diff --git a/Cargo.toml b/Cargo.toml
index 1e4b160..b882c9d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,7 @@
 [workspace]
 resolver = "2"
 members = [
+  "contracts/completion_anchor",
   "contracts/backend_core",
   "contracts/subscription",
   "contracts/achievement_collection",
diff --git a/contracts/completion_anchor/Cargo.toml b/contracts/completion_anchor/Cargo.toml
new file mode 100644
index 0000000..1b3847c
--- /dev/null
+++ b/contracts/completion_anchor/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "completion-anchor"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+soroban-sdk = { workspace = true }
+
+[dev-dependencies]
+soroban-sdk = { workspace = true, features = ["testutils"] }
+
+[features]
+testutils = ["soroban-sdk/testutils"]
diff --git a/contracts/completion_anchor/src/lib.rs b/contracts/completion_anchor/src/lib.rs
new file mode 100644
index 0000000..c973997
--- /dev/null
+++ b/contracts/completion_anchor/src/lib.rs
@@ -0,0 +1,218 @@
+#![no_std]
+
+use soroban_sdk::{
+    contract, contractimpl, contracttype, Address, BytesN, Env, Symbol,
+};
+
+#[contracttype]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct AnchorRecord {
+    pub player: Address,
+    pub puzzle_id: u32,
+    pub completion_hash: BytesN<32>,
+    pub ledger_sequence: u32,
+    pub timestamp: u64,
+}
+
+#[contracttype]
+pub enum DataKey {
+    Admin,
+    Verifier,
+    Anchor(Address, u32),
+}
+
+#[contract]
+pub struct CompletionAnchor;
+
+#[contractimpl]
+impl CompletionAnchor {
+    pub fn initialize(env: Env, admin: Address, verifier: Address) {
+        if env.storage().instance().has(&DataKey::Admin) {
+            panic!("already initialized");
+        }
+        admin.require_auth();
+        env.storage().instance().set(&DataKey::Admin, &admin);
+        env.storage().instance().set(&DataKey::Verifier, &verifier);
+    }
+
+    pub fn set_verifier(env: Env, new_verifier: Address) {
+        let admin: Address = env
+            .storage()
+            .instance()
+            .get(&DataKey::Admin)
+            .expect("admin not set");
+        admin.require_auth();
+        env.storage().instance().set(&DataKey::Verifier, &new_verifier);
+    }
+
+    pub fn get_verifier(env: Env) -> Address {
+        env.storage()
+            .instance()
+            .get(&DataKey::Verifier)
+            .expect("verifier not set")
+    }
+
+    pub fn anchor_completion(
+        env: Env,
+        verifier: Address,
+        player: Address,
+        puzzle_id: u32,
+        completion_hash: BytesN<32>,
+    ) -> AnchorRecord {
+        verifier.require_auth();
+
+        let registered_verifier: Address = env
+            .storage()
+            .instance()
+            .get(&DataKey::Verifier)
+            .expect("verifier not set");
+
+        if verifier != registered_verifier {
+            panic!("unauthorized verifier");
+        }
+
+        let key = DataKey::Anchor(player.clone(), puzzle_id);
+        if env.storage().instance().has(&key) {
+            panic!("duplicate anchor rejected");
+        }
+
+        let record = AnchorRecord {
+            player: player.clone(),
+            puzzle_id,
+            completion_hash,
+            ledger_sequence: env.ledger().sequence(),
+            timestamp: env.ledger().timestamp(),
+        };
+
+        env.storage().instance().set(&key, &record);
+
+        env.events().publish(
+            (Symbol::new(&env, "anchor"), Symbol::new(&env, "completed")),
+            (player, puzzle_id, record.ledger_sequence),
+        );
+
+        record
+    }
+
+    pub fn has_anchor(env: Env, player: Address, puzzle_id: u32) -> bool {
+        let key = DataKey::Anchor(player, puzzle_id);
+        env.storage().instance().has(&key)
+    }
+
+    pub fn get_anchor(env: Env, player: Address, puzzle_id: u32) -> Option<AnchorRecord> {
+        let key = DataKey::Anchor(player, puzzle_id);
+        env.storage().instance().get(&key)
+    }
+
+    pub fn get_completion_hash(env: Env, player: Address, puzzle_id: u32) -> Option<BytesN<32>> {
