diff --git a/heromodels/Cargo.lock b/heromodels/Cargo.lock
index c78e694..d8cd394 100644
--- a/heromodels/Cargo.lock
+++ b/heromodels/Cargo.lock
@@ -183,6 +183,12 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "heromodels"
 version = "0.1.0"
@@ -199,6 +205,8 @@ dependencies = [
  "rhai_wrapper",
  "serde",
  "serde_json",
+ "strum",
+ "strum_macros",
  "tst",
 ]
 
@@ -415,7 +423,7 @@ dependencies = [
 name = "rhai_autobind_macros"
 version = "0.1.0"
 dependencies = [
- "heck",
+ "heck 0.4.1",
  "proc-macro2",
  "quote",
  "syn",
@@ -550,6 +558,25 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[package]]
+name = "strum"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fec0f0aef304996cf250b31b5a10dee7980c85da9d759361292b8bca5a18f06"
+
+[[package]]
+name = "strum_macros"
+version = "0.26.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c6bee85a5a24955dc440386795aa378cd9cf82acd5f764469152d2270e581be"
+dependencies = [
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.101"
diff --git a/heromodels/examples/biz_rhai/biz.rhai b/heromodels/examples/biz_rhai/biz.rhai
index bbbba7c..1bcbfd3 100644
--- a/heromodels/examples/biz_rhai/biz.rhai
+++ b/heromodels/examples/biz_rhai/biz.rhai
@@ -14,14 +14,13 @@ print(`BusinessType Global: ${BusinessTypeConstants::Global}`);
 // --- Testing Company Model ---
 print("\n--- Testing Company Model ---");
 
-let company1_id = 1001;
 let company1_uuid = "comp-uuid-alpha-001";
 let company1_name = "Innovatech Solutions Ltd.";
 let company1_reg = "REG-ISL-2024";
 let company1_inc_date = 1672531200; // Jan 1, 2023
 
-print(`Creating a new company (ID: ${company1_id}, UUID: ${company1_uuid})...`);
-let company1 = new_company(company1_id, company1_name, company1_reg, company1_inc_date)
+print(`Creating a new company (UUID: ${company1_uuid})...`);
+let company1 = new_company(company1_name, company1_reg, company1_inc_date)
     .email("contact@innovatech.com")
     .phone("+1-555-0100")
     .website("https://innovatech.com")
@@ -38,26 +37,26 @@ print(`Company 1 Name: ${company1.name}, Status: ${company1.status}`);
 print(`Company 1 Email: ${company1.email}, Industry: ${company1.industry}`);
 // Save the company to the database
 print("\nSaving company1 to database...");
-set_company(company1);
+company1 = set_company(company1); // Capture the company with the DB-assigned ID
 print("Company1 saved.");
 
 // Retrieve the company
-print(`\nRetrieving company by ID (${company1_id})...`);
-let retrieved_company = get_company_by_id(company1_id);
+print(`\nRetrieving company by ID (${company1.id})...`);
+let retrieved_company = get_company_by_id(company1.id);
 print(`Retrieved Company: ${retrieved_company.name}, Status: ${retrieved_company.status}`);
 print(`Retrieved Company Reg No: ${retrieved_company.registration_number}, Website: ${retrieved_company.website}`);
 
 // --- Testing Shareholder Model ---
 print("\n--- Testing Shareholder Model ---");
 
-let sh1_id = 2001;
+
 let sh1_user_id = 3001; // Example user ID
 let sh1_name = "Alice Wonderland";
 let sh1_since = 1672617600; // Example timestamp (Jan 2, 2023)
 
-print(`Creating shareholder 1 (ID: ${sh1_id}) for company ${company1_id}...`);
-let shareholder1 = new_shareholder(sh1_id)
-    .company_id(company1_id)
+print(`Creating shareholder 1 for company ${company1.id}...`);
+let shareholder1 = new_shareholder()
+    .company_id(company1.id)
     .user_id(sh1_user_id)
     .name(sh1_name)
     .shares(1000.0)
@@ -66,20 +65,20 @@ let shareholder1 = new_shareholder(sh1_id)
     .since(sh1_since)
     .set_base_created_at(1672617600);
 
-set_shareholder(shareholder1);
+shareholder1 = set_shareholder(shareholder1);
 print("Shareholder 1 saved.");
 
-let retrieved_sh1 = get_shareholder_by_id(sh1_id);
+let retrieved_sh1 = get_shareholder_by_id(shareholder1.id);
 print(`Retrieved Shareholder 1: ${retrieved_sh1.name}, Type: ${retrieved_sh1.type_}, Shares: ${retrieved_sh1.shares}`);
 
-let sh2_id = 2002;
+
 let sh2_entity_id = 4001; // Example corporate entity ID
 let sh2_name = "Mad Hatter Inc.";
 let sh2_since = 1672704000; // Example timestamp (Jan 3, 2023)
 
-print(`\nCreating shareholder 2 (ID: ${sh2_id}) for company ${company1_id}...`);
-let shareholder2 = new_shareholder(sh2_id)
-    .company_id(company1_id)
+print(`\nCreating shareholder 2 for company ${company1.id}...`);
+let shareholder2 = new_shareholder()
+    .company_id(company1.id)
     .user_id(sh2_entity_id) // Using user_id field for entity_id for simplicity in example
     .name(sh2_name)
     .shares(5000.0)
@@ -88,10 +87,10 @@ let shareholder2 = new_shareholder(sh2_id)
     .since(sh2_since)
     .set_base_created_at(1672704000);
 
-set_shareholder(shareholder2);
+shareholder2 = set_shareholder(shareholder2);
 print("Shareholder 2 saved.");
 
-let retrieved_sh2 = get_shareholder_by_id(sh2_id);
+let retrieved_sh2 = get_shareholder_by_id(shareholder2.id);
 print(`Retrieved Shareholder 2: ${retrieved_sh2.name}, Type: ${retrieved_sh2.type_}, Percentage: ${retrieved_sh2.percentage}`);
 
 // --- Testing Update for Company (Example - if setters were fully implemented for complex updates) ---
@@ -105,7 +104,7 @@ print(`Updated Company - Name: ${updated_company.name}, New Phone: ${updated_com
 set_company(updated_company);
 print("Updated Company saved.");
 
-let final_retrieved_company = get_company_by_id(company1_id);
+let final_retrieved_company = get_company_by_id(company1.id);
 print(`Final Retrieved Company - Description: '${final_retrieved_company.description}', Phone: ${final_retrieved_company.phone}`);
 
 print("\n--- Testing Product Model ---");
@@ -127,12 +126,12 @@ let component1 = new_product_component("Super Capacitor")
 print(`\nCreated Product Component: ${component1.name}, Qty: ${component1.quantity}`);
 
 // Create Product 1 (a physical product with a component)
-let product1_id = 3001;
+
 let product1_name = "Advanced Gadget X";
 let product1_creation_time = 1672876800; // Example timestamp (Jan 5, 2023)
 
-print(`\nCreating Product 1 (ID: ${product1_id}): ${product1_name}...`);
-let product1 = new_product(product1_id)
+print(`\nCreating Product 1: ${product1_name}...`);
+let product1 = new_product()
     .name(product1_name)
     .description("A revolutionary gadget with cutting-edge features.")
     .price(299.99)
@@ -146,11 +145,11 @@ let product1 = new_product(product1_id)
     .set_base_created_at(product1_creation_time);
 
 print("Saving Product 1...");
-set_product(product1);
+product1 = set_product(product1);
 print("Product 1 saved.");
 
-print(`\nRetrieving Product 1 (ID: ${product1_id})...`);
-let retrieved_product1 = get_product_by_id(product1_id);
+print(`\nRetrieving Product 1 (ID: ${product1.id})...`);
+let retrieved_product1 = get_product_by_id(product1.id);
 print(`Retrieved Product 1: ${retrieved_product1.name}, Price: ${retrieved_product1.price}, Type: ${retrieved_product1.type_}`);
 if retrieved_product1.components.len() > 0 {
     print(`Product 1 Component 1: ${retrieved_product1.components[0].name}, Desc: ${retrieved_product1.components[0].description}`);
@@ -159,12 +158,12 @@ if retrieved_product1.components.len() > 0 {
 }
 
 // Create Product 2 (a service)
-let product2_id = 3002;
+
 let product2_name = "Cloud Backup Service - Pro Plan";
 let product2_creation_time = 1672963200; // Example timestamp (Jan 6, 2023)
 
-print(`\nCreating Product 2 (ID: ${product2_id}): ${product2_name}...`);
-let product2 = new_product(product2_id)
+print(`\nCreating Product 2: ${product2_name}...`);
+let product2 = new_product()
     .name(product2_name)
     .description("Unlimited cloud backup with 24/7 support.")
     .price(19.99) // Monthly price
@@ -175,11 +174,11 @@ let product2 = new_product(product2_id)
     .set_base_created_at(product2_creation_time);
 
 print("Saving Product 2...");
-set_product(product2);
+product2 = set_product(product2);
 print("Product 2 saved.");
 
-print(`\nRetrieving Product 2 (ID: ${product2_id})...`);
-let retrieved_product2 = get_product_by_id(product2_id);
+print(`\nRetrieving Product 2 (ID: ${product2.id})...`);
+let retrieved_product2 = get_product_by_id(product2.id);
 print(`Retrieved Product 2: ${retrieved_product2.name}, Category: ${retrieved_product2.category}, Status: ${retrieved_product2.status}`);
 if retrieved_product2.components.len() > 0 {
     print(`Product 2 has ${retrieved_product2.components.len()} components.`);
@@ -198,7 +197,7 @@ print(`Sale Status Completed: ${SaleStatusConstants::Completed}`);
 print(`Sale Status Cancelled: ${SaleStatusConstants::Cancelled}`);
 
 // Create SaleItem 1 (using product1 from above)
-let sale_item1_product_id = product1_id; // Using product1_id from product example
+let sale_item1_product_id = product1.id; // Using product1.id after it's set // Using product1_id from product example
 let sale_item1_name = retrieved_product1.name; // Using name from retrieved product1
 let sale_item1_qty = 2;
 let sale_item1_unit_price = retrieved_product1.price;
@@ -209,7 +208,7 @@ let sale_item1 = new_sale_item(sale_item1_product_id, sale_item1_name, sale_item
 print(`SaleItem 1: Product ID ${sale_item1.product_id}, Qty: ${sale_item1.quantity}, Subtotal: ${sale_item1.subtotal}`);
 
 // Create SaleItem 2 (using product2 from above)
-let sale_item2_product_id = product2_id; // Using product2_id from product example
+let sale_item2_product_id = product2.id; // Using product2.id after it's set // Using product2_id from product example
 let sale_item2_name = retrieved_product2.name;
 let sale_item2_qty = 1;
 let sale_item2_unit_price = retrieved_product2.price;
@@ -220,14 +219,13 @@ let sale_item2 = new_sale_item(sale_item2_product_id, sale_item2_name, sale_item
 print(`SaleItem 2: Product ID ${sale_item2.product_id}, Qty: ${sale_item2.quantity}, Subtotal: ${sale_item2.subtotal}`);
 
 // Create a Sale
-let sale1_id = 4001;
-let sale1_customer_id = company1_id; // Example: company1 is the customer
+
+let sale1_customer_id = company1.id; // Example: company1 is the customer
 let sale1_date = 1673049600; // Example timestamp (Jan 7, 2023)
 let sale1_total_amount = sale_item1.subtotal + sale_item2.subtotal;
 
-print(`\nCreating Sale 1 (ID: ${sale1_id}) for Customer ID: ${sale1_customer_id}...`);
+print(`\nCreating Sale 1 for Customer ID: ${sale1_customer_id}...`);
 let sale1 = new_sale(
-    sale1_id, 
     sale1_customer_id, // for company_id_i64 in Rhai registration
     "Temp Buyer Name",   // for buyer_name in Rhai registration
     "temp@buyer.com",  // for buyer_email in Rhai registration
@@ -262,12 +260,12 @@ print(`Sale 1 Base Comments: ${sale1.comments}`);
 
