Capsule

README.md

@@ -0,0 +1,104 @@
+# TimeCapsule 🕰️🔒
+
+## Overview
+
+TimeCapsule is a decentralized, secure time-locked asset vault built on the Stacks blockchain. It allows users to lock their STX tokens for a predetermined period, providing a robust mechanism for long-term asset management, controlled fund release, and beneficiary-based asset protection.
+
+## 🌟 Key Features
+
+### Time-Locked Asset Management
+- Lock STX tokens for a customizable duration
+- Minimum lock period: 1 day
+- Maximum lock period: 1 year
+- Flexible lock duration controls
+
+### Beneficiary System
+- Optional beneficiary nomination
+- Fallback mechanism for asset recovery
+- Grace period for beneficiary claims
+- Secure beneficiary status management
+
+### Advanced Vault Controls
+- Extend lock periods
+- Update beneficiary details
+- Deposit and withdraw functionality
+- Activity tracking and vault management
+
+## 🛡️ Security Mechanisms
+
+- Strict validation for lock periods
+- Beneficiary status tracking
+- Comprehensive error handling
+- Contract-level access controls
+- Immutable vault creation rules
+
+## 🚀 Core Functions
+
+### Vault Creation
+```clarity
+(create-vault 
+  (lock-duration uint) 
+  (beneficiary (optional principal)) 
+  (grace-period uint)
+)
+```
+
+### Key Operations
+- `deposit-stx`: Add funds to vault
+- `withdraw-stx`: Withdraw after unlock period
+- `extend-lock-period`: Prolong vault duration
+- `update-beneficiary`: Change beneficiary details
+- `claim-as-beneficiary`: Claim funds as nominated beneficiary
+
+## 📋 Usage Scenarios
+
+1. **Personal Savings Vault**
+   - Lock STX for future financial goals
+   - Set a long-term saving commitment
+
+2. **Inheritance Planning**
+   - Nominate a beneficiary
+   - Ensure asset transfer if original owner is inactive
+
+3. **Investment Lockup**
+   - Prevent impulsive withdrawals
+   - Enforce disciplined investment strategy
+
+## 🔍 Technical Details
+
+- **Blockchain**: Stacks
+- **Language**: Clarity Smart Contract
+- **Token Support**: STX (expandable)
+- **Minimum Lock**: 1 day (144 blocks)
+- **Maximum Lock**: 1 year (52,560 blocks)
+
+## 🛠️ Installation & Deployment
+
+### Requirements
+- Stacks Wallet
+- Web3 Compatibility
+- Clarity Smart Contract Support
+
+### Deployment Steps
+1. Compile the Clarity contract
+2. Deploy to Stacks blockchain
+3. Interact via compatible wallet or interface
+
+## ⚠️ Considerations
+
+- Double-check lock periods
+- Carefully select beneficiaries
+- Understand grace period mechanics
+- Keep track of vault activity
+
+## 🔮 Future Roadmap
+- Multi-token support
+- Enhanced beneficiary features
+- Improved activity tracking
+- Potential integrations with DeFi protocols
+
+## 🤝 Contributing
+Contributions, issues, and feature requests are welcome!
+
+## 💡 Disclaimer
+ Always review and understand smart contract mechanics before deployment.

timecapsule/contracts/timecapsule.clar

@@ -1,16 +1,30 @@
 ;; TimeCapsule - Decentralized Time-Locked Asset Vault
-;; A secure way to lock STX and fungible tokens with time-based release and beneficiary support
+;; A secure way to lock STX and fungible tokens with enhanced beneficiary system
 
 (define-data-var contract-owner principal tx-sender)
 
