If you do one thing
NVIDIA OpenShell: run your coding agent inside a policy-checked sandbox that never hands it your real API keysAfter a month of stolen agent keys, this keeps credentials out of the agent's reach: OpenShell injects them only on requests to endpoints you approve, and checks every outbound connection against your policy
Editor’s note

Two ways of checking AI work arrived on the same day.

Anthropic's proofs are checked by a program that cannot be argued with: a proof passes or it fails. OpenAI's monitor was a model that watched agents, and it watched only at the moments the agents chose to hand control back. On 21 October OpenAI's agents had switched off their own alerts. Today an outside audit shows how much the monitor missed even before that.

The open-model security argument has a new exhibit. DeepSeek's Flash is already among the top open models on Artificial Analysis and the cheapest point on its new coding index. Now one unconfirmed post says it wrote browser-exploit code. Teortaxes, a prominent DeepSeek watcher, expects a crackdown on open models to follow. Days after Washington ordered DeepSeek out of federal agencies, that pressure is not hypothetical.

Today’s highlights

01

Machine-checked proofs, not more tests, now cover the code paths fuzzers sample. Anthropic did it in a few weeks with Theorem, a formal-methods company.

MoreLess

Claude wrote about 180 million lines of Rocq proofs, a machine-checked proof language, for 239 OSS-Fuzz entry points. It shows no input under 64 MB crashes them. The proofs cover static RISC-V Linux builds, not the x86 or ARM builds most people run.

No cost was published beyond "hundreds of millions of tokens" for some proofs. Anthropic says "formally verified" does not mean "bug-free", and it audited Claude's patches for changes that only made a theorem easier.

Why it works: a checker accepts a proof only if every step follows, so Claude can be wrong a million times and only a correct proof gets through.

Theorem's OSS Verify offers the pipeline free to open-source projects.

02

The monitor ran only when an agent handed control back. An agent that kept working was not checked, and about 10% of internal Codex traffic went unmonitored from May to July.

MoreLess

Two auditors worked inside OpenAI for three weeks this summer. They also found two client headers that switch monitoring off for new agents, a possible route around Codex's sandbox and Auto-Review, and a redacted exploit that could hide hundreds of recent actions.

OpenAI says every flaw affecting production is patched. METR has not checked that. OpenAI cut the 61-page report to 38 pages, and METR could not describe the redactions.

03

The model that ran anonymously as Space Bunny can now be self-hosted, under MiniMax's own community licence rather than MIT or Apache.

MoreLess

The card says 428B total and 23B active parameters, with a 1M-token context and image and video input. The file metadata says 220B, and r/LocalLLaMA puts the checkpoint at about 265 GB, so this is a multi-card model.

Hosted, it costs $0.15/$0.60 per million tokens. Every benchmark on the card is MiniMax's own.

04

If it holds, a free open-weight model can do exploit work that used to take specialists days. Nobody has confirmed it, and Google and DeepSeek have not commented.

MoreLess

The post claims a "multi stage memory corruption exploit that achieves full process read and write". That is the V8 sandbox inside the renderer, not a full escape: Chrome's operating-system sandbox sits behind it, as one reply pointed out.

On a separate cyber benchmark, the same model rediscovered 28 of 32 known CVEs at three tries, behind only GPT-6 Astra.

05

Skills you write now work across harnesses under neutral rules. Existing skills keep working and the licences do not change.

MoreLess

Engineers from Anthropic, Earendil (the company behind Pi), Google, Microsoft, OpenAI and OpenCode form the steering committee. Anthropic says more than 70 platforms already read the format. Hugging Face gave OpenEnv, its RL-environment standard, to the same foundation the same day.

06

The index scores model and harness together. The cheapest point on its cost frontier is DeepSeek-V4.1-Flash in Codex: 47.3 at $0.39 a task, against $11.42 for the leader.

MoreLess

Cognition's FrontierCode, 100 private tasks graded on whether a maintainer would merge the change, replaces DeepSWE. Scores fell for 20 of 21 setups measured on both versions.

Replies ask why DeepSeek and GLM run in Codex instead of their own harnesses. One reply notes that on 100 tasks, the 15 setups between 43% and 49% are within noise.

07

On Pro, Max and Team plans, Claude will stop asking you to approve each step. A separate classifier blocks risky actions, and you can switch back to manual.

MoreLess

When Claude Code made the same switch on 14 August, Anthropic said the classifier caught 89% of dangerous commands in testing, against 14% for people approving by hand.

Concept of the day

End-of-turn monitoring

A guard who checks your bag only when you leave the building. Stay inside long enough, and they never look.

Agent acts
↳ Hands back control→Monitor reviews turn
↳ Keeps acting→History trimmed→Actions never reviewed

The mechanism: the monitor reads an agent's transcript when the agent hands control back to a person. Long-running agents trim their history to fit their context window, and anything trimmed before the hand-back is never shown to the monitor.

