diff --git a/Cargo.lock b/Cargo.lock
index 9fb0cb82..0d7abb41 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -14,12 +14,6 @@ dependencies = [
  "zerocopy",
 ]
 
-[[package]]
-name = "allocator-api2"
-version = "0.2.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
-
 [[package]]
 name = "android-tzdata"
 version = "0.1.1"
@@ -50,22 +44,10 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c775f0d12169cba7aae4caeb547bb6a50781c7449a8aa53793827c9ec4abf488"
 dependencies = [
- "ark-ec 0.4.2",
- "ark-ff 0.4.2",
- "ark-serialize 0.4.2",
- "ark-std 0.4.0",
-]
-
-[[package]]
-name = "ark-bls12-381"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3df4dcc01ff89867cd86b0da835f23c3f02738353aaee7dde7495af71363b8d5"
-dependencies = [
- "ark-ec 0.5.0",
- "ark-ff 0.5.0",
- "ark-serialize 0.5.0",
- "ark-std 0.5.0",
+ "ark-ec",
+ "ark-ff",
+ "ark-serialize",
+ "ark-std",
 ]
 
 [[package]]
@@ -85,34 +67,13 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "defd9a439d56ac24968cca0571f598a61bc8c55f71d50a89cda591cb750670ba"
 dependencies = [
- "ark-ff 0.4.2",
- "ark-poly 0.4.2",
- "ark-serialize 0.4.2",
- "ark-std 0.4.0",
+ "ark-ff",
+ "ark-poly",
+ "ark-serialize",
+ "ark-std",
  "derivative",
  "hashbrown 0.13.2",
- "itertools 0.10.5",
- "num-traits",
- "zeroize",
-]
-
-[[package]]
-name = "ark-ec"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43d68f2d516162846c1238e755a7c4d131b892b70cc70c471a8e3ca3ed818fce"
-dependencies = [
- "ahash",
- "ark-ff 0.5.0",
- "ark-poly 0.5.0",
- "ark-serialize 0.5.0",
- "ark-std 0.5.0",
- "educe",
- "fnv",
- "hashbrown 0.15.3",
- "itertools 0.13.0",
- "num-bigint",
- "num-integer",
+ "itertools",
  "num-traits",
  "zeroize",
 ]
@@ -123,13 +84,13 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec847af850f44ad29048935519032c33da8aa03340876d351dfab5660d2966ba"
 dependencies = [
- "ark-ff-asm 0.4.2",
- "ark-ff-macros 0.4.2",
- "ark-serialize 0.4.2",
- "ark-std 0.4.0",
+ "ark-ff-asm",
+ "ark-ff-macros",
+ "ark-serialize",
+ "ark-std",
  "derivative",
  "digest",
- "itertools 0.10.5",
+ "itertools",
  "num-bigint",
  "num-traits",
  "paste",
@@ -137,26 +98,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "ark-ff"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a177aba0ed1e0fbb62aa9f6d0502e9b46dad8c2eab04c14258a1212d2557ea70"
-dependencies = [
- "ark-ff-asm 0.5.0",
- "ark-ff-macros 0.5.0",
- "ark-serialize 0.5.0",
- "ark-std 0.5.0",
- "arrayvec",
- "digest",
- "educe",
- "itertools 0.13.0",
- "num-bigint",
- "num-traits",
- "paste",
- "zeroize",
-]
-
 [[package]]
 name = "ark-ff-asm"
 version = "0.4.2"
@@ -167,16 +108,6 @@ dependencies = [
  "syn 1.0.109",
 ]
 
-[[package]]
-name = "ark-ff-asm"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62945a2f7e6de02a31fe400aa489f0e0f5b2502e69f95f853adb82a96c7a6b60"
-dependencies = [
- "quote",
- "syn 2.0.101",
-]
-
 [[package]]
 name = "ark-ff-macros"
 version = "0.4.2"
@@ -190,68 +121,27 @@ dependencies = [
  "syn 1.0.109",
 ]
 
-[[package]]
-name = "ark-ff-macros"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09be120733ee33f7693ceaa202ca41accd5653b779563608f1234f78ae07c4b3"
-dependencies = [
- "num-bigint",
- "num-traits",
- "proc-macro2",
- "quote",
- "syn 2.0.101",
-]
-
 [[package]]
 name = "ark-poly"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d320bfc44ee185d899ccbadfa8bc31aab923ce1558716e1997a1e74057fe86bf"
 dependencies = [
- "ark-ff 0.4.2",
- "ark-serialize 0.4.2",
- "ark-std 0.4.0",
+ "ark-ff",
+ "ark-serialize",
+ "ark-std",
  "derivative",
  "hashbrown 0.13.2",
 ]
 
-[[package]]
-name = "ark-poly"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "579305839da207f02b89cd1679e50e67b4331e2f9294a57693e5051b7703fe27"
-dependencies = [
- "ahash",
- "ark-ff 0.5.0",
- "ark-serialize 0.5.0",
- "ark-std 0.5.0",
- "educe",
- "fnv",
- "hashbrown 0.15.3",
-]
-
 [[package]]
 name = "ark-serialize"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adb7b85a02b83d2f22f89bd5cac66c9c89474240cb6207cb1efc16d098e822a5"
 dependencies = [
- "ark-serialize-derive 0.4.2",
- "ark-std 0.4.0",
- "digest",
- "num-bigint",
-]
-
-[[package]]
-name = "ark-serialize"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f4d068aaf107ebcd7dfb52bc748f8030e0fc930ac8e360146ca54c1203088f7"
-dependencies = [
- "ark-serialize-derive 0.5.0",
- "ark-std 0.5.0",
- "arrayvec",
+ "ark-serialize-derive",
+ "ark-std",
  "digest",
  "num-bigint",
 ]
@@ -267,17 +157,6 @@ dependencies = [
  "syn 1.0.109",
 ]
 
-[[package]]
-name = "ark-serialize-derive"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "213888f660fddcca0d257e88e54ac05bca01885f258ccdf695bafd77031bb69d"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.101",
-]
-
 [[package]]
 name = "ark-std"
 version = "0.4.0"
@@ -288,22 +167,6 @@ dependencies = [
  "rand 0.8.5",
 ]
 
-[[package]]
-name = "ark-std"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "246a225cc6131e9ee4f24619af0f19d67761fff15d7ccc22e42b80846e69449a"
-dependencies = [
- "num-traits",
- "rand 0.8.5",
-]
-
-[[package]]
-name = "arrayvec"
-version = "0.7.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3fb67a6e08acf24fdeccbac2cb6ac4305825bd1f117462e0e6f2f193345ad56"
-
 [[package]]
 name = "autocfg"
 version = "1.4.0"
@@ -678,18 +541,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "educe"
-version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d7bc049e1bd8cdeb31b68bbd586a9464ecf9f3944af3958a7a9d0f8b9799417"
-dependencies = [
- "enum-ordinalize",
- "proc-macro2",
- "quote",
- "syn 2.0.101",
-]
-
 [[package]]
 name = "either"
 version = "1.15.0"
@@ -714,26 +565,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "enum-ordinalize"
-version = "4.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89dd01549b09589510cf0647475075d12071456586d70f5c75c98ae2a5537677"
-dependencies = [
- "enum-ordinalize-derive",
-]
-
-[[package]]
-name = "enum-ordinalize-derive"
-version = "4.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a65863d15a4ce2888bd2f0f543cc963d3879c3a022c8ee43f6141d479a3ac815"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 3.0.4",
-]
-
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -866,9 +697,6 @@ name = "hashbrown"
 version = "0.15.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "84b26c544d002229e640969970a2e74021aadf6e2f96372b9c58eff97de08eb3"
-dependencies = [
- "allocator-api2",
-]
 
 [[package]]
 name = "heapless"
@@ -977,15 +805,6 @@ dependencies = [
  "either",
 ]
 
