report(&schedules);
+        assert!(report.contains("token1"));
+        assert!(report.contains("token2"));
+        assert!(report.contains("DUE NOW"));
+        assert!(report.contains("in 60 days"));
+        
+        let empty_report = RotationEngine::format_schedule_report(&[]);
+        assert_eq!(empty_report, "No scheduled rotations");
+    }
+}