Inspiration
PayPal sellers often face a hard choice: refund a dispute or fight it.
Refunding every dispute loses money. Fighting every dispute wastes time. AI can help, but it can also suggest actions that PayPal does not allow.
I built Verdict to make these decisions safer and easier.
What it does
Verdict is an AI-powered dispute decision assistant for PayPal sellers.
It:
- Reviews dispute details, evidence, and seller protection.
- Recommends whether to refund or submit evidence.
- Explains each decision and what could change it.
- Checks PayPal’s rules before taking action.
- Lets sellers approve every action.
How I built it
I used Python, FastAPI, PayPal APIs, and Claude.
A rule-based engine makes decisions. AI helps explain them. PayPal’s API controls which actions are allowed.
I also built automated tests, a state machine, and a replay mode that works without PayPal credentials.
Challenges
PayPal’s API sometimes behaved differently from its documentation. I found these issues through real sandbox tests and fixed how Verdict handled them.
I also needed to test decisions without relying only on AI. I used PayPal’s API, its OpenAPI specification, and random test cases to check the system.
Results
- 100% agreement on 95 rule-based evaluation cases.
- 0% invalid actions in the final evaluation.
- 11/11 invalid actions rejected by PayPal’s sandbox.
- 400 generated evidence cases used to test API validation.
- 2 real PayPal actions completed in the demo: submitting evidence and issuing a refund.
The 100% result measures agreement with my test rules, not real-world dispute success.
What I learned
AI should help people understand decisions, but it should not control financial actions without checks.
Clear rules, API validation, and human approval make the system more reliable.
What’s next
I plan to test Verdict with real sellers, improve decisions using real dispute outcomes, and support more dispute types.