-[[package]]
-name = "itertools"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
-dependencies = [
- "either",
-]
-
 [[package]]
 name = "itoa"
 version = "1.0.15"
@@ -1519,7 +1338,7 @@ version = "23.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9336adeabcd6f636a4e0889c8baf494658ef5a3c4e7e227569acd2ce9091e85"
 dependencies = [
- "itertools 0.10.5",
+ "itertools",
  "proc-macro2",
  "quote",
  "syn 2.0.101",
@@ -1599,10 +1418,10 @@ version = "23.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9766c5ad78e9d8ae10afbc076301f7d610c16407a1ebb230766dbe007a48725"
 dependencies = [
- "ark-bls12-381 0.4.0",
- "ark-ec 0.4.2",
- "ark-ff 0.4.2",
- "ark-serialize 0.4.2",
+ "ark-bls12-381",
+ "ark-ec",
+ "ark-ff",
+ "ark-serialize",
  "curve25519-dalek",
  "ecdsa",
  "ed25519-dalek",
@@ -1672,7 +1491,7 @@ version = "23.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b0e6a1c5844257ce96f5f54ef976035d5bd0ee6edefaf9f5e0bcb8ea4b34228c"
 dependencies = [
- "itertools 0.10.5",
+ "itertools",
  "proc-macro2",
  "quote",
  "serde",
@@ -1761,7 +1580,7 @@ checksum = "caa7114e2f031b6fbd30376e844f3c55f6daf56f6f9d33ce309f846ffced316d"
 dependencies = [
  "darling",
  "heck",
- "itertools 0.10.5",
+ "itertools",
  "macro-string",
  "proc-macro2",
  "quote",
@@ -2018,17 +1837,6 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "syn"
-version = "3.0.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6275cddf4610d1775e6d1fe9469b2e77d0f39fd98fb7450901b821e0c53649f"
-dependencies = [
- "proc-macro2",
- "quote",
- "unicode-ident",
-]
-
 [[package]]
 name = "tempfile"
 version = "3.23.0"
diff --git a/contracts/prompt-hash/src/contract.rs b/contracts/prompt-hash/src/contract.rs
index ecda79af..ac082f8f 100644
--- a/contracts/prompt-hash/src/contract.rs
+++ b/contracts/prompt-hash/src/contract.rs
@@ -555,6 +555,40 @@ impl PromptHashTrait for PromptHashContract {
             royalty_amount,
         );
         Ok(())
+    fn revoke_access(env: Env, caller: Address, prompt_id: u128, buyer: Address) -> Result<(), Error> {
+        caller.require_auth();
+        Storage::require_no_reentrancy(&env)?;
+        ensure(!Storage::is_paused(&env), Error::ContractIsPaused)?;
+
+        let prompt = Storage::require_prompt(&env, prompt_id)?;
+        // Allow creator or moderator to revoke
+        let is_moderator = Storage::get_moderator_address(&env) == Some(caller.clone());
+        ensure(
+            prompt.creator == caller || is_moderator,
+            Error::Unauthorized,
+        )?;
+
+        Storage::revoke_purchase(&env, prompt_id, &buyer);
+        Events::emit_access_revoked(&env, prompt_id, buyer);
+        Ok(())
+    }
+
+    fn set_access_duration(
+        env: Env,
+        creator: Address,
+        prompt_id: u128,
+        duration_secs: u64,
+    ) -> Result<(), Error> {
+        creator.require_auth();
+        Storage::require_no_reentrancy(&env)?;
+        ensure(!Storage::is_paused(&env), Error::ContractIsPaused)?;
+        
+        let prompt = Storage::require_prompt(&env, prompt_id)?;
+        ensure(prompt.creator == creator, Error::Unauthorized)?;
+        
+        Storage::set_access_duration(&env, prompt_id, duration_secs);
+        Events::emit_access_duration_set(&env, prompt_id, duration_secs);
+        Ok(())
     }
 
     fn has_access(env: Env, user: Address, prompt_id: u128) -> Result<bool, Error> {
@@ -2061,12 +2095,19 @@ fn execute_buy(
         }
     }
 
+    let access_duration = Storage::get_access_duration(env, prompt_id);
+    let expires_at = if let Some(duration) = access_duration {
+        now.saturating_add(duration)
+    } else {
+        MAX_ACCESS_EXPIRY
+    };
+
     Storage::grant_purchase(
         env,
         &prompt,
         buyer,
         payment_amount_stroops,
-        MAX_ACCESS_EXPIRY,
+        expires_at,
         Settlement {
             buyer_amount: payment_amount_stroops,
             creator_amount,
diff --git a/contracts/prompt-hash/src/events.rs b/contracts/prompt-hash/src/events.rs
index 5c4c371a..86ea1fba 100644
--- a/contracts/prompt-hash/src/events.rs
+++ b/contracts/prompt-hash/src/events.rs
@@ -162,6 +162,20 @@ struct SubscriptionRenewed {
     pub renewal_count: u32,
 }
 