 // Save Sale 1 to database
 print("\nSaving Sale 1 to database...");
-set_sale(sale1);
+sale1 = set_sale(sale1);
 print("Sale 1 saved.");
 
 // Retrieve Sale 1 from database
-print(`\nRetrieving Sale 1 by ID (${sale1_id})...`);
-let retrieved_sale1 = get_sale_by_id(sale1_id);
+print(`\nRetrieving Sale 1 by ID (${sale1.id})...`);
+let retrieved_sale1 = get_sale_by_id(sale1.id);
 print(`Retrieved Sale 1: ID ${retrieved_sale1.id}, Customer: ${retrieved_sale1.customer_id}, Status: ${retrieved_sale1.status}`);
 print(`Retrieved Sale 1 Total: ${retrieved_sale1.total_amount}, Notes: '${retrieved_sale1.notes}'`);
 if retrieved_sale1.items.len() > 0 {
diff --git a/heromodels/examples/calendar_rhai/calendar.rhai b/heromodels/examples/calendar_rhai/calendar.rhai
index 40fa0da..f5886ab 100644
--- a/heromodels/examples/calendar_rhai/calendar.rhai
+++ b/heromodels/examples/calendar_rhai/calendar.rhai
@@ -2,29 +2,31 @@
 let db = get_db();
 
 // Create a new calendar using the constructor and builder methods
-print("Creating a new calendar with ID 1 via registered constructor...");
-let calendar = new_calendar(1).
+print("Creating a new calendar (ID will be DB-assigned) via registered constructor...");
+let calendar = new_calendar(). // ID removed
     name("My First Calendar").
     description("A calendar for testing Rhai integration");
 
-let event = new_event(1).
+let event = new_event(). // ID removed
     title("My First Event").
     description("An event for testing Rhai integration")
-    .add_attendee(new_attendee(1));
+    .add_attendee(new_attendee(1)); // new_attendee(contact_id), not Attendee ID
 
-calendar.add_event(1);
+// Add event's ID to calendar. event.id will be 0 if not saved separately.
+// Calendar::add_event returns the modified calendar, so we re-assign.
+calendar = calendar.add_event(event.id);
 
 print("Type of calendar object: " + type_of(calendar));
 print("Created calendar: " + calendar.name);
 
-// Save the calendar to the database
-set_calendar(db, calendar);
+// Save the calendar to the database and capture the result with DB-assigned ID
+let calendar = set_calendar(db, calendar); // Capture result
 print("Calendar saved to database");
 
 // Check if calendar exists and retrieve it
-if calendar_exists(db, 1) {
-    let retrieved_calendar = get_calendar_by_id(db, 1);
-    print("Retrieved calendar: " + retrieved_calendar.name);
+if calendar_exists(db, calendar.id) { // Use calendar.id from the saved object
+    let retrieved_calendar = get_calendar_by_id(db, calendar.id); // Use calendar.id
+    print("Retrieved calendar ID: " + retrieved_calendar.id + ", Name: " + retrieved_calendar.name);
     // Access the 'description' field directly. 
     // Note: 'description' is Option<String>. Rhai handles options.
     // You might want to check for 'is_some()' or 'is_none()' or use 'unwrap_or()' pattern if needed.
@@ -35,17 +37,17 @@ if calendar_exists(db, 1) {
         print("No description available or it's None");
     }
 } else {
-    print("Failed to retrieve calendar with ID 1");
+    print("Failed to retrieve calendar with ID " + calendar.id);
 }
 
 // Create another calendar
-print("Creating a new calendar with ID 2 using builder methods...");
-let calendar2 = new_calendar(2).
+print("Creating another new calendar (ID will be DB-assigned) using builder methods...");
+let calendar2 = new_calendar(). // ID removed
     name("My Second Calendar").
     description("Another calendar for testing");
 
-set_calendar(db, calendar2);
-print("Second calendar saved");
+let calendar2 = set_calendar(db, calendar2); // Capture result
+print("Second calendar saved with ID: " + calendar2.id);
 
 // Get all calendars
 let all_calendars = get_all_calendars(db);
@@ -57,14 +59,14 @@ for cal_item in all_calendars { // Renamed loop variable to avoid conflict if 'c
 }
 
 // Delete a calendar
-delete_calendar_by_id(db, 1);
-print("Deleted calendar with ID 1");
+delete_calendar_by_id(db, calendar.id); // Use ID from the first calendar object
+print("Attempted to delete calendar with ID " + calendar.id);
 
 // Verify deletion
-if !calendar_exists(db, 1) {
-    print("Calendar with ID 1 was successfully deleted");
+if !calendar_exists(db, calendar.id) { // Use ID from the first calendar object
+    print("Calendar with ID " + calendar.id + " was successfully deleted");
 } else {
-    print("Failed to delete calendar with ID 1");
+    print("Failed to delete calendar with ID " + calendar.id + ", or it was not the one intended.");
 }
 
 // Count remaining calendars
diff --git a/heromodels/examples/finance_rhai/finance.rhai b/heromodels/examples/finance_rhai/finance.rhai
index 546d9ae..4589761 100644
--- a/heromodels/examples/finance_rhai/finance.rhai
+++ b/heromodels/examples/finance_rhai/finance.rhai
@@ -2,139 +2,141 @@
 
 print("--- Starting Finance Rhai Script ---");
 
-// 1. Create an Account
-let acc1_id = 101;
-let user1_id = 1;
-let acc1 = new_account(acc1_id, "User1 Main Account", user1_id, "Primary account for User 1", "LedgerX", "0x123MainSt", "pubkeyUser1");
-print(`Created account: ${acc1.name} with ID ${acc1.id}`);
+// 1. Create an Account using the builder pattern
+let user1_id = 1; // Assuming this user_id is a separate concept, e.g. from an auth system
+let acc1 = new_account()
+    .set_name("User1 Main Account")
+    .set_user_id(user1_id) // user_id is i64 in Rhai, u32 in Rust. Conversion handled by setter.
+    .set_description("Primary account for User 1")
+    .set_ledger("LedgerX")
+    .set_address("0x123MainSt")
+    .set_pubkey("pubkeyUser1");
+print(`Created account (pre-save): ${acc1.get_name()} with temp ID ${acc1.get_id()}`);
 
-// 2. Save Account to Mock DB
-set_account(acc1);
-print(`Account ${acc1.id} saved to DB.`);
+// 2. Save Account to Mock DB and get the version with DB-assigned ID
+let acc1 = set_account(acc1); // Shadowing acc1 with the returned instance
+print(`Account ${acc1.get_name()} saved to DB with ID ${acc1.get_id()}.`);
 
-// 3. Retrieve Account from Mock DB
-let fetched_acc1 = get_account_by_id(acc1_id);
-print(`Fetched account from DB: ${fetched_acc1.name}, User ID: ${fetched_acc1.user_id}`);
+// 3. Retrieve Account from Mock DB (using the new ID)
+let fetched_acc1 = get_account_by_id(acc1.get_id()); // Use the ID from the saved acc1
+print(`Fetched account from DB: ${fetched_acc1.get_name()}, User ID: ${fetched_acc1.get_user_id()}`);
 
-// 4. Create an Asset
-let asset1_id = 201;
-let asset1 = new_asset(asset1_id, "HeroCoin", "Utility token for Hero Platform", 1000.0, "0xTokenContract", "Erc20", 18);
-print(`Created asset: ${asset1.name} (ID: ${asset1.id}), Amount: ${asset1.amount}, Type: ${asset1.asset_type_str}`);
+// 4. Create an Asset using the builder pattern
+let asset1 = new_asset()
+    .set_name("HeroCoin")
+    .set_description("Utility token for Hero Platform")
+    .set_amount(1000.0)
+    .set_address("0xTokenContract")
+    .set_asset_type("Erc20") // Setter handles string to enum
+    .set_decimals(18);
+print(`Created asset (pre-save): ${asset1.get_name()} (temp ID: ${asset1.get_id()}), Amount: ${asset1.get_amount()}, Type: ${asset1.get_asset_type_str()}`);
 
-// 5. Save Asset to Mock DB
-set_asset(asset1);
-print(`Asset ${asset1.id} saved to DB.`);
+// 5. Save Asset to Mock DB and get the version with DB-assigned ID
+let asset1 = set_asset(asset1); // Shadowing asset1
+print(`Asset ${asset1.get_name()} (ID: ${asset1.get_id()}) saved to DB.`);
 
-// 6. Retrieve Asset from Mock DB
-let fetched_asset1 = get_asset_by_id(asset1_id);
-print(`Fetched asset from DB: ${fetched_asset1.name}, Address: ${fetched_asset1.address}`);
+// 6. Retrieve Asset from Mock DB (using the new ID)
+let fetched_asset1 = get_asset_by_id(asset1.get_id()); // Use the ID from the saved asset1
+print(`Fetched asset from DB: ${fetched_asset1.get_name()}, Address: ${fetched_asset1.get_address()}`);
 
-// 7. Add Asset to Account (using the fetched instances)
-// Note: Account::add_asset takes Asset by value. We have 'fetched_asset1'.
-// The 'add_asset' method on the Account object in Rhai should work with the asset object.
-// First, let's ensure fetched_acc1 is mutable if 'add_asset' modifies it directly.
-// Or, if add_asset returns a new Account, we'd do: fetched_acc1 = fetched_acc1.add_asset(fetched_asset1);
-// For now, assuming add_asset modifies in place (Rust methods taking `&mut self` often allow this if the object itself is mutable in Rhai scope)
-// If Account.add_asset was registered as `fn(&mut Account, Asset)` then: 
-// fetched_acc1.add_asset(fetched_asset1);
-// Let's assume for now that `add_asset` is available and works. We'll test this.
-// For the current setup, `Account::add_asset` takes `&mut self`, so the object must be mutable in Rhai.
-// We might need to re-fetch or re-set the account if we modify it and want the DB to know.
-// Let's try to add and then re-save the account.
+// 7. Add Asset to Account
+// We have 'acc1' and 'asset1' from previous steps, both saved to DB and have their IDs.
+print(`Attempting to add asset ${asset1.get_id()} to account ${acc1.get_id()}`);
 
-// For simplicity in this first script, let's focus on marketplace.
-// Adding asset to account might require more setup in Rhai regarding object mutability
-// or how the add_asset method is exposed. We can refine this later.
-print("Skipping adding asset to account directly in this script version for brevity, focusing on listing.");
+// Fetch the latest version of the account before modifying
+// let mut acc1_for_update = get_account_by_id(acc1.get_id());
+// // Fetch the asset to add (or use fetched_asset1 if it's the correct one)
+// let asset_to_add = get_asset_by_id(asset1.get_id());
+// 
+// try {
+//     acc1_for_update = acc1_for_update.add_asset(asset_to_add); // add_asset returns the modified account
+//     acc1_for_update = set_account(acc1_for_update); // Save the account with the new asset
+//     print(`Asset '${asset_to_add.get_name()}' added to account '${acc1_for_update.get_name()}'.`);
+//     print(`Account now has ${acc1_for_update.get_assets_cloned().len()} assets.`);
+//     // Verify the asset is there
+    if (acc1_for_update.get_assets_cloned().len() > 0) {
+        let first_asset_in_account = acc1_for_update.get_assets_cloned()[0];
+        print(`First asset in account: ${first_asset_in_account.get_name()} (ID: ${first_asset_in_account.get_id()})`);
+    }
+} catch (err) {
+    print(`Error adding asset to account: ${err}`);
+}
 
-// 8. Create a Listing for the Asset
-let listing1_id = 301;
+// 8. Create a Listing for the Asset using the builder pattern
 let current_timestamp = timestamp(); // Rhai's built-in for current unix timestamp (seconds)
 let expires_at_ts = current_timestamp + (24 * 60 * 60 * 7); // Expires in 7 days
 
