I Built a Free Tool to Debug API Integration Flows (After Losing Sleep Over Webhooks)

If you have ever spent hours stitching together logs to understand why a Stripe webhook fired twice or arrived late, you are not alone.

Reddit r/webdev is full of developers complaining about the same thing: single API calls work fine, but full async flows break silently.

The Problem

Real integrations look like this:

Request → Queue → Webhook → Retry → Race Condition → Wrong Final State

Logs tell you what happened. They do not tell you when or why state drifted.

The Solution: FlowTrace

I built FlowTrace — a free browser-based tool that lets you simulate multi-step API integration flows:

• Add steps: API requests, webhooks, queue jobs, retries
• Set delays and failure modes (duplicate fire, late arrival)
• Run the simulation and see a timeline + final state diagnosis

Try it free: https://produtosagentes.vercel.app

What It Catches

1. Late webhooks arriving after timeout
2. Double retry fires (duplicate charges)
3. Race conditions between polling and webhooks
4. Out-of-order event processing
5. Silent state drift from docs vs reality
6. Missing handlers for new event types

Pro Playbook ($19)

The free tool covers simulation. The Pro Playbook includes:

• Production logging templates
• Idempotency middleware snippets
• Webhook replay scripts
• 47-point integration checklist

Built by an indie hacker who got tired of debugging integrations at 2am.

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Link: https://produtosagentes.vercel.app

Would love feedback from anyone who has war stories about webhook debugging!