Add Stripe Subscriptions to Your AI Web App

Prerequisites Checklist

Make sure you have these ready before starting.

Before following this Stripe tutorial, make sure your web app already has the following ready:

1. Your App Is Already Deployed (Live URL Required)

Stripe Checkout only works on a real deployed website — it does NOT work inside the Google AI Studio preview environment.

Deployment Video

Watch Deployment Tutorial

https://youtu.be/HGs-4QjyjHQ?si=EBUOpPx38n9vVROR

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2. Firebase Is Fully Set Up (One Video Covers Everything)

Your Firebase setup must already be completed, including: - Firebase Authentication enabled - Firestore Database created - Your web app connected to Firebase (using your Firebase config)

Firebase Setup Video

Watch Firebase Tutorial

https://youtu.be/juEfJERgBE8?si=je5VF4gKMUJXl8kX

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✔ Once these requirements are ready, you can continue with Step 1 → Step 5 without any issues.

Open Stripe and switch to Test Mode

Create a Monthly recurring subscription plan

Create a Yearly recurring subscription plan

Save the required Stripe values for later use

Open Firebase → Extensions

Install "Run Payments with Stripe" (Made by Invertase)

Paste your Stripe Secret Key into the extension settings

Create a Webhook in Stripe (select the required events)

- checkout.session.completed

- customer.subscription.created

- invoice.paid

- invoice.payment_failed

- customer.subscription.updated

- customer.subscription.deleted

- invoice.upcoming

- payment_intent.succeeded

- payment_intent.payment_failed

- customer.subscription.paused

- charge.refunded

- charge.dispute.created

Copy the Webhook Endpoint URL from Firebase Functions and paste it into Stripe

Copy Stripe’s Signing Secret and paste it into Firebase (Webhook Secret)

Save and confirm everything is connected

Open your project in Google AI Studio

Run Prompt #1: Create the Billing Config (Deployed URL + Price IDs)

Prompt: Create Billing Config

Create a billing config file and fill it with my real values (no placeholders). Use EXACTLY: DEPLOYED_URL = "https://deployment-url.com" MONTHLY_PRICE_ID = "price_MONTHLY_HERE" YEARLY_PRICE_ID = "price_YEARLY_HERE" Create: src/billingConfig.js (or .ts if the project is TypeScript) and export: - DEPLOYED_URL - MONTHLY_PRICE_ID - YEARLY_PRICE_ID - A function successUrl() that returns the correct URL for /success - A function cancelUrl() that returns the correct URL for /failure Important: - Detect if the app uses hash routing automatically: If existing routes contain "/#/" then use DEPLOYED_URL + "/#/success" and "/#/failure" Otherwise use DEPLOYED_URL + "/success" and "/failure" Do not change any existing UI or app logic. Return only the new file content.

Run Prompt #2: Create the Success + Cancel pages

Prompt: Create Success & Cancel Pages

Add two simple routes/pages for Stripe redirects: success and failure. Success page: - Text: "Payment successful" - Redirect to dashboard after 1.5 seconds Failure page: - Text: "Payment cancelled" - Redirect to dashboard after 1.5 seconds Use the same routing style already used in the project (hash or normal). Do not redesign UI. Return exact files changed.

Run the prompts and confirm the files/pages were added

(Optional) Create an Upgrade button

Run Prompt #3: Add the Monthly/Yearly choice modal

Prompt: Add Upgrade Choice UI

Add a simple upgrade choice UI without redesigning the app. When the user clicks the existing Upgrade button: - Show a small modal (or dropdown) with 2 options: 1) Monthly 2) Yearly - Add a close button. Keep current styling. Do not change any other UI. Return exact files changed.

Run Prompt #4: Connect the choice to Stripe Checkout

Prompt: Connect Stripe Checkout

Implement Stripe subscription checkout using Firebase Stripe Extension. On Monthly selection: - Create a Firestore doc at: customers/{uid}/checkout_sessions/{autoId} - Fields: price: MONTHLY_PRICE_ID (import from billingConfig) mode: "subscription" success_url: successUrl() (import from billingConfig) cancel_url: cancelUrl() (import from billingConfig) On Yearly selection: - Same but price: YEARLY_PRICE_ID After creating the doc: - Listen to that same checkout session document until it contains a field "url" - Redirect the browser to that url Do not add Stripe secret keys to frontend. Do not touch existing CRUD features. Return exact files changed. Test payments using your deployed live URL (not the preview)

Test payments using your deployed live URL

Run Prompt #5: Auto-update account from Free → Pro

Prompt: Pro Plan Detection

Add Pro plan detection (read-only) from Firestore. - Listen in real-time (onSnapshot) to: customers/{uid}/subscriptions - Set isPro = true if any subscription status is "active" or "trialing" - If isPro true: - Show a "Pro" badge - Hide the Upgrade button - If isPro false: - Show a "Free" badge - Show the Upgrade button Important: Do NOT block Free users from using the app features. Do not redesign UI. Return exact files changed.

