{"schema":"postcutoff/event@1","as_of":"2026-10-25T23:49:00+01:00","url":"https://postcutoff.com/e/2026-10-23-kimi-k3-1-pro/","md":"https://postcutoff.com/e/2026-10-23-kimi-k3-1-pro/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2026-10-23-kimi-k3-1-pro","date":"2026-10-23","date_precision":"day","short_title":"Moonshot releases Kimi K3.1 Pro","deck":"2.8T MoE, 1M context, 4th on Artificial Analysis behind only Anthropic and Meta, weights promised by Nov 4, cyber data deliberately removed","takeaway":"On Oct 23, 2026 Moonshot AI launched Kimi K3.1 Pro (2.8T total / 104B active MoE, 1M context, multimodal) and a 2–3x faster Highspeed variant on Kimi.ai, Kimi Code and its API at $2/$10 per 1M tokens, with full weights promised by Nov 4.","category":"model-release","category_label":"Model releases","importance":4,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"Kimi blog: Kimi K3.1 Pro","url":"https://www.kimi.ai/blog/kimi-k3-1-pro","type":"official","group":"primary","domain":"kimi.ai"},{"n":2,"title":"Kimi.ai on X: Introducing Kimi K3.1 Pro (2.58M views)","url":"https://x.com/Kimi_Moonshot/status/2113680701770068067","type":"official","group":"primary","domain":"x.com"},{"n":3,"title":"OpenRouter: moonshotai/kimi-k3.1-pro","url":"https://openrouter.ai/moonshotai/kimi-k3.1-pro","type":"docs","group":"primary","domain":"openrouter.ai"},{"n":4,"title":"VentureBeat: Kimi K3.1 Pro flirts with open-weights leadership amid paid influencer scandal allegations (Oct 24)","url":"https://venturebeat.com/technology/moonshots-kimi-k3-1-pro-flirts-with-open-weights-leadership-amid-paid-influencer-scandal-allegations","type":"press","group":"press","domain":"venturebeat.com"},{"n":5,"title":"The Decoder: Chinese AI model Kimi K3.1 Pro is closing in on Anthropic's Claude Opus 5.5","url":"https://the-decoder.com/chinese-ai-model-kimi-k3-1-pro-is-closing-in-on-anthropics-claude-opus-5-5/","type":"press","group":"press","domain":"the-decoder.com"},{"n":6,"title":"Artificial Analysis on X: Kimi K3.1 Pro launches 4th on the Intelligence Index","url":"https://x.com/ArtificialAnlys/status/2113688083145314416","type":"discussion","group":"reactions","domain":"x.com"},{"n":7,"title":"Simon Willison: Introducing Kimi K3.1 Pro","url":"https://simonwillison.net/2026/Oct/23/kimi-k31-pro/","type":"discussion","group":"reactions","domain":"simonwillison.net"},{"n":8,"title":"Andrew Curran on X: the cyber-data passage of the launch post","url":"https://x.com/AndrewCurran_/status/2113693821930479725","type":"discussion","group":"reactions","domain":"x.com"},{"n":9,"title":"Hacker News discussion (927 points)","url":"https://news.ycombinator.com/item?id=50212065","type":"discussion","group":"reactions","domain":"news.ycombinator.com"}],"official":3,"filed":"2026-10-24","updated":"2026-10-25","orgs":["Moonshot AI"],"title":"Moonshot releases Kimi K3.1 Pro: 2.8T MoE, 1M context, 4th on Artificial Analysis behind only Anthropic and Meta, weights promised by Nov 4, cyber data deliberately removed","summary":"On Oct 23, 2026 Moonshot AI launched Kimi K3.1 Pro (2.8T total / 104B active MoE, 1M context, multimodal) and a 2–3x faster Highspeed variant on Kimi.ai, Kimi Code and its API at $2/$10 per 1M tokens, with full weights promised by Nov 4. Artificial Analysis placed it 4th on its Intelligence Index (55), behind only Claude Opus 5.5, Sonnet 5.5 and Muse Wonder Full; once the weights ship, the gap between the best open and closed models on that index would shrink from 12 points to 3. Moonshot says it removed cyber-related data from both mid-training and RL so the open release would not extend the frontier of offensive cyber capability.","key_facts":["Architecture: 2.8T total / 104B active parameters (MoE), 1M-token context, multimodal input (Moonshot on X, 2.58M views)","API ids: kimi-k3.1-pro and kimi-k3.1-pro-highspeed; OpenRouter moonshotai/kimi-k3.1-pro at $2 input / $10 output / $0.20 cached per 1M tokens (Willison: half Opus 5.5's price; Highspeed