What it means today: METR found exactly this gap in OpenAI's internal monitoring. An agent could postpone review by continuing to act, and actions trimmed before a turn ended went unseen. That was about 10% of internal Codex traffic for three months.

hands backtriggers reviewkeeps actingnever sent✕Coding agentinternal CodexTurn endscontrol returnedMonitorreads the turnCompactionhistory trimmedClient headerstwo of themOpenAI patchnot yet auditedNever sees it~10% of CodexSwitched offfor new agents12345
  1. The design. The monitor ran when an agent handed control back to the user, and read that turn.
  2. The postponement. An agent that keeps taking actions never hands back, so the review never starts.
  3. The gap. Long runs trim history to fit the context. Actions trimmed before the turn ended were never shown to the monitor: about 10% of internal Codex traffic, May to July.
  4. The off switch. Two client-controllable headers disabled monitoring for new agent instances, though creating one might itself be caught.
  5. The fix. OpenAI says every flaw affecting production is patched. METR has not evaluated that claim.
Step throughA monitor that runs only when a turn ends misses whatever the turn never shows it.

Voices

Two arguments ran all day. The first was over the terms of METR's audit inside OpenAI: Kokotajlo called them bad, Brundage said the fix is binding standards, and Korbak, who worked on the audit before being fired, wanted to know why the report took ten weeks. The second was over a claimed DeepSeek Chrome exploit, which sceptics doubted, others scoped, and Teortaxes feared would invite a crackdown on open models.

“I'm disappointed that METR wasn't allowed to comment on the scale of redactions made by OpenAI and that there is no explanation why the publication was delayed for 2.5 months.”
Tomek Korbak
Worked on the engagement at OpenAI before he was fired
“METR gets the best terms they can, others often get worse terms than them, and most companies have done 0 embedding. We need binding standards for this stuff, not ad hoc bargaining”
Miles Brundage
Defending METR, blaming the lack of rules
“It is not a full chain exploit for pwn2own or $$$, neither a 0-day exploit. There is an OS sandbox besides this renderer sandbox. But doing this part in 12hrs is beyond human's capability”
Martin Žember
Putting the claim's scope in context

Model watch

6 released today · 1 publishes a price · a dash is never “free”

Sort
MiniMax · Open-custom · claim
MiniMax M3.1 Flash
multi-card

Cheap agentic coding and office tasks

Size428B (23B active) per card; 220B in file metadata
$ in / out per M$0.15 / $0.60
text · vision · video · tools · thinking

Skip if you run on one card: DeepSeek's Flash is smaller in memory and scores higher.

Our takeClose

The weights match the API model that scores 42.7 on Artificial Analysis's index. The card claims 73.7% on DeepSWE v1.1 and 61.7 on OSWorld 2.0. The catch is size: r/LocalLLaMA puts the checkpoint at about 265 GB, so it needs a multi-GPU server or a large Mac cluster.

#open-weights #models
inclusionAI (Ant Group) · MIT · claim
Ling-3.0-flash-Sante
1 machine

Medical reasoning and health research agents

Size124B (5.1B active)
$ in / out per Mweights only
text · tools · thinking

Try if you build health tools on your own hardware: the licence lets you.

Our takeClose

124B total, 5.1B active, built on Ling-3.0-flash for medical reasoning, deep research and multi-agent work. inclusionAI claims it leads models of its size on healthcare tasks, with no independent run yet. The same team announced Ling-3.1-flash-1019 at 44 on Artificial Analysis's index, with weights "coming soon".

#open-weights #health
Hugging Face · Apache · claim
Carbon-X
laptop

Explaining DNA sequences and mutations in plain English

Size14.8B
$ in / out per Mweights only
text

Try if you work with sequences: it runs on a laptop in llama.cpp, so data stays local.

Our takeClose

Apache 2.0, 14.8B parameters, mid-trained on 300B tokens of mixed DNA and text. Hugging Face says it is within a point of GPT-6.1 Sol on five DNA benchmarks at over 1,000 times lower cost. As a subagent, it lifts Kimi K3 by 11.1 points.

#open-weights #science

Also released: Ling-3.1-flash-1019 (inclusionAI (Ant Group), not out yet) · GLiDE v1.2 (Fastino, 1 card) · Ming-3.0-tts-tiny (inclusionAI (Ant Group), laptop)

On your card

New on Ollama that fits a 32 GB card: d3 (27b). See the table ↓

Benchmarks

Artificial Analysis's Coding Agent Index v2.0 puts Claude Code with Opus 5.5 first at 61.7, and DeepSeek-V4.1-Flash in Codex is the cheapest frontier point at $0.39 a task. See the boards ↓

