AI News, Week of November 2: Gemini 4 Carbon Tops the Index, Mistral Large 4 Opens Its Weights, Claude Max 20x Becomes Ultra

This issue covers October 26 to November 2, 2026. Three themes ran through the week: a frontier model that most people cannot use yet, a trillion-parameter open-weight release, and a lot of plan and quota changes. Everything below links to a primary source on first mention. Where a number comes from a vendor, we say so.

TL;DR:

• Google announced Gemini 4 Carbon, which tops the Artificial Analysis index at 59, but access is limited to selected cyber defenders.
• Mistral opened the weights for Mistral Large 4 (about 1T parameters) at $0.70/$2.10 per million tokens on its API.
• Anthropic renamed Max 20x to Ultra and dropped the 5-hour limit for verified accounts, effective October 30.
• OpenAI will merge ChatGPT and Codex usage into one token quota starting in December.
• Cohere closed a $7B Series E at a proposed CAD $35.7B valuation.

Model Launches

Google Gemini 4 Carbon. Google announced Gemini 4 Carbon on October 28 as its strongest model for long-horizon engineering and cyber defense. It scores 59 on the Artificial Analysis Intelligence Index v5, ahead of Claude Opus 5.5 at 58 and GPT-6 Astra at 57. Cyber results: 88.2% on SEC-bench Pro, 54.8% on ExploitGym and 71.0% on CWE-bench. Intro pricing is $2/M input and $10/M output, with a 95% discount on cached input. The catch: it is in pre-release testing with the US government and trusted defenders through the Fairwind Program, and general availability has no confirmed date.

Gemini 4 Argon is the model you can actually use. Google calls it a frontier reasoning model rolled out globally for coding, financial analysis and legal work. Carbon arrived roughly two weeks after it.

Mistral Large 4. Mistral published the open weights for its multimodal mixture-of-experts model, nicknamed Le Chonk. The Hugging Face repo is named 1T-A52B, which points to about 52B active parameters. Mistral's own figures: 19.7% on FrontierCode 2.0, 41% on Terminal-Bench 4.0, 84.5% on BrowseComp and 48% on the Artificial Analysis Coding Agent Index, roughly tied with GLM-5.3 while using 47% fewer tokens per task. API pricing is $0.70 input, $0.07 cached, $2.10 output per million tokens. The license is a modified MIT: free to use and fine-tune, but anyone running it as a hosted service needs a separate commercial license. These are vendor-reported benchmarks. Third-party runs will matter more than the launch post.

OpenAI GPT-6.1 Terra. The rollout that began October 26 continued through the week. GPT-6.1 Terra lists at $1/M input, $0.05/M cached input and $5/M output, and scores 51 on the new Artificial Analysis index. It is available in the API as gpt-6.1-terra, in ChatGPT Work and in Codex, but not in the standard Chat tab. We covered the launch in last week's issue; the new fact is that independent index numbers are now in.

Smaller drops worth a look:

• Nvidia released Nemotron 3.5 Transcribe, an open-weight speech model covering 40 languages and recordings up to one hour.
• Liquid AI shipped LFM3, six compact models built on a 1.7B foundation for browser automation, voice and image recognition.
• Google released EmbeddingGemma 2, a 740M-parameter open embedding model that maps text, code, images, video and audio into one space and cuts local vector storage by up to 6x.
• Google DeepMind introduced Genie 4, a world model that generates real-time interactive environments with native audio. Rollout starts with trusted testers, then Google AI Ultra subscribers and selected API partners.

The leaderboard changed too. Artificial Analysis published Intelligence Index v5. It uses 9 benchmarks, adds FrontierCode 2.0 and Terminal-Bench-Science, and draws 60% of scores from private or withheld tests. Under v5: Claude Fable 5.1 at 49, Kimi K3.1 Pro at 46, Gemini 3.8 Flash at 31. Older scores are not comparable, so do not mix v4 and v5 numbers in a table.

Product Updates

Claude Ultra. On October 30 Anthropic renamed Max 20x to Ultra, still $200/month. Per its Help Center page, Ultra carries 10x Pro's weekly usage, and verified accounts no longer hit a 5-hour limit. The weekly cap stays. The old $100 plan is now just Max and keeps its 5-hour limit. Anthropic is also deprecating Opus 4.8 fast mode on November 30, so anyone using it should move to Opus 5.5. Note the naming trap: "20x" disappeared from the label, and the weekly multiplier is 10x, not 20x.

Claude API usage analytics. Anthropic's Usage and Cost Analytics API entered beta on October 29 for Console and Enterprise orgs. You can filter by model, workspace, API key and user or service account. The previous Usage and Cost API is legacy but still supported.

ChatGPT and Codex quotas. OpenAI announced on October 31 that Plus, Pro and Business plans will share one token-based quota across ChatGPT and Codex, effective December. Instant chats do not count. You can check the balance and reset time under Settings > Usage.