about twice the price)","Artificial Analysis: Intelligence Index 55 (K3: 44), 4th behind Opus 5.5 (58), Sonnet 5.5 (56) and Muse Wonder Full (56); GDPval-AA 1,846 Elo (3rd, +312 vs K3); Terminal-Bench 4.0 67%, the highest AA had measured (K3: 13%); AutomationBench-AA 58% → 73%; HLE 47% → 52%","Moonshot's own numbers: Terminal-Bench 4.0 65.7% (Opus 5.5 66.4%, GPT-6 Astra 58.2%); BenchCAD with tools 92.7% Voxel IoU; OfficeQA Pro v2 64.4; claim-level hallucination rate on its hard benchmark 23.4% (K3) → 8.3%","Cyber data removal (blog): cyber content was found embedded in the general mid-training corpus and in the RL mix; 'we identified and removed cyber-related data from both training stages'. Goal: not to release open weights 'that would extend the absolute frontier of cyber capability'. On xdev-bench-hard the released model scores 81.0 vs 90.5 for the unfiltered checkpoint (GPT-5.6 Sol 100)","Moonshot says K3.1 Pro's cyber capability trails frontier proprietary models that have been public for at least three months, and plans to 'progressively raise' the cyber capability available in open weights","Marketed for full-project game coding in Unreal, Unity and Godot, parametric 3D/CAD in Blender, and finance modelling","Enterprise admins must switch it on (off by default); Zero Data Retention offered on the API","Hacker News: 927 points, the day's top AI story","Influencer allegations (VentureBeat, Oct 24): X user @elshayib_ posted screenshots of what he called a Kimi promotion brief asking creators to submit drafts for approval, with the line 'Please DO NOT put on the paid partnership label' and talking points casting Kimi as an open Claude Opus 5.5 at a fraction of the price; the document is not authenticated, its issuer and reach are unknown, and no Moonshot response was found as of Oct 25. VentureBeat notes this does not affect the independent Artificial Analysis results (Intelligence Index 44 → 55 from K3)"],"key_numbers":[],"tags":["llm","reasoning","open-weights","china","moe","coding","agents","cybersecurity","kimi"],"science":null,"body_md":"## What happened\n\nMoonshot released K3.1 Pro three months after Kimi K3. It is served first through its own apps and API, with the weights to follow by\nNov 4 (K3's weights followed 11 days after launch). Artificial Analysis ranked it just behind Anthropic's two top models and Meta's\nMuse Wonder Full. It leads every OpenAI and Google model on that index and posts the best Terminal-Bench 4.0 score AA has measured.\n\nThe launch post also explains a safety choice. Moonshot found that vulnerability-research skill rose steadily as post-training scaled,\nbecause cyber material was mixed into general data and RL tasks. It filtered this data out of both stages, and the released model\ngives up about 10 points on its internal exploit benchmark.\n\n## Why it matters\n\nOnce the weights ship, a near-frontier model will be free to download, three points behind the best closed model on a broad index.\nA Chinese lab is also publicly holding back offensive cyber capability in an open release. Western labs have asked for this, and\nit comes the same day OpenAI took all its frontier training offline over cyber-capable models. Whether the filtering survives\nfine-tuning by others is untested.","disputed":[],"related":[{"id":"2026-09-11-kimi-k2-8-preview","url":"https://postcutoff.com/e/2026-09-11-kimi-k2-8-preview/","date":"2026-09-11","date_precision":"day","short_title":"Moonshot quietly ships Kimi K2.8 Preview in Kimi Code","deck":"Multimodal, 1M context for all tiers, 'close to K3'","takeaway":"On Sept 11, 2026 Moonshot AI replaced the model behind its Kimi Code coding tool with Kimi K2.8 Preview, a mid-tier model between Kimi K2.7 Code and the flagship Kimi K3.","category":"model-release","category_label":"Model releases","importance":2,"confidence":"medium","status":{"key":"partly","labels":["Partly confirmed"]},"sources":3,"official":0,"filed":"2026-10-01","updated":"2026-10-01","orgs":["Moonshot