Steam Microtransaction Bridge API [](https://discord.gg/NF7Fuhr2FZ)

An intermediate API to handle Steam microtransactions (in-game purchases) and subscriptions using Steam web services.

You can use this repo to fork and host an API to be used with Unity, Unreal, Godot, or any engine you want to develop a Steam game.

READ BEFORE USE

This Bridge API has been created based on the Steam Partner API recommendations.

If you need to implement microtransactions in your game, you must create a web service to handle and request the Steam WEB API, and that's precisely the purpose of this repository.

To help game developers save time and money, I've created a single codebase that enables them to implement microtransactions quickly.

With this repository, you can use Heroku or DigitalOcean to deploy your own API with just a few clicks. See Heroku Git Deploy or DigitalOcean Deploy, or choose any other host you prefer.

WHY DO I NEED TO USE THIS REPO OR CREATE MY OWN? CAN I MAKE REQUESTS DIRECTLY FROM MY GAME?

First of all, it's important to read Steam's recommendations on this topic: https://partner.steamgames.com/doc/features/microtransactions

Steam doesn't recommend calling the Steam Partner API directly from your game. Instead, you should create your own API to act as a bridge between your game and Steam. That's the purpose of this API repository.

HOW TO START THE API?

This is a TypeScript (Node.js v22+) based API, and you can use services like Heroku or DigitalOcean to publish it.

To get started, follow these steps:

1. Install Node.js v22+.
2. Clone or fork this repository.
3. Generate your Steam WEB API key.

To run the API locally and for testing, duplicate the file env.example and rename it to .env, and then update it with the correct values.

4. Run yarn to install the dependencies.
5. To test if everything is working, run yarn test.
6. To start the application, run yarn start.

CONFUSION ABOUT WEB API KEY GENERATION FOR STEAM IN-APP PURCHASES

There is some confusion about which web key to use for Steam in-app purchases and in-game API integration. Here are the instructions for generating the correct key:

1. Go to the Steam Developer Page.
2. Click on the "Menu" button, and then select "User & Permissions."
3. Click on "Manage Groups" and select your app's name.
4. On the sidebar, you'll see a link that says "Generate WebAPI Key." Click on that link to generate the proper key.

LIST OF PRODUCTS

To prevent users from sending arbitrary amounts for products, there is a file called products.json in the src/ directory. Make sure to replace the ID and amount according to your list of products.

INTEGRATING WITH YOUR GAME

You can check the documentation of this API here: https://jasielmacedo.github.io/steam-microtransaction-api/ Note that this site is static and does not provide a live API endpoint.

The flow is as follows:

1. The user (player) clicks on the UI product.
2. Your game calls the /InitPurchase endpoint to start the purchase.
3. The game will display a confirmation dialog (inside the game).
4. The user buys the item (pays for it).
5. The game receives a callback confirmation about the purchase.
6. Your game calls the /FinalizePurchase endpoint.
7. That's it.

If the user has parental control and the callback was not called, you can check the status by calling the /CheckPurchaseStatus endpoint.

SECURITY CHECK

In-game purchases are not complicated, but you need to be sure that the Steam user is reliable. To avoid scammers, simply call the /GetReliableUserInfo endpoint. If the return is true, you can start the microtransaction.

API ENDPOINTS

Microtransactions

Endpoint	Description
POST /GetReliableUserInfo	Check if user is reliable to start a purchase
POST /CheckAppOwnership	Verify user owns the app
POST /InitPurchase	Initialize a purchase (triggers Steam overlay)
POST /CheckPurchaseStatus	Check current transaction status
POST /FinalizePurchase	Complete the transaction

Subscriptions (Recurring Billing)

Endpoint	Description
POST /GetUserAgreements	Get user's billing agreements
POST /ProcessAgreement	Process a recurring charge
POST /AdjustAgreement	Adjust next billing date
POST /CancelAgreement	Cancel a subscription

Reports

Endpoint	Description
POST /GetReport	Get sales and transaction reports

EXAMPLE WITH UNITY (C#)

You can check the example folder to see an example using Unity.

ABOUT

You might be wondering, "Has this code been properly tested?" I used a similar version of this code inside a game called Deliverace. It's no longer available on Steam, but this code works.

If you have any questions, suggestions, or issues, feel free to use the Issues area.

CONTRIBUTION

You can contribute by opening a pull request. Together, we can help many developers implement in-game purchases.