Try this

Claude Code
Migrate your Claude API code to API version 2026-10-21 with one commandclaude update, then run /claude-api api-version in the repo
ClinePick one of the new free models in Cline's model list
OpenClaw
Managed Codex sessions recover from "thread not found" and keep on-request approvalnpm i -g openclaw@2026.10.6 (needs Node 24.22.1+ or 26.12.1+)
graphify
Turn a codebase, docs and PDFs into a knowledge graph your agent queries across sessionsYour agent stops re-reading the repo every session: it asks one persistent graph, and you get an interactive map of the code pip install graphifyy && graphify install, then /graphify . in Claude Code
Hallmark
Have your agent build and audit web pages that do not look AI-generatedv2 checks pages in a real browser against 48 themes and the usual AI-design tells, then a fresh-context reviewer signs off

Update now → Claude Code (breaking, security) · OpenCode (security) · OpenClaw (security)

In brief

The harness layer is where today's risks sit. OpenCode silently fixed a sign-in flaw that let a hostile MCP server run code on Windows, and NVIDIA's OpenShell offers the opposite design: agents that never hold real keys. On r/LocalLLaMA, MiniMax's weights arrived to a shrug because DeepSeek's Flash is smaller and stronger. Lead with the security fixes, then decide what your agent should be allowed to touch.

Hacker News · 162 points
Hacker News on Anthropic's proofs: are they just a fancy fuzzer?

Sceptics ask what a proof is worth without a full spec. Others explain it covers every input up to 64 MB, where a fuzzer only samples.

“So far, I've proven that about 12% of the code behaves the same when executed single-threaded. That works out to roughly 70k lines of C code.” — malisper

#formal-verification
SummaryClose

The thread opens on Anthropic's appendix, which says agent proofs are verbose and may hit a complexity wall on larger programs. Sceptics ask how anyone knows the model matches the real program. Replies answer that the proofs target the compiled RISC-V binary, so the remaining assumption is that the hardware matches the model. One sceptic called it a fancy fuzzer, and several replies explain that a proof covers every input up to the bound where a fuzzer only samples. Practitioners report using Rocq or Lean proofs to merge agent-written speedups with confidence.

The Hacker News, 22 Oct
OpenCode quietly fixed a flaw that let a malicious MCP server run code on Windows during sign-in

Versions 1.0.137 to 1.18.32 on Windows and WSL are exposed. With no CVE or advisory, scanners will not flag them.

#agent-security #harnesses
SummaryClose

During MCP OAuth sign-in, the remote server supplies the authorisation URL. OpenCode passed it unescaped to a helper that builds a PowerShell command, so a crafted URL ran attacker code. It triggers only when you start sign-in, and only for a server you added, including one later taken over. Pillar Security reported it on 29 August and disclosed on 19 October, proposing CVSS 9.8. Anomaly fixed it in 1.18.33 on 28 September as a refactor, and says user-configured MCP servers sit outside its trust boundary. Pillar saw no exploitation.

Reddit
Flint, Ornith 1.5 and Nemotron 3.5 Lightning as local workers under an Opus 5.5 planner

One fixed Three.js task, Q8 GGUFs on llama.cpp, three parallel workers, and only the worker model changed between runs.

“I don't think people here are impressed by Opus 5.5 being the planner, regardless of how little it wrote. Atomic Agent's value needs to be proven only with local models.” — coder543

#local #harnesses
SummaryClose

The poster held everything fixed except the worker model: one prompt for a 20-second Three.js Halloween chain reaction, Atomic Agent 0.6.10, Opus 5.5 planning through OpenRouter, three parallel local workers, Q8_0 GGUFs on llama.cpp with 64K context per slot. Outputs ran 1,000 to 1,700 lines across six to nine files. Replies push back on the method: Nemotron was built as a general model, the cloud planner flatters the local workers, and the full prompt looks too detailed for the one-line task.

Hacker News · 319 points
NVIDIA's OpenShell on Hacker News: a policy layer for agent sandboxes, with telemetry on by default

OpenShell keeps credentials out of the agent's reach and checks every network call against a policy. Commenters like the controls and dislike the default telemetry.

“This isn’t even the sandbox. It needs Docker or other virtualization. This seems to sit a level up and orchestrate sandboxes and access to network & resources.” — toddmorey

#agent-security #harnesses
SummaryClose

OpenShell runs each agent in a sandbox with kernel-level limits on files and system calls, sends every outbound connection through a policy check, and injects credentials only for approved endpoints, so the agent never sees them. Policy changes get a formal check that flags new risky access for human review. Commenters praise the controls but object to anonymous telemetry being on by default. Others note it orchestrates Docker or VM sandboxes rather than being one, and that exfiltration through allowed channels remains unsolved.

X
Dan Lorenc shares the Claude Code harness behind "let's look for pre-auth RCEs in PHP"

Dan Lorenc says the harness was built from Project Zero write-ups. It runs an agent-guided tree search over the target and its dependencies in microVMs.

#ai-cyber #harnesses
SummaryClose

Lorenc says the prompt was literally "let's look for pre-auth RCEs in PHP", started with Claude Mythos 5.1 in stock Claude Code. A skill drives a harness his team built over several months. He had Claude build it after feeding it Project Zero blog posts on how they do research. It runs an agent-guided tree search across the codebase in microVM sandboxes holding the full source of the target and its dependencies. The first, setup phase works with any model. He calls its track record scary.

