x402 Papercheck

The problem it solves

x402-Papercheck makes research paper verification affordable, on-demand, and fair.

Today, plagiarism and AI-content checks are locked behind expensive subscriptions, even though most users need them only occasionally. Students writing a single research paper, or educators reviewing selected submissions, are forced to overpay or rely on low-quality free tools.

With x402-Papercheck, users can:

1. Verify plagiarism and AI-generated content in research papers
2. Pay once per document, based on actual paper size
3. Avoid monthly subscriptions and account lock-ins
4. Get transparent pricing before execution
5. Safely use premium verification tools only when needed

This makes academic integrity checks easier, safer, and more accessible for students, researchers, and educators, while ensuring payment is enforced fairly and only when real work is performed.

Challenges we ran into

A key challenge was calculating the verification cost before running plagiarism or AI checks, as x402 requires upfront pricing. This was solved by separating document metadata extraction from the analysis pipeline. Another hurdle was preventing duplicate payments on retries, addressed using x402 nonces and expiry to ensure safe, idempotent requests.