If you're trying to set up a roblox studio developer product script, you've probably realized it's a bit more involved than just toggling a setting in the properties panel. Unlike Game Passes, which are usually a "buy once and own forever" kind of deal, Developer Products are meant to be bought over and over again. Think of things like in-game currency, health refills, or temporary boosts. Because these are repeatable, the game needs a reliable way to check that the payment actually went through before it hands over the goods.
Why Developer Products are different from Game Passes
Before we get into the weeds with the code, it's worth talking about why we even bother with a specific roblox studio developer product script instead of just using the same logic we use for Game Passes.
Game Passes are tied to a player's inventory. Once they buy it, Roblox essentially puts a checkmark next to their name. Developer Products don't work like that. They're meant for transactions that happen "in the moment." If someone wants to buy 100 Gold ten times in a row, the game needs to handle each of those ten purchases individually. This is where ProcessReceipt comes in, which is basically the brain of your monetization system.
Setting things up in the Dashboard
You can't really write the script until you have a product to point it at. You'll need to head over to the Roblox Creator Dashboard, find your game, and create a new Developer Product. Give it a name, a price, and maybe an icon if you're feeling fancy.
Once you save it, you'll get a Product ID. This is a long string of numbers that is absolutely vital. Keep this ID handy because your script won't know what the player is trying to buy without it. I usually keep a notepad open or just leave the browser tab active while I'm working in Studio.
Making the prompt appear
First things first, you need to actually show the player the "Buy" window. This part is pretty straightforward and usually happens in a LocalScript attached to a button in your UI.
When the player clicks a button, you use MarketplaceService:PromptProductPurchase(). It takes the player object and that Product ID we just talked about. It's a simple one-liner, but remember: this only shows the prompt. It doesn't actually give them the items. If you stop here, you're basically just taking people's Robux and giving them nothing in return, which is a one-way ticket to getting bad reviews or even getting your game flagged.
The meat of the logic: ProcessReceipt
Now for the part that everyone gets stuck on: the server-side roblox studio developer product script. This has to be a Script (not a LocalScript) and it usually lives in ServerScriptService.
The ProcessReceipt callback is what Roblox calls every time a purchase is made. It sends over a bunch of data in a table called receiptInfo. This table tells you who bought the item, what the item was, and how much they paid.
The most important thing to remember here is that you must return a status at the end of the script. If the purchase was successful and you've given the player their item, you return Enum.ProductPurchaseDecision.PurchaseGranted. If something went wrong—maybe your data store is down or the player left the game—you return Enum.ProductPurchaseDecision.NotProcessedYet. This tells Roblox to try again later so the player doesn't lose their money.
Handling different products in one script
Most games have more than one thing for sale. You don't want to write ten different scripts for ten different items. Instead, you can use a simple if or elseif chain (or even a table) inside your ProcessReceipt function.
For example, you might check if the ProductId matches your "100 Gold" ID. If it does, you run the code to add gold to the player's leaderstats. If it matches the "Speed Boost" ID, you change their WalkSpeed. It keeps everything organized in one place, which makes debugging a whole lot easier when things eventually go sideways.
Dealing with data and saving
It's all fun and games until a player buys something and then loses it because the game crashed. When you're writing a roblox studio developer product script, you really should be thinking about saving that data immediately.
If someone buys currency, don't just update the number on their screen. You need to make sure that change is reflected in your DataStore. A good flow is: 1. Player buys product. 2. Server verifies the purchase. 3. Server updates the player's data. 4. Server saves the data (or at least marks it to be saved). 5. Only then do you return PurchaseGranted.
If you grant the purchase before the data is safe, you run the risk of "item loss" complaints, and trust me, you don't want to spend your weekends answering support emails from angry ten-year-olds.
Testing without spending real Robux
One of the best things about working in Roblox Studio is that you can test these purchases without actually spending your own money. When you click a buy button in the Studio play-tester, a window pops up saying it's a "test purchase" and it won't charge you.
This is where you should spend a good amount of time. Try to break your script. What happens if you buy something and then immediately reset your character? What happens if you buy something and the script errors out? You want to find these bugs now, not when your game has 500 active players.
Don't forget the player experience
While the technical side of the roblox studio developer product script is important, the "feel" of the purchase matters too. There's nothing more nerve-wracking for a player than clicking "Buy," seeing their Robux disappear, and then nothing happens for three seconds.
It's always a good idea to have some kind of visual feedback. Maybe a sound plays, or a "Thank You!" message pops up on the screen. Since the server handles the logic, you can use a RemoteEvent to tell the client when the purchase has been successfully processed so you can trigger some cool fireworks or a UI animation.
Common pitfalls to watch out for
I've seen a lot of developers make the same few mistakes when setting this up. The biggest one is putting the ProcessReceipt logic inside a loop or a local script. It just won't work. It has to be a single assignment to the MarketplaceService.ProcessReceipt property on the server.
Another common issue is not handling the case where a player leaves the game before the purchase finishes. If your script tries to find game.Players:GetPlayerByUserId(receiptInfo.PlayerId) and the player is gone, the script might error. Always check if the player still exists before trying to give them items!
Keeping your code clean
As your game grows, that ProcessReceipt function can get pretty messy. A pro tip is to move the actual "giving items" logic into separate modules. For instance, you could have a CurrencyManager module and a PowerUpManager module. Then, your main roblox studio developer product script just acts as a traffic cop, directing the purchase info to the right module. It makes the code way more readable and easier to update later on when you decide to add 20 more items to your shop.
Building a solid monetization system isn't just about making money; it's about making sure the system is fair and reliable. If your script is robust, players will feel much more comfortable spending their hard-earned Robux in your world. Take your time, test everything twice, and you'll be good to go.