Clause50 is an EU AI Act evidence platform. It classifies an AI system against the whole Act from one intake — prohibited practices under Article 5 are refused, high-risk systems are screened against all eight Annex III areas and documented across the nine sections of the Annex IV technical file, and the four Article 50 transparency duties are evidenced — and it answers every obligation that applies with append-only, Ed25519-signed evidence that anyone can verify without an account. It records evidence against the 2027 high-risk obligations today, so the file exists on the day they bind — or on the day a significant change brings a legacy system into scope. It pre-fills the EU declaration of conformity and refuses to sign it. The same intake also screens the system against the GDPR duties an AI system that processes personal data owes — the data protection impact assessment, Article 22 automated decisions, notices to the people whose data it processes, its Article 30 record entry and transfers — scored separately from the AI Act. It is not the quality management system, conformity assessment, EU database registration or the fundamental rights impact assessment — those stay yours, whichever tool you use.
Prove every client’s Article 50 position — one signed pack per system.
Every client’s chatbots and AI-generated content, their evidence and their gaps, in one workspace — and a signed pack anyone can verify. When a client’s system turns out to be high-risk, the same intake records its Annex IV technical file for 2 December 2027. Where it processes personal data, the same intake screens its GDPR duties too — already in force.
An example client roll-up: four clients, three on Article 50 and one high-risk, each with its evidence status and its signed documents.
You ship AI on dozens of client sites. Each one is a separate Article 50 question — and you are the one asked to answer it.
Every client is a separate audit
A regulator's complaint or a client's enterprise buyer can ask for proof that a chatbot says it is AI and that generated images are marked. Screenshots in a shared folder do not survive that question.
Proof goes stale every release
Redesign a site, swap a model, change a prompt — and last month's evidence no longer describes what is live. Keeping it current by hand, across a whole client book, does not scale.
The questionnaire line
The vendor questionnaire now has an "EU AI Act evidence?" line. Answering it credibly, per client, on demand, is either a billable headache or a lost deal.
Add. Prove. Watch. Export.
Add a client system
Record the system and answer the intake. The risk class is derived from your answers and confirmed by you.
Connect or upload
Upload documents, connect read-only sources, or attest against a checklist. Every item enters an append-only, hash-chained store.
Watch coverage
See what is evidenced and what is missing, per client. When evidence ages, you record a change, or the rule pack is updated, the system is re-scored and anything newly stale or missing is flagged.
Export the signed pack
The Article 50 evidence pack — or the Annex IV technical file — Ed25519-signed and verifiable without an account.
Clause50 documents; it does not sit in your live traffic. Nothing to install on client sites, and nothing of ours in the critical path.
The method in full — and the role of AI →Article 50 is the front door. The same intake screens the rest.
One intake · 32 obligations per system — 6 in force today, 26 recorded now for 2 December 2026 and 2 December 2027 · rule pack 2026.35
Chatbots and assistants
Art. 50(1) — people must be told they are talking to AI.
AI-generated content
Art. 50(2)/(4) — synthetic content marked and disclosed. Systems on the market before 2 Aug 2026 have until 2 Dec 2026 to mark.
Emotion and biometric systems
Art. 50(3) — the people exposed must be informed.
Prohibited practices
screened · refusedArt. 5 — no evidence pack at any plan level; the classification memo is still yours.
See the refusal boundary →When a client’s system is high-risk
25 recorded nowAnnex III — screened from the same answers. Nine Annex IV sections, recordable now.
See what high-risk requires →Also from the same record, scored separately: 17 GDPR duties for AI systems that process personal data, all in force today, with 5 documents built from them. GDPR for AI systems →
Everyone can sign an event. Clause50 signs a case.
- Structured factsThe system, recorded as answers to a fixed intake. Every change is a new version.
- Regulatory assessmentA versioned rule pack, cited to the article, decides what applies — from those answers.
- Supporting evidenceEach requirement bound to the documents, records and events it rests on, by content hash.
- Human attestationYou confirm the risk class and attest what the evidence shows. The record names who, and when.
- Signed recordAn Ed25519-signed manifest that names the rule pack version it was assessed against.
- Versioned historyAppend-only and hash-chained. A correction is a new entry; the original stays.
A signature proves a file was not edited afterwards. It does not show how the file was made, or who accepted it. Clause50 keeps the whole chain, and the signed record names its links: the rule pack version, the evidence by hash, and who confirmed and attested.
Clause50 assembles evidence toward your obligations. It is not the compliance programme, and no software is.
Explore a real, signed specimen, then verify it →What Clause50 proves — and what stays yours →Security in depth →
Product claims on this page are asserted by tests in our codebase; the legal content of the rule pack is not yet reviewed by counsel.
Breadth by subscription. Depth per system.
Free to classify and read your coverage. Every plan generates the same signed, verifiable documents. Monthly prices, excl. VAT — 14-day free trial.
Solo
One system, signed and verifiable.
Starter
Build your evidence record — every system in one organisation.
Boutique
Run evidence for your clients — each a separate, sealed organisation.
Growth
Run a multi-client evidence operation, under your own branding.
Included on every plan, including Free and one-time packs: Evidence volume is never metered · Ingestion is never gated by plan · Cryptographically signed, independently verifiable · Per-requirement evidence traceability · Machine-readable marking evidence · Signed audit-log export What each means →
Classify a system for free. Take the signed document when you need it.
Anyone may record a system, answer every screening question and read their full coverage. A plan decides one thing: whether the signed document leaves.
Four free ways to see where a client stands.
Article 50 free tools, no sign-in. They show where a site stands; none of them records evidence.