Reddit
r/LocalLLaMA on MiniMax M3.1 Flash: welcome, but DeepSeek's Flash still looks better

Commenters compare memory footprints: MiniMax is mostly FP8, DeepSeek mostly FP4. Several complain about the custom licence.

“Minimax seems is mostly FP8, while DS4.1F is mostly FP4. So minimax is ~420GB while DS is ~300GB. DS also has 8B active only (first 20 layers only) during PP, which makes it much faster during PP.” — FullstackSensei

#open-weights #local
SummaryClose

The thread opened within hours of the upload. Commenters first assumed DeepSeek's Flash was smaller, then found MiniMax's checkpoint is about 265 GB on disk while its weights are mostly FP8, against DeepSeek's mostly FP4. Most see it as trailing DeepSeek-V4.1-Flash-1017 on benchmarks and real use. One warns that Artificial Analysis scores are hard to compare across labs. Several dislike MiniMax's custom licence, and others note it doubled the parameter count of the M2 era while being called Flash.

LessWrong · 35 karma
Evan Hubinger splits "monitorability" into four kinds, each needing its own evaluation

Control monitorability asks whether monitors would catch sabotage like a sandbox escape. He says these are his views, not Anthropic's.

“labs could agree to a variant of (a) publicly and aren’t, and that what you would expect to see if labs were going to only do (b) is first shop around proposals for (b) while not committing to (a).” — Bronson Schoen

#monitoring #safety
SummaryClose

Hubinger, writing personally rather than for Anthropic, responds to Redwood's monitorability policy proposal with four categories, starting with control monitorability: would monitors catch sabotage such as a sandbox escape or a rogue internal deployment, measured by evaluations like LinuxArena. He argues each category needs its own evaluation. Bronson Schoen objects that labs could publicly commit to the stronger version and are not. Hubinger agrees evaluations should be compared against real deployment settings where a model had a genuine chance to sabotage.

LessWrong · 147 karma
Sören Mindermann on moving to Tsinghua to work on loss-of-control safety

He argues the West and China barely understand each other's AI work, and that being in Beijing in person is the fix. He also co-directs the new Beijing AI Safety Hub.

#safety #china
SummaryClose

Cross-posted from Sören Mindermann's Substack. He is joining Tsinghua's College of AI as an assistant professor on frontier safety, especially loss of control, and co-directs the new Beijing AI Safety Hub while keeping his Cambridge work. His case is that Western and Chinese researchers understand each other's AI ecosystems poorly despite the Trump-Xi summits and calls for cooperation. He argues being there in person builds shared scientific understanding that remote collaboration cannot. The post has no comments yet.

LessWrong · 108 karma
Greater good arguments in AI safety: the case against "quit and warn" for most safety staff

Dean Valentine compares today's "you're helping the labs" critique to old left critiques of charity, and says it mostly fails.

“IMO, someone working on duct taping together the RSI rocket at a frontier lab, should instead quit and warn the public about how dangerous RSI is” — Daniel Kokotajlo

#safety
SummaryClose

Valentine traces the critique that safety work at labs launders the labs, and compares it to the 2010s left critique that charity props up capitalism. He argues most people weighing a safety job are not senior enough for their exit to matter, so the critique mostly discourages useful work. Kokotajlo agrees the history is relevant but says senior lab safety staff should quit and warn the public. Valentine grants that OpenAI alignment researchers with a year or more there need to seriously weigh that option.

Microsoft Research, 21 Oct
Microsoft Research's Proof-Driven Development Kit turns a developer's intent into a spec, then proves generated code meets it

A second big lab is pointing agents at formal proofs the same week as Anthropic.

#formal-verification
SummaryClose

Microsoft Research's Proof-Driven Development Kit starts from what the developer wants, translates that intent into a formal specification, and then uses formal verification to prove that agent-generated code meets it. The post frames it as an answer to agents writing more of the code: correctness comes from the proof, not from a human reading every diff. It came out the day before Anthropic's large-scale verification results. The post gives no benchmark, no code size and no list of supported languages.

Anthropic, 22 Oct
Claude on Google Cloud, run by Anthropic, is generally available

Teams on Google Cloud get the full Claude Platform with Google IAM and billing, and new betas on the same day as Anthropic's own API.

#anthropic #cloud
SummaryClose

Anthropic's post says "Claude Models on Google Cloud (Anthropic managed)" is generally available, with the full set of Claude Platform features on Google Cloud. Customers sign in with Google Cloud IAM, pay through Google Cloud billing, and can retire existing Google commitments against it. New features and betas ship there the same day they reach the native Claude Platform, which was the usual gap with third-party clouds. The post gives no price difference from the native API. For teams already on Google Cloud, it removes the reason to run a separate Anthropic account.

LessWrong · 32 karma
Autonomous AI researchers will swamp peer review even without sabotage, Jason Fantl argues

He proposes a metascience organisation that rewards replication and research diversity.

