feat: add remove_service_price to clear a configured service price

README.md

@@ -19,6 +19,17 @@ A service's metadata (`description` + `owner`) and its registration flag live in
 independent storage slots. `clear_service_metadata` (admin-gated, idempotent)
 removes only the metadata; the registration flag and per-(agent, service) usage
 history are untouched.
+### Service pricing: removed vs. set-to-zero
+
+`set_service_price` stores a per-request price under
+`DataKey::ServicePrice(service_id)`. `remove_service_price` (admin-gated,
+honours the pause gate, idempotent) deletes that slot and emits `price_rm`.
+After removal, `get_service_price` and `compute_billing` read back `0`, exactly
+as for a service that was never priced. The zero-vs-removed distinction is about
+storage, not the read value: removal frees the storage slot (and emits
+`price_rm`), whereas `set_service_price(service_id, 0)` leaves a stored slot
+holding `0`. Both cases bill to zero, but only removal reclaims the slot.
+
 ### Admin proposal validation
 
 `propose_admin_transfer` rejects proposing the current admin as the new admin

contracts/escrow/src/lib.rs

@@ -323,6 +323,37 @@ impl Escrow {
             .set(&DataKey::ServicePrice(service_id), &price_stroops);
     }
 
+    /// Remove the configured per-request price for a service, freeing the
+    /// `DataKey::ServicePrice(service_id)` storage slot.
+    ///
+    /// Admin-gated and honours the pause gate (panics with
+    /// [`EscrowError::ContractPaused`] when paused, consistent with other
+    /// admin mutations). Idempotent — removing the price of a service that
+    /// was never priced is a no-op.
+    ///
+    /// After removal, `get_service_price` and `compute_billing` read back
+    /// `0`, exactly as for a service that was never priced. Note the
+    /// zero-vs-removed distinction: removal frees the underlying storage
+    /// slot and emits a `price_rm` event, whereas `set_service_price(_, 0)`
+    /// leaves a stored slot holding `0`. Both read back as `0`, but only
+    /// removal reclaims the slot. Emits `price_rm(service_id)`.
+    pub fn remove_service_price(env: Env, service_id: Symbol) {
+        if read_flag(&env, &DataKey::Paused) {
+            panic_with_error!(&env, EscrowError::ContractPaused);
+        }
+        let admin: Address = env
+            .storage()
+            .persistent()
+            .get(&DataKey::Admin)
+            .unwrap_or_else(|| panic_with_error!(&env, EscrowError::NotInitialized));
+        admin.require_auth();
+        env.storage()
+            .persistent()
+            .remove(&DataKey::ServicePrice(service_id.clone()));
+        env.events()
+            .publish((symbol_short!("price_rm"),), service_id);
+    }
+
     /// Get the per-request price (in stroops) for a service, or 0 if
     /// no price has been configured (the service is free / unset).
     pub fn get_service_price(env: Env, service_id: Symbol) -> i128 {

contracts/escrow/src/test.rs

@@ -697,3 +697,100 @@ fn test_pause_pause_unpause_ends_unpaused() {
 
     assert!(!client.is_paused());
 }
+
+#[test]
+fn test_remove_service_price_clears_price() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &500i128);
+    assert_eq!(client.get_service_price(&svc), 500i128);
+
+    client.remove_service_price(&svc);
+
+    // Reads back 0, same as a never-priced service.
+    assert_eq!(client.get_service_price(&svc), 0i128);
+}
+
+#[test]
+fn test_remove_service_price_is_idempotent() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "never_set");
+    // Removing the price of a never-priced service is a no-op (no panic).
+    client.remove_service_price(&svc);
+    assert_eq!(client.get_service_price(&svc), 0i128);
+}
+
+#[test]
+fn test_remove_service_price_then_reset_works() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &500i128);
+    client.remove_service_price(&svc);
+    assert_eq!(client.get_service_price(&svc), 0i128);
+
+    // Re-setting after removal works and round-trips.
+    client.set_service_price(&svc, &750i128);
+    assert_eq!(client.get_service_price(&svc), 750i128);
+}
+
+#[test]
+fn test_compute_billing_zero_after_price_removed() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let agent = Address::generate(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &10i128);
+    client.record_usage(&agent, &svc, &42u32);
+    assert_eq!(client.compute_billing(&agent, &svc), 420i128);
+
+    client.remove_service_price(&svc);
+
+    // Usage is untouched, but with no price the bill is zero.
+    assert_eq!(client.compute_billing(&agent, &svc), 0i128);
+}
+
+#[test]
+fn test_remove_service_price_emits_price_rm_event() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &500i128);
+
+    client.remove_service_price(&svc);
+
+    let events = env.events().all();
+    assert!(!events.is_empty());
+    let (_addr, topics, data) = events.last().unwrap();
+    let expected_topics: soroban_sdk::Vec<soroban_sdk::Val> =
+        (symbol_short!("price_rm"),).into_val(&env);
+    assert_eq!(topics, expected_topics);
+    let decoded: Symbol = data.into_val(&env);
+    assert_eq!(decoded, svc);
+}
+
+#[test]
+#[should_panic(expected = "Error(Contract, #4)")]
+fn test_remove_service_price_rejected_while_paused() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &500i128);
+    client.pause();
+    client.remove_service_price(&svc);
+}
+
+#[test]
+#[should_panic(expected = "Unauthorized")]
+fn test_remove_service_price_non_admin_panics() {
+    let env = Env::default();
+    let (client, _admin) = setup_initialized(&env);
+    let svc = Symbol::new(&env, "infer");
+    client.set_service_price(&svc, &500i128);
+    // Drop the mocked auths so the admin's require_auth() is unsatisfied,
+    // simulating a caller without the admin signature.
+    env.set_auths(&[]);
+    client.remove_service_price(&svc);
+}