{"event":{"id":"evt-hist-2026phase29-openai-textgrain-api-optin","dedupe_key":"text_provenance_api_opt_in_release:2026-10-05:openai-introduces-optional-textgrain-text-watermarking-for-selected-api-models","event_type":"text_provenance_api_opt_in_release","title":"OpenAI introduces optional textGrain text watermarking for selected API models","summary":"OpenAI announced Oct 5 optional textGrain watermarking for eligible API customers globally, while planned eligible ChatGPT/Codex EU rollout and researcher detector access were future steps. Detection is fallible and does not identify a user or prove human versus AI authorship.","occurred_at":"2026-10-05T00:00:00.000Z","published_at":"2026-10-05T00:00:00.000Z","observed_at":"2026-10-18T08:45:00.000Z","reconstructed_at":"2026-10-18T08:45:00.000Z","ingest_type":"historical_backfill","locations":null,"status":"verified","confidence":0.87,"metadata":{"global_canonical_novelty_not_proven":1,"no_unproven_outcomes":1,"original_index_position":1040,"publication_milestone_only":1},"created_at":"2026-10-19T05:54:47.217Z","updated_at":"2026-10-19T05:54:47.217Z"},"artifacts":[{"id":"art-hist-2026phase29-openai-textgrain-api-optin","dedupe_key":"529bed7c06db0cf4b2ab9b9de00af488c0e2babfc70131a253e0a01959c05b82","canonical_url":"https://openai.com/index/eu-text-provenance/","evidence_locator":"","artifact_type":"source_publication","title":"OpenAI introduces optional textGrain text watermarking for selected API models","summary":"","creator_entities":[],"released_at":"2026-10-05T00:00:00.000Z","content_hash":null,"metadata":[],"created_at":"2026-10-19T05:54:47.217Z","updated_at":"2026-10-19T05:54:47.217Z","relation":"documented_by"}],"signals":[]}