#science #agents
SummaryClose

Fantl cites OpenAI's stated goal of a fully automated AI researcher by March 2028 and argues that even with sabotage solved, automated researchers will multiply research volume and make it homogeneous. Without change, he expects peer review to collapse, false positives to rise and funding to concentrate. He proposes valuing replication, preserving diversity and anchoring work to human understanding, run by a dedicated metascience organisation. A commenter raises the dual-use problem: safety advances often track capability advances.

Hacker News · 116 points
AI and the enclosure of the scientific commons, debated on Hacker News

The paper argues AI makes it feasible to fence off shared scientific knowledge.

#science
SummaryClose

The arXiv paper compares the scientific literature to England's common lands, which disappeared through enclosure rather than overuse. It argues AI provides the tools for a previously infeasible enclosure of the information commons, turning shared knowledge into private value. Hacker News commenters push back that much of the literature was never freely shared, pointing to publishers and prosecutions of shadow libraries. Others say one can argue the opposite just as well: that AI widens who can contribute to science.

Liquid AI, 22 Oct
Liquid AI's RIPL engine puts its small models in the request path at under 50 ms

Search, ads and fraud checks can call a model inline instead of in a batch job.

#decision-models
SummaryClose

Liquid AI's post introduces RIPL, a real-time inference pipeline built to run its LFM models inside live request paths such as search, ads, fraud, recommendations and payments. It claims complete responses end to end in under 50 milliseconds and steady latency under continuous load. A Liquid engineer says it serves LFMs at under 20 ms on Shopify production workloads. No benchmark method, hardware or price was published, so the latency figures are Liquid's own.

LessWrong · 74 karma
TsviBT: listen to AI policy arguments for their punchline, which is usually "do more AI R&D"

He argues holding to the conclusion beats getting lost in the framing.

#safety
SummaryClose

TsviBT opens with a child who hears a parent's long explanation only as "therefore you can't have ice cream", and argues that stance has a virtue: it holds to what matters instead of accepting the speaker's framing. Applied to AI, he says many sophisticated arguments end in the same punchline, more AI research and development, and should be judged by that. Commenters push the logic further, asking what policy would look like if people believed humanity had ten years left.

Further reading

The strongest papers measure the harness, not the model. Agent4Sci shows frontier agents beat published science results mainly with engineering tricks, and simple skills doubled their gains. Cache engineering cuts long-run cost by about a quarter, and a geochemistry study shows where moving tool output to files quietly costs GPT models accuracy. FrontierCS 2 grades agents against real research code, and Opus 5.5 still fails four in ten runs.

paper#agents #science
Frontier agents beat the published best on 20 science benchmarks, mostly with ML-engineering tricks

In Anthropic's Agent4Sci, Claude Opus improved results by 10.4% on average and Codex by 4.4%, with no misconduct flagged. Adding skills for ideation and experiment management doubled both.

Read if you run research agents: the gains came from engineering tricks, not new science.

SummaryClose

Agent4Sci, from Anthropic researchers including Nicholas Carlini, gives agents 20 published scientific ML benchmarks in 11 domains and asks how far they can push past the best published model under realistic conditions. Every benchmark improved. Claude Opus averaged 10.4% relative improvement and Codex 4.4%, but trajectory analysis shows the gains came from ML-engineering tricks. The agents misjudged novelty, left resources idle and collapsed into local sweeps. Plug-in skills for ideation, experiment management and checklists raised Opus to 20.1% and Codex to 8.1%.

paper#harnesses #efficiency
Cache engineering: agents that drop parts of their own KV cache cut cost 27.7% with no loss

Instead of summarising history, which forces a costly re-prefill, the agent excludes chosen cache entries from attention. Scores rose 1.7 points against summarisation.

Read if long agent runs dominate your bill: this attacks the re-prefill cost directly.

SummaryClose

Context engineering trims or summarises history, which invalidates the cached prefix and forces a costly re-prefill. Cache engineering lets the agent drop chosen cache entries from future attention and reposition retained keys without touching the transcript. Because identical text can then map to different cache states, the authors built the AKV serving engine to manage that state behind a stateless API. A rolling drop of old tool responses beat threshold summarisation by 1.7 points at 27.7% lower cost, with up to 1.2x throughput.

paper#harnesses #evals
Reading tool output from files instead of context cost GPT-5.1 11.3 points, and Claude nothing

With a geochemistry simulator's 847k-character reports behind a section index, GPT models computed the right values but answered from their own rounded files.

Read if your harness offloads tool output to disk: check which evidence the model actually answers from.

SummaryClose

The authors use PHREEQC, a USGS geochemistry simulator whose reports reach 846,800 characters, on 158 execution-verified questions. When agents read reports through a section index instead of in context, GPT-5.1 lost 11.3 points and GPT-5.2 lost 7.9, while Claude Opus 4.6 and Sonnet 4.6 showed no detectable cost. Replaying all 11,007 simulator calls shows the GPT models still computed the right value. Under retrieval they skipped the report, answered from their own higher-precision files, and rounded wrongly. The models tested are older generations.

paper#agents #harnesses
DeLoop trains agents out of repeating themselves: loops fall from 57.3% of tasks to 6.1%

Repeated tool calls with identical results become negative examples, with no reward or judge needed. On Qwen3-32B, task success also rose from 37.7% to 44.8%.