+;; Constants for validation
+(define-constant MIN-LOCK-PERIOD u144) ;; Minimum 1 day (assuming 144 blocks per day)
+(define-constant MAX-LOCK-PERIOD u52560) ;; Maximum 1 year
+(define-constant MIN-GRACE-PERIOD u144) ;; Minimum 1 day grace period
+(define-constant DEFAULT-GRACE-PERIOD u4320) ;; Default 30 days grace period
+
+;; Beneficiary Status
+(define-constant BENEFICIARY-ACTIVE u1)
+(define-constant BENEFICIARY-PENDING u2)
+(define-constant BENEFICIARY-INACTIVE u0)
+
 ;; Vault structure
 (define-map vaults
     { owner: principal }
     {
         amount: uint,
         unlock-height: uint,
+        lock-duration: uint,
         beneficiary: (optional principal),
+        beneficiary-status: uint,
         grace-period: uint,
+        last-activity: uint,
         token-type: (string-ascii 32)
     }
 )
@@ -22,6 +36,11 @@
 (define-constant ERR-NOT-UNLOCKED (err u103))
 (define-constant ERR-GRACE-PERIOD-EXPIRED (err u104))
 (define-constant ERR-INSUFFICIENT-FUNDS (err u105))
+(define-constant ERR-INVALID-LOCK-PERIOD (err u106))
+(define-constant ERR-EXTENSION-TOO-SHORT (err u107))
+(define-constant ERR-INVALID-BENEFICIARY (err u108))
+(define-constant ERR-NO-BENEFICIARY (err u109))
+(define-constant ERR-BENEFICIARY-NOT-ACTIVE (err u110))
 
 ;; Read-only functions
 (define-read-only (get-vault-details (owner principal))
@@ -36,33 +55,107 @@
     (>= current-height (get unlock-height vault)))
 )
 
+(define-read-only (get-remaining-lock-time (owner principal))
+    (let (
+        (vault (unwrap! (get-vault-details owner) u0))
+        (current-height block-height)
+    )
+    (if (>= current-height (get unlock-height vault))
+        u0
+        (- (get unlock-height vault) current-height)))
+)
+
+(define-read-only (can-claim-as-beneficiary (owner principal) (beneficiary principal))
+    (let (
+        (vault (unwrap! (get-vault-details owner) false))
+        (current-height block-height)
+        (grace-end (+ (get unlock-height vault) (get grace-period vault)))
+        (inactive-period (- current-height (get last-activity vault)))
+    )
+    (and
+        (is-eq (some beneficiary) (get beneficiary vault))
+        (is-eq (get beneficiary-status vault) BENEFICIARY-ACTIVE)
+        (or 
+            (>= current-height grace-end)
+            (>= inactive-period (get grace-period vault))
+        )
+    ))
+)
+
 ;; Public functions
-(define-public (create-vault (lock-period uint) (beneficiary (optional principal)) (grace-period uint))
+(define-public (create-vault (lock-duration uint) (beneficiary (optional principal)) (grace-period uint))
     (let (
-        (unlock-height (+ block-height lock-period))
+        (unlock-height (+ block-height lock-duration))
+        (actual-grace-period (if (< grace-period MIN-GRACE-PERIOD) 
+                                DEFAULT-GRACE-PERIOD 
+                                grace-period))
     )
     (asserts! (is-none (get-vault-details tx-sender)) ERR-VAULT-EXISTS)
+    (asserts! (and (>= lock-duration MIN-LOCK-PERIOD) (<= lock-duration MAX-LOCK-PERIOD)) ERR-INVALID-LOCK-PERIOD)
+
     (map-set vaults
         { owner: tx-sender }
         {
             amount: u0,
             unlock-height: unlock-height,
+            lock-duration: lock-duration,
             beneficiary: beneficiary,
-            grace-period: grace-period,
+            beneficiary-status: (if (is-some beneficiary) BENEFICIARY-ACTIVE BENEFICIARY-INACTIVE),
+            grace-period: actual-grace-period,
+            last-activity: block-height,
             token-type: "STX"
         }
     )
     (ok true))
 )
 
