Privacy statement
Fizzl's x402 services ยท last updated 14 October 2026
This statement covers x402 Doctor (with its Trust Index), presign-guard, Ichimoku Signal and PlainText: their paid APIs, their MCP servers, their free checks and their web pages. The Fizzl Agent Wallet has its own statement, which also covers the visit counter on the Fizzl websites.
These services have no accounts. An agent or a person sends a request, pays for it per call (or not, for the free checks) and gets an answer. We keep little, and nothing that needs a name or an e-mail address.
1. Who is responsible
The controller is Frits Zwager, trading as Fizzl, the Netherlands. For anything about your data, write to Fizzl13@protonmail.com.
2. What we process, and why
| Data | Why | Legal basis (GDPR) |
|---|---|---|
Your request: what you send to be checked or answered. For example an endpoint URL, a token or wallet address, a transaction or signature to check, the sentence describing what your agent means to do (intent), the site asking for a signature (origin), a contract to explain, or a market symbol | To give the answer you asked for. Answers may be cached in memory for up to 10 minutes, so the same question isn't worked out twice | Contract (art. 6(1)(b)) |
| Your payment: the paying wallet address, the amount, the network and the transaction. If you buy a credit pack: the credit key and its balance | To take the payment and, for credits, to know what is left | Contract |
| Usage records, one per call: the time, the service and route, the HTTP status, whether it was paid and how much, the network, the paying address and transaction, the kind of client (for example "node", "browser" or a bot's name, taken from the User-Agent), a visitor code, and a short summary of the request and the answer (such as the URL, token or address checked and the verdict; never a full transaction, and never a key). The visitor code is made from your IP address with a secret and cut to 12 characters: it tells repeat callers apart, but can't be turned back into the address without the secret | To see how the services are used, find and fix errors, spot abuse, and count payments | Legitimate interest: running and improving the services (art. 6(1)(f)) |
Feedback you send (POST /feedback or the MCP feedback tool): your message | So a person can read it and fix what you report | Legitimate interest |
| Outcome reports (x402 Doctor): what happened after you paid an endpoint, with the signed preflight answer it follows (which names the paying address) | To warn later buyers when payments to an endpoint keep failing. Only counts per endpoint are shown, never who reported | Legitimate interest |
| Delivery checks you order (x402 Doctor, $0.25): the endpoint URL and method | We buy that endpoint once with our own wallet and publish the outcome: the URL, the result and our own transaction. Your address is not published | Contract |
| Sellers in the Trust Index (x402 Doctor): for each x402 resource listed publicly in the CDP Bazaar, the MPP directory or GoPlausible, its URL, listing description, price, payout address, daily verdicts and their reasons. For an endpoint with a problem, the contact address its owner published in the listing may be used to tell them | To show buyers which paid APIs work today, and help sellers fix theirs. This is public on /trust and in the open data. A seller can ask to be left out | Legitimate interest: safer payments for buyers and sellers |
| Your IP address, briefly | Held in memory only, to apply rate limits and stop floods. Not stored by us | Legitimate interest: security |
Please don't put personal data of other people in requests, intents or feedback.
3. Cookies
The APIs and MCP servers set no cookies. The services' own web pages load no analytics and no advertising scripts. The visit counter and the optional Google Analytics on fizzl.eu are described in the wallet statement.
4. What we never do
We never ask for, see or store a private key or recovery phrase, and never hold your funds: your agent signs and pays itself. We don't sell or rent data, don't use it for advertising or profiling, and don't use it to train AI models.
5. Who helps us (processors and services we call)
- Render: hosting. Render may keep server logs, including IP addresses, for a limited time.
- GitHub: a private repository holds the usage records. Public repositories hold the open data: the Trust Index, the weekly spot-buy and delivery-check results.
- Upstash: credit pack balances and paid-session state.
- Payment facilitators, which verify and settle the payment you sign: Coinbase (CDP) for Base, PayAI for Solana, GoPlausible for Algorand. XRP Ledger payments are settled by our own server, or by t54 for clients built on t54. MPP payments on Tempo go through the Tempo network.
- Data sources that receive only what one check needs, never who asked: GoPlus and PG1 (token and address risk), MetaMask's site scanner (the
originyou send), public blockchain RPC providers (reading and simulating transactions), and the US Treasury (we download its sanctions list). - TypeSafe (AI checks): the intent sentence with what the transaction would do, listing descriptions in the Trust Index, and news headlines for Ichimoku. TypeSafe doesn't train on it.
- Anthropic (Claude): the request, when you ask for a plain-language explanation (presign-guard
/v1/check/explain, PlainText).
Render, GitHub, Upstash, Coinbase and Anthropic are based in the United States, and other providers may process data outside the European Economic Area too. Where that happens, it is under the safeguards these providers offer, such as the EU standard contractual clauses.
6. The blockchain is public
Payments happen on public blockchains (Base, Solana, Algorand, the XRP Ledger, Tempo). Your address, the amounts and the times are public there and permanent. Nobody, including us, can delete them.
7. How long we keep it
| Data | Kept |
|---|---|
| Your request and the answer | Only while answering, plus at most 10 minutes in a memory cache |
| Usage records (including payments and feedback summaries) | At most 2 years |
| Credit packs | The key and its balance until the credits expire (one year after purchase) |
| Outcome reports | Counted for 30 days; the record itself with the usage records |
| Trust Index history per resource | The last 30 days; a resource that stays gone is dropped |
| Records Dutch bookkeeping law requires | 7 years |
8. Your rights
You have the right to access, correct and delete your data, to get it in a portable format, to object to processing based on legitimate interest, and to ask us to restrict processing. Because there are no accounts, tell us which wallet address or which request it is about, and write to Fizzl13@protonmail.com. We answer within one month. If you think we handle your data wrongly, you can complain to the Dutch data protection authority, the Autoriteit Persoonsgegevens. We'd appreciate hearing from you first.
9. Age
The services are not meant for anyone under 16.
10. Changes
If we change this statement in a way that matters, we update it here before it takes effect. The date at the top shows the current version. See also the terms of use.