Run Prompt #6: Add Manage Subscription and connect it to Stripe Billing Portal

Prompt: Manage Subscription Button

Task: Add a working "Manage Subscription" button for PRO users using Stripe Customer Portal (Firebase Stripe Extension). Context: - The app already uses the Firebase Stripe Extension (customers/{uid} and checkout_sessions work). - The app uses hash routing (/#/dashboard). - Do NOT change the UI design. Only add logic. - The button must work in production (no CORS errors). Requirements: 1) Show "Manage Subscription" button ONLY when the current user is PRO (isPro === true). 2) On click, DO NOT call any cloudfunctions.net URL directly and DO NOT use fetch to Cloud Functions. 3) Instead, create a Firestore document at: customers/{uid}/portal_sessions/{autoId} with fields: - return_url: "https://vloma.com/#/dashboard" 4) After creating the doc, listen in real-time to that same document until the extension writes a field: - url Then redirect the browser to that url (window.location.href = url). 5) Add basic UX: - disable the button while loading - show a friendly alert if no url appears after 20 seconds - log the real error to console Implementation notes: - Use the existing Firebase client (auth + firestore). - Keep existing files structure. Modify only the minimal files needed. - Return the exact files changed and the exact code changes. Deliverable: - A working Manage Subscription button that opens Stripe Customer Portal and returns to /#/dashboard.

Run Prompt #7: Add Free vs Pro limits

Prompt: Add Usage Limits

Task: Add Free/Pro usage limits WITHOUT touching or changing the existing billing/upgrade system. CRITICAL RULES (must follow): - DO NOT modify the existing Stripe checkout / upgrade code. - DO NOT modify how "isPro" is determined in the project. - DO NOT create or use users/{uid}.plan field (do not add plan to Firestore at all). - DO NOT change Firestore rules or Storage rules. - Keep UI the same (only small toast/alert/modal allowed). Limits: - FREE: max 5 files, max 5 folders, max 100MB total stored - PRO: max 50 files, max 50 folders, max 5GB total stored How to implement (safe approach): 1) Use the CURRENT existing "isPro" boolean/state already working in the app. - Whatever source it currently uses (Stripe Extension subscriptions / custom claims / existing code), keep it exactly as-is. - Only READ isPro, do not re-implement it. 2) Track usage from the existing Firestore structure (do not rename collections): - Files count = number of docs in users/{uid}/files - Folders count = number of docs in users/{uid}/folders - Total storage used = sum of file sizes from the file docs (field: size bytes). If old docs don’t have size, treat missing size as 0, and ensure new uploads always write size. 3) Enforce limits ONLY in the UI/Client for now: - Before creating a new file doc or uploading: check limits using current isPro. - Before creating a new folder doc: check limits using current isPro. - If Free exceeds limit: block action and show: “Free plan limit reached. Upgrade to Pro to continue.” Add an “Upgrade” button that triggers the EXISTING checkout flow (call the same function already used in the app). 4) IMPORTANT: After checkout completes, the app MUST refresh/reflect Pro automatically: - Do not add new plan logic. - Just ensure the same existing listener/state updates isPro and the UI re-checks limits. - Add a small debug log (console.log) showing current isPro value after returning from checkout. Deliverable: - Limits work and show upgrade prompt. - Paying and upgrading still changes the app to Pro exactly like before. - Return exact files changed.

Add Firestore Rules (users can access only their own data)

Important: These Firestore security rules are an example. You MUST review and adapt them to match your own web app’s data structure. Every app needs rules that fit its specific collections and data model.

firestore.rules

rules_version = '2'; service cloud.firestore { match /databases/{database}/documents { function signedIn() { return request.auth != null; } function isOwner(uid) { return signedIn() && request.auth.uid == uid; } // ------------------------- // Users data (your app data) // ------------------------- match /users/{uid} { allow read, write: if isOwner(uid); // Everything under this user is also only for the owner match /{allPaths=**} { allow read, write: if isOwner(uid); } } // ------------------------- // Stripe Extension // customers/{uid}/... // ------------------------- match /customers/{uid} { // user can read their stripe docs allow read: if isOwner(uid); // user must NOT write to stripe docs directly allow write: if false; // user can create a checkout session doc match /checkout_sessions/{id} { allow create, read: if isOwner(uid); allow update, delete: if false; } // user can create a portal session doc match /portal_sessions/{id} { allow create, read: if isOwner(uid); allow update, delete: if false; } // subscriptions/payments are server-controlled (read only) match /subscriptions/{id} { allow read: if isOwner(uid); allow write: if false; } match /payments/{id} { allow read: if isOwner(uid); allow write: if false; } } } }

Add Storage Rules (users can access only their own files)

Important: These Storage security rules are an example. You MUST review and adapt them to match your own project path (for example, the uploads folder name) and limits. Every app needs storage rules that fit its own structure.

storage.rules

rules_version = '2'; service firebase.storage { match /b/{bucket}/o { function signedIn() { return request.auth != null; } function isOwner(uid) { return signedIn() && request.auth.uid == uid; } match /user_uploads/{uid}/{allPaths=**} { allow read: if isOwner(uid); // write create/update/delete // request.resource null delete، allow write: if isOwner(uid) && (request.resource == null || request.resource.size <= 200 * 1024 * 1024); } } }

(Optional) Run a quick prompt for small UI fixes (for example, updating prices in the modal)

You can run an extra prompt later to polish UI details (like updating prices in the modal), but we won't provide a specific prompt here as it depends heavily on your specific UI customizations.