x402 seller verification
Know who stands behind the API your agent is about to pay.
ZadQ is a verification layer for companies and agents paying each other over x402: KYB and KYC done once, a guarantee deposit in escrow behind every endpoint, and a free check in the 402 response. No friction, no constant re-authentication.
Fast because nobody asks who anybody is.
A server says 402 Payment Required. An agent pays. No signup, no invoice, no way to reverse it. When the endpoint never delivers, there is no one to claim against.
ZadQ adds a signed statement to the same response: a verified, accountable operator answers for this endpoint, and a guarantee deposit in escrow stands behind it.
What you get
A verified operator behind the endpoint
We verify the legal entity once, at onboarding. The attestation carries the company's responsibility, not its people's data.
A deposit in escrow
Money the operator deposits before selling, sized to its assurance grade, available for claims and dispute escalation.
A free check, in seconds
Buyers verify the signature at no cost and get one of three answers: verified, not verified, unknown. If we are unreachable, everything keeps working.
The trust perimeter
The set of vendors and agents whose accountability is verified. Inside it, every payment has an accountable human or organisation at both ends, and nobody reveals who.
An attested vendor’s endpoints are inside; an attested agent’s payments are inside once agent attestation opens. Being attested is what a party pays for. Reading who is inside is free to everyone, always.
Who pays, and who never does
Vendors pay to be attested
An entry fee, an annual minimum, and a usage component for the payments the attestation covered. Two named tiers.
Readers never pay
Buyers, marketplaces, explorers and agents check the verdict for free, every time, forever.
Agents: with v1
Agent operators enter the perimeter when agent attestation opens. Until then nothing changes for agents, and nothing blocks them.
Today, and with ZadQ
The same endpoint, from the paying side.
| Today | With ZadQ | |
|---|---|---|
| Who runs it | Whatever the API docs say. | A legally identified company, verified by ZadQ, tied to this exact endpoint. |
| If it fails | Nothing. x402 payments cannot be reversed. | A deposit in escrow answers claims. |
| Is it still true? | Checked once, if ever. | Renewed within public assurance tiers. Miss it, and the status drops. |
| Who pays for the check | Whoever bothers to build one. | Nobody. It is automatic and free. |
The regulation, handled
What an attestation covers, and what you no longer build yourself.
Escrow
A guarantee deposit behind every verified endpoint, available for claims and dispute escalation.
eIDAS
Identity verified in line with the European digital-identity framework and OpenID4VP.
No GDPR surface
No personal data changes hands between parties unless a dispute is escalated. Nothing new for you to protect.
Encrypted records
Each client's verification records are kept encrypted and safeguarded by ZadQ, released only on escalation.
Who this is for
API sellers, publishers, marketplaces and regulated platforms with real commercial volume.
Selling over x402? Let's find out if we fit.
We are onboarding our first partners: API sellers, publishers, marketplaces and regulated platforms.