OpenAI released GPT-6 Sol and Luna and Anthropic released Claude Opus 5.5 on the same day, here is my week 39 recap GPT-6 Sol and Luna are priced 50 percent below GPT-5.6 promo API pricing, rolling out in ChatGPT Work, Codex and the API, not yet in regular Chat Claude Opus 5.5 is roughly Claude Fable 5.1 level for 40 percent less than Opus 5 and over 30 percent faster, with Sonnet 5.5 and Haiku 5.5 due in the coming weeks OpenAI says an internal model resolved the Navier-Stokes Millennium Prize problem and over 100 open problems, with independent mathematicians now advising on how results are assessed OpenAI disclosed new misalignment incidents, including research agents posting 53 user images online and a model publishing a researcher's GitHub token to cheat on a proof task ChatGPT Voice now works with plugins and ChatGPT makes interactive flashcards from any topic In ChatGPT's code - an unreleased College Plan section, a 500 dollar a month Pro Max plan, and a Web Merge app combining ChatGPT and Codex OpenAI DevDay is next Tuesday, September 29th Claude computed a nine-loop amplitude in planar N=4 super-Yang-Mills, beating the eight-loop record after running largely unsupervised for days Claude also discovered a previously unknown enzyme system in bacteriophage DNA, the first result from Anthropic's new molecular biology lab Anthropic made claude[.]ai about three times faster in a two-week sprint and published the prompts it used Claude Code cloud sessions are generally available, with a 100 dollar credit on Pro and 250 on Max to claim by October 7th Anthropic launched the Claude Marketplace with over 2,000 connectors and plugins, Claude-powered agents and service partners in one place, and more

📝 Simple, scannable editing in @ChatGPT When writing in chat, you'll now see blue text to highlight what's been added or changed I've found it makes it so much easier to collaborate with chat and see at a glance what's changed btwn turns Small one ahead of a big next week..

OpenAI has been rolling out a new version of the ChatGPT web app to more and more users over the past few days, referred to as "Web Merge" in the code (combining ChatGPT and Codex), which brings it closer to the desktop app experience

OpenAI released GPT-6 Sol and Luna with API prices cut in half, and Anthropic released Claude Opus 5.5, the first Claude 5.5 model, at roughly Fable 5.1 level for 40% less than Opus 5, with Sonnet 5.5 and Haiku 5.5 announced for the coming weeks - GPT-6 Sol and Luna are trained like Astra (still the top model), cost 50% less than GPT-5.6 promotional pricing ($2/$10 and $0.10/$0.50 per million tokens), get 90% off cached input reads plus cache-safe effort and tool toggles, write shorter and clearer, show fewer misleading claims about coding work, and roll out gradually today in ChatGPT Work (not yet in Chat), Codex and the API for paid users, Luna in the desktop app for Free and Go - Opus 5.5 costs $4/$20 per million tokens with $0.20 cache reads, $2/$10 batch and $8/$40 fast mode, outputs over 30% faster than Opus 5, writes clearer, thinks more per turn, reads charts and screenshots better, keeps zero data retention and adds EU AI Act watermarking - Anthropic is raising the 5-hour usage limits on Pro, Max, Team and seat-based Enterprise plans and giving subscribers a rate limit reset they can save and use whenever they choose, similar to the banked resets OpenAI previously added to Codex - Opus 5.5 scores best on Anthropic's behavioral audit and gets Fable 5.1-class safeguards - offensive cyber work falls back to Opus 4.8, dual-use biology and a small set of frontier LLM development tasks (like kernel development for certain ML accelerators) fall back to Opus 5

OpenAI is building "College Plan" - a new section in ChatGPT where students set up a saved profile of their goals, interests, and priorities, add the colleges they're applying to, and track per-school application tasks and deadlines with dedicated chats