-let listing1 = new_listing(
-    listing1_id, 
-    "Rare HeroCoin Batch", 
-    "100 HeroCoins for sale", 
-    asset1_id.to_string(), // asset_id as string
-    "Erc20",               // asset_type as string
-    user1_id.to_string(),  // seller_id as string
-    50.0,                  // price
-    "USD",                 // currency
-    "FixedPrice",          // listing_type as string
-    expires_at_ts,         // expires_at_ts_opt as i64
-    ["token", "herocoin", "sale"], // tags as array of strings
-    ()                   // image_url_opt as string or ()
-);
-print(`Created listing: ${listing1.title} (ID: ${listing1.id}), Price: ${listing1.price} ${listing1.currency}`);
-print(`Listing type: ${listing1.listing_type_str}, Status: ${listing1.status_str}`);
-print(`Listing expires_at_ts_opt: ${listing1.expires_at_ts_opt}`);
+let listing1 = new_listing()
+    .set_title("Rare HeroCoin Batch")
+    .set_description("100 HeroCoins for sale")
+    .set_asset_id(asset1.get_id().to_string()) // Use ID from the saved asset1
+    .set_asset_type("Erc20")               // asset_type as string
+    .set_seller_id(user1_id.to_string())  // seller_id as string (using the predefined user1_id)
+    .set_price(50.0)                  // price
+    .set_currency("USD")                 // currency
+    .set_listing_type("FixedPrice")    // listing_type as string
+    .set_expires_at_ts_opt(expires_at_ts) // expires_at_ts_opt as i64
+    .set_tags(["token", "herocoin", "sale"]); // tags as array of strings
+    // image_url is None by default from new_listing(), so no need to call set_image_url_opt for None
 
-// 9. Save Listing to Mock DB
-set_listing(listing1);
-print(`Listing ${listing1.id} saved to DB.`);
+print(`Created listing (pre-save): ${listing1.get_title()} (temp ID: ${listing1.get_id()}), Price: ${listing1.get_price()} ${listing1.get_currency()}`);
+print(`Listing type: ${listing1.get_listing_type_str()}, Status: ${listing1.get_status_str()}`);
+print(`Listing expires_at_ts_opt: ${listing1.get_expires_at_ts_opt()}`);
 
-// 10. Retrieve Listing from Mock DB
-let fetched_listing1 = get_listing_by_id(listing1_id);
-print(`Fetched listing from DB: ${fetched_listing1.title}, Seller ID: ${fetched_listing1.seller_id}`);
-print(`Fetched listing asset_id: ${fetched_listing1.asset_id}, asset_type: ${fetched_listing1.asset_type_str}`);
+// 9. Save Listing to Mock DB and get the version with DB-assigned ID
+let listing1 = set_listing(listing1); // Shadowing listing1
+print(`Listing ${listing1.get_title()} (ID: ${listing1.get_id()}) saved to DB.`);
 
-// 11. Demonstrate an auction listing (basic structure)
-let listing2_id = 302;
-let auction_listing = new_listing(
-    listing2_id,
-    "Vintage Hero Figurine",
-    "Rare collectible, starting bid low!",
-    "asset_nft_123", // Mock asset ID for an NFT
-    "Erc721",
-    user1_id.to_string(),
-    10.0, // Starting price
-    "USD",
-    "Auction",
-    (), // No expiration for this example
-    ["collectible", "rare", "auction"],
-    "http://example.com/figurine.png"
-);
-set_listing(auction_listing);
-print(`Created auction listing: ${auction_listing.title} (ID: ${auction_listing.id})`);
+// 10. Retrieve Listing from Mock DB (using the new ID)
+let fetched_listing1 = get_listing_by_id(listing1.get_id()); // Use the ID from the saved listing1
+print(`Fetched listing from DB: ${fetched_listing1.get_title()}, Seller ID: ${fetched_listing1.get_seller_id()}`);
+print(`Fetched listing asset_id: ${fetched_listing1.get_asset_id()}, asset_type: ${fetched_listing1.get_asset_type_str()}`);
 
-// 12. Create a Bid for the auction listing
-let bid1 = new_bid(auction_listing.id.to_string(), 2, 12.0, "USD"); // User 2 bids 12 USD
+// 11. Demonstrate an auction listing using the builder pattern
+let auction_listing = new_listing()
+    .set_title("Vintage Hero Figurine")
+    .set_description("Rare collectible, starting bid low!")
+    .set_asset_id("asset_nft_123") // Mock asset ID for an NFT - this asset isn't created/saved in script
+    .set_asset_type("Erc721")
+    .set_seller_id(user1_id.to_string()) // Using the predefined user1_id
+    .set_price(10.0) // Starting price
+    .set_currency("USD")
+    .set_listing_type("Auction")
+    // expires_at_ts_opt is None by default
+    .set_tags(["collectible", "rare", "auction"])
+    .set_image_url_opt("http://example.com/figurine.png");
+
+// Save Auction Listing to Mock DB and get the version with DB-assigned ID
+let auction_listing = set_listing(auction_listing); // Shadowing auction_listing
+print(`Created auction listing: ${auction_listing.get_title()} (ID: ${auction_listing.get_id()})`);
+
+// 12. Create a Bid for the auction listing (Bid model not using builder pattern in this refactor)
+let bid1 = new_bid(auction_listing.get_id().to_string(), 2, 12.0, "USD"); // User 2 bids 12 USD
 print(`Created bid for listing ${bid1.listing_id} by bidder ${bid1.bidder_id} for ${bid1.amount} ${bid1.currency}`);
 print(`Bid status: ${bid1.status_str}, Created at: ${bid1.created_at_ts}`);
 
-// Add bid to listing - this requires the listing object to be mutable
-// and the add_listing_bid function to be correctly registered to modify it.
-// For now, we'll assume the function works and we'd need to re-set the listing to DB if modified.
-// To test `add_listing_bid` properly, we would typically do:
-// let mut mutable_auction_listing = get_listing_by_id(listing2_id);
-// mutable_auction_listing.add_listing_bid(bid1);
-// set_listing(mutable_auction_listing);
-// print(`Bid added to listing ${mutable_auction_listing.id}. New bid count: ${mutable_auction_listing.bids_cloned.len()}`);
-// For this initial script, we will call the function but acknowledge the db update step for a full flow.
-
-// Get the listing again to add a bid
-let auction_listing_for_bid = get_listing_by_id(listing2_id);
-print(`Listing '${auction_listing_for_bid.title}' fetched for bidding. Current price: ${auction_listing_for_bid.price}, Bids: ${auction_listing_for_bid.bids_cloned.len()}`);
+// 13. Add bid to listing
+let mut auction_listing_for_bid = get_listing_by_id(auction_listing.get_id()); 
+print(`Listing '${auction_listing_for_bid.get_title()}' fetched for bidding. Current price: ${auction_listing_for_bid.get_price()}, Bids: ${auction_listing_for_bid.get_bids_cloned().len()}`);
 
 try {
-    auction_listing_for_bid.add_listing_bid(bid1);
-    print(`Bid added to '${auction_listing_for_bid.title}'. New bid count: ${auction_listing_for_bid.bids_cloned.len()}, New price: ${auction_listing_for_bid.price};`);
-    set_listing(auction_listing_for_bid); // Save updated listing to DB
+    let updated_listing_after_bid = auction_listing_for_bid.add_listing_bid(bid1);
+    print(`Bid added to '${updated_listing_after_bid.get_title()}'. New bid count: ${updated_listing_after_bid.get_bids_cloned().len()}, New price: ${updated_listing_after_bid.get_price()};`);
+    set_listing(updated_listing_after_bid); // Save updated listing to DB
     print("Auction listing with new bid saved to DB;");
 } catch (err) {
     print(`Error adding bid: ${err}`);
 }
 
