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Trace a Stripe Payment Flow End-to-End

Use Ask Devin to map every file and function in a Stripe checkout flow — from the Subscribe button to the webhook handler — before writing a single line of code.
AuthorCognition
CategoryFeature Development
FeaturesMCP
1

Ask Devin to trace the payment flow

You’ve been assigned a ticket to add retry logic to the Stripe webhook handler, but you joined the team two weeks ago and haven’t touched payments before. Instead of spending an hour clicking through source files, open Ask Devin and ask it to trace the flow for you.Select Ask Devin from the left sidebar, choose your repo, and describe the flow you need to understand:Devin reads the DeepWiki documentation for your repo, searches through the actual source code, and traces function calls across files to build a complete picture. It returns a structured map of the entire flow:
## Payment Flow: Subscribe → Database

1. src/pages/pricing/PricingCard.tsx:45
   handleSubscribe() → POST /api/v2/subscriptions

2. src/api/v2/subscriptions/create.ts:12
   Validates input, checks eligibility → calls SubscriptionService.create()

3. src/services/SubscriptionService.ts:89
   Creates Stripe subscription via stripe.subscriptions.create()
   Stores pending record with status="pending"

4. src/webhooks/stripe.ts:34
   Receives invoice.payment_succeeded → calls SubscriptionService.activate()
   ⚠ No retry logic here — this is where you'll make changes

5. src/services/SubscriptionService.ts:134
   Updates status to "active", creates invoice record, emits event
In under a minute you have a file-level map of the payment pipeline — five files, the exact function names, and the spot where your change goes.
2

Drill into the webhook handler with follow-ups

Ask Devin is conversational — you can ask as many follow-up questions as you need. Now that you can see the pipeline, drill into the area you’ll be changing:Keep asking follow-ups until you have the full picture — Ask Devin retains context from the entire conversation, so each question builds on the previous answers.
3

Start a coding session directly from Ask Devin

You now know the exact file to change (src/webhooks/stripe.ts), the existing retry utility to reuse (src/lib/retry.ts), and the dead letter queue that other handlers already push to (src/queues/dlq.ts).Press ⌥ Option + Enter (or click the arrow icon) to start a Devin session directly from your Ask Devin conversation. Devin carries over everything it learned — the file map, the error handling patterns, the retry utility — so it skips the investigation phase and goes straight to implementation.You can also type a specific implementation prompt before pressing ⌥ Enter to guide what Devin builds:Because the session inherits context from your Ask conversation, Devin produces a more accurate PR with fewer iterations. This Ask-to-Agent workflow is the fastest way to go from “I don’t know this codebase” to “here’s a PR.” Learn more in the Ask Devin guide.