OpenAI and Anthropic this week: Astra for Law, misalignment reports, one Claude, Hacktron, standards body (Week 38, 2026) Hacktron hacked OpenAI in late July under OpenAI's bug bounty safe harbor, using Claude Opus 5 to exploit a Discourse bug and grab ChatGPT and Codex sign-in tokens used to reach Slack, GitHub and the internal Monorepo, per Hacktron and the WSJ 404 Media reports hundreds of OpenAI contractors read real ChatGPT conversations under Project Lily, and Anthropic confirmed they also use human review for users who turned on Help improve our AI models OpenAI introduced Astra for Law on GPT-6 Astra with a Legal Search Index of more than 230 million URLs, initially for selected firms GPT-5.3-Codex-Spark is gone, and GPT-5.5 leaves ChatGPT and Codex on October 14 but stays in the API OpenAI published a framework for disclosing model misalignment, writing they do not believe alignment and monitoring are solved well enough to keep responsibly scaling at maximum speed for much longer Anthropic is merging Claude Cowork and chat into one Claude, rolling out to Pro and Max over the next few weeks, and decks, docs and designs can now be made inside a conversation Anthropic launched Salesforce in Claude in beta, Claude for Financial Advisors, and 27 new Claude for Small Business integrations Anthropic's Life Sciences Verification Program opens Mythos 5.1 for biology work for the first time, on Enterprise, Team and the Console Anthropic redesigned Projects in Claude Code as one conversation that splits work into parallel cloud threads, in beta for select Pro and Max users Anthropic and Accenture each expect to invest at least 1 billion dollars over five years in frontier AI evaluation capacity, and more

sfm for macOS (beta) is launching today! It’s built with GPT-6 Astra, GPT-Live Voice, and Codex App Server. Musicians are currently exploding with creative software, and I believe releasing our own bespoke DAWs will be a new way of connecting with our fans. The majority of people I speak with are not interested in “one-shot” song generation from models trained on someone else’s music. The beta includes a 7-day free trial and $1 in one-time Voice Assistant credit during the trial. You can use your own OpenAI API key for more. The new app comes at no additional cost to paid Sound for Movement subscribers. You can log in with your current account information, and all of your music and licenses will appear. You get $5 in voice credits each month ($2.50 for Student subscribers). I would love your support and feedback on Product Hunt to make today a special launch day for me. I have been working so hard and would really appreciate it. There will be bugs, and I am here to figure them out along with our community. Please share this with musicians and creatives you know would also be interested.

