EU AI Act Article 50(1): adding a chatbot AI-disclosure notice in 20 lines
Article 50 of the EU AI Act (Regulation (EU) 2024/1689) has applied since 2 August 2026. If your product lets people chat with an AI system and those people are in the EU, Article 50(1) is the rule that usually shows up first in an engineering backlog. This post is for developers. It is readiness s
Posted on Oct 20 • Originally published at rulereddy.com
Article 50 of the EU AI Act (Regulation (EU) 2024/1689) has applied since 2 August 2026. If your product lets people chat with an AI system and those people are in the EU, Article 50(1) is the rule that usually shows up first in an engineering backlog.
This post is for developers. It is readiness support, not legal advice. This article was AI-assisted and then edited.
In plain terms, Article 50(1) requires that providers of AI systems intended to interact directly with natural persons design those systems so that the person is informed that they are interacting with an AI system, unless that is obvious from the circumstances and the context of use.
Official text: Regulation (EU) 2024/1689, Article 50.
The European Commission has also published transparency guidance and FAQ material for these duties. Start here: Commission enforcement and transparency requirements from 2 August 2026.
Important related deadlines many U.S. teams mix up:
If you only remember one engineering takeaway: a chatbot disclosure banner is not the same workstream as watermarking or content marking.
Ask a product lawyer for your case. From an implementation checklist perspective, teams usually treat a notice as needed when all of these are true:
Exemptions and "obvious from context" are fact-specific. Do not ship a banner and assume you are done for Article 50 overall. Articles 50(2)–50(4) cover other duties (machine-readable marking, emotion recognition / biometric categorisation notices, and certain deepfake / public-interest labelling rules).
Goal: show a persistent, readable notice before the first message, keep it available to assistive tech, and avoid dark patterns (do not hide the only disclosure behind a one-time toast that vanishes forever with no other cue).
<div id= "chat-root" > <!-- chat UI mounts here --> </div> <script> ( function () { var root = document. getElementById ( " chat-root " ); if (! root || root. dataset. aiNoticeMounted ) return; root. dataset. aiNoticeMounted = " 1 "; var notice = document. createElement ( " div " ); notice. setAttribute ( " role ", " note " ); notice. setAttribute ( " aria-live ", " polite " ); notice. style. cssText = " background:#0F1729;color:#FCFBF8;border-left:4px solid #D9A520; " + " padding:10px 12px;font:14px/1.4 system-ui,sans-serif; " + " border-radius:6px;margin:0 0 8px "; notice. textContent = " You are interacting with an AI system. Responses are generated automatically. "; // Keep the notice at the top of the chat surface so it stays visible // while the conversation scrolls underneath (or pin it in your CSS). root. insertBefore ( notice, root. firstChild ); })(); </script> Enter fullscreen mode Exit fullscreen mode React sketch:
export function AiDisclosure ({ lang = " en " }) { const copy = { en: " You are interacting with an AI system. Responses are generated automatically. ", de: " Sie interagieren mit einem KI-System.
Antworten werden automatisch erzeugt. ", fr: " Vous interagissez avec un système d'IA. Les réponses sont générées automatiquement.
", }; return ( < div role = "note" aria-live = "polite" style = { { background: " #0F1729 ", color: " #FCFBF8 ", borderLeft: " 4px solid #D9A520 ", padding: " 10px 12px ", font: " 14px/1.4 system-ui, sans-serif ", borderRadius: 6, marginBottom: 8, } } > { copy [ lang ] || copy. en } </ div > ); } Enter fullscreen mode Exit fullscreen mode Recording which notice shipped A disclosure you can't evidence later is hard to defend in a review. A tiny, privacy-light log of which notice version rendered on which surface goes a long way. Don't put message content or user identifiers in it.
const AI_NOTICE_VERSION = " 2026-10-20.1 "; export function logNoticeShown ({ surface, lang }) { const payload = JSON. stringify ({ v: AI_NOTICE_VERSION, surface, // e.g. "web-chat", "ios-assistant", "voice-ivr" lang, ts: new Date (). toISOString (), }); // sendBeacon survives page unloads; fall back to fetch. if (! navigator. sendBeacon?.( " /api/ai-notice-log ", payload )) { fetch ( " /api/ai-notice-log ", { method: " POST ", body: payload, keepalive: true }); } } Enter fullscreen mode Exit fullscreen mode Bump the version string whenever the copy or placement changes, and keep a short changelog next to it in your repo.