-// Try to complete sale for the fixed price listing
-let listing_to_sell = get_listing_by_id(listing1_id);
+// 14. Try to complete sale for the fixed price listing
+let mut listing_to_sell = get_listing_by_id(listing1.get_id()); 
 let buyer_user_id = 3;
-print(`Attempting to complete sale for listing: ${listing_to_sell.title} by buyer ${buyer_user_id}`);
+print(`Attempting to complete sale for listing: ${listing_to_sell.get_title()} by buyer ${buyer_user_id}`);
 try {
-    listing_to_sell.complete_listing_sale(buyer_user_id.to_string(), listing_to_sell.price);
-    print(`Sale completed for listing ${listing_to_sell.id}. New status: ${listing_to_sell.status_str}`);
-    print(`Buyer ID: ${listing_to_sell.buyer_id_opt}, Sale Price: ${listing_to_sell.sale_price_opt}`);
-    set_listing(listing_to_sell); // Save updated listing
+    let sold_listing = listing_to_sell.complete_listing_sale(buyer_user_id.to_string(), listing_to_sell.get_price());
+    print(`Sale completed for listing ${sold_listing.get_id()}. New status: ${sold_listing.get_status_str()}`);
+    print(`Buyer ID: ${sold_listing.get_buyer_id_opt()}, Sale Price: ${sold_listing.get_sale_price_opt()}`);
+    set_listing(sold_listing); // Save updated listing
 } catch (err) {
     print(`Error completing sale: ${err}`);
 }
diff --git a/heromodels/examples/project_rhai_wasm/.cargo/config.toml b/heromodels/examples/project_rhai_wasm/.cargo/config.toml
new file mode 100644
index 0000000..f603c8f
--- /dev/null
+++ b/heromodels/examples/project_rhai_wasm/.cargo/config.toml
@@ -0,0 +1,9 @@
+[build]
+# Set the default build target for this project
+target = "wasm32-unknown-unknown"
+
+# Configuration for the wasm32-unknown-unknown target
+[target.wasm32-unknown-unknown]
+# Pass --cfg=wasm_js to rustc when compiling for this target.
+# This is required by the getrandom crate.
+rustflags = ["--cfg=wasm_js"] # For getrandom v0.3.x WASM support (required by rhai via ahash)
diff --git a/heromodels/examples/project_rhai_wasm/Cargo.toml b/heromodels/examples/project_rhai_wasm/Cargo.toml
new file mode 100644
index 0000000..cf9b426
--- /dev/null
+++ b/heromodels/examples/project_rhai_wasm/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "project_rhai_wasm_example"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+heromodels = { path = "../..", features = ["rhai"] } # Match heromodels main crate
+wasm-bindgen = "0.2"
+web-sys = { version = "0.3", features = ["console"] }
+console_error_panic_hook = "0.1.7"
+js-sys = "0.3"
+getrandom = { version = "0.3.3", features = ["js"] } # Align with rhai's dependency
+
+[profile.release]
+# Tell `rustc` to optimize for small code size.
+lto = true
+opt-level = 's'
diff --git a/heromodels/examples/project_rhai_wasm/index.html b/heromodels/examples/project_rhai_wasm/index.html
new file mode 100644
index 0000000..ec6ccdb
--- /dev/null
+++ b/heromodels/examples/project_rhai_wasm/index.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>HeroModels Project Rhai WASM Test</title>
+    <style>
+        body { font-family: sans-serif; margin: 20px; background-color: #f4f4f4; color: #333; }
+        #output { margin-top: 20px; padding: 10px; border: 1px solid #ccc; background-color: #fff; white-space: pre-wrap; }
+        button { padding: 10px 15px; font-size: 16px; cursor: pointer; background-color: #007bff; color: white; border: none; border-radius: 5px; }
+        button:hover { background-color: #0056b3; }
+        h1 { color: #0056b3; }
+    </style>
+</head>
+<body>
+    <h1>HeroModels Project Rhai WASM Test</h1>
+    <p>Open your browser's developer console to see detailed logs from the Rhai script.</p>
+    <button id="runScriptButton">Run Rhai Script in WASM</button>
+    
+    <script type="module">
+        // Import the WASM module
+        import init, { run_project_script_wasm } from './pkg/project_rhai_wasm_example.js';
+
+        async function main() {
+            // Initialize the WASM module
+            await init();
+            console.log("WASM module initialized.");
+
+            const runButton = document.getElementById('runScriptButton');
+            runButton.onclick = () => {
+                console.log("Button clicked, attempting to run script...");
+                try {
+                    run_project_script_wasm();
+                    console.log("run_project_script_wasm called.");
+                } catch (e) {
+                    console.error("Error calling run_project_script_wasm:", e);
+                }
+            };
+             // Automatically run the script on load if desired
+            // console.log("Attempting to run script on load...");
+            // try {
+            //     run_project_script_wasm();
+            //     console.log("run_project_script_wasm called on load.");
+            // } catch (e) {
+            //     console.error("Error calling run_project_script_wasm on load:", e);
+            // }
+        }
+
+        main().catch(console.error);
+    </script>
+</body>
+</html>
diff --git a/heromodels/examples/project_rhai_wasm/src/lib.rs b/heromodels/examples/project_rhai_wasm/src/lib.rs
new file mode 100644
index 0000000..21aff17
--- /dev/null
+++ b/heromodels/examples/project_rhai_wasm/src/lib.rs
@@ -0,0 +1,126 @@
+use heromodels::db::{OurDB, Db}; // Import Db trait
+use heromodels::models::projects::rhai::register_projects_rhai_module;
+use rhai::{Engine, Scope, Dynamic, EvalAltResult, Position};
+use std::sync::Arc;
+use wasm_bindgen::prelude::*;
+use web_sys::console;
+
+// Called once when the WASM module is instantiated.
+#[wasm_bindgen(start)]
+pub fn main_wasm() -> Result<(), JsValue> {
+    // For better panic messages in the browser console
+    std::panic::set_hook(Box::new(console_error_panic_hook::hook));
+    Ok(())
+}
+
+#[wasm_bindgen]
+pub fn run_project_script_wasm() -> Result<(), JsValue> {
+    console::log_1(&"Starting Rhai script execution in WASM...".into());
+
+    let script = r#"
+// Test script for Project Rhai integration
+
+print("--- Testing Project Rhai Integration (WASM) ---");
+
+// Create a new project
+let p1 = new_project()
+    .name("Project Alpha WASM")
+    .description("This is the first test project in WASM.")
+    .owner_id(101)
+    .add_member_id(102)
+    .add_member_id(103)
+    .member_ids([201, 202, 203]) 
+    .add_tag("important")
+    .add_tag("rhai_test")
+    .add_tag("wasm")
+    .tags(["core", "feature_test", "wasm_run"]) 
+    .status(Status::InProgress)
+    .priority(Priority::High)
+    .item_type(ItemType::Feature)
+    .add_base_comment(1001);
+
+print("Created project p1: " + p1);
+print("p1.name: " + p1.name);
+print("p1.description: " + p1.description);
+print("p1.owner_id: " + p1.owner_id);
+print("p1.member_ids: " + p1.member_ids);
+print("p1.tags: " + p1.tags);
+print(`p1.status: ${p1.status.to_string()}`);
+print(`p1.priority: ${p1.priority.to_string()}`);
+print(`p1.item_type: ${p1.item_type.to_string()}`);
+print("p1.id: " + p1.id);
+print("p1.created_at: " + p1.created_at);
+print("p1.modified_at: " + p1.modified_at);
+print("p1.comments: " + p1.comments);
+
+// Save to DB
+try {
+    set_project(p1);
+    print("Project p1 saved successfully.");
+} catch (err) {
+    print("Error saving project p1: " + err);
+}
+
+// Retrieve from DB
+try {
+    let retrieved_p1 = get_project_by_id(1);
+    if retrieved_p1 != () { // Check if Some(project) was returned (None becomes '()')
+        print("Retrieved project by ID 1: " + retrieved_p1);
+        print("Retrieved project name: " + retrieved_p1.name);
+        print("Retrieved project tags: " + retrieved_p1.tags);
+    } else {
+        print("Project with ID 1 not found.");
+    }
+} catch (err) {
+    print("Error retrieving project by ID 1: " + err);
+}
+
+// Test non-existent project
+try {
+    let non_existent_project = get_project_by_id(999);
+    if non_existent_project != () {
+        print("Error: Found non-existent project 999: " + non_existent_project);
+    } else {
+        print("Correctly did not find project with ID 999.");
+    }
+} catch (err) {
+    print("Error checking for non-existent project: " + err);
+}
+
+print("--- Project Rhai Integration Test Complete (WASM) ---");
+"#;
+
+    let mut engine = Engine::new();
+
+    // Redirect Rhai's print to browser console
+    engine.on_print(|text| {
+        console::log_1(&text.into());
+    });
+
+    // Attempt to initialize OurDB. Sled's behavior in WASM with paths is experimental.
+    // It might work as an in-memory/temporary DB, or it might fail.
+    // Using a specific path and reset=true.
+    let db = match OurDB::new("/project_rhai_wasm_db", true) {
+        Ok(db_instance) => Arc::new(db_instance),
+        Err(e) => {
+            let err_msg = format!("Failed to initialize OurDB for WASM: {}", e);
+            console::error_1(&err_msg.into());
+            return Err(JsValue::from_str(&err_msg));
+        }
+    };
+
+    register_projects_rhai_module(&mut engine, db);
+
+    let mut scope = Scope::new();
+
+    match engine.run_with_scope(&mut scope, script) {
+        Ok(_) => console::log_1(&"Rhai script executed successfully in WASM!".into()),
+        Err(e) => {
+            let err_msg = format!("Rhai script execution failed in WASM: {}\nDetails: {:?}", e, e.to_string());
+            console::error_1(&err_msg.into());
+            return Err(JsValue::from_str(&e.to_string()));
+        }
+    }
+
+    Ok(())
+}
diff --git a/heromodels/src/db.rs b/heromodels/src/db.rs
index a03173a..e5736fd 100644
--- a/heromodels/src/db.rs
+++ b/heromodels/src/db.rs
@@ -97,8 +97,13 @@ impl<E: std::fmt::Debug + std::fmt::Display> std::fmt::Display for Error<E> {
             Error::DB(e) => write!(f, "Database error: {}", e),
             Error::Decode(e) => write!(f, "Failed to decode model: {}", e),
             Error::Encode(e) => write!(f, "Failed to encode model: {}", e),
+            Error::InvalidId(s) => write!(f, "Invalid ID: {}", s),
+            Error::IdMismatch(s) => write!(f, "ID Mismatch: {}", s),
+            Error::IdCollision(s) => write!(f, "ID Collision: {}", s),
+            Error::TypeError => write!(f, "Type error"),
         }
     }
+}
 /// A transaction that can be committed or rolled back
 pub trait Transaction {
     /// Error type for transaction operations
diff --git a/heromodels/src/models/biz/company.rs b/heromodels/src/models/biz/company.rs
index 1b8753b..7fcd02d 100644
--- a/heromodels/src/models/biz/company.rs
+++ b/heromodels/src/models/biz/company.rs
@@ -99,9 +99,9 @@ impl Index for CompanyRegistrationNumberIndex {
 // --- Builder Pattern ---
 
 impl Company {
-    pub fn new(id: u32, name: String, registration_number: String, incorporation_date: i64) -> Self { // incorporation_date to i64
+    pub fn new(name: String, registration_number: String, incorporation_date: i64) -> Self { // incorporation_date to i64
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             name,
             registration_number,
             incorporation_date, // This is i64 now
diff --git a/heromodels/src/models/biz/product.rs b/heromodels/src/models/biz/product.rs
index c49f807..031a593 100644
--- a/heromodels/src/models/biz/product.rs
+++ b/heromodels/src/models/biz/product.rs
@@ -84,9 +84,9 @@ impl Model for Product {
 }
 
 impl Product {
-    pub fn new(id: u32) -> Self {
+    pub fn new() -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             name: String::new(),
             description: String::new(),
             price: 0.0,
diff --git a/heromodels/src/models/biz/rhai.rs b/heromodels/src/models/biz/rhai.rs
index 46cbe2f..7a8c2ec 100644
--- a/heromodels/src/models/biz/rhai.rs
+++ b/heromodels/src/models/biz/rhai.rs
@@ -43,7 +43,7 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
     engine.register_type_with_name::<Company>("Company");
 
     // Constructor
-    engine.register_fn("new_company", |id: i64, name: String, registration_number: String, incorporation_date: i64| -> Result<Company, Box<EvalAltResult>> { Ok(Company::new(id as u32, name, registration_number, incorporation_date)) });
+    engine.register_fn("new_company", |name: String, registration_number: String, incorporation_date: i64| -> Result<Company, Box<EvalAltResult>> { Ok(Company::new(name, registration_number, incorporation_date)) });
 
     // Getters for Company
     engine.register_get("id", |company: &mut Company| -> Result<i64, Box<EvalAltResult>> { Ok(company.get_id() as i64) });
@@ -85,9 +85,7 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
     engine.register_type_with_name::<Shareholder>("Shareholder");
 
     // Constructor for Shareholder (minimal, takes only ID)
-    engine.register_fn("new_shareholder", |id: i64| -> Result<Shareholder, Box<EvalAltResult>> {
-        Ok(Shareholder::new(id as u32))
-    });
+    engine.register_fn("new_shareholder", || -> Result<Shareholder, Box<EvalAltResult>> { Ok(Shareholder::new()) });
 
     // Getters for Shareholder
     engine.register_get("id", |shareholder: &mut Shareholder| -> Result<i64, Box<EvalAltResult>> { Ok(shareholder.get_id() as i64) });
@@ -147,7 +145,7 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
 
     // --- Product ---
     engine.register_type_with_name::<Product>("Product")
-        .register_fn("new_product", |id: i64| -> Result<Product, Box<EvalAltResult>> { Ok(Product::new(id as u32)) })
+        .register_fn("new_product", || -> Result<Product, Box<EvalAltResult>> { Ok(Product::new()) })
         // Getters for Product
         .register_get("id", |p: &mut Product| -> Result<i64, Box<EvalAltResult>> { Ok(p.base_data.id as i64) })
         .register_get("name", |p: &mut Product| -> Result<String, Box<EvalAltResult>> { Ok(p.name.clone()) })
@@ -212,9 +210,7 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
 
     // --- Sale ---
     engine.register_type_with_name::<Sale>("Sale");
-    engine.register_fn("new_sale", |id_i64: i64, company_id_i64: i64, buyer_name: String, buyer_email: String, total_amount: f64, status: SaleStatus, sale_date: i64| -> Result<Sale, Box<EvalAltResult>> {
-        Ok(Sale::new(id_from_i64(id_i64)?, id_from_i64(company_id_i64)?, buyer_name, buyer_email, total_amount, status, sale_date))
-    });
+    engine.register_fn("new_sale", |company_id_i64: i64, buyer_name: String, buyer_email: String, total_amount: f64, status: SaleStatus, sale_date: i64| -> Result<Sale, Box<EvalAltResult>> { Ok(Sale::new(id_from_i64(company_id_i64)?, buyer_name, buyer_email, total_amount, status, sale_date)) });
 
     // Getters for Sale
     engine.register_get("id", |s: &mut Sale| -> Result<i64, Box<EvalAltResult>> { Ok(s.get_id() as i64) });
@@ -257,11 +253,14 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
         });
 
     // DB functions for Product
-    let captured_db_for_set_prod = Arc::clone(&db);
-    engine.register_fn("set_product", move |product: Product| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set_prod.set(&product).map_err(|e| {
-            Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Product (ID: {}): {}", product.get_id(), e).into(), Position::NONE))
-        })
+    let captured_db_for_set_product = Arc::clone(&db);
+    engine.register_fn("set_product", move |product: Product| -> Result<Product, Box<EvalAltResult>> {
+        let original_id_for_error = product.get_id();
+        captured_db_for_set_product.set(&product)
+            .map(|(_id, updated_product)| updated_product)
+            .map_err(|e| {
+                Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Product (Original ID: {}): {}", original_id_for_error, e).into(), Position::NONE))
+            })
     });
 
     let captured_db_for_get_prod = Arc::clone(&db);
@@ -274,10 +273,13 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
 
     // DB functions for Sale
     let captured_db_for_set_sale = Arc::clone(&db);
-    engine.register_fn("set_sale", move |sale: Sale| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set_sale.set(&sale).map_err(|e| {
-            Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Sale (ID: {}): {}", sale.get_id(), e).into(), Position::NONE))
-        })
+    engine.register_fn("set_sale", move |sale: Sale| -> Result<Sale, Box<EvalAltResult>> {
+        let original_id_for_error = sale.get_id();
+        captured_db_for_set_sale.set(&sale)
+            .map(|(_id, updated_sale)| updated_sale)
+            .map_err(|e| {
+                Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Sale (Original ID: {}): {}", original_id_for_error, e).into(), Position::NONE))
+            })
     });
 
     let captured_db_for_get_sale = Arc::clone(&db);
@@ -289,11 +291,14 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
     });
 
