The guarantees that are the same for everyone
Whatever tier you use, four things never change:
- Verification is always free and unlimited, for anyone — even for those who have never attested anything. A certificate has value because anyone can check it, without paying and without registering.
- The proof of existence never expires. Your work's fingerprint, the Bitcoin anchoring, the certificate's permanent page, and the signature verification remain valid forever, in every tier. What varies between tiers is only how long we keep a copy of the PDF (the "recover a lost certificate" feature) — the certificate you download is yours and never stops working.
- No retroactive effects. Certificates issued before these terms were published remain retrievable with no expiry.
- Privacy doesn't change. Basic use remains at zero personal data; an identity (your email) comes into play only in the tiers that need it to work — and only for that.
| Basic | Developer | Professional | Convention | |
|---|---|---|---|---|
| Who it's for | Anyone, for occasional use | Developing and testing integrations — not for production | Those who attest regularly: artists, photographers, studios | Academies, institutions, businesses |
| Identity required | None — zero data | Verified email (Google/Microsoft/LinkedIn) | Verified email + subscription | Email from the agreement's domain (e.g. @students.youracademy.edu) |
| Channels | Website, Telegram bot | API, MCP server | Website with email access · API | Website with email access · API |
| Cost | Free | Free | Annual subscription — 20 €/year promotional price until 31 December 2026 (list price 24 €); the actual price is always shown before payment | As agreed |
| Attestations | No nominal quota, with anti-abuse limits (Telegram bot: 5 per day) | 50 per month | 200 per month | Agreed monthly pool, shared among the domain's members |
| Verifications | Unlimited | Unlimited | Unlimited | Unlimited |
| PDF retrieval from the archive | Guaranteed for at least 6 months | Guaranteed for at least 12 months | Guaranteed for at least 5 years | Guaranteed for at least 5 years (or as agreed) |
| Proof of existence | Forever | Forever | Forever | Forever |
| Usage reporting | — | Monthly key counter | Personal profile page, always up to date | Monthly summary, per member |
| Support | Best effort | Priority email | Dedicated contact |
Basic — free and anonymous
This is the service you'll find on the homepage, just as it's always been: no registration, no personal data, your work never leaves your device. There's no nominal quota: there are anti-abuse protections (anti-bot checks and rate limits) designed to stop automation, not people.
Developer — free, with verified email
To integrate attestation into your code or your AI agent: confirm your email with Google, Microsoft, or LinkedIn and receive an API key with 50 attestations per month. Everything is self-service, all described on the developer page.
This tier is meant for building and testing an integration, not for running it in production — that's why the quota is deliberately low. If your application is (or is about to go) into production, the right tier is Professional: same email-based identity, a larger quota, a longer retention guarantee.
Professional — for those who attest regularly
A lightweight annual subscription for those who produce works regularly: 200 attestations per month and retention of the certificate copy for at least 5 years. No account and no password: your verified email is your identity, and you can attest directly from the website, just as you do today. Until 31 December 2026 it's available at a promotional price of 20 € per year (list price 24 €) — full details on the Professional tier page. Activate and manage it from your profile page — subscription status, this month's usage, the certificate archive, and the top-up log are always there, updated in real time.
Convention — for academies, institutions, and businesses
The institution signs an agreement and registers its email domains: from that moment, anyone with an address on that domain (students, teachers, staff) attests with their own email, and usage is deducted from the organization's monthly pool, with a summary per member. No key to distribute, no technical skill required from individuals. To start an agreement, write to [email protected].
Once the pool is exhausted, members can still continue attesting in the Basic tier (free, with 6-month retrieval): the service is never denied, only the tier changes.
This also applies to software companies: if your app attests on behalf of your customers, an agreement gives you a dedicated monthly pool, and your users remain anonymous to us. Contact us for a quote: [email protected]. Applications that integrate attestation — with or without an agreement — can apply to the public Integrations showcase.
What "PDF retrieval" means
When you attest a work, you download the PDF certificate: that's yours, forever, and it stays verifiable forever. We archive a copy of it so you can re-download it if you lose it (the "recover certificate" feature). The length of this retention is what changes between tiers. Even after it expires, the work's proof of existence — fingerprint, date, Bitcoin anchoring, permanent page — remains public and verifiable with no time limit.