+(define-public (extend-lock-period (extension-blocks uint))
+    (let (
+        (vault (unwrap! (get-vault-details tx-sender) ERR-NO-VAULT))
+        (current-height block-height)
+        (new-unlock-height (+ (get unlock-height vault) extension-blocks))
+        (new-duration (+ (get lock-duration vault) extension-blocks))
+    )
+    (asserts! (>= extension-blocks MIN-LOCK-PERIOD) ERR-EXTENSION-TOO-SHORT)
+    (asserts! (<= new-duration MAX-LOCK-PERIOD) ERR-INVALID-LOCK-PERIOD)
+
+    (map-set vaults
+        { owner: tx-sender }
+        (merge vault {
+            unlock-height: new-unlock-height,
+            lock-duration: new-duration,
+            last-activity: block-height
+        })
+    )
+    (ok true))
+)
+
+(define-public (update-beneficiary (new-beneficiary (optional principal)))
+    (let (
+        (vault (unwrap! (get-vault-details tx-sender) ERR-NO-VAULT))
+    )
+    (map-set vaults
+        { owner: tx-sender }
+        (merge vault {
+            beneficiary: new-beneficiary,
+            beneficiary-status: (if (is-some new-beneficiary) BENEFICIARY-ACTIVE BENEFICIARY-INACTIVE),
+            last-activity: block-height
+        })
+    )
+    (ok true))
+)
+
 (define-public (deposit-stx (amount uint))
     (let (
         (vault (unwrap! (get-vault-details tx-sender) ERR-NO-VAULT))
     )
     (try! (stx-transfer? amount tx-sender (as-contract tx-sender)))
     (map-set vaults
         { owner: tx-sender }
-        (merge vault { amount: (+ (get amount vault) amount) })
+        (merge vault {
+            amount: (+ (get amount vault) amount),
+            last-activity: block-height
+        })
     )
     (ok true))
 )
@@ -74,10 +167,14 @@
     )
     (asserts! (>= current-height (get unlock-height vault)) ERR-NOT-UNLOCKED)
     (asserts! (<= amount (get amount vault)) ERR-INSUFFICIENT-FUNDS)
+
     (try! (as-contract (stx-transfer? amount (as-contract tx-sender) tx-sender)))
     (map-set vaults
         { owner: tx-sender }
-        (merge vault { amount: (- (get amount vault) amount) })
+        (merge vault {
+            amount: (- (get amount vault) amount),
+            last-activity: block-height
+        })
     )
     (ok true))
 )
@@ -87,24 +184,30 @@
         (vault (unwrap! (get-vault-details owner) ERR-NO-VAULT))
         (current-height block-height)
         (grace-end (+ (get unlock-height vault) (get grace-period vault)))
+        (inactive-period (- current-height (get last-activity vault)))
     )
-    (asserts! (>= current-height grace-end) ERR-NOT-UNLOCKED)
-    (asserts! (is-some (get beneficiary vault)) ERR-NOT-AUTHORIZED)
+    ;; Verify beneficiary status and conditions
+    (asserts! (is-some (get beneficiary vault)) ERR-NO-BENEFICIARY)
     (asserts! (is-eq (some tx-sender) (get beneficiary vault)) ERR-NOT-AUTHORIZED)
+    (asserts! (is-eq (get beneficiary-status vault) BENEFICIARY-ACTIVE) ERR-BENEFICIARY-NOT-ACTIVE)
+    (asserts! (or 
+        (>= current-height grace-end)
+        (>= inactive-period (get grace-period vault))
+    ) ERR-NOT-UNLOCKED)
 
+    ;; Transfer funds and close vault
     (try! (as-contract (stx-transfer? (get amount vault) (as-contract tx-sender) tx-sender)))
     (map-delete vaults { owner: owner })
     (ok true))
 )
 
-;; Administrative functions
-(define-public (update-beneficiary (new-beneficiary (optional principal)))
+(define-public (ping)
     (let (
         (vault (unwrap! (get-vault-details tx-sender) ERR-NO-VAULT))
     )
     (map-set vaults
         { owner: tx-sender }
-        (merge vault { beneficiary: new-beneficiary })
+        (merge vault { last-activity: block-height })
     )
     (ok true))
 )