     // Mock DB functions for Shareholder
-    let captured_db_for_set_sh = Arc::clone(&db);
-    engine.register_fn("set_shareholder", move |shareholder: Shareholder| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set_sh.set(&shareholder).map_err(|e| {
-            Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Shareholder (ID: {}): {}", shareholder.get_id(), e).into(), Position::NONE))
-        })
+    let captured_db_for_set_shareholder = Arc::clone(&db);
+    engine.register_fn("set_shareholder", move |shareholder: Shareholder| -> Result<Shareholder, Box<EvalAltResult>> {
+        let original_id_for_error = shareholder.get_id();
+        captured_db_for_set_shareholder.set(&shareholder)
+            .map(|(_id, updated_shareholder)| updated_shareholder)
+            .map_err(|e| {
+                Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Shareholder (Original ID: {}): {}", original_id_for_error, e).into(), Position::NONE))
+            })
     });
 
     let captured_db_for_get_sh = Arc::clone(&db);
@@ -305,11 +310,14 @@ pub fn register_biz_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
     });
 
     // Mock DB functions for Company
-    let captured_db_for_set = Arc::clone(&db);
-    engine.register_fn("set_company", move |company: Company| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set.set(&company).map_err(|e| {
-            Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Company (ID: {}): {}", company.get_id(), e).into(), Position::NONE))
-        })
+    let captured_db_for_set_company = Arc::clone(&db);
+    engine.register_fn("set_company", move |company: Company| -> Result<Company, Box<EvalAltResult>> {
+        let original_id_for_error = company.get_id(); // Capture ID before it's potentially changed by DB
+        captured_db_for_set_company.set(&company)
+            .map(|(_id, updated_company)| updated_company) // Use the model returned by db.set()
+            .map_err(|e| {
+                Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Company (Original ID: {}): {}", original_id_for_error, e).into(), Position::NONE))
+            })
     });
 
     let captured_db_for_get = Arc::clone(&db);
diff --git a/heromodels/src/models/biz/sale.rs b/heromodels/src/models/biz/sale.rs
index 3c45af4..2d6d39f 100644
--- a/heromodels/src/models/biz/sale.rs
+++ b/heromodels/src/models/biz/sale.rs
@@ -102,7 +102,6 @@ impl Model for Sale {
 impl Sale {
     /// Creates a new `Sale`.
     pub fn new(
-        id: u32,
         company_id: u32,
         buyer_name: String,
         buyer_email: String,
@@ -111,7 +110,7 @@ impl Sale {
         sale_date: i64,
     ) -> Self {
         Sale {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             company_id,
             buyer_name,
             buyer_email,
diff --git a/heromodels/src/models/biz/shareholder.rs b/heromodels/src/models/biz/shareholder.rs
index 0b982f9..e449301 100644
--- a/heromodels/src/models/biz/shareholder.rs
+++ b/heromodels/src/models/biz/shareholder.rs
@@ -26,9 +26,9 @@ pub struct Shareholder {
 }
 
 impl Shareholder {
-    pub fn new(id: u32) -> Self {
+    pub fn new() -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             company_id: 0, // Default, to be set by builder
             user_id: 0,    // Default, to be set by builder
             name: String::new(), // Default
diff --git a/heromodels/src/models/calendar/calendar.rs b/heromodels/src/models/calendar/calendar.rs
index 404a2d3..2ca849c 100644
--- a/heromodels/src/models/calendar/calendar.rs
+++ b/heromodels/src/models/calendar/calendar.rs
@@ -60,17 +60,13 @@ pub struct Event {
 
 impl Event {
     /// Creates a new event
-    pub fn new(
-        id: i64,
-        title: impl ToString,
-        start_time: DateTime<Utc>,
-        end_time: DateTime<Utc>,
-    ) -> Self {
-            base_data: BaseModelData::new(id as u32),
-            title: String::new(),
+    pub fn new(title: impl ToString, start_time: DateTime<Utc>, end_time: DateTime<Utc>) -> Self {
+        Self {
+            base_data: BaseModelData::new(),
+            title: title.to_string(),
             description: None,
-            start_time: Utc::now(),
-            end_time: Utc::now(),
+            start_time,
+            end_time,
             attendees: Vec::new(),
             location: None,
         }
diff --git a/heromodels/src/models/calendar/rhai.rs b/heromodels/src/models/calendar/rhai.rs
index b91f3b2..d4e1f12 100644
--- a/heromodels/src/models/calendar/rhai.rs
+++ b/heromodels/src/models/calendar/rhai.rs
@@ -1,25 +1,50 @@
-use rhai::{Engine, EvalAltResult, NativeCallContext};
+use rhai::{Engine, EvalAltResult, NativeCallContext, ImmutableString};
 use std::sync::Arc;
 
 use heromodels_core::BaseModelData;
 use crate::db::hero::OurDB;
 use super::calendar::{Calendar, Event, Attendee, AttendanceStatus};
 use adapter_macros::{adapt_rhai_i64_input_fn, adapt_rhai_i64_input_method};
-use rhai_wrapper::wrap_vec_return;
+use adapter_macros::rhai_timestamp_helpers;
 
 // Helper function for get_all_calendars registration
-fn get_all_calendars_helper(_db: Arc<OurDB>) -> Vec<Calendar> { 
-    // In a real implementation, this would retrieve all calendars from the database
-    vec![Calendar::new(1 as u32), Calendar::new(2 as u32)] 
+
+
+fn new_calendar_rhai(name: String) -> Result<Calendar, Box<EvalAltResult>> {
+        Ok(Calendar::new(None, name))
+}
+
+fn new_event_rhai(
+    context: NativeCallContext,
+    title_rhai: ImmutableString,
+    start_time_ts: i64,
+    end_time_ts: i64,
+) -> Result<Event, Box<EvalAltResult>> {
+    let start_time = rhai_timestamp_helpers::rhai_timestamp_to_datetime(start_time_ts)
+        .map_err(|e_str| Box::new(EvalAltResult::ErrorRuntime(
+            format!("Failed to convert start_time for Event: {}", e_str).into(),
+            context.position(),
+        )))?;
+
+    let end_time = rhai_timestamp_helpers::rhai_timestamp_to_datetime(end_time_ts)
+        .map_err(|e_str| Box::new(EvalAltResult::ErrorRuntime(
+            format!("Failed to convert end_time for Event: {}", e_str).into(),
+            context.position(),
+        )))?;
+
+        Ok(Event::new(title_rhai.to_string(), start_time, end_time))
 }
 
 pub fn register_rhai_engine_functions(engine: &mut Engine, db: Arc<OurDB>) {
-    engine.register_fn("new_calendar", adapt_rhai_i64_input_fn!(Calendar::new, u32));
     engine.register_fn("name", move |calendar: Calendar, name: String| Calendar::name(calendar, name));
     engine.register_fn("description", move |calendar: Calendar, description: String| Calendar::description(calendar, description));
-    engine.register_fn("add_event", Calendar::add_event); // Corrected: expects i64, Rhai provides i64
+        engine.register_fn("add_event", Calendar::add_event);
+    // Note: Event IDs are i64 in Calendar.events, but Event model's base_data.id is u32.
+    // This might require adjustment if events are fetched by ID from the DB via Calendar.events.
     
-    engine.register_fn("new_event", Event::new); // Corrected: expects i64, Rhai provides i64
+        engine.register_fn("new_event", |context: NativeCallContext, title_rhai: ImmutableString, start_time_ts: i64, end_time_ts: i64| -> Result<Event, Box<EvalAltResult>> {
+        new_event_rhai(context, title_rhai, start_time_ts, end_time_ts)
+    });
     engine.register_fn("title", move |event: Event, title: String| Event::title(event, title));
     engine.register_fn("description", move |event: Event, description: String| Event::description(event, description));
     engine.register_fn("add_attendee", move |event: Event, attendee: Attendee| Event::add_attendee(event, attendee));
@@ -36,6 +61,8 @@ pub fn register_rhai_engine_functions(engine: &mut Engine, db: Arc<OurDB>) {
 
     engine.register_fn("new_attendee", adapt_rhai_i64_input_fn!(Attendee::new, u32));
 
+        engine.register_fn("new_calendar", |name: String| -> Result<Calendar, Box<EvalAltResult>> { new_calendar_rhai(name) });
+
     // Register a function to get the database instance
     engine.register_fn("get_db", move || db.clone());
     
@@ -53,24 +80,8 @@ pub fn register_rhai_engine_functions(engine: &mut Engine, db: Arc<OurDB>) {
     // Register getters for BaseModelData
     engine.register_get("id", |bmd: &mut BaseModelData| -> Result<i64, Box<EvalAltResult>> { Ok(bmd.id.into()) }); 
 
-    // Mock database interaction functions from the example - these would typically interact with the `db` Arc
-    engine.register_fn("set_calendar", |_db: Arc<OurDB>, calendar: Calendar| { 
-        println!("Mock save: Calendar saved: {}", calendar.name);
-    });
-    
-    engine.register_fn("get_calendar_by_id", |_db: Arc<OurDB>, id_i64: i64| -> Calendar { 
-        Calendar::new(id_i64 as u32) 
-    });
-    
-    engine.register_fn("calendar_exists", |_db: Arc<OurDB>, id_i64: i64| -> bool { 
-        id_i64 == 1 || id_i64 == 2 // Mock check
-    });
-        
-    engine.register_fn("get_all_calendars", wrap_vec_return!(get_all_calendars_helper, Arc<OurDB> => Calendar)); 
-    
-    engine.register_fn("delete_calendar_by_id", |_db: Arc<OurDB>, id_i64: i64| { 
-        println!("Mock delete: Calendar deleted with ID: {}", id_i64);
-    });
+    // Database interaction functions for Calendar are expected to be provided by #[rhai_model_export(..)] on the Calendar struct.
+    // Ensure that `db.rs` or similar correctly wires up the `OurDB` methods for these.
 
     // Getters for Event
     engine.register_get("id", |e: &mut Event| -> Result<i64, Box<EvalAltResult>> { Ok(e.base_data.id as i64) });
diff --git a/heromodels/src/models/finance/account.rs b/heromodels/src/models/finance/account.rs
index 719dcb5..d6f9648 100644
--- a/heromodels/src/models/finance/account.rs
+++ b/heromodels/src/models/finance/account.rs
@@ -4,8 +4,6 @@ use serde::{Deserialize, Serialize};
 use rhai::{CustomType, TypeBuilder};
 use heromodels_derive::model;
 use heromodels_core::BaseModelData;
-use heromodels_derive::model;
-use serde::{Deserialize, Serialize};
 
 use super::asset::Asset;
 
diff --git a/heromodels/src/models/finance/asset.rs b/heromodels/src/models/finance/asset.rs
index 8363c22..40a5acf 100644
--- a/heromodels/src/models/finance/asset.rs
+++ b/heromodels/src/models/finance/asset.rs
@@ -4,8 +4,6 @@ use serde::{Deserialize, Serialize};
 use rhai::{CustomType, TypeBuilder};
 use heromodels_derive::model;
 use heromodels_core::BaseModelData;
-use heromodels_derive::model;
-use serde::{Deserialize, Serialize};
 