+        Self::get_anchor(env, player, puzzle_id).map(|r| r.completion_hash)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use soroban_sdk::testutils::{Address as _, Ledger as _};
+
+    #[test]
+    fn test_initialize_and_verifier_management() {
+        let env = Env::default();
+        let contract_id = env.register_contract(None, CompletionAnchor);
+        let client = CompletionAnchorClient::new(&env, &contract_id);
+
+        let admin = Address::generate(&env);
+        let verifier = Address::generate(&env);
+        let new_verifier = Address::generate(&env);
+
+        env.mock_all_auths();
+        client.initialize(&admin, &verifier);
+        assert_eq!(client.get_verifier(), verifier);
+
+        client.set_verifier(&new_verifier);
+        assert_eq!(client.get_verifier(), new_verifier);
+    }
+
+    #[test]
+    fn test_anchor_completion_success() {
+        let env = Env::default();
+        let contract_id = env.register_contract(None, CompletionAnchor);
+        let client = CompletionAnchorClient::new(&env, &contract_id);
+
+        let admin = Address::generate(&env);
+        let verifier = Address::generate(&env);
+        let player = Address::generate(&env);
+
+        env.mock_all_auths();
+        client.initialize(&admin, &verifier);
+
+        env.ledger().set_sequence_number(12345);
+        env.ledger().set_timestamp(1_700_000_000);
+
+        let hash = BytesN::from_array(&env, &[0xab; 32]);
+        let record = client.anchor_completion(&verifier, &player, &101, &hash);
+
+        assert_eq!(record.player, player);
+        assert_eq!(record.puzzle_id, 101);
+        assert_eq!(record.completion_hash, hash);
+        assert_eq!(record.ledger_sequence, 12345);
+        assert_eq!(record.timestamp, 1_700_000_000);
+
+        assert_eq!(client.has_anchor(&player, &101), true);
+        assert_eq!(client.get_completion_hash(&player, &101), Some(hash));
+
+        let retrieved = client.get_anchor(&player, &101).expect("anchor record");
+        assert_eq!(retrieved, record);
+    }
+
+    #[test]
+    #[should_panic(expected = "duplicate anchor rejected")]
+    fn test_duplicate_anchor_rejected() {
+        let env = Env::default();
+        let contract_id = env.register_contract(None, CompletionAnchor);
+        let client = CompletionAnchorClient::new(&env, &contract_id);
+
+        let admin = Address::generate(&env);
+        let verifier = Address::generate(&env);
+        let player = Address::generate(&env);
+
+        env.mock_all_auths();
+        client.initialize(&admin, &verifier);
+
+        let hash1 = BytesN::from_array(&env, &[1u8; 32]);
+        let hash2 = BytesN::from_array(&env, &[2u8; 32]);
+
+        client.anchor_completion(&verifier, &player, &1, &hash1);
+        client.anchor_completion(&verifier, &player, &1, &hash2);
+    }
+
+    #[test]
+    #[should_panic(expected = "unauthorized verifier")]
+    fn test_unauthorized_verifier_rejected() {
+        let env = Env::default();
+        let contract_id = env.register_contract(None, CompletionAnchor);
+        let client = CompletionAnchorClient::new(&env, &contract_id);
+
+        let admin = Address::generate(&env);
+        let verifier = Address::generate(&env);
+        let imposter = Address::generate(&env);
+        let player = Address::generate(&env);
+
+        env.mock_all_auths();
+        client.initialize(&admin, &verifier);
+
+        let hash = BytesN::from_array(&env, &[3u8; 32]);
+        client.anchor_completion(&imposter, &player, &1, &hash);
+    }
+
+    #[test]
+    fn test_nonexistent_anchor_returns_none() {
+        let env = Env::default();
+        let contract_id = env.register_contract(None, CompletionAnchor);
+        let client = CompletionAnchorClient::new(&env, &contract_id);
+
+        let player = Address::generate(&env);
+        assert_eq!(client.has_anchor(&player, &999), false);
+        assert_eq!(client.get_anchor(&player, &999), None);
+        assert_eq!(client.get_completion_hash(&player, &999), None);
+    }
+}