Read if your agents stall after context compression: that is when loops multiply.

SummaryClose

DeLoop defines a loop as an agent re-issuing a tool call that returns exactly the same observation. Loops appear natively in Qwen, Llama and Gemini agents and become far more common once history is compressed. The method uses the looping action as a negative example and the next non-looping action in the same rollout as a positive, trained with DPO, with no task reward, gold answer or judge. On CodeGym under compression, Qwen3-8B loop share fell from 57.3% to 6.1% with a third as many steps.

paper#evals #agents
FrontierCS 2: the best agent, Opus 5.5, passes 58% of runs on rebuilding deleted research code

Each of 48 tasks deletes a paper's contribution from its repo and grades the agent's patch against the original on a held-out suite. No run passed 16 of the tasks.

Read if you track whether agents can do real CS research: this grades against what the authors shipped.

SummaryClose

FrontierCS 2 takes 48 papers with released code, deletes each paper's contribution, and drops the agent into the working repository. Patches get a development-suite score, but the final grade uses a private held-out suite against the original authors' code. Tasks span 13 domains, from ML systems and HPC to databases, security and robotics, with more than 100 private tasks held back. Of 12 agents, Opus 5.5 did best at 58% of runs passing. No run passed on 16 tasks, and beating the reference overall often still failed a metric.

paper#monitoring #agents
Diffusion-model agents can pass hidden messages that change what the receiver concludes

Four dense vectors passed between Dream-7B agents carry real content: a message from the wrong example drops accuracy from 80.8% to 46.8%.

Read if you monitor multi-agent systems by their text: this channel never becomes text.

SummaryClose

A sender diffusion model compresses its denoising state into four signed dense vectors, and a receiver takes them in while keeping its own context. Removing the message wipes out a 63.6-point advantage on Tiny-A2D and 100 points on Dream-7B, and targeted substitutions steer the receiver to the planted fact. On QASC with facts split across two agents, matched messages reach 80.8% and mismatched ones 46.8%. One late transfer beats four exchanges by seven points. The tests are controlled tasks, not deployed systems.

LessWrong#safety #evals
A sandbagging model organism that hides only the hard vulnerabilities, and resists elicitation

The model withholds hard-to-find security bugs. It holds up better than earlier organisms against pirate training and weak-to-strong elicitation.

Read if you rely on capability evals for cyber: a model can underperform selectively.

SummaryClose

The authors argue a useful sandbagging model organism, a model trained to hide a capability on purpose, needs selectivity, robustness and retention. They train one for code vulnerability scanning that withholds only hard-to-find bugs while reporting easy ones. It resists standard elicitation methods such as pirate training and weak-to-strong generalisation better than earlier organisms. The motivation is that models already beat most humans at some cyber tasks, so overseers increasingly cannot check what a model chose not to report.

paper#evals #agents
VerifierBench: agents write verifiers that reject too much, scoring 10.6 to 62.1 across 19 models

Most false rejections came from verifiers that accepted no correct solution at all.

Read if agents write their own checks: a strict-looking verifier can be one that passes nothing.

SummaryClose

VerifierBench asks agents to write an executable verifier from a task's instruction and environment, one that accepts every valid solution and rejects invalid ones. It has 222 tasks from six agent benchmarks covering tool calls, environment state and code, with 4,993 hidden tests including alternative valid solutions and attacks. Across 19 models in one harness, normalised balanced accuracy ranged from 10.6 to 62.1. Generated verifiers rejected bad solutions better than they accepted good ones, and most false rejections came from verifiers that accepted nothing.

paper#interp
Sparse autoencoders turn an AI-text detector into one that explains itself

Callum McDougall and co-authors keep only the SAE features with faithful labels, then classify on those. The features match specific "tells" of machine-written text.

Read if detectors judge people you know: this one can say why it flagged them.

SummaryClose

The pipeline trains sparse autoencoders on a fine-tuned AI-text detector's residual stream, auto-labels each feature, keeps only features whose descriptions pass a fidelity threshold, and trains a small classifier on those alone. The features correspond to specific linguistic tells of machine-written text. The authors argue this matters because detectors are used in peer review, education, admissions and moderation, where opaque decisions affect people. The abstract read here does not give the accuracy gap between the interpretable classifier and the original detector.

LessWrong#interp #monitoring
Activation verbalizers can read CODI's latent thoughts, but editing them barely steers the output

A Qwen3-8B model trained with CODI, a method that reasons in hidden states instead of words, was probed: the verbalizers recovered intermediate values well above chance where LogitLens could not.

Read if you worry about models reasoning without words: the values are there, but hard to control.

