diff --git a/contracts/prompt-hash/src/lib.rs b/contracts/prompt-hash/src/lib.rs
index 6194090f..c9ef27d8 100644
--- a/contracts/prompt-hash/src/lib.rs
+++ b/contracts/prompt-hash/src/lib.rs
@@ -1,6 +1,8 @@
-#![no_std]
-#![allow(dead_code)]
-#![allow(clippy::too_many_arguments)]
+#clo_std]
+
+#[allow(dead_code)]
+
+#[allow(clippy::too_many_arguments)]
 
 // Test builds get `std` (and therefore `alloc`) back so dev-dependencies like
 // `proptest` work normally; the deployed wasm contract stays strictly `no_std`.
@@ -15,10 +17,13 @@ mod types;
 #[cfg(test)]
 mod mock_asset;
 
-#[cfg(all(test, not(feature = "isolate-gas-bench")))]
+#[cfg(test)]
+mod mock_has_access;
+
+#[cfg(all(test, not(feature = "isolate-gas-bench"))]
 mod test;
 
-#[cfg(all(test, not(feature = "isolate-gas-bench")))]
+#[cfg(all(test, not(feature = "isolate-gas-bench"))]
 mod fuzz;
 
 #[cfg(test)]
diff --git a/contracts/prompt-hash/src/mock_has_access.rs b/contracts/prompt-hash/src/mock_has_access.rs
new file mode 100644
index 00000000..37325e20
--- /dev/null
+++ b/contracts/prompt-hash/src/mock_has_access.rs
@@ -0,0 +1,34 @@
+use soroban_sdk:{contract, contractimpl, Address, Env};
+#[contract]
+pub struct MockHasAccess;
+
+#[contractimpl]
+impl MockHasAccess {
+    pub fn has_access(_env: Env, _user: Address) -> bool {
+        // Happy path mock always grants access.
+        true
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::contract::PromptHashContract;
+    use soroban_sdk::testutils::Address as _;
+
+    #[test]
+    fn unlock_happy_path() {
+        let env = Env::default();
+        env.mock_all_auths();
+
+        let user = Address::generate(&env);
+        let has_access_id = env.register_contract(None, MockHasAccess);
+        let contract_id = env.register_contract(None, PromptHashContract);
+
+        let challenge = PromptHashContract::challenge(&env, &contract_id, &user);
+        let signature = PromptHashContract::sign(&env, &contract_id, &user, &challenge);
+        let unlocked = PromptHashContract::unlock(&env, &contract_id, &user, &signature, &has_access_id);
+
+        assert(unlocked);
+    }
+}
\ No newline at end of file
diff --git a/contracts/prompt-hash/src/test.rs b/contracts/prompt-hash/src/test.rs
index 72bcbf26..2ad29d14 100644
--- a/contracts/prompt-hash/src/test.rs
+++ b/contracts/prompt-hash/src/test.rs
@@ -4,7 +4,7 @@ use crate::storage::Storage;
 use crate::types::{Error, ListingConfig, Split};
 extern crate std;
 use soroban_sdk::{
-    testutils::{Address as _, Events as _, Ledger},
+    testutils::{ed25519::Sign, Address as _, Events as _, Ledger},
     token, Address, Bytes, BytesN, Env, String, Vec,
 };
 
@@ -47,6 +47,28 @@ fn setup(env: &Env) -> PromptHashContext {
     }
 }
 
+#[test]
+fn test_unlock_happy_path() {
+    let env: Env = Default::default();
+    let context = setup(&env);
+    let client = PromptHashContractClient::new(&env, &context.contract);
+
+    let creator = Address::generate(&env);
+    let prompt_id = create_prompt(
+        &env,
+        &client,
+        &creator,
+        "Unlock Prompt",
+        10_000,
+        &context.xlm,
+    );
+    assert!(client.has_access(&creator, &prompt_id));
+
+    let challenge = client.challenge(&creator, &prompt_id);
+    let signature = creator.sign(&env, &challenge);
+    assert!(client.unlock(&creator, &prompt_id, &signature));
+}
+
 fn set_pause(client: &PromptHashContractClient<'_>, context: &PromptHashContext, paused: bool) {
     client.set_pause_status(&paused, &context.admin, &context.admin_two);
 }