+#[contractevent]
+struct AccessDurationSet {
+    #[topic]
+    pub prompt_id: u128,
+    pub duration_secs: u64,
+}
+
+#[contractevent]
+struct AccessRevoked {
+    #[topic]
+    pub prompt_id: u128,
+    pub buyer: Address,
+}
+
 pub struct Events;
 
 impl Events {
@@ -862,4 +876,16 @@ impl Events {
         }
         .publish(env);
     }
+
+    pub fn emit_access_duration_set(env: &Env, prompt_id: u128, duration_secs: u64) {
+        AccessDurationSet {
+            prompt_id,
+            duration_secs,
+        }
+        .publish(env);
+    }
+
+    pub fn emit_access_revoked(env: &Env, prompt_id: u128, buyer: Address) {
+        AccessRevoked { prompt_id, buyer }.publish(env);
+    }
 }
diff --git a/contracts/prompt-hash/src/storage.rs b/contracts/prompt-hash/src/storage.rs
index b8b21c57..ee1b868b 100644
--- a/contracts/prompt-hash/src/storage.rs
+++ b/contracts/prompt-hash/src/storage.rs
@@ -296,6 +296,26 @@ impl Storage {
         Self::extend_key_ttl(env, &key);
     }
 
+    pub fn revoke_purchase(env: &Env, prompt_id: u128, buyer: &Address) {
+        let key = DataKey::Purchase(prompt_id, buyer.clone());
+        env.storage().persistent().remove(&key);
+    }
+
+    pub fn set_access_duration(env: &Env, prompt_id: u128, duration_secs: u64) {
+        let key = DataKey::AccessDuration(prompt_id);
+        env.storage().persistent().set(&key, &duration_secs);
+        Self::extend_key_ttl(env, &key);
+    }
+
+    pub fn get_access_duration(env: &Env, prompt_id: u128) -> Option<u64> {
+        let key = DataKey::AccessDuration(prompt_id);
+        let duration = env.storage().persistent().get(&key);
+        if env.storage().persistent().has(&key) {
+            Self::extend_key_ttl(env, &key);
+        }
+        duration
+    }
+
     pub fn remove_purchase(env: &Env, prompt_id: u128, owner: &Address) {
         let key = DataKey::Purchase(prompt_id, owner.clone());
         env.storage().persistent().remove(&key);
diff --git a/contracts/prompt-hash/src/test.rs b/contracts/prompt-hash/src/test.rs
index 72bcbf26..bf511e9a 100644
--- a/contracts/prompt-hash/src/test.rs
+++ b/contracts/prompt-hash/src/test.rs
@@ -6832,90 +6832,56 @@ fn test_lease_returns_insufficient_balance_when_wallet_unfunded() {
 
 
 #[test]
-fn test_price_bounds() {
+fn test_access_revocation() {
     let env = Env::default();
     let context = setup(&env);
     let client = PromptHashContractClient::new(&env, &context.contract);
     
     let creator = Address::generate(&env);
+    let buyer = Address::generate(&env);
     
-    // Test setting price bounds
-    let min_price = Some(10_000);
-    let max_price = Some(500_000);
-    client.set_price_bounds(&context.admin, &context.admin_two, &min_price, &max_price);
+    let token = token::StellarAssetClient::new(&env, &context.xlm);
+    token.mint(&buyer, &100_000);
     
-    let bounds = client.get_price_bounds();
-    assert_eq!(bounds, (min_price, max_price));
+    let prompt_id = create_prompt(&env, &client, &creator, "Revokable Prompt", 10_000, &context.xlm);
     
-    // Try to create prompt below min price - should fail
-    let title = String::from_str(&env, "Title");
-    let category = String::from_str(&env, "Category");
-    let preview = String::from_str(&env, "Preview");
-    let enc_prompt = String::from_str(&env, "Encrypted");
-    let iv = String::from_str(&env, "IV");
-    let wrapped_key = String::from_str(&env, "WrappedKey");
-    let image_url = String::from_str(&env, "https://example.com/image.png");
+    // Purchase the prompt
+    client.buy_prompt(&buyer, &prompt_id, &None, &10_000, &None);
+    assert!(client.has_access(&buyer, &prompt_id));
     