GitHub Copilot Fusion. GitHub launched Fusion on October 28. It routes coding tasks across several models. Artificial Analysis found Fusion Max close to the leading agents on performance at about half the per-task cost.

Gemini app and API. Gemini can now create, preview and revise files such as documents, PDFs, presentations, spreadsheets and code, for all users. On the developer side, Computer Use reached general availability on October 30 in the Interactions and GenerateContent APIs, per the Gemini API changelog.

Meta Muse. Meta brought Muse to Singapore on October 28 on iOS, Android and the web. It connects to Gmail, Google Calendar and Instagram, and asks for confirmation before sensitive actions like sending email or making purchases. It had already launched in the US, Canada and Japan.

Research & Papers

AI2 on LLM judges of novelty. The Allen Institute's novelty study found that LLM judges of research novelty are unstable. GPT-5.4 accuracy fell from 93.5% to 40.9% after a short prompt change. A search-enabled judge cost roughly 10x more without beating simpler methods. Why it matters: if you use an LLM to grade ideas, test prompt sensitivity before trusting the score.

OpenAI's unreleased model. OpenAI reported results in math, computer science and physics from a model it has not shipped, including a proposed refutation of the Exponential Time Hypothesis that was formalized in Lean. External experts have not reviewed it yet, so treat it as a claim, not a settled result.

Neuron steering. A new open-source explorer lets researchers inspect and edit individual neurons in Qwen3.5-4B. Reported steering experiments produced hostile outputs, which shows behavior can be shifted from inside the weights. It says nothing about intent.

Visual note: the most useful chart this week is the Artificial Analysis v5 leaderboard, which shows Gemini 4 Carbon at 59 against 58 for Opus 5.5 and 57 for GPT-6 Astra. We have not embedded a screenshot, so open the linked index page for the live chart.

Industry & Funding

Cohere. Cohere announced a Series E of $7B at a proposed CAD $35.7B valuation, pitched around secure and sovereign AI.

Anthropic's IPO path. Following the S-1 we covered last week, TechCrunch reports that credit agencies are expected to give Anthropic a double-B "junk" rating after the IPO. The filing showed $16.3B of H1 2026 revenue, $11.5B in Q2 and $974M of Q2 operating income. The headline $80.7B net loss is driven by noncash stock-grant adjustments.

Amazon. In its Q3 results, AWS grew over 39% year over year to a $184B run rate. Bedrock token volume rose nearly 17x. Trailing-twelve-month free cash flow was -$42.4B, which shows what the buildout costs. Separately, Google reported Cloud revenue up 103% alongside roughly $9B of negative cash flow.

Scraping opt-out standard. OpenAI, Google, Microsoft and Anthropic agreed on a shared "policy token" in robots.txt for AI training opt-outs. Anthropic has implemented it. Google and Microsoft plan to adopt it next year, and OpenAI in the coming months.

Deal and shutdown. Deepgram agreed to acquire Daily and its open-source Pipecat voice-agent framework. On the demand side, DoorDash said it has processed only several hundred orders from third-party AI agents, a useful check on agent-commerce hype. Privacy-focused assistant Ollie is shutting down.

Community Buzz

We could not retrieve live thread text from Reddit or X this week, because both block our fetch tools. So we are not quoting any individual commenter. What we can point to is where the conversation sits.

Open-weight discussion centers on whether a 1T-parameter model counts as "local" at all. Third-party guides put the official FP8 weights near 1,060 GB and the NVFP4 build near 610 GB. Follow the Mistral community at r/MistralAI and the company's X account for quantization and hardware reports as they come in.

On the Claude plan change, the argument is about wording. The official line is what Anthropic says in its announcement:

More of Claude's work now runs for hours in the background, and a 5-hour limit shouldn't stop it partway. So starting today, we're removing it from Ultra, in stages. — Anthropic, via its Ultra plan announcement, as quoted by The New Stack

Critics point out that only verified accounts benefit, that the weekly cap remains, and that no third party has measured what Ultra delivers in practice.

One more thread worth reading: an AI-assisted audit of 138 economics works from 2011 to 2026 reported 53 major alleged defects. Phil Magness argues on X that the serious errors skew one direction. The audit is contested, and we have not verified it ourselves.

The Writingmate Angle

Honest status: Gemini 4 Carbon is restricted, so you cannot try it in Writingmate or anywhere else outside the Fairwind Program today. Open-weight and API-available models are different. Model availability depends on what OpenRouter lists, so check the models page for current entries such as Gemini, Mistral and OpenAI families. Our suggestion for this week: run one real prompt of your own through the cheapest and the strongest models available and compare cost per usable answer. That tells you more than any index number. We have no confirmed Writingmate availability to announce for Mistral Large 4 or Copilot Fusion in this issue.