API Terms

Version api-terms-2026-10-15 · Karl Finance Technologies Ltd ("we"), company 17308197, 128 City Road, London EC1V 2NX.

What we provide

The API lets you ask your customers to prove they control a crypto wallet by signing a message and, depending on the tier you choose, to complete identity, AML and company checks run by our providers. We return the result, signed by us, and issue a VerifiedWallet certificate. Test keys run the same flow with simulated results and are free.

A verification is a point-in-time result based on the signature and our providers' data at that time. It is not financial, legal or compliance advice, and you remain responsible for your own regulatory obligations (including Travel Rule, AML and sanctions duties) and for the decisions you make using our results.

Your account and keys

You must give accurate company details and keep them up to date. Keep your API keys and webhook secret confidential and on your servers; you are responsible for activity made with your keys. Tell us straight away if you think a key has been exposed, and revoke it in your dashboard.

Acceptable use

• Only send people to verifications they have chosen to take part in, for your own business purposes, and tell them how you use the result.
• Don't resell or give API access to others, try to get around limits, probe or overload the service, or use it for anything unlawful.
• Don't use results to discriminate unlawfully, or as the only basis for a decision with legal or similarly significant effects on a person without a way for them to ask for a human review.

We may pause or close accounts that break these terms, put the service at risk, or that our providers or the law require us to stop serving.

Data protection

For verifications you request, you decide why they happen and we carry them out for you: you are the controller of the results you receive, and we process your customers' data on your behalf, using the subprocessors in our Privacy Policy (including Didit for identity, AML and company checks, Stripe for payments, and Cloudflare for hosting). We process that data only to provide the verification, keep it secure, help you with your customers' data-protection requests, and delete it in line with our retention periods. The certificate's public page is part of the service the customer takes part in. A full data processing agreement is available on request and forms part of these terms once signed.

Fees and payment

• Prices are on our developers page (or as agreed in writing). Test mode is free.
• We invoice monthly, in US dollars, for the previous month's live usage and any plan fee, and charge the card saved in your account. Prices exclude any taxes that apply.
• New accounts have a monthly spending limit, which rises once invoices are paid. Live requests over the limit are refused until the next month or until the limit is raised.
• If a payment fails and the invoice is still unpaid 7 days after it was due, live verifications pause until it's paid. Test mode keeps working.
• Plan changes: upgrading applies to the current month; downgrading applies from the start of the next month. Fees already paid aren't refunded except where the law requires.
• We may change prices with 30 days' notice by email; the new prices apply from the next month after that.

Availability and changes

We aim to keep the API available and to give notice of planned changes, but we don't promise uninterrupted service in these terms (an uptime commitment is available on Enterprise terms). Within a version (/api/v1) we add fields but don't remove or rename them.

Liability

Nothing in these terms limits liability that can't be limited by law. Otherwise, neither of us is liable for indirect or consequential loss, or loss of profit, revenue or data; and each party's total liability under these terms in any 12 months is limited to the fees you paid us in that period.

Ending the agreement

You can stop using the API and revoke your keys at any time; usage up to then is invoiced. We can end the agreement with 30 days' notice, or straight away for a serious breach or unpaid fees. Certificates already issued stay valid and checkable.

General

We may update these terms; for material changes we'll email you at least 30 days before they apply. These terms are governed by the law of England and Wales, and its courts have jurisdiction. Questions: contact us.