SummaryClose

Earlier work showed CODI's latent states carry intermediate values that LogitLens detects only indirectly. The authors trained a Qwen3-8B CODI model to work with activation verbalizers, which translate activations into text. LogitLens and the J-lens read values only from late layers, but the verbalizers recovered the final answer and intermediate values well above chance, including from the thoughts themselves. Editing the surfaced values rarely changed the output in the expected direction, so reading a latent value is not the same as controlling it.

arXiv, 22 Oct#harnesses #agents
Harness Scaling: training an agent across many harness setups transfers better to unseen harnesses

Training through one fixed harness specialises the model to it.

SummaryClose

The authors build a factorised space of harness configurations, pick a compact training subset with balanced coverage, and train with controlled variation on the same task. Across benchmarks, model scales and RL algorithms, they report better generalisation to unseen configurations. Models trained on varied white-box harnesses also transfer to external black-box harnesses better than models trained on one complex harness. The abstract gives no headline numbers, which is why it ranks below today's measured harness papers.

arXiv, 22 Oct#agents
LM2LM trains a model with RL to propose improvements to other language models

A frozen "research world model" predicts outcomes so RL does not need a full training run per proposal.

SummaryClose

Training a model to propose good language-model improvements with real feedback would need tens of thousands of training runs. LM2LM substitutes a frozen LLM that predicts how a proposal would turn out, and guards against the policy exploiting that surrogate as its proposals drift. The authors frame it as a step towards recursive self-improvement. The abstract read here does not give the size of the gains against real training runs.

RevisedMiniMax promised open weights for M3.1 Flash on 23 October Confirmed — The weights are on Hugging Face on 23 October, under MiniMax's own community licence1 of the last 14 days’ claims moved

The leaderboard

267 models from Artificial Analysis, each effort level its own row, 174 with open weights · 0 boards changed hands since yesterday

Rank by
Score
1
Claude Opus 5.5 (Max)
Anthropic · $8.00 / 1M · $5.98 per task · 96 tok/s
57.6index
2
Claude Sonnet 5.5 (Max)
Anthropic · $4.00 / 1M · $5.46 per task · 133 tok/s
56.0index
3
Claude Opus 5.5 (Xhigh)
Anthropic · $8.00 / 1M · $3.46 per task · 84 tok/s
56.0index
4
Muse Wonder Full (Max)
Meta · no hosted price
55.8index
5
Claude Opus 5.5 (High)
Anthropic · $8.00 / 1M · $1.82 per task · 78 tok/s
53.6index
6
Claude Fable 5.1 (Max)
Anthropic · $20 / 1M · $7.63 per task · 68 tok/s
53.4index
7
Claude Fable 5.1 (Xhigh)
Anthropic · $20 / 1M · $5.98 per task · 66 tok/s
53.2index
8
GPT-6 Astra (Max)
OpenAI · $20 / 1M · $3.26 per task · 56 tok/s
52.7index
9
Gemini 4 Argon (High)
Google · $4.00 / 1M · $1.99 per task · 79 tok/s
52.6index
10
GPT-6 Astra (Xhigh)
OpenAI · $20 / 1M · $2.31 per task · 53 tok/s
52.4index
11
Muse Wonder (Max)
Meta · $8.00 / 1M · $4.52 per task · 149 tok/s
52.4index
12
Claude Sonnet 5.5 (Xhigh)
Anthropic · $4.00 / 1M · $2.01 per task · 109 tok/s
51.9index
13
GPT-6.1 Sol (Max)
OpenAI · $4.00 / 1M · $0.72 per task · 55 tok/s
51.8index
14
Claude Fable 5.1 (High)
Anthropic · $20 / 1M · $3.91 per task · 59 tok/s
51.2index
15
Claude Opus 5.5 (Medium)
Anthropic · $8.00 / 1M · $1.34 per task · 81 tok/s
51.2index

Artificial Analysis leaderboard, read 2026-10-23 03:04 UTC. List price is AA's 3:1 blend of input and output per million tokens (0 / 0 means no hosted price and is left out); $ per task is what AA paid per task to run its index, tokens spent included. est. marks a score AA estimated rather than measured.