 /// AssetType defines the type of blockchain asset
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
diff --git a/heromodels/src/models/finance/marketplace.rs b/heromodels/src/models/finance/marketplace.rs
index 431251e..701e1cd 100644
--- a/heromodels/src/models/finance/marketplace.rs
+++ b/heromodels/src/models/finance/marketplace.rs
@@ -5,8 +5,6 @@ use rhai::{CustomType, TypeBuilder};
 use chrono::{DateTime, Utc};
 use heromodels_core::BaseModelData;
 use heromodels_derive::model;
-use chrono::{DateTime, Utc};
-use serde::{Deserialize, Serialize};
 
 use super::asset::AssetType;
 
diff --git a/heromodels/src/models/finance/rhai.rs b/heromodels/src/models/finance/rhai.rs
index 6aaae98..7185078 100644
--- a/heromodels/src/models/finance/rhai.rs
+++ b/heromodels/src/models/finance/rhai.rs
@@ -1,13 +1,22 @@
-use rhai::{Engine, Array, ImmutableString, INT, EvalAltResult};
+use rhai::{Engine, Array, Dynamic, ImmutableString, INT, EvalAltResult, NativeCallContext};
 use std::sync::{Arc, Mutex};
 use std::collections::HashMap;
+use std::error::Error as StdError; // For Box<dyn StdError>
 
-use chrono::Utc;
+// Custom error type for Rhai that wraps a String
+#[derive(Debug)]
+struct RhaiStringError(String);
 
-use adapter_macros::register_rhai_enum_accessors;
-use adapter_macros::register_rhai_datetime_accessors;
-use adapter_macros::register_rhai_vec_string_accessors;
-use adapter_macros::rhai_timestamp_helpers;
+impl std::fmt::Display for RhaiStringError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl StdError for RhaiStringError {}
+
+
+use chrono::{DateTime, Utc};
 
 use crate::models::finance::account::Account;
 use crate::models::finance::asset::{Asset, AssetType};
@@ -67,7 +76,6 @@ fn string_to_bid_status(s: &str) -> Result<BidStatus, Box<EvalAltResult>> {
     }
 }
 
-
 pub fn register_rhai_engine_functions(
     engine: &mut Engine, 
     db_accounts: Arc<Mutex<HashMap<u32, Account>>>,
@@ -75,68 +83,213 @@ pub fn register_rhai_engine_functions(
     db_listings: Arc<Mutex<HashMap<u32, Listing>>>,
 ) {
     // --- Account model --- 
-    engine.build_type::<Account>()
-        .register_fn("new_account", 
-            |id_rhai: INT, name_rhai: ImmutableString, user_id_rhai: INT, desc_rhai: ImmutableString, ledger_rhai: ImmutableString, addr_rhai: ImmutableString, pubkey_rhai: ImmutableString| -> Account {
-                Account::new(id_rhai as u32, name_rhai, user_id_rhai as u32, desc_rhai, ledger_rhai, addr_rhai, pubkey_rhai)
-            }
-        )
-        .register_get_set("name", 
-            |obj: &mut Account| -> ImmutableString { obj.name.clone().into() }, 
-            |obj: &mut Account, val: ImmutableString| obj.name = val.to_string()
-        )
-        .register_get_set("user_id", 
-            |obj: &mut Account| obj.user_id as INT, 
-            |obj: &mut Account, val: INT| obj.user_id = val as u32
-        )
-        .register_get_set("description", 
-            |obj: &mut Account| -> ImmutableString { obj.description.clone().into() }, 
-            |obj: &mut Account, val: ImmutableString| obj.description = val.to_string()
-        )
-        .register_get_set("ledger", 
-            |obj: &mut Account| -> ImmutableString { obj.ledger.clone().into() }, 
-            |obj: &mut Account, val: ImmutableString| obj.ledger = val.to_string()
-        )
-        .register_get_set("address", 
-            |obj: &mut Account| -> ImmutableString { obj.address.clone().into() }, 
-            |obj: &mut Account, val: ImmutableString| obj.address = val.to_string()
-        )
-        .register_get_set("pubkey", 
-            |obj: &mut Account| -> ImmutableString { obj.pubkey.clone().into() }, 
-            |obj: &mut Account, val: ImmutableString| obj.pubkey = val.to_string()
-        )
-        .register_get("created_at_ts", |obj: &mut Account| obj.base_data.created_at);
-    engine.register_get("assets_list", |acc: &mut Account| -> Array { 
-        acc.assets.iter().cloned().map(rhai::Dynamic::from).collect()
+    engine.register_type_with_name::<Account>("Account");
+    engine.register_fn("new_account", || -> Account {
+        Account::new(None, "", 0, "", "", "", "")
+    });
+    // Getters
+    engine.register_get("id", |acc: &mut Account| acc.base_data.id as INT);
+    engine.register_get("created_at_ts", |acc: &mut Account| acc.base_data.created_at);
+    engine.register_get("name", |acc: &mut Account| -> ImmutableString { acc.name.clone().into() });
+    engine.register_get("user_id", |acc: &mut Account| acc.user_id as INT);
+    engine.register_get("description", |acc: &mut Account| -> ImmutableString { acc.description.clone().into() });
+    engine.register_get("ledger", |acc: &mut Account| -> ImmutableString { acc.ledger.clone().into() });
+    engine.register_get("address", |acc: &mut Account| -> ImmutableString { acc.address.clone().into() });
+    engine.register_get("pubkey", |acc: &mut Account| -> ImmutableString { acc.pubkey.clone().into() });
+    engine.register_get("assets_list", |acc: &mut Account| -> Result<Array, Box<EvalAltResult>> { 
+        Ok(acc.assets.iter().cloned().map(rhai::Dynamic::from).collect())
+    });
+    engine.register_get("modified_at_ts", |acc: &mut Account| acc.base_data.modified_at);
+    
+    // Setters (Builder Pattern)
+    engine.register_fn("set_name", |mut acc: Account, name: ImmutableString| -> Result<Account, Box<EvalAltResult>> {
+        acc.name = name.to_string(); Ok(acc)
+    });
+    engine.register_fn("set_user_id", |mut acc: Account, user_id: INT| -> Result<Account, Box<EvalAltResult>> {
+        acc.user_id = user_id as u32; Ok(acc)
+    });
+    engine.register_fn("set_description", |mut acc: Account, description: ImmutableString| -> Result<Account, Box<EvalAltResult>> {
+        acc.description = description.to_string(); Ok(acc)
+    });
+    engine.register_fn("set_ledger", |mut acc: Account, ledger: ImmutableString| -> Result<Account, Box<EvalAltResult>> {
+        acc.ledger = ledger.to_string(); Ok(acc)
+    });
+    engine.register_fn("set_address", |mut acc: Account, address: ImmutableString| -> Result<Account, Box<EvalAltResult>> {
+        acc.address = address.to_string(); Ok(acc)
+    });
+    engine.register_fn("set_pubkey", |mut acc: Account, pubkey: ImmutableString| -> Result<Account, Box<EvalAltResult>> {
+        acc.pubkey = pubkey.to_string(); Ok(acc)
+    });
+    // Action: Add an Asset object to the account's asset list
+    engine.register_fn("add_asset", |mut acc: Account, asset: Asset| -> Result<Account, Box<EvalAltResult>> {
+        acc.assets.push(asset);
+        Ok(acc)
     });
 
     // --- Asset model --- 
-    engine.build_type::<Asset>()
-        .register_fn("new_asset", 
-            |id_rhai: INT, name: ImmutableString, description: ImmutableString, amount: f64, address: ImmutableString, asset_type_str_rhai: ImmutableString, decimals_rhai: INT| -> Result<Asset, Box<EvalAltResult>> {
-                let asset_type = self::string_to_asset_type(asset_type_str_rhai.as_str())?;
-                Ok(Asset::new(id_rhai as u32, name, description, amount, address, asset_type, decimals_rhai as u8))
-            }
-        )
-        .register_get("id", |asset: &mut Asset| asset.base_data.id as INT)
-        .register_get_set("name", 
-            |asset: &mut Asset| -> ImmutableString { asset.name.clone().into() }, 
-            |asset: &mut Asset, val: ImmutableString| asset.name = val.to_string()
-        )
-        .register_get_set("description", 
-            |asset: &mut Asset| -> ImmutableString { asset.description.clone().into() }, 
-            |asset: &mut Asset, val: ImmutableString| asset.description = val.to_string()
-        )
-        .register_get_set("amount", |asset: &mut Asset| asset.amount, |asset: &mut Asset, amount_val: f64| asset.amount = amount_val)
-        .register_get_set("address", 
-            |asset: &mut Asset| -> ImmutableString { asset.address.clone().into() }, 
-            |asset: &mut Asset, val: ImmutableString| asset.address = val.to_string()
-        )
-        .register_get("decimals", |asset: &mut Asset| asset.decimals as INT)
-        .register_get("created_at_ts", |obj: &mut Asset| obj.base_data.created_at);
-    register_rhai_enum_accessors!(engine, Asset, asset_type, "asset_type_str", self::asset_type_to_string, self::string_to_asset_type);
+    engine.register_type_with_name::<Asset>("Asset");
+    engine.register_fn("new_asset", || -> Asset {
+        Asset::new(None, "", "", 0.0, "", AssetType::Native, 0)
+    });
+    // Getters
+    engine.register_get("id", |asset: &mut Asset| asset.base_data.id as INT);
+    engine.register_get("created_at_ts", |asset: &mut Asset| asset.base_data.created_at);
+    engine.register_get("name", |asset: &mut Asset| -> ImmutableString { asset.name.clone().into() });
+    engine.register_get("description", |asset: &mut Asset| -> ImmutableString { asset.description.clone().into() });
+    engine.register_get("amount", |asset: &mut Asset| asset.amount);
+    engine.register_get("address", |asset: &mut Asset| -> ImmutableString { asset.address.clone().into() });
+    engine.register_get("asset_type_str", |asset: &mut Asset| -> ImmutableString { self::asset_type_to_string(&asset.asset_type) });
+    engine.register_get("decimals", |asset: &mut Asset| asset.decimals as INT);
+    engine.register_get("modified_at_ts", |asset: &mut Asset| asset.base_data.modified_at);
+    
+    // Setters (Builder Pattern)
+    engine.register_fn("set_name", |mut asset: Asset, name: ImmutableString| -> Result<Asset, Box<EvalAltResult>> {
+        asset.name = name.to_string(); Ok(asset)
+    });
+    engine.register_fn("set_description", |mut asset: Asset, description: ImmutableString| -> Result<Asset, Box<EvalAltResult>> {
+        asset.description = description.to_string(); Ok(asset)
+    });
+    engine.register_fn("set_amount", |mut asset: Asset, amount: f64| -> Result<Asset, Box<EvalAltResult>> {
+        asset.amount = amount; Ok(asset)
+    });
+    engine.register_fn("set_address", |mut asset: Asset, address: ImmutableString| -> Result<Asset, Box<EvalAltResult>> {
+        asset.address = address.to_string(); Ok(asset)
+    });
+    engine.register_fn("set_asset_type_str", |mut asset: Asset, asset_type_str: ImmutableString| -> Result<Asset, Box<EvalAltResult>> {
+        asset.asset_type = self::string_to_asset_type(asset_type_str.as_str())?;
+        Ok(asset)
+    });
+    engine.register_fn("set_decimals", |mut asset: Asset, decimals: INT| -> Result<Asset, Box<EvalAltResult>> {
+        asset.decimals = decimals as u8; Ok(asset)
+    });
 
