# Codex

Type: Product

Source: Legal & RegTech Intelligence Brief — https://getlegalbrief.com/entity/codex
Canonical HTML page: https://getlegalbrief.com/entity/codex

## Timeline

- **2026-12-02**: Legacy-system compliance deadline — Deadline for AI systems placed on the EU market before August 2, 2026 to meet the marking and detection obligation.
- **2026-10-05**: OpenAI announces EU watermark rollout — OpenAI reveals the textGrain watermark for ChatGPT and Codex in the EU and opens a worldwide API opt-in for select models, off by default.
- **2026-08-02**: Article 50 transparency rules take effect — The EU AI Act's transparency rules begin applying, requiring AI companies to mark AI-generated content in a machine-identifiable way.
- **2026-07-31**: 190 organizations sign Code of Practice — By the end of July, about 190 organizations have signed the transparency code.
- **2026-06**: OpenAI backs Code of Practice — OpenAI publicly supports the EU's voluntary Code of Practice on Transparency of AI-generated Content.
- **2024-08**: OpenAI declines ChatGPT watermarking — After an internal survey found nearly 30% of ChatGPT users would use the service less, OpenAI decided against text watermarking.

## Recent coverage (1 stories)

### OpenAI EU Watermark: 92% Detection Falls to 17% After Synonym Edits
2026-10-06 01:33:00 · Sentiment: Neutral · Impact: 7/10 · Sources: 2

OpenAI will watermark ChatGPT and Codex text across the EU to satisfy Article 50 of the EU AI Act, with a global API opt-in now live. The textGrain method embeds a detectable statistical signal in word choices, but OpenAI's own tests show synonym edits erode detection sharply. Legal teams must weigh the December 2, 2026 deadline, the ~190-signatory Code of Practice, and unresolved scope questions.
Full story: https://getlegalbrief.com/story/openai-eu-watermark-article-50-compliance

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