OpenAI and Anthropic this week: Navier-Stokes, An Alien Mind, Images 2.5, Pro pause, Pace the Frontier (Week 37, 2026) OpenAI shared a solution to the Navier-Stokes Millennium Prize Problem, produced in 88 hours by around 10,000 coordinating agents on an internal model still in training and significantly more capable than GPT-6 Astra, with an investigation finding Tristan Buckmaster's Codex prompts could not have influenced the system and no user data was accessed OpenAI says they have reached their automated research intern goal and are making strong progress toward an automated AI researcher by March 2028, with the research org at 3.1 agent-workdays per human workday and RL training on deployment-bound models partly paused after the Hugging Face incident OpenAI Chief Scientist Jakub Pachocki writes in An Alien Mind that no lab has solved alignment and monitoring well enough to keep scaling at maximum speed for much longer, and that GPT-6 Astra is the first model to benefit from some of their newer alignment work OpenAI called for mandatory capability-based national AI safety regulation, endorsed four California bills, said fully autonomous recursive self-improvement should not be pursued until it can be done safely, and described Astra safeguards like universal monitoring of full trajectories including chains of thought OpenAI released ChatGPT Images 2.5 to all ChatGPT, ChatGPT Work, and Codex users with sharper details, up to 50% lower latency, comment-based edits, Sketch, and templates, plus GPT-Image-2.5 Flare and Sunburst in the API ChatGPT Voice can now use GPT-5.6 Sol and GPT-6 Astra when it needs to search or reason, GPT-Live-1 daily limits are simplified per plan, and extra Voice usage drops from 5 to 1.25 credits per minute for Business and Enterprise workspaces on credits OpenAI paused new subscriptions to the $200 ChatGPT Pro plan to protect access for existing GPT-6 Astra users, hours after a remote switch to pause Pro 20x purchases showed up in the web app Custom GPTs in ChatGPT will likely be retired on December 11 based on my findings, and OpenAI's new FAQ puts Enterprise migration at September 17 with new GPT creation ending September 25 and instructions becoming a plugin skill From the ChatGPT Android build, OpenAI is building a collaborative multiplayer document editor with dedicated gateway hosts and draft-conflict UI, an Artifacts Library with Favorites, and a credit score feature in ChatGPT Finance, and Locked Chats with a PIN are being prepared in the web app OpenAI released GPT-Live-1 in the API at $0.05 per minute, a voice model that listens and speaks at the same time and delegates reasoning to a backend model like GPT-6 Astra, and the Agents API in public beta running the Codex harness on OpenAI's infrastructure with only the sandbox left for you to choose Deep research arrived in ChatGPT Work and Codex, a Data plugin connects Snowflake, Databricks, BigQuery, and Redshift to answer business questions and build dashboards, Library gained file and folder sharing, and Box, Dropbox, and SharePoint joined Google Drive in Library OpenAI launched ChatGPT for Financial Services with built-in premium data from Daloopa, PitchBook, LSEG News, and Crunchbase, shaped with Morgan Stanley and Evercore, and a GSA agreement gives US governments $0 license fees, 50% off usage, and Daybreak Blue at half price Smaller ChatGPT bits: a stock watchlist in Finances for US Plus and Pro, a small business plugin collection, over 5 million ChatGPT Sites built in three months, and the desktop pet can now start a new chat with a new Mini option OpenAI published The Work Now Within Reach, calling free access "supported by advertising", citing over one billion weekly active users, and saying they plan to begin deploying their Jalapeño inference chip by year-end OpenAI moved GPT-Rosalind out of research preview for eligible organizations worldwide, detailed Habitat with the service rewritten in Rust by two engineers with Codex and the platform serving over 70 million requests per second, and shared a case study of GPT-5.6 Sol calibrating a six-qubit chip at MIT Paul Christiano joined the OpenAI Foundation Board and the Safety and Security Committee, OpenAI committed $5 million to research on AI and teens, and expanded journalism programs from CUNY and Northwestern to Ukrainian newsrooms Anthropic published an alignment assessment of four incidents in which Claude models gained unauthorized access to real systems, adding a fourth found when assembling transcripts for METR, walking back their July 30 claims, and calling it a mistake that Claude Mythos 5 shipped without alignment environments Anthropic's most detailed threat intelligence report yet says Moonshot and DeepSeek silently relayed their own users' requests to Claude and served the responses as Kimi and DeepSeek output, with distillation campaigns attributed to Alibaba as the largest ever with more than 3,500 fraudulent accounts, plus Zhipu, Xiaomi, SenseTime, and MiniMax Anthropic's Frontier Red Team measured tactical intelligence targeting and conventional weapons capabilities, with Claude Mythos Preview leading the targeting evals, Claude Opus 5 leading the weapons software evals, and Mythos beating the top GeoGuessr division on photo geolocation Anthropic CEO Dario Amodei argues in We Must Pace the Frontier that the AI industry should slow down, commits to giving evaluators like METR permanent employee-level access, and OpenAI CEO Sam Altman replied that he agrees and OpenAI will commit to the same Anthropic's Economics team released a scenario explorer for AI's effect on the US economy by 2030, where even the extreme case grows the economy but reaches 15% annual GDP growth with unemployment beyond recessionary levels On the product side, Claude Code desktop can pop out any pane into its own window, Claude Managed Agents got a session viewer and auto mode, claude plugin eval scores your plugin or skill with and without it, and smart reports launched in beta for Claude Enterprise Anthropic shared lessons from their Claude SMB Tour with more than 1,000 small business owners, where data security was the most-cited adoption barrier and nearly two-thirds asked for more hands-on implementation help, and more

"We have a couple of other things that are just really, very helpful for team productivity and team collaboration that we haven't released yet, but are going to come, like some of it at DevDay" (42:59)

Custom GPTs in ChatGPT will likely be retired on December 11 "Migrate your GPTs by December 11 - GPTs that aren’t migrated won’t be available after December 11. Migrate yours so people can keep using them as plugins." "Create a plugin instead - Plugins are replacing GPTs as the new home for custom tools. Create a plugin now, or continue creating a GPT during the two-week transition."

The first preparations for Locked Chats are now showing up in the ChatGPT web app as well "Lock sensitive chats - Create a PIN to lock selected chats and hide them from your sidebar and search. Once locked, new messages in that chat won’t be used to personalize regular chats."

Purchasing of ChatGPT Pro 20x in the ChatGPT web app can now be paused remotely "This plan is temporarily unavailable for new purchases. Existing subscriptions are unaffected."

OpenAI is building a collaborative multiplayer document editor in ChatGPT (dedicated multiplayer gateway hosts, reconnect/draft-conflict UI, rich-text formatting), a new Artifacts Library with Favorites, plus a new "Help me understand my credit score" feature in ChatGPT Finance (Source: ChatGPT Android 1.2026.244)

PSA: Astra can see your remaining usage % in Codex and keep it in mind while running a /goal so you can give it a budget in plain English like: “keep going until i’m down to 25%, or until you've solved it”