-    // --- Bid model --- 
+    // --- Listing model --- 
+    engine.register_type_with_name::<Listing>("Listing");
+    engine.register_fn("new_listing", || -> Listing {
+        Listing::new(None, "", "", "", AssetType::Native, "", 0.0, "", ListingType::FixedPrice, None, Vec::new(), None::<String>)
+    });
+    // Getters
+    engine.register_get("id", |l: &mut Listing| l.base_data.id as INT);
+    engine.register_get("created_at_ts", |l: &mut Listing| l.base_data.created_at);
+    engine.register_get("modified_at_ts", |l: &mut Listing| l.base_data.modified_at);
+    engine.register_get("title", |l: &mut Listing| -> ImmutableString { l.title.clone().into() });
+    engine.register_get("description", |l: &mut Listing| -> ImmutableString { l.description.clone().into() });
+    engine.register_get("asset_id", |l: &mut Listing| -> ImmutableString { l.asset_id.clone().into() });
+    engine.register_get("asset_type_str", |l: &mut Listing| -> ImmutableString { self::asset_type_to_string(&l.asset_type) });
+    engine.register_get("seller_id", |l: &mut Listing| -> ImmutableString { l.seller_id.clone().into() });
+    engine.register_get("price", |l: &mut Listing| l.price);
+    engine.register_get("currency", |l: &mut Listing| -> ImmutableString { l.currency.clone().into() });
+    engine.register_get("listing_type_str", |l: &mut Listing| -> ImmutableString { self::listing_type_to_string(&l.listing_type) });
+    engine.register_get("status_str", |l: &mut Listing| -> ImmutableString { self::listing_status_to_string(&l.status) });
+    engine.register_get("expires_at_ts", |l: &mut Listing| l.expires_at);
+    engine.register_get("tags", |l: &mut Listing| -> Result<Array, Box<EvalAltResult>> { 
+        Ok(l.tags.iter().map(|s| Dynamic::from(s.clone())).collect())
+    });
+    engine.register_get("image_url", |l: &mut Listing| -> Option<ImmutableString> { l.image_url.as_ref().map(|s| s.clone().into()) });
+    engine.register_get("bids_list", |l: &mut Listing| -> Result<Array, Box<EvalAltResult>> { 
+        Ok(l.bids.iter().cloned().map(rhai::Dynamic::from).collect())
+    });
+    // Setters (Builder Pattern)
+    engine.register_fn("set_title", |mut l: Listing, title: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.title = title.to_string(); Ok(l)
+    });
+    engine.register_fn("set_description", |mut l: Listing, description: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.description = description.to_string(); Ok(l)
+    });
+    engine.register_fn("set_asset_id", |mut l: Listing, asset_id: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.asset_id = asset_id.to_string(); Ok(l)
+    });
+    engine.register_fn("set_asset_type_str", |mut l: Listing, asset_type_str: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.asset_type = self::string_to_asset_type(asset_type_str.as_str())?;
+        Ok(l)
+    });
+    engine.register_fn("set_seller_id", |mut l: Listing, seller_id: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.seller_id = seller_id.to_string(); Ok(l)
+    });
+    engine.register_fn("set_price", |mut l: Listing, price: f64| -> Result<Listing, Box<EvalAltResult>> {
+        l.price = price; Ok(l)
+    });
+    engine.register_fn("set_currency", |mut l: Listing, currency: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.currency = currency.to_string(); Ok(l)
+    });
+    engine.register_fn("set_listing_type_str", |mut l: Listing, listing_type_str: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.listing_type = self::string_to_listing_type(listing_type_str.as_str())?;
+        Ok(l)
+    });
+    engine.register_fn("set_status_str", |mut l: Listing, status_str: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.status = self::string_to_listing_status(status_str.as_str())?;
+        Ok(l)
+    });
+    engine.register_fn("set_expires_at_ts", |mut l: Listing, expires_at_ts: Option<INT>| -> Result<Listing, Box<EvalAltResult>> {
+        l.expires_at = expires_at_ts.map(|ts| DateTime::from_timestamp(ts, 0).unwrap_or_else(|| Utc::now()));
+        Ok(l)
+    });
+    engine.register_fn("set_tags", |mut l: Listing, tags_array: Array| -> Result<Listing, Box<EvalAltResult>> {
+        l.tags = tags_array.into_iter().map(|d| d.into_string().unwrap_or_default()).collect();
+        Ok(l)
+    });
+    engine.register_fn("add_tag", |mut l: Listing, tag: ImmutableString| -> Result<Listing, Box<EvalAltResult>> {
+        l.tags.push(tag.to_string());
+        Ok(l)
+    });
+    engine.register_fn("set_image_url", |mut l: Listing, image_url: Option<ImmutableString>| -> Result<Listing, Box<EvalAltResult>> {
+        l.image_url = image_url.map(|s| s.to_string());
+        Ok(l)
+    });
+    // Listing Action Methods (preserved)
+    engine.register_fn("add_listing_bid", |listing: Listing, bid: Bid| -> Result<Listing, Box<EvalAltResult>> {
+        listing.add_bid(bid).map_err(|e_str| {
+            Box::new(EvalAltResult::ErrorSystem(
+                "Failed to add bid".to_string(),
+                Box::new(RhaiStringError(e_str.to_string())),
+            ))
+        })
+    });
+    engine.register_fn("accept_listing_bid", |listing: Listing, bid_index_rhai: i64| -> Result<Listing, Box<EvalAltResult>> {
+            let bid_index = bid_index_rhai as usize;
+            if bid_index >= listing.bids.len() {
+                return Err(Box::new(EvalAltResult::ErrorSystem(
+                    "Invalid bid index".to_string(),
+                    Box::new(RhaiStringError(format!("Bid index {} out of bounds for {} bids", bid_index, listing.bids.len()))),
+                )));
+            }
+
+            let bid_to_accept = listing.bids[bid_index].clone();
+
+            if bid_to_accept.status != BidStatus::Active {
+                 return Err(Box::new(EvalAltResult::ErrorSystem(
+                    "Bid not active".to_string(),
+                    Box::new(RhaiStringError(format!("Cannot accept bid at index {} as it is not active (status: {:?})", bid_index, bid_to_accept.status))),
+                )));
+            }
+
+            let mut listing_after_sale = listing.complete_sale(bid_to_accept.bidder_id.to_string(), bid_to_accept.amount)
+                .map_err(|e_str| Box::new(EvalAltResult::ErrorSystem(
+                    "Failed to complete sale".to_string(),
+                    Box::new(RhaiStringError(e_str.to_string())),
+                )))?;
+
+            // Update bid statuses on the new listing state
+            for (idx, bid_in_list) in listing_after_sale.bids.iter_mut().enumerate() {
+                if idx == bid_index {
+                    *bid_in_list = bid_in_list.clone().update_status(BidStatus::Accepted);
+                } else {
+                    if bid_in_list.status == BidStatus::Active { // Only reject other active bids
+                       *bid_in_list = bid_in_list.clone().update_status(BidStatus::Rejected);
+                    }
+                }
+            }
+            Ok(listing_after_sale)
+        });
+    engine.register_fn("cancel_listing", |_ctx: NativeCallContext, listing: Listing| -> Result<Listing, Box<EvalAltResult>> {
+        listing.cancel().map_err(|e_str| {
+            Box::new(EvalAltResult::ErrorSystem(
+                "Failed to cancel listing".to_string(),
+                Box::new(RhaiStringError(e_str.to_string()))
+            ))
+        })
+    });
+    // --- Bid model (preserved as is) --- 
     engine.register_type_with_name::<Bid>("Bid")
         .register_fn("new_bid", 
             |listing_id_rhai: ImmutableString, bidder_id_rhai: INT, amount_rhai: f64, currency_rhai: ImmutableString| -> Bid {
@@ -152,110 +305,41 @@ pub fn register_rhai_engine_functions(
         .register_get_set("currency", 
             |bid: &mut Bid| -> ImmutableString { bid.currency.clone().into() }, 
             |bid: &mut Bid, val: ImmutableString| bid.currency = val.to_string()
-        );
-    register_rhai_enum_accessors!(engine, Bid, status, "status_str", self::bid_status_to_string, self::string_to_bid_status);
-    register_rhai_datetime_accessors!(engine, Bid, created_at, "created_at_ts", _required); 
-    engine.register_fn("update_bid_status_script", 
-        |bid: Bid, status_str_rhai: ImmutableString| -> Result<Bid, Box<EvalAltResult>> { 
-            let status = self::string_to_bid_status(status_str_rhai.as_str())?;
-            let updated_bid = bid.update_status(status); 
-            Ok(updated_bid)
+        )
+        .register_get("status_str", |bid: &mut Bid| -> ImmutableString { self::bid_status_to_string(&bid.status) });
+    
+    engine.register_fn("accept_bid_script", |bid: Bid| -> Result<Bid, Box<EvalAltResult>> {
+        // Ensure the bid is active before accepting
+        if bid.status != BidStatus::Active {
+            return Err(Box::new(EvalAltResult::ErrorSystem(
+                "Bid not active".to_string(),
+                Box::new(RhaiStringError(format!("Cannot accept bid as it is not active (status: {:?})", bid.status)))
+            )));
         }
-    );
-
-    // --- Listing --- (id is u32)
-    engine.register_type_with_name::<Listing>("Listing")
-        .register_fn("new_listing", 
-            |id_rhai: INT, title_rhai: ImmutableString, description_rhai: ImmutableString, 
-             asset_id_rhai: ImmutableString, asset_type_str_rhai: ImmutableString, seller_id_rhai: ImmutableString, 
-             price_rhai: f64, currency_rhai: ImmutableString, listing_type_str_rhai: ImmutableString, 
-             expires_at_ts_opt_rhai: Option<INT>, tags_dyn_rhai: Array, image_url_opt_rhai: Option<ImmutableString>|
-             -> Result<Listing, Box<EvalAltResult>> {
-                
-                let asset_type = self::string_to_asset_type(asset_type_str_rhai.as_str())?;
-                let listing_type = self::string_to_listing_type(listing_type_str_rhai.as_str())?;
-                let expires_at = rhai_timestamp_helpers::option_rhai_timestamp_to_datetime(expires_at_ts_opt_rhai)?;
-                
-                let tags = tags_dyn_rhai.into_iter().map(|d| d.into_string().unwrap_or_default()).collect();
-                let image_url = image_url_opt_rhai.map(|s| s.to_string()); 
-
-                Ok(Listing::new(
-                    id_rhai as u32, title_rhai, description_rhai, asset_id_rhai, 
-                    asset_type, seller_id_rhai, price_rhai, currency_rhai, listing_type, 
-                    expires_at, tags, image_url
-                ))
-            }
-        )
-        .register_get("id", |l: &mut Listing| l.base_data.id as INT)
-        .register_get_set("title", 
-            |l: &mut Listing| -> ImmutableString { l.title.clone().into() }, 
-            |l: &mut Listing, v: ImmutableString| l.title = v.to_string()
-        )
-        .register_get_set("description", 
-            |l: &mut Listing| -> ImmutableString { l.description.clone().into() }, 
-            |l: &mut Listing, v: ImmutableString| l.description = v.to_string()
-        )
-        .register_get_set("asset_id", 
-            |l: &mut Listing| -> ImmutableString { l.asset_id.clone().into() }, 
-            |l: &mut Listing, v: ImmutableString| l.asset_id = v.to_string()
-        )
-        .register_get_set("seller_id", 
-            |l: &mut Listing| -> ImmutableString { l.seller_id.clone().into() }, 
-            |l: &mut Listing, v: ImmutableString| l.seller_id = v.to_string()
-        )
-        .register_get_set("price", |l: &mut Listing| l.price, |l: &mut Listing, v: f64| l.price = v)
-        .register_get_set("currency", 
-            |l: &mut Listing| -> ImmutableString { l.currency.clone().into() }, 
-            |l: &mut Listing, v: ImmutableString| l.currency = v.to_string()
-        )
-        .register_get_set("buyer_id", 
-            |l: &mut Listing| -> Option<ImmutableString> { l.buyer_id.clone().map(ImmutableString::from) },
-            |l: &mut Listing, v_opt: Option<ImmutableString>| l.buyer_id = v_opt.map(|s| s.to_string())
-        )
-        .register_get_set("sale_price", 
-            |l: &mut Listing| -> Option<f64> { l.sale_price },
-            |l: &mut Listing, v_opt: Option<f64>| l.sale_price = v_opt
-        )
-        .register_get_set("image_url", 
-            |l: &mut Listing| -> Option<ImmutableString> { l.image_url.clone().map(ImmutableString::from) }, 
-            |l: &mut Listing, v: Option<ImmutableString>| l.image_url = v.map(|s| s.to_string())
-        )
-        .register_get("created_at_ts", |obj: &mut Listing| obj.base_data.created_at);
-
-    register_rhai_enum_accessors!(engine, Listing, listing_type, "listing_type_str", self::listing_type_to_string, self::string_to_listing_type);
-    register_rhai_enum_accessors!(engine, Listing, status, "status_str", self::listing_status_to_string, self::string_to_listing_status);
-    register_rhai_enum_accessors!(engine, Listing, asset_type, "asset_type_str_listing", self::asset_type_to_string, self::string_to_asset_type);
-
-    register_rhai_datetime_accessors!(engine, Listing, expires_at, "expires_at_ts_opt");
-    register_rhai_datetime_accessors!(engine, Listing, sold_at, "sold_at_ts_opt");
-
-    register_rhai_vec_string_accessors!(engine, Listing, tags, "tags_cloned");
-
-    engine.register_fn("add_listing_bid", 
-        |listing: Listing, bid: Bid| -> Result<Listing, Box<EvalAltResult>> {
-            listing.add_bid(bid).map_err(|e| e.into())
+        Ok(bid.update_status(BidStatus::Accepted))
+    });
+    engine.register_fn("reject_bid_script", |bid: Bid| -> Result<Bid, Box<EvalAltResult>> {
+         // Ensure the bid is active before rejecting
+        if bid.status != BidStatus::Active {
+            return Err(Box::new(EvalAltResult::ErrorSystem(
+                "Bid not active".to_string(),
+                Box::new(RhaiStringError(format!("Cannot reject bid as it is not active (status: {:?})", bid.status)))
+            )));
         }
-    );
-    engine.register_fn("get_bids_cloned", |listing: &mut Listing| listing.bids.clone()); 
-    engine.register_fn("complete_listing_sale_script",
-        |listing: Listing, buyer_id_rhai: ImmutableString, sale_price_rhai: f64| -> Result<Listing, Box<EvalAltResult>> { 
-            listing.complete_sale(buyer_id_rhai.as_str(), sale_price_rhai).map_err(|e| e.into())
+        Ok(bid.update_status(BidStatus::Rejected))
+    });
+    engine.register_fn("cancel_bid_script", |bid: Bid| -> Result<Bid, Box<EvalAltResult>> {
+         // Ensure the bid is active before cancelling
+        if bid.status != BidStatus::Active {
+            return Err(Box::new(EvalAltResult::ErrorSystem(
+                "Bid not active".to_string(),
+                Box::new(RhaiStringError(format!("Cannot cancel bid as it is not active (status: {:?})", bid.status)))
+            )));
         }
-    );
-    engine.register_fn("cancel_listing_script", 
-        |listing: Listing| -> Result<Listing, Box<EvalAltResult>> { 
-            listing.cancel().map_err(|e| e.into())
-        }
-    );
-    engine.register_fn("add_listing_tags_script", 
-        |listing: Listing, tags_dyn_rhai: Array| -> Result<Listing, Box<EvalAltResult>> {
-            let tags_to_add: Vec<String> = tags_dyn_rhai.into_iter().map(|d| d.into_string().unwrap_or_default()).collect();
-            Ok(listing.add_tags(tags_to_add)) 
-        }
-    );
+        Ok(bid.update_status(BidStatus::Cancelled))
+    });
 
