AI Transparency
How SignGuard uses artificial intelligence — explained in plain language, with the legal context.
🤖 In short: SignGuard is an AI system that analyzes contracts and flags clauses that stand out. You receive a structured assessment — not legal advice. We use a custom-adapted OpenAI language model on EU-based servers together with our own and public legal databases, and we treat your contract data as strictly confidential.
1. What is SignGuard?
SignGuard is an app that checks uploaded contracts with the help of artificial intelligence. It spots common risks (e.g. invalid clauses, unusual notice periods, missing mandatory information) and explains them in plain language.
SignGuard does not replace advice from a lawyer. For complex or existentially important contracts, we recommend consulting a lawyer as well. That is exactly what the Lawyer Check in the app is for: where a contract shows high risk, we can — on request and only with your consent — refer you for a free initial legal assessment through our partner advocado.
Legal classification (EU AI Act): Under Regulation (EU) 2024/1689, SignGuard is an AI system with limited risk (Art. 50 AI Act). It does not fall under the high-risk use cases listed in Annex III.
The transparency obligations under Art. 50 AI Act apply from August 2, 2026. SignGuard already meets them today — through this page, the notice shown when you open the app, and the permanent notice in the footer of every page.
2. Which AI do we use?
For contract analysis we rely on a foundation language model from OpenAI (GPT family) that we have adapted for our purposes. It represents the state of the art for the structured evaluation of German and English contract texts.
Processing takes place via API endpoints located in the EU (EU hosting). The content of your contracts is used exclusively for the analysis — no training of new AI models on your contract data (the OpenAI API's "no training on customer data" commitment).
How SignGuard analyzes your contract (in plain language)
- Step 1: You upload your contract in the app (PDF or photo).
- Step 2: The text is extracted in a structured way and anonymized. That means all personal details are replaced with placeholders (your name becomes "Max Mustermann" — the German equivalent of John Doe; your address becomes a generic town). Only then is the anonymized text passed to the AI model.
- Step 3: The model compares your contract against typical patterns drawn from thousands of published decisions of Germany's Federal Court of Justice (BGH) and the ECJ, statutory requirements (the German Civil Code (BGB), AGB law, consumer protection law) and standard clause libraries, as well as our own legal database.
- Step 4: You receive a list of findings — ranked by how much they stand out, each with a short explanation in everyday language.
3. What SignGuard can do — and what it can't
What SignGuard can do:
- Classify standard clauses and compare them against common templates.
- Flag typical risks (e.g. excessive notice periods, invalid Schönheitsreparaturen clauses — tenant redecoration obligations in German leases — or unusual AGB, i.e. standard terms under German law).
- Check mandatory information (e.g. the withdrawal notice in online purchases, required details in a German residential lease).
- Translate complex legalese into plain language.
What SignGuard cannot do:
- Give a conclusive legal assessment of your specific case.
- Replace a lawyer.
- Negotiate, litigate or amend contracts on your behalf.
- Guarantee that individual clauses are valid or invalid.
German Legal Services Act (RDG): SignGuard does not provide a legal service within the meaning of Section 2 (1) RDG. A legal service is an "activity in specific third-party matters as soon as it requires a legal examination of the individual case".
SignGuard performs no such individual-case examination. It runs a schematic deviation comparison: your contract is checked against general, typified clause patterns — comparable to a technical checking tool. There is no evaluative legal assessment of your specific personal circumstances.
This distinction follows the case law of Germany's Federal Court of Justice on legal-tech tools, in particular BGH, judgment of December 9, 2021 — I ZR 233/20 ("smartlaw"): pure template comparisons and schematic flagging tools are not a legal service; an individual assessment of a specific case, by contrast, is.
3a. Limits of the AI analysis (error rates, hallucinations)
AI language models are extremely capable — but not flawless. SignGuard knows the limits of this technology and communicates them openly:
- Hallucinations: language models can occasionally invent content or misclassify clauses. We reduce this risk with structured prompts and cross-checks against clause databases — but we cannot technically eliminate it 100%.
- Error rates: for standard clauses (rental, AGB, subscriptions), accuracy in our internal tests is typically in the high 90-percent range; for rare, highly specialized contracts (e.g. complex shareholder agreements, international contracts) it is considerably lower.
- Context limitations: the AI does not know your personal circumstances. It cannot know, for example, whether a rental contract in Berlin (with its rent-cap history) should be read differently from identical wording in Munich.
- Training-data cutoff: the model has a knowledge cutoff. Very recent legislative changes or BGH rulings from the past few weeks may not yet be reflected — we update our clause database regularly to close this gap.
- Language: best results for German and English. Other languages are technically supported, but with reduced accuracy.
What this means for you in practice: treat the analysis result as a structured pointer, not as binding advice. For decisions with major financial or personal stakes, also speak to a lawyer.
4. Sub-processors
To operate SignGuard we work with the following processors (Art. 28 GDPR). Your contract content is only transmitted to the parties strictly required for the analysis.
| Provider | Purpose | Location | Status |
|---|---|---|---|
| OpenAI Ireland Ltd. | AI contract analysis (GPT API) | Ireland (EU) · EU-region API endpoint | EU processing |
| RevenueCat, Inc. | Subscription management | USA | Third country · SCCs |
| Apple Inc. / Apple Distribution International | App Store distribution + in-app purchases | Ireland (EU) · some processing by US group companies | Third country · SCCs |
Third-country transfers: Where processing steps take place outside the EU, they are based on the European Commission's Standard Contractual Clauses (Decision 2021/914 of June 4, 2021) plus supplementary technical and organizational measures.
5. Your rights as a user
Notice under Art. 22 GDPR (automated decision-making)
SignGuard's AI analysis is not a decision based solely on automated processing that produces legal effects concerning you. The result is a non-binding assessment; any legal consequence (e.g. termination, withdrawal, legal action) remains your own decision — where appropriate, after consulting a lawyer.
Right to object under Art. 21 GDPR
You can object to the processing of your data at any time. Just send a short email to info@signguard.app. We will review your objection and delete the data concerned unless compelling legitimate grounds prevail.
Further data-subject rights
Access, rectification, erasure, restriction of processing and data portability (Art. 15–20 GDPR), plus the right to lodge a complaint with a data protection supervisory authority (Art. 77 GDPR) — details in our Privacy Policy, section 5.
6. Oversight of AI systems
In Germany, market surveillance of AI systems under the EU AI Act is expected to be led by the Federal Network Agency (Bundesnetzagentur, BNetzA) — through the Coordination and Competence Center for AI Enforcement (KoKIVO) and the AI Service Desk.
The national authority structure is being defined by Germany's AI Market Surveillance and Innovation Promotion Act (KI-MIG) — a pure implementation statute for the EU AI Act. Key date: August 2, 2026.
Once the national body has been formally designated, you will be able to address complaints about SignGuard's AI to the competent AI supervisory authority, in addition to exercising your data protection rights. We will update this page as soon as the authority structure is finalized.
7. Contact for AI-specific questions
Questions about how SignGuard uses AI, about our methodology or about your rights? Write to us: