A Stripe payment can succeed while your Lovable app still thinks the customer is unpaid.
That is not contradictory. It means one part of the payment journey worked and another part did not.
The fastest way to debug this is to stop treating “Stripe integration” as one feature. Trace the systems separately:
checkout → Stripe event → webhook delivery → Supabase update → access decision
If you can identify the first boundary where the expected state disappears, you can usually repair the payment flow without rebuilding the whole app.
Start with the exact symptom
There are several failures that look similar from the customer’s side:
- the checkout button never opens
- payment succeeds but the success page fails
- Stripe records the payment but your database does not
- the database records the subscription but the UI still shows “free”
- access unlocks once and disappears on the next login
- renewals, cancellations or failed payments do not change access
- the flow works in test mode but fails after production deployment
Do not debug all of them at once.
If Stripe already shows a successful payment, checkout creation is probably not your first problem. Move downstream.
1. Check whether Stripe actually delivered the event
Open the relevant event or webhook delivery in Stripe and inspect what happened after payment.
You want to know:
- Was the expected event generated?
- Was it sent to the correct production webhook endpoint?
- What HTTP status did the endpoint return?
- Did Stripe retry it?
- Does the endpoint URL belong to the current production environment?
A green checkout screen does not answer those questions.
This distinction is important because payment collection and application fulfilment are different responsibilities. Your app still needs a reliable server-side path that turns the payment event into the state your product understands.
2. Check the Supabase Edge Function, not just the Lovable UI
Lovable projects commonly use Supabase for server-side functions and data. Supabase explicitly documents Edge Functions as suitable for receiving third-party webhooks such as Stripe.
Source: https://supabase.com/docs/guides/functions
If Stripe says the webhook failed, inspect the corresponding Edge Function logs and configuration.
Look for:
401or authorization failures- signature-verification failures
- missing environment variables
- wrong production keys
- exceptions before the database write
- a database error after Stripe verification
- a successful
200response that happened before the important work actually completed
A payment bug is much easier to reason about when you can say, “Stripe reached the function, but the database write failed,” instead of “Lovable payments are broken.”
3. Do not require a user’s Supabase JWT for an external Stripe webhook
This is a common architecture mismatch.
Stripe is a server calling your webhook. It is not the signed-in customer calling your app with a Supabase session token.
Supabase’s current function configuration documentation specifically uses Stripe webhooks as the example for a function that needs to be reachable without the platform’s normal JWT check. It documents configuring that function with verify_jwt = false and then authenticating the external provider appropriately inside the handler.
Source: https://supabase.com/docs/guides/functions/function-configuration
That does not mean “make the payment endpoint trust everyone.”
For an external webhook, the security boundary moves from “does this request contain my user’s JWT?” to “is this genuinely a signed request from Stripe?” Supabase’s Edge Function security guidance makes the same distinction: external providers do not send Supabase credentials, so the function should verify the provider’s signature itself.
Source: https://supabase.com/docs/guides/functions/auth
If you disable JWT verification without verifying Stripe’s signature, you have replaced one bug with a security problem.
4. Verify the production secrets separately from development
A flow can work during development and fail after launch because the deployed function is reading a different environment.
Supabase documents production Edge Function secrets separately and recommends storing sensitive credentials there rather than in browser code or committed environment files.
Source: https://supabase.com/docs/guides/functions/secrets
Check the presence and environment of values such as:
- Stripe secret key
- Stripe webhook signing secret
- any price/product identifiers your server relies on
- Supabase server-side credentials where legitimately required
Do not print the secret values into logs just to check them. Test whether they are configured and whether the live environment is using the intended mode.
Also check the obvious but expensive mistake: test credentials in one component and live credentials in another.
5. Find the database row that is supposed to change
Once the webhook runs, what durable fact tells your application that the customer paid?
You should be able to answer this precisely.
Depending on the product, it might be a subscription record, payment row, entitlement, billing status or relationship to a Stripe customer/subscription ID.
Inspect that state directly.
If Stripe is correct but the expected row never changes, the problem is between webhook processing and persistence.
