SAL — Resolved

Sal-Resolved

SAL Resolve Inspiration A PayPal dispute is decided by proof, and proof can't be created after the fact. A wrong quantity, a changed price or a different address happens weeks before the buyer complains. SAL catches those mistakes before delivery, and keeps the proof ready if a dispute comes anyway. Built for small sellers who trade across borders, freelancers, and businesses whose AI agents buy and sell for them.

What it does Deal Check, before delivery. Upload the buyer's purchase order and your invoice (PDF or photo). OpenAI reads both; you confirm each value. SAL then compares items, quantities, prices, totals, the approved limit, currency and address. Any difference puts the deal on hold, with what to fix and a ready correction message.

AI agents trade through SAL. Buyer and seller agents connect over MCP, each with its own key and role. In the demo, a wrong invoice is held, the seller's agent fixes it, and the buyer's agent pays only when SAL says CLEAR. PayPal disputes, with proof ready. SAL syncs cases from the PayPal Disputes API, shows what your documents prove and what's missing, and drafts a reply only from facts it can trace. Nothing is sent to PayPal until you approve it.

How we built it PayPal Sandbox: Disputes API (read cases, send evidence), Invoicing API (check a PayPal invoice against the order before it is sent), Transaction Search API, webhooks. OpenAI gpt-5-nano: reads documents and drafts replies. The verdict is plain code, never the model. MCP server for AI agents. Next.js, FastAPI, PostgreSQL with row-level security, two-step sign-in, and 529 automated tests. Challenges we ran into AI misreads documents. On real purchase orders it got the PO number, total and tax right, but once swapped quantity and price. So SAL keeps a value only if it appears on the page, the seller confirms it, and any mismatch holds the deal instead of letting it through.

Accomplishments that we're proud of A deal check no document can trick. Two real AI agents completing a deal through SAL. Dispute replies where every sentence has a source. What we learned AI works best here as a reader, not a judge.

What's next Letting each seller connect their own PayPal account, reading long invoices better, and supporting more agent payment protocols.