Stripe Webhook and DB Insert Issue

To address the issue where the database (Neon tech) was not updating after receiving data from a Stripe webhook, we had to carefully analyze multiple aspects of the integration between Stripe and the database, as well as the flow of the application code. Below is a detailed 5000-word breakdown of the entire process from identification of the problem to resolution, covering the various debugging steps, configurations, and final solutions applied.

Problem Overview: Stripe Webhook and DB Insert Issue

The core problem revolved around the Stripe webhook not successfully updating the database after receiving Stripe checkout information. The Stripe webhook was triggered upon successful checkout sessions, but for some reason, the data intended to be inserted into the Neon database wasn’t getting saved.

When a user completes a payment through Stripe, a webhook is triggered. The webhook handler is supposed to process this event (such as a successful payment or subscription creation) and update the corresponding records in the database. In our case, we had created the logic for listening to these events and inserting them into the database, but the database updates weren’t happening as expected.

Initial Setup

Stripe Webhook Setup

The application was built to listen for specific Stripe webhook events such as checkout.session.completed or invoice.paid. This was done using the Stripe CLI and an endpoint (/api/webhook) on our Next.js app that processed these webhook events.

A typical Stripe webhook handler might look something like this:

Import { NextApiRequest, NextApiResponse } from 'next'; import Stripe from 'stripe'; import { db } from '@/lib/db'; // Custom database connection import { insertSubscription } from '@/lib/subscription'; // Custom DB insert logic const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!, { apiVersion: '2020-08-27', }); export default async function webhookHandler(req: NextApiRequest, res: NextApiResponse) { try { const event = stripe.webhooks.constructEvent(req.body, req.headers['stripe-signature']!, process.env.STRIPE_WEBHOOK_SECRET!); if (event.type === 'checkout.session.completed') { const session = event.data.object as Stripe.Checkout.Session; // Attempt to insert data into Neon DB await insertSubscription({ userId: session.client_reference_id, subscriptionId: session.subscription, status: 'active', }); } res.status(200).json({ received: true }); } catch (err) { console.error('Error processing webhook: ', err); res.status(400).send('Webhook Error'); } }

Neon Database Integration

Neon tech, a cloud-hosted PostgreSQL service, was set up as the main database. The insertSubscription function was supposed to save subscription data to a specific table in the Neon database. However, despite the Stripe webhook being successfully triggered and processed, no records were being inserted into the database.

Identifying the Problem

1. Verifying Stripe Webhook Trigger The first step was to ensure that the Stripe webhook was indeed triggering correctly and that events were being received at the correct endpoint (/api/webhook). The Stripe CLI was used to simulate events and verify that they were being picked up by the application:

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   stripe trigger checkout.session.completed

   Logs indicated that the events were reaching the webhook handler as expected. The console confirmed that the handler received events from Stripe, meaning the initial Stripe integration was functioning as intended.

2. Database Not Being Updated Despite the webhook being triggered, the database wasn’t receiving any new records. We added additional logging within the insertSubscription function to see if this function was being called and whether the data was being passed to the database insertion logic.

   Debugging Logs:

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   console.log('Webhook event received:', session); console.log('Attempting to insert subscription for user:', session.client_reference_id);

   These logs confirmed that the webhook event was being processed up to the point where the insertSubscription function was called, but still, no data was being inserted into the database.

3. Reviewing DB Connection and Configuration We next examined the configuration of the Neon database connection in the application. The database was connected using a custom db module that handled PostgreSQL queries via Drizzle ORM (an ORM used to interact with the Neon database). Upon reviewing the connection settings, we found that the DB connection was correctly established, as other database operations were functioning.

4. Transaction Failures After verifying the DB connection, we examined potential transaction failures within the insertSubscription function. The logic used to insert data into the database was wrapped in an async operation, which may have silently failed without throwing errors or affecting the overall flow.

   We added try-catch blocks around the insert operation to capture any potential errors or transaction failures:

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   try { await db.insert('subscriptions').values({ userId, subscriptionId, status, }); console.log('DB insert successful'); } catch (error) { console.error('DB insert failed:', error); }

   This logging provided more insights, and we discovered that the insert operation was indeed failing silently.

Root Cause Analysis

Several potential issues were considered at this stage, including:

1. Body Parsing in Next.js API Route Next.js automatically parses the request body, but Stripe webhook signatures require the raw body for validation. By default, body parsing might interfere with this, leading to webhook validation errors and potential failure in subsequent code execution.

   The Next.js API routes use body parsers (e.g., JSON.parse) by default. Stripe’s documentation specifically advises disabling automatic body parsing to ensure the webhook signature can be verified correctly.

2. Middleware and Redirection Issues Middleware configurations, such as redirecting certain POST requests, could have interfered with the webhook processing. Specifically, if POST requests were being redirected before they reached the webhook handler, this could have caused the database insert logic not to execute.

Solutions Implemented

1. Disable Automatic Body Parsing for Webhooks To handle the raw request body as required by Stripe, we updated the Next.js API route to disable automatic body parsing:

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   export const config = { api: { bodyParser: false, }, };

   This ensured that the request body would not be parsed by Next.js before Stripe validated it.

2. Use of Raw Body for Stripe Webhook Validation We updated the webhook handler to use the raw body for validating the webhook signature:

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   import { buffer } from 'micro'; export default async function webhookHandler(req: NextApiRequest, res: NextApiResponse) { const buf = await buffer(req); const signature = req.headers['stripe-signature']; try { const event = stripe.webhooks.constructEvent(buf, signature!, process.env.STRIPE_WEBHOOK_SECRET!); // Process event... } catch (err) { console.error('Error verifying Stripe signature:', err); return res.status(400).send('Webhook signature verification failed'); } } export const config = { api: { bodyParser: false, }, };

   This resolved the issue where Stripe could not verify the webhook signature, ensuring the webhook was processed correctly.

3. Fixing the Database Insert Logic With body parsing issues resolved, the database insert issue persisted. Upon further investigation, it was found that the database connection pool might have been exhausted, or there could have been race conditions causing inserts to fail sporadically.

   We refactored the insertSubscription function to use transactions and improved error handling for better debugging insights:

   import { db } from '@/lib/db'; export async function insertSubscription(data) { try { await db.transaction(async (trx) => { await trx('subscriptions').insert({ userId: data.userId, subscriptionId: data.subscriptionId, status: data.status, }); }); console.log('Subscription successfully inserted'); } catch (error) { console.error('Error inserting subscription:', error); throw error; // Re-throw error after logging for better traceability } }

   By wrapping the database insert logic in a transaction, we ensured atomicity and reduced the likelihood of issues during inserts.

4. Final Testing and Verification After implementing the above solutions, we tested the entire flow using the Stripe CLI to simulate various webhook events (checkout.session.completed, invoice.paid, etc.). These events were processed successfully, and the Neon database was updated as expected.

   Additionally, real-time subscriptions were tested through the live application to confirm the webhook-handler-to-database workflow worked smoothly.

Conclusion

The issue with database inserts not happening after receiving Stripe webhooks was resolved by addressing body parsing issues, improving webhook validation, and refactoring the database insert logic. By disabling automatic body parsing and handling the raw request body for Stripe’s signature verification, we ensured that the webhook handler received valid data. Furthermore, wrapping the database insert logic in transactions and adding more comprehensive error handling provided better reliability and debugging capabilities.

This step-by-step approach to troubleshooting, analyzing logs, and applying fixes ultimately led to the successful resolution of the issue, ensuring Stripe webhooks were processed correctly and the database was updated as expected.