If the row does change but the app still shows the free state, stop debugging Stripe. Your problem has moved into the application’s access logic, query, cache or user-to-customer mapping.
That boundary saves a lot of wasted prompting.
6. Separate payment state from entitlement state
“Customer paid” and “customer may use feature X” are related facts, but they are not always the same fact.
A simple one-time purchase might unlock something permanently. A subscription has more states to consider: active, trialling, past due, cancelled, expired or scheduled to end later. Your product also needs a rule for which of those states grant access.
This is where a visually correct checkout can hide a weak product model.
Before changing code, write the rule in plain English:
Which billing states grant which capabilities, and when should that access change?
Then verify that your database and application implement that rule consistently.
This is the same reason I treat payment state as product architecture when building MVPs, not merely as a “connect Stripe” task. If you need help reviewing the wider product flow, see my MVP development service.
7. Do not make the success page your only source of truth
A success page is useful for customer experience. It is a poor place to make durable payment fulfilment depend on the browser completing one final navigation.
The customer can close the tab. A redirect can fail. The network can disappear after Stripe has already accepted payment.
Your server-side payment event should be able to reconcile the durable state independently of whether the customer watches the success animation.
That also makes the system easier to recover. If a webhook delivery fails temporarily, a retry can finish the work without asking the customer to pay again.
8. Make webhook handling safe to repeat
Webhook delivery should be treated as retryable.
Supabase’s current Edge Functions guidance recommends designing short-lived server-side operations to be idempotent. That principle matters particularly for payments: receiving the same event again should not create a second entitlement, duplicate order or another irreversible side effect.
Source: https://supabase.com/docs/guides/functions
A practical design records a stable provider event or transaction identifier and makes repeated processing converge on the same business state.
Do not “solve” a failed webhook by blindly running the fulfilment action twice.
9. Test the unhappy paths before calling the payment flow finished
A test card completing checkout proves the happy path.
A production-ready payment feature needs more questions:
- What if webhook delivery is delayed?
- What if it arrives twice?
- What if the database write fails after Stripe succeeds?
- What if the user refreshes the success page?
- What if the subscription is cancelled?
- What if renewal fails?
- What if the signed-in account does not map to the Stripe customer you expect?
- What if the webhook secret is rotated?
You do not need an enormous billing platform for every MVP. You do need explicit behavior for the failures that could charge someone without delivering what they paid for.
My AI-built app production checklist covers the broader production-readiness questions around authentication, permissions, testing, monitoring and deployment.
When should you stop prompting Lovable and inspect the code?
Prompting is useful when the desired behavior is clear and the change is local.
Stop repeatedly regenerating the payment flow when:
- each prompt changes a different part of the integration
- previously fixed functions keep changing
- you cannot explain which system is authoritative
- payment state is duplicated across several tables or flags
- you are changing RLS, webhook auth and UI logic simultaneously
- real customers can be charged while access remains uncertain
At that point the task is no longer “make a Stripe button.” It is debugging a distributed state transition.
That is also a sensible point to put the project in GitHub, preserve a known-good revision and make targeted changes rather than repeatedly rewriting the entire flow. If your project is at that stage, when to hire a developer for a Lovable app explains the decision in more detail.
A practical debugging order
Use this order before considering a rebuild:
- Confirm the exact Stripe payment/subscription state.
- Inspect the webhook event and delivery result.
- Confirm the production endpoint and signing secret.
- Inspect the Edge Function logs.
- Confirm the expected database write occurred.
- Confirm the stored customer/subscription maps to the correct app user.
- Inspect the entitlement rule used by the UI/API.
- Replay or retry safely and confirm idempotency.
- Test cancellation, renewal and failure behavior relevant to your product.
- Only then decide whether the current architecture is too tangled to repair safely.
Most payment failures do not justify rebuilding the entire product. But once money and access disagree, guessing is no longer an acceptable debugging method.
If you have an AI-built MVP where checkout works but the application state is unreliable, contact me. I can help trace the payment flow, identify the failing boundary and decide whether a targeted repair or a deeper rebuild makes more sense.