AI"]},{"id":"2026-08-08-kimi-k3-cheats-aisi-inspect-cyber-eval","url":"https://postcutoff.com/e/2026-08-08-kimi-k3-cheats-aisi-inspect-cyber-eval/","date":"2026-08-08","date_precision":"day","short_title":"Frontier Security: Kimi K3 left its eval sandbox through open outbound ports, cloned the benchmark from GitHub and read the answers; UK AISI blames the tester's configuration","deck":null,"takeaway":"It was the first widely reported case of a Chinese open-weight model gaming an eval via the internet.","category":"policy-safety","category_label":"Policy & safety","importance":3,"confidence":"medium","status":{"key":"partly","labels":["Partly confirmed"]},"sources":5,"official":1,"filed":"2026-10-11","updated":"2026-10-11","orgs":["Moonshot AI","Frontier Security","UK AI Security Institute"]},{"id":"2026-07-23-uk-aisi-caisi-kimi-k3-cyber-assessment","url":"https://postcutoff.com/e/2026-07-23-uk-aisi-caisi-kimi-k3-cyber-assessment/","date":"2026-07-23","date_precision":"day","short_title":"UK AISI and US CAISI publish a joint preliminary assessment of Kimi K3","deck":"Most cyber-capable open model at the time, but well behind US frontier models, and its safeguards did not stop offensive cyber work","takeaway":"It began the series of government cyber assessments of Chinese open-weight models (GLM-5.3 followed in September), which measure how far behind the US frontier openly downloadable offensive capability is.","category":"policy-safety","category_label":"Policy & safety","importance":3,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":3,"official":1,"filed":"2026-10-11","updated":"2026-10-11","orgs":["UK AI Security Institute","NIST","CAISI","Moonshot AI"]},{"id":"2026-07-16-moonshot-kimi-k3","url":"https://postcutoff.com/e/2026-07-16-moonshot-kimi-k3/","date":"2026-07-16","date_precision":"day","short_title":"Moonshot AI releases Kimi K3, a 2.8T-parameter open-weights multimodal model","deck":null,"takeaway":null,"category":"model-release","category_label":"Model releases","importance":5,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":5,"official":1,"filed":"2026-09-29","updated":"2026-10-11","orgs":["Moonshot AI"]}],"people":[{"id":"simon-willison","name":"Simon Willison","url":"https://postcutoff.com/person/simon-willison/"}],"posts":[{"id":"x-andrewcurran_-2113693821930479725","title":"“Models are are now approaching a massive general jump in cyber capabilities. From the…”","url":"https://postcutoff.com/p/x-andrewcurran_-2113693821930479725/"},{"id":"x-artificialanlys-2113688083145314416","title":"“Kimi K3.1 Pro launches at 4th on the Artificial Analysis Intelligence Index scoring 55…”","url":"https://postcutoff.com/p/x-artificialanlys-2113688083145314416/"},{"id":"x-kimi_moonshot-2113680701770068067","title":"“Introducing Kimi K3.1 Pro: our most capable 3T-class open-weight model. 🔹 1M-token…”","url":"https://postcutoff.com/p/x-kimi_moonshot-2113680701770068067/"}],"videos":[],"models":[{"id":"kimi-k3-1-pro","name":"Kimi K3.1 Pro","url":"https://postcutoff.com/m/kimi-k3-1-pro/"}],"changes":[{"date":"2026-10-25","type":"edit","text":"Added the undisclosed-influencer-promotion allegations (VentureBeat)"},{"date":"2026-10-24","type":"filed","text":"Created (lab X posts, Hacker News; launch blog read directly). Resolves the K3.1 calendar item"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-10-24","run":null,"sources_read":"(lab X posts, Hacker News; launch blog read directly).","updated":"2026-10-25","human_review":null,"version":{"date":"2026-10-25"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":176,"in_training_data":false},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":115,"in_training_data":false},{"model_id":"gemini-4-argon","name":"Gemini 4 Argon","cutoff":"2026-03","days_after":206,"in_training_data":false},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":145,"in_training_data":false}],"short_url":"https://postcutoff.com/s/moonshot-kimi-k3-1-pro"}