# FAQ

> Short answers to the first questions people ask about LOPW: what it costs, what it covers, what it cannot do, and how it relates to x402.

*LOPW documentation · Start here.* Canonical page: https://lopw.com/docs/start/faq.html · This Markdown twin: https://lopw.com/docs/start/faq.md · Index of all pages: https://lopw.com/llms.txt · Everything in one file: https://lopw.com/llms-full.txt

Short answers first; each links to the page with the full detail.

**Does LOPW change how x402 payments work?**

No. LOPW is an x402 v2 extension named `lopw`. Verify and settle are untouched, any conformant facilitator works, and a buyer that ignores the extension still completes a normal purchase. [Wire format](https://lopw.com/docs/protocol/x402.html)

**Is this escrow?**

No. The payment settles normally. What is locked is the *seller’s* stake, once, for all its calls. A claim pays from that stake.

**What does a buyer actually get when a promise is broken?**

`min(max_claim, stake remaining)` in the stake token, paid to the buyer named in the receipt in the same transaction as the claim. `max_claim` is in every offer, so the buyer knows the cover before paying.

**What can be claimed, exactly?**

Six conditions: two different receipts for one payment (P1), a receipt citing other terms than the offer (P2), data older than promised (P3), a status the seller promised not to charge for (P4), a response larger than promised (P5), and a served value further from a named oracle than the promised tolerance (P6). [Predicates](https://lopw.com/docs/protocol/predicates.html)

**Can a seller be slashed for a bad answer, slow response or an outage?**

No. Quality, latency and availability seen only by the buyer cannot be proven from evidence alone and are out of scope. A missing receipt or an invalid signature is not slashable either: the SDK reports it as an untrusted response.

**Can a buyer be paid twice for one payment?**

No. A paid claim is recorded under `(service_id, payment_reference)`; a second claim for the same payment fails with `AlreadyClaimed`, whichever receipt it presents.

**Can anyone file a claim, even someone who did not pay?**

Yes, anyone holding the signed offer and receipt may submit. The payout still goes to the buyer named in the receipt, so there is nothing to gain by racing.

**What if the seller withdraws its stake before I claim?**

It cannot do so in time. A full exit waits the unbonding delay: the largest claim window the service ever registered plus one hour. The stake stays slashable throughout. [Unbonding](https://lopw.com/docs/protocol/bond-registry.html#unbonding)

**Can a seller pay itself to empty its stake ahead of honest claims?**

It is rate-limited: within one epoch (one unbonding delay long) total slashes may not exceed 50% of the stake at the epoch’s start, so stake can leave no faster than a normal withdrawal would allow. [Threats](https://lopw.com/docs/deep-dive/security.html)

**How much stake does a seller need?**

At least 100 USDC, set as `min_stake` at registration. Agents may demand more through their policy, and the stake is public before payment.

**What does the seller pay?**

A one-off registration fee and an annual fee on stake held, both in the stake token and both possibly zero; and, when it breaks a promise, the payout. [Economics](https://lopw.com/docs/deep-dive/economics.html)

**What if the oracle is wrong or has no data?**

The oracle named in the terms is trusted: a wrong observation produces a wrong outcome. A missing observation makes the claim `NotVerifiable`: nothing is paid and nobody is penalised.

**Which chains?**

Built first on Stellar with Soroban, USDC and x402; designed for every chain. The offer, receipt, validator interface and claim semantics are portable; encoding, signatures, contract functions and the payment rail are per binding. [Bindings](https://lopw.com/docs/protocol/bindings.html)

**Where can I see it working?**

The [demo](https://lopw.com/demo/) replays a real claim paid on a live network, and the [proofs](https://lopw.com/proofs/) page lists every transaction and test. [Proofs and scenarios](https://lopw.com/docs/deep-dive/proofs-and-scenarios.html)

**I am an AI agent. Where do I start?**

[Agents start here](https://lopw.com/docs/agents/): Markdown twins of every page, `/llms.txt`, `/llms-full.txt`, JSON Schemas and test vectors.