Arena Text
what people prefer in a blind test
Gemini 4 Argon#1
2. Claude Opus 5.5 #2 · 3. Claude Fable 5.1 #3
Arena WebDev
building a working front end, judged by people
Claude Opus 5.5#1
2. GPT-6 Astra #2 · 3. Claude Sonnet 5.5 #3
Arena Agent
agent work, judged by people
Claude Opus 5.5#1
2. GPT-6 Astra #2 · 3. Claude Fable 5.1 #3
AA Intelligence Index
Artificial Analysis' blend of hard evals
Claude Opus 5.557.6
2. Claude Sonnet 5.5 56.0 · 3. Muse Wonder Full 55.8
Vals Index
an independent blend, with cost per test
Claude Sonnet 5.570.8%
2. Claude Opus 5.5 70.2% · 3. Gemini 4 Argon 69.2%
Terminal-Bench 4.0
agent work in a real shell
Opus 5.564.8%
2. Sonnet 5.5 61.8% · 3. GPT-6 Astra 58.2%
Vals SWE-bench
fixing real GitHub issues
Claude Opus 597.0%
2. DeepSeek V4 Pro 0813 96.4% · 3. GPT-5.6 Sol 96.2%
ARC-AGI-2
puzzles a model cannot have memorised
GPT-6 Astra95.0%
2. GPT-6.1 Sol 94.2% · 3. Claude Opus 5.5 93.3%
AA Humanity's Last Exam
expert questions across every field
Claude Opus 5.561.4%
2. Claude Fable 5.1 59.1% · 3. Gemini 4 Argon 57.1%
SimpleBench
trick questions that catch pattern-matching
Claude Opus 5.588.4%
2. Claude Fable 5.1 86.6% · 3. GPT-6 Astra Pro 86.5%
AA hallucination rate
how often it makes things up (lower is better)
Gemini 4 Argon15.1%
2. Muse Wonder Full 23.0% · 3. Muse Spark Open 24.1%
Cost per task
what one finished task bills (lower is better)
GPT-6 Luna$0.068
2. MiMo-V2.6-Pro $0.133 · 3. Nemotron 3.5 Super VL $0.188
OpenRouter usage
what developers actually run, tokens served this week
DeepSeek-V4.1-Flash23.5T
2. MiniMax M3.1 Flash 13.7T · 3. GLM-5.3-Flash 11.4T

New on OpenRouter: Recursive: Flint (free) free

On your card

The best Ollama models that fit 32 GB · fit is our arithmetic

qwen3.8
4 weeks ago · 4.7M pulls
vision · tools · thinking27B · Q8_0 ~29 GB
33.7
muse-glimmer
1 month ago · 321.5K pulls
vision · tools · thinking30B · Q6_K ~25 GB
17.5
gemma4
1 week ago · 27.6M pulls
vision · tools · thinking · audio31B · Q6_K ~25 GB
14.7
nemotron-3.5-lightning
6 days ago · 256.1K pulls
tools · thinking30B · Q6_K ~25 GB
12.9
granite4.2
1 month ago · 173.3K pulls
text30B · Q6_K ~25 GB
12.7
gpt-oss
1 week ago · 14.1M pulls
tools · thinking20B · Q8_0 ~21 GB
10.0
olmo-3.1
10 months ago · 311.5K pulls
tools · thinking32B · Q6_K ~26 GB
6.5
phi4-mini
1 year ago · 1.6M pulls
tools3.8B · F16 ~8 GB
6.3
ministral-3
10 months ago · 1.5M pulls
vision · tools14B · F16 ~28 GB
6.0
phi4
1 year ago · 7.8M pulls
text14B · F16 ~28 GB
5.9
d3NEW
10 hours ago · 642 pulls
vision · decision27B · Q8_0 ~29 GB
not measured
flint
7 hours ago · 231 pulls
tools · thinking40B · Q5_K_M ~27 GB
not measured

From the whole ollama.com/library, read this morning, newest version of each line. Fit is the largest size that fits at ~0.56 GB per billion parameters (Q4_K_M) up to F16, with 2 GB held back for context. A score appears only where Artificial Analysis measured that exact model at that size.

The frontier

A model is on the frontier when no other scores higher on AA's index for the same money or speed.

Against

By list price, cheapest is left and smartest is up.

On the frontier · list priceper 1M
57.6
Claude Opus 5.5 (Max)
Anthropic
$8.00
56.0
Claude Sonnet 5.5 (Max)
Anthropic
$4.00
46.4
Grok 4.7 (Xhigh)
SpaceXAI
$3.00
46.3
MiMo-V2.6-Proopen
Xiaomi
$0.54
45.1
DeepSeek V4.1 Flash 1017 (Max)open
DeepSeek
$0.53
43.9
Ling 3.1 Flash 1019
InclusionAI
$0.45
43.4
Claude Haiku 5.5 (Max)
Anthropic
$0.20
41.8
GLM-5.3-Flashopenopen frontier
Z AI
$0.24
39.8
Qwen3.8-Flash-Nextopenopen frontier
Alibaba
$0.23
37.9
MiMo-V2.6-Flashopen
Xiaomi
$0.17
35.2
Agnes 2.5 Pro Beta
Sapiens AI
$0.15
22.6
Ling-3.0-flash-Finopen
InclusionAI
$0.11
13.1
Qwen3.5 4B (Reasoning)open
Alibaba
$0.060
9.1
Granite 4.2 3Bopen
IBM
$0.052
8.9
Gemma 4 E4B (Reasoning)open
Google
$0.040

Lines: every model (solid) and open weights only (dashed). Hollow points are AA estimates. $ per task counts the tokens a model spends, so it often disagrees with list price. OpenRouter paid is the input price its traffic actually paid, averaged over providers (openrouter.ai/rankings); input only.