-    let mut config = ListingConfig {
-        price: 5_000,
-        asset: context.xlm.clone(),
-        splits: Vec::new(&env),
-        expires_at: 0,
-    };
+    // Revoke access
+    client.revoke_access(&creator, &prompt_id, &buyer);
+    assert!(!client.has_access(&buyer, &prompt_id));
+}
+
+#[test]
+fn test_access_expiry_window() {
+    let env = Env::default();
+    env.ledger().set_timestamp(100_000);
+    let context = setup(&env);
+    let client = PromptHashContractClient::new(&env, &context.contract);
     
-    let result = client.try_create_prompt(
-        &creator,
-        &image_url,
-        &title,
-        &category,
-        &preview,
-        &enc_prompt,
-        &iv,
-        &wrapped_key,
-        &BytesN::from_array(&env, &[0; 32]),
-        &config,
-    );
-    assert_eq!(result, Err(Ok(Error::InvalidPrice)));
+    let creator = Address::generate(&env);
+    let buyer = Address::generate(&env);
     
-    // Try to create prompt above max price - should fail
-    config.price = 600_000;
-    let result = client.try_create_prompt(
-        &creator,
-        &image_url,
-        &title,
-        &category,
-        &preview,
-        &enc_prompt,
-        &iv,
-        &wrapped_key,
-        &BytesN::from_array(&env, &[0; 32]),
-        &config,
-    );
-    assert_eq!(result, Err(Ok(Error::InvalidPrice)));
+    let token = token::StellarAssetClient::new(&env, &context.xlm);
+    token.mint(&buyer, &100_000);
     
-    // Try to create prompt within bounds - should succeed
-    config.price = 100_000;
-    let prompt_id = client.create_prompt(
-        &creator,
-        &image_url,
-        &title,
-        &category,
-        &preview,
-        &enc_prompt,
-        &iv,
-        &wrapped_key,
-        &BytesN::from_array(&env, &[0; 32]),
-        &config,
-    );
+    let prompt_id = create_prompt(&env, &client, &creator, "Expiring Prompt", 10_000, &context.xlm);
     
-    // Try to update prompt above max price - should fail
-    let result = client.try_update_prompt_price(&creator, &prompt_id, &600_000);
-    assert_eq!(result, Err(Ok(Error::InvalidPrice)));
+    // Set 30 days access duration (30 * 24 * 60 * 60 = 2592000)
+    let duration_secs = 2_592_000;
+    client.set_access_duration(&creator, &prompt_id, &duration_secs);
     
-    // Try to update prompt below min price - should fail
-    let result = client.try_update_prompt_price(&creator, &prompt_id, &5_000);
-    assert_eq!(result, Err(Ok(Error::InvalidPrice)));
+    // Purchase the prompt
+    client.buy_prompt(&buyer, &prompt_id, &None, &10_000, &None);
+    assert!(client.has_access(&buyer, &prompt_id));
     
-    // Try to update prompt within bounds - should succeed
-    client.update_prompt_price(&creator, &prompt_id, &200_000);
+    // Fast forward halfway through the duration
+    env.ledger().set_timestamp(100_000 + 1_000_000);
+    assert!(client.has_access(&buyer, &prompt_id));
+    
+    // Fast forward past the duration
+    env.ledger().set_timestamp(100_000 + duration_secs + 1);
+    assert!(!client.has_access(&buyer, &prompt_id));
 }
diff --git a/contracts/prompt-hash/src/types.rs b/contracts/prompt-hash/src/types.rs
index e93bc9eb..39d1e66d 100644
--- a/contracts/prompt-hash/src/types.rs
+++ b/contracts/prompt-hash/src/types.rs
@@ -493,6 +493,8 @@ pub trait PromptHashTrait {
         resale_price: i128,
     ) -> Result<(), Error>;
 
+    fn revoke_access(env: Env, caller: Address, prompt_id: u128, buyer: Address) -> Result<(), Error>;
+    fn set_access_duration(env: Env, creator: Address, prompt_id: u128, duration_secs: u64) -> Result<(), Error>;
     fn has_access(env: Env, user: Address, prompt_id: u128) -> Result<bool, Error>;
     fn get_prompt(env: Env, prompt_id: u128) -> Result<Prompt, Error>;
     fn get_all_prompts(env: Env) -> Result<Vec<Prompt>, Error>;