INTEGRATIONS
Connecting APIs, third-party services, and external platforms to your application.
Duplicate Stripe Charges Were Causing Customer Complaints
Customers were being charged twice. The Stripe integration worked correctly. The problem was missing idempotency keys, no server-side duplicate detection, and a frontend that allowed multiple submissions. Here is the full investigation and the fixes that brought duplicate charges to zero.
Google OAuth Verification Kept Getting Rejected Until We Fixed These Issues
Our Google OAuth verification was rejected five times. The application worked perfectly every time. Here is what we actually got wrong and the systematic approach that finally got us approved.
Our Facebook and Instagram App Review Kept Failing Until We Fixed These Issues
Our Meta app review failed five times. The code worked perfectly every time. Here is what we actually got wrong and the systematic approach that finally got us approved.
Salesforce Integration Guide: Accounts, Leads, Opportunities, Sync, and Enterprise Automation
A complete Salesforce CRM integration guide covering accounts, leads, opportunities, Platform Events, Change Data Capture, OAuth 2.0, and enterprise automation across every major frontend and backend stack.
HubSpot CRM Integration Guide: Contacts, Deals, Workflows, Webhooks, and Automation
A complete HubSpot CRM integration guide covering contacts, deals, webhooks, OAuth 2.0, and workflow automation across every major frontend and backend stack.
Stripe Connect Verification Failed for Marketplace Users
Users completing your marketplace onboarding hit a verification wall Stripe rejects their identity documents or the connected account silently enters a restricted state. Here is the exact diagnosis path we followed.
Stripe Subscription Status Not Updating After Payment
Customers pay successfully, Stripe shows the subscription as active, but your database still shows past_due or canceled. The webhook handler exists but it is not running the right logic for the right events.
Stripe Checkout Successful but Order Was Never Created
Payment succeeded, customer sees the success URL, but no order was created in your backend. This is one of the most costly bugs in an e-commerce integration here is exactly how it happens and how to fix it.
Payment Succeeded but User Access Was Never Activated
Payment goes through on Stripe's end, but the user's account tier never changes. This is almost always a webhook event type mismatch combined with no fallback synchronization. Here is the full diagnosis.
Stripe Processing Duplicate Webhook Events
Stripe guarantees at-least-once webhook delivery. That means duplicates are not a bug in Stripe they are a fact of life. Your webhook handler must be idempotent. Here is how to build that correctly.
Clerk Authentication Redirect Loop After Deployment
A Next.js app with Clerk auth works perfectly in development but enters an infinite redirect loop in production. The root cause is almost always middleware misconfiguration publicRoutes not declared, afterSignInUrl pointing back to a protected route, or a missing environment variable in the deployment.
Google OAuth Verification Keeps Getting Rejected
Google's OAuth app review process rejects applications for reasons that are rarely obvious from the rejection email. This post documents the exact requirements for sensitive and restricted scopes, what your privacy policy page must contain, and how to configure the OAuth consent screen to pass review.
Facebook App Review Rejected: Common Reasons and Fixes
Meta's app review process rejects applications with error messages that rarely indicate what actually needs to change. This post documents the real reasons apps get rejected, what the review team looks for in screencasts, and the exact configuration changes that lead to approval.
Instagram App Review Keeps Failing? Here's What Meta Wants
Instagram Graph API permissions require App Review approval and the review criteria are specific to Instagram's platform policies. This post documents why instagram_basic, instagram_content_publish, and related permissions get rejected and the exact steps to get them approved.
Auth0 Callback URL Mismatch in Production
An Auth0 application that works perfectly in development starts throwing 'callback URL mismatch' errors after deploying to production. The fix is in the Auth0 dashboard Allowed Callback URLs list, but the details matter: HTTP vs HTTPS, trailing slashes, environment-specific configuration, and wildcard URL gotchas all contribute to the problem.
WhatsApp Business API Messages Not Delivering
Your API calls return 200 OK but recipients never see the messages. Walk through every layer number verification, template approval, session windows, quality ratings, opt-outs, and rate limits to find exactly which gate is closed.
WhatsApp Webhooks Not Reaching Your Server
Meta is sending webhook events but your server never processes inbound messages or delivery receipts. Trace the failure through token verification, SSL validation, response codes, body parsing, and subscription field configuration.
WhatsApp Quality Rating Dropped Suddenly
Your number's quality rating dropped to YELLOW or RED and your messaging tier was downgraded. Learn what triggers the drop, how Meta calculates quality, and the exact steps to recover without losing your phone number.
Clerk Authentication Integration Guide: Secure Auth for Modern SaaS Applications
Building authentication from scratch is expensive and risky. Clerk gives SaaS products enterprise-grade auth, social logins, organizations, and RBAC in days. This guide covers the full integration across every major frontend and backend stack.
Slack API Integration Guide: Automating Notifications, Workflows, and Internal Operations
Missed alerts, manual workflows, and slow team communication cost engineering teams hours every week. This complete Slack API integration guide covers webhooks, bots, slash commands, Events API, and automation examples across every major backend and frontend stack.
OpenAI API Integration Guide: Architecture, Implementation, Security, and Automation
Everything you need to integrate the OpenAI API into a production application, from architecture decisions and frontend code to backend implementation, security, automation, and deployment.
WhatsApp Business API Integration Guide: Architecture, Automation, Security, and Implementation
Everything you need to integrate the WhatsApp Business API into a production system, from Meta App setup and webhook handling to AI automation, CRM sync, security, and a deployment checklist.
Stripe Payment Integration Guide: Architecture, Webhooks, Security, and Subscription Billing
Everything you need to integrate Stripe into a production application, from Checkout Sessions and Payment Intents to webhook handling, subscription lifecycle management, failed payment recovery, and PCI compliance.