     // --- Global Helper Functions (Enum conversions, potentially already covered by macros but good for direct script use) ---
-    // These are useful if scripts need to convert strings to enums outside of object setters.
     engine.register_fn("str_to_asset_type", |s: ImmutableString| self::string_to_asset_type(s.as_str()));
     engine.register_fn("asset_type_to_str", self::asset_type_to_string);
     engine.register_fn("str_to_listing_status", |s: ImmutableString| self::string_to_listing_status(s.as_str()));
@@ -265,12 +349,16 @@ pub fn register_rhai_engine_functions(
     engine.register_fn("str_to_bid_status", |s: ImmutableString| self::string_to_bid_status(s.as_str()));
     engine.register_fn("bid_status_to_str", self::bid_status_to_string);
 
-
-    // --- Mock DB functions ---
+    // --- Mock DB functions (preserved) ---
     let accounts_db_clone = Arc::clone(&db_accounts);
-    engine.register_fn("set_account", move |account: Account| {
+    engine.register_fn("set_account", move |mut account: Account| -> Account {
         let mut db = accounts_db_clone.lock().unwrap();
-        db.insert(account.base_data.id, account); 
+        if account.base_data.id == 0 {
+            let next_id = db.keys().max().cloned().unwrap_or(0) + 1;
+            account.base_data.update_id(next_id);
+        }
+        db.insert(account.base_data.id, account.clone());
+        account
     });
 
     let accounts_db_clone_get = Arc::clone(&db_accounts);
@@ -283,9 +371,14 @@ pub fn register_rhai_engine_functions(
     });
 
     let assets_db_clone = Arc::clone(&db_assets);
-    engine.register_fn("set_asset", move |asset: Asset| {
+    engine.register_fn("set_asset", move |mut asset: Asset| -> Asset {
         let mut db = assets_db_clone.lock().unwrap();
-        db.insert(asset.base_data.id, asset);
+        if asset.base_data.id == 0 {
+            let next_id = db.keys().max().cloned().unwrap_or(0) + 1;
+            asset.base_data.update_id(next_id);
+        }
+        db.insert(asset.base_data.id, asset.clone());
+        asset
     });
 
     let assets_db_clone_get = Arc::clone(&db_assets);
@@ -298,9 +391,14 @@ pub fn register_rhai_engine_functions(
     });
 
     let listings_db_clone = Arc::clone(&db_listings);
-    engine.register_fn("set_listing", move |listing: Listing| {
+    engine.register_fn("set_listing", move |mut listing: Listing| -> Listing {
         let mut db = listings_db_clone.lock().unwrap();
-        db.insert(listing.base_data.id, listing);
+        if listing.base_data.id == 0 {
+            let next_id = db.keys().max().cloned().unwrap_or(0) + 1;
+            listing.base_data.update_id(next_id);
+        }
+        db.insert(listing.base_data.id, listing.clone());
+        listing
     });
 
     let listings_db_clone_get = Arc::clone(&db_listings);
diff --git a/heromodels/src/models/flow/flow.rs b/heromodels/src/models/flow/flow.rs
index 6fb6e53..71a0e46 100644
--- a/heromodels/src/models/flow/flow.rs
+++ b/heromodels/src/models/flow/flow.rs
@@ -29,9 +29,9 @@ impl Flow {
     /// Create a new flow.
     /// The `id` is the database primary key.
     /// The `flow_uuid` should be a Uuid::new_v4().to_string().
-    pub fn new(id: u32, flow_uuid: impl ToString) -> Self {
+    pub fn new(_id: u32, flow_uuid: impl ToString) -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             flow_uuid: flow_uuid.to_string(),
             name: String::new(), // Default name, to be set by builder
             status: String::from("Pending"), // Default status, to be set by builder
diff --git a/heromodels/src/models/flow/flow_step.rs b/heromodels/src/models/flow/flow_step.rs
index 908efa3..432279f 100644
--- a/heromodels/src/models/flow/flow_step.rs
+++ b/heromodels/src/models/flow/flow_step.rs
@@ -22,9 +22,9 @@ pub struct FlowStep {
 
 impl FlowStep {
     /// Create a new flow step.
-    pub fn new(id: u32, step_order: u32) -> Self {
+    pub fn new(_id: u32, step_order: u32) -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             description: None,
             step_order,
             status: String::from("Pending"), // Default status
diff --git a/heromodels/src/models/flow/rhai.rs b/heromodels/src/models/flow/rhai.rs
index 362e751..dff653d 100644
--- a/heromodels/src/models/flow/rhai.rs
+++ b/heromodels/src/models/flow/rhai.rs
@@ -103,7 +103,7 @@ pub fn register_flow_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
 
     let captured_db_for_set_flow = Arc::clone(&db);
     engine.register_fn("set_flow", move |flow: Flow| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set_flow.set(&flow).map_err(|e| {
+        captured_db_for_set_flow.set(&flow).map(|_| ()).map_err(|e| {
             Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set Flow (ID: {}): {}", flow.base_data.id, e).into(), Position::NONE))
         })
     });
@@ -121,7 +121,7 @@ pub fn register_flow_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
 
     let captured_db_for_set_sig_req = Arc::clone(&db);
     engine.register_fn("set_signature_requirement", move |sr: SignatureRequirement| -> Result<(), Box<EvalAltResult>> {
-        captured_db_for_set_sig_req.set(&sr).map_err(|e| {
+        captured_db_for_set_sig_req.set(&sr).map(|_| ()).map_err(|e| {
              Box::new(EvalAltResult::ErrorRuntime(format!("Failed to set SignatureRequirement (ID: {}): {}", sr.base_data.id, e).into(), Position::NONE))
         })
     });
diff --git a/heromodels/src/models/flow/signature_requirement.rs b/heromodels/src/models/flow/signature_requirement.rs
index 46f4e69..44007cb 100644
--- a/heromodels/src/models/flow/signature_requirement.rs
+++ b/heromodels/src/models/flow/signature_requirement.rs
@@ -31,9 +31,9 @@ pub struct SignatureRequirement {
 
 impl SignatureRequirement {
     /// Create a new signature requirement.
-    pub fn new(id: u32, flow_step_id: u32, public_key: impl ToString, message: impl ToString) -> Self {
+    pub fn new(_id: u32, flow_step_id: u32, public_key: impl ToString, message: impl ToString) -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             flow_step_id,
             public_key: public_key.to_string(),
             message: message.to_string(),
diff --git a/heromodels/src/models/legal/contract.rs b/heromodels/src/models/legal/contract.rs
index 0b7fe8e..4e871fc 100644
--- a/heromodels/src/models/legal/contract.rs
+++ b/heromodels/src/models/legal/contract.rs
@@ -161,9 +161,9 @@ pub struct Contract {
 }
 
 impl Contract {
-    pub fn new(base_id: u32, contract_id: String) -> Self {
+    pub fn new(_base_id: u32, contract_id: String) -> Self {
         Self {
-            base_data: BaseModelData::new(base_id),
+            base_data: BaseModelData::new(),
             contract_id,
             title: String::new(),
             description: String::new(),
diff --git a/heromodels/src/models/legal/rhai.rs b/heromodels/src/models/legal/rhai.rs
index 5d9f5f6..d374d54 100644
--- a/heromodels/src/models/legal/rhai.rs
+++ b/heromodels/src/models/legal/rhai.rs
@@ -239,7 +239,7 @@ pub fn register_legal_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
     let captured_db_for_set = Arc::clone(&db);
     engine.register_fn("set_contract", 
         move |contract: Contract| -> Result<(), Box<EvalAltResult>> {
-            captured_db_for_set.set(&contract).map_err(|e| {
+            captured_db_for_set.set(&contract).map(|_| ()).map_err(|e| {
                 Box::new(EvalAltResult::ErrorRuntime(
                     format!("Failed to set Contract (ID: {}): {}", contract.base_data.id, e).into(),
                     Position::NONE,
diff --git a/heromodels/src/models/projects/base.rs b/heromodels/src/models/projects/base.rs
index b85119a..d3ffefd 100644
--- a/heromodels/src/models/projects/base.rs
+++ b/heromodels/src/models/projects/base.rs
@@ -91,9 +91,9 @@ impl Model for Project {
 }
 
 impl Project {
-    pub fn new(id: u32, name: String, description: String, owner_id: u32) -> Self {
+    pub fn new(_id: u32, name: String, description: String, owner_id: u32) -> Self {
         Self {
-            base_data: BaseModelData::new(id),
+            base_data: BaseModelData::new(),
             name,
             description,
             owner_id,
@@ -207,8 +207,10 @@ impl Model for Label {
 
 impl Label {
     pub fn new(id: u32, name: String, color: String) -> Self {
+        let mut base_data = BaseModelData::new();
+        base_data.update_id(id);
         Self {
-            base_data: BaseModelData::new(id),
+            base_data,
             name,
             color,
         }
diff --git a/heromodels/src/models/projects/rhai.rs b/heromodels/src/models/projects/rhai.rs
index 89e8456..27fd7ce 100644
--- a/heromodels/src/models/projects/rhai.rs
+++ b/heromodels/src/models/projects/rhai.rs
@@ -217,7 +217,7 @@ pub fn register_projects_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
             ))
         })?;
 
-        collection.set(&project).map_err(|e| {
+        collection.set(&project).map(|_| ()).map_err(|e| {
             Box::new(EvalAltResult::ErrorSystem(
                 "Failed to save project".to_string(),
                 format!("DB operation failed: {:?}", e).into(),