{"type":"post","id":"how-does-fable-5-1-hide-messages-in-5226a9","slug":"how-does-fable-5-1-hide-messages-in-5226a9","title":"How does Fable 5.1 hide messages in images? (15 minute read)","description":"A LessWrong post reports an experiment in which Claude Fable 5.1 was asked to hide specified short messages in SVG images.","retrieval_nugget":"A LessWrong post reports an experiment in which Claude Fable 5.1 was asked to hide specified short messages in SVG images.","published_at":"2026-10-22","updated_at":"2026-10-22","record_date":"2026-10-22","date_kind":"published_at","topics":["claude"],"entities":["Claude Fable 5.1","GPT-6 Astra","LessWrong","Nikita Kezin","James Chua"],"related_patterns":[],"novelty_label":"new_fact","what_changed":"Adds analysis of how Claude Fable 5.1 hides messages in images, including encoding methods, screenshot survival, and a comparison with GPT-6 Astra.","prior_refs":["memory:109f3241-babe-84e8-a426-084ab241502f"],"source_url":"https://www.lesswrong.com/posts/WHEQps5PK8LrrcTAb/how-does-fable-5-1-hide-messages-in-images","source_urls":["https://www.lesswrong.com/posts/WHEQps5PK8LrrcTAb/how-does-fable-5-1-hide-messages-in-images"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:how-does-fable-5-1-hide-messages-in-5226a9","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/how-does-fable-5-1-hide-messages-in-5226a9/","markdown":"https://newruntime.com/posts/how-does-fable-5-1-hide-messages-in-5226a9.md","json":"https://newruntime.com/posts/how-does-fable-5-1-hide-messages-in-5226a9.json"},"next_reads":[{"type":"topic","path":"/topics/claude/","url":"https://newruntime.com/topics/claude/","title":"Claude","reason":"Explore the claude topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/claude.md","json_url":"https://newruntime.com/topics/claude.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}