{"type":"post","id":"the-model-checked-its-own-plan-writing-and-c98cff","slug":"the-model-checked-its-own-plan-writing-and-c98cff","title":"The model checked its own plan, writing and running code to confirm, atom by atom, that each compound followed from its starting materials.","description":"Anthropic tested three Claude versions on four unpublished synthesis targets shared by chemists at Stanford, Yale, and Caltech.","retrieval_nugget":"Anthropic tested three Claude versions on four unpublished synthesis targets shared by chemists at Stanford, Yale, and Caltech. The models produced 12 complete proposed routes, which the professors reviewed blind; none has been run in a laboratory. The result suggests useful early-stage planning, but not experimentally validated chemistry.","published_at":"2026-11-09","updated_at":"2026-11-09","record_date":"2026-11-09","date_kind":"published_at","topics":["claude","anthropic"],"entities":["Anthropic","Claude Opus 5.5","Claude Mythos 5.2","Claude Mythos 5.1","Noah Burns","Timothy Newhouse","Sarah Reisman"],"related_patterns":["scientific-agents-need-artifact-evidence"],"novelty_label":"new_fact","what_changed":"Anthropic reports blind tests in which three Claude models planned routes for four unpublished synthesis targets, with chemistry professors assessing the proposals against their lab work.","prior_refs":["https://newruntime.com/posts/agentic-cheminformatics-with-google-antigravity-da8ea6/"],"source_url":"https://www-cdn.anthropic.com/d9fab5459563a779c65b97040ad4d2e41f0b9464.pdf","source_urls":["https://www-cdn.anthropic.com/d9fab5459563a779c65b97040ad4d2e41f0b9464.pdf"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:the-model-checked-its-own-plan-writing-and-c98cff","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/the-model-checked-its-own-plan-writing-and-c98cff/","markdown":"https://newruntime.com/posts/the-model-checked-its-own-plan-writing-and-c98cff.md","json":"https://newruntime.com/posts/the-model-checked-its-own-plan-writing-and-c98cff.json"},"markdown_url":"https://newruntime.com/posts/the-model-checked-its-own-plan-writing-and-c98cff.md","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":"topic","path":"/topics/anthropic/","url":"https://newruntime.com/topics/anthropic/","title":"Anthropic","reason":"Explore the anthropic topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/anthropic.md","json_url":"https://newruntime.com/topics/anthropic.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":"/sources/","url":"https://newruntime.com/sources/","title":"Sources","reason":"See the original sources this archive cites.","media_type":"text/html"}]}