Yesterday was Grok 4.7 (pelicans) and MiMo v2.6 Flash/Pro (more pelicans). Today Anthropic released Claude Opus 5.5, and around an hour later OpenAI released GPT-6 Sol and GPT-6 Luna. It's going to take a while to get a good read on all of these new models, but here are my impressions so far.
GPT-6 Sol and Luna are half the price of their GPT-5.6 equivalents
GPT-5.6 Luna was already my favorite mo
Anthropic today launched Claude Opus 5.5, which it says is the first model in a new 5.5 model family. Opus 5.5 performs at the level of Claude Fable 5.1 on most work, but costs 40 percent less to run than Opus 5.
According to Anthropic, Opus 5.5 is a "major step up" from Opus 5 with improvements in performance and safety. Opus 5.5 is comparable to Mythos 5.1 in biology and cybersecurity, so A
OpenAI today launched GPT–6 Sol and GPT–6 Luna, two new models that follow GPT–6 Astra. OpenAI says the new models were developed using methods similar to Astra's for improvements in professional work, factuality, coding, computer use, and alignment.
GPT–6 Sol is for everyday work, and it costs less than Astra. GPT–6 Luna is an even cheaper model. Luna is optimized for fast responses and high
OpenAI’s GPT-6 family is expanding in GitHub Copilot with two additional models: GPT-6 Sol, and GPT-6 Luna. Joining the previously released GPT-6 Astra, these new options let you select the…
The post OpenAI’s GPT-6 Sol and GPT-6 Luna now available appeared first on The GitHub Blog.
Learn how GPT-6 improves prompt caching with higher cache hit rates, new diagnostics, explicit breakpoints, and controls that reduce latency and costs.
Release: llm 0.36
New OpenAI models: gpt-6-sol for GPT-6 Sol and gpt-6-luna for GPT-6 Luna. #1702
Model plugins can now declare supports_conversation = False for models that only accept single-turn prompts. LLM raises llm.ConversationNotSupported when these models receive assistant or tool history, and llm chat rejects them before starting a session. See Models that do not support conver
Claude Opus 5.5 from Anthropic is now available on AI Gateway. It is a step-change improvement over Opus 5, with its biggest gains in agentic coding, long-running agent tasks, and knowledge work. Anthropic cites that Opus 5.5 performs at the level of Fable 5.1, but ~30% faster and ~40% cheaper than Opus 5 per task.Opus 5.5 is also a better collaborator over long runs. It reports back in plain lang
GPT-6 Sol and GPT-6 Luna from OpenAI are now available on AI Gateway.Both models bring GPT-6 improvements in professional work, coding, computer use, factuality, and communication at a lower price than GPT-6 Astra.GPT-6 Sol (openai/gpt-6-sol) is suited to complex professional workflows and sustained coding tasks where quality and room to iterate both matter.GPT-6 Luna (openai/gpt-6-luna) is the lo
#803 — September 22, 2026
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JavaScript Weekly
tinyjs: Build JavaScript Desktop Apps in <10MB — I built an app with this and was impressed. You get a txiki.js-powered backend with full system access (including FFI!), native webview rendering, and tiny macOS, Linux, and Windows builds. It even makes it easy to sign/notarize the final app.
Tarwin Stroh-Spijer
Claude Opus 5.5, Anthropic’s newest Opus model, is now available in GitHub Copilot. You can use it for agentic coding, long-running agentic tasks, and knowledge work. In early testing, Opus…
The post Claude Opus 5.5 is now available in GitHub Copilot appeared first on The GitHub Blog.
We’re removing several SSH algorithms, adding a new algorithm, and requiring larger RSA SSH keys to improve security. The changes are as follows: We’re removing the ability to use RSA…
The post Security improvements for SSH appeared first on The GitHub Blog.
Worker Previews gives every branch its own URL, configuration, state, and observability, so you and your agents can test changes in parallel without affecting production.
GitHub Copilot for JetBrains 1.18.0 brings AI-assisted tool approvals, more control over agent conversations, and shared skills and instructions for your organization. You can also review plans with the Codex…
The post New features and improvements in Copilot for JetBrains appeared first on The GitHub Blog.
Understand how Copilot agents perform and interact with models and tools. The GitHub Copilot app now supports OpenTelemetry (OTel) configuration through enterprise-managed settings. OTel is an open source observability framework.…
The post OpenTelemetry in the GitHub Copilot app appeared first on The GitHub Blog.
Starting with CodeQL CLI 2.27.0, the all-platform CodeQL bundle (i.e., codeql-bundle.tar.gz and codeql-bundle.tar.zst), which includes the binaries for all supported platforms up to this release, is marked as deprecated. In…
The post Deprecation notice: All-platform CodeQL bundle appeared first on The GitHub Blog.
Drives for Vercel Sandbox are now available in public beta on Hobby, Pro, and Enterprise.A Drive is persistent storage that you mount as a directory in a Vercel Sandbox. It isn’t tied to a single sandbox, so you can reuse the same Drive across runs and different sandbox instances.Use Drives to preserve an agent's workspace or on-disk memory, or to reuse datasets, models, and dependency trees.Creat
Vary support is now available in Cache Rules on every plan. You can normalize known negotiation headers, pass exact values through to the origin when those small differences matter, or bypass cache when the variation is too unpredictable.
We analyzed billions of transactions on Stripe from January 2022 to March 2026 to understand how card fraud patterns differ by region and country, what's driving those differences, and how businesses can respond.
Monday Google opened preorders for its "Googlebook" laptops, pricing them at $899. A Google's blog post added that "At launch, you can choose between Intel Core Ultra Series 3 and Snapdragon X Elite processors" (paired with NPUs to power AI features).
"Devices will hit shelves on October 4 in the U.S. and on October 5 in Canada, the U.K., Ireland, France, Germany, and Australia," TechCrunch poin
Big model release today - I wrote about Claude Opus 5.5, GPT-6 Sol, and GPT-6 Luna - plus comparison grids of pelicans by the different model families at different reasoning levels simonwillison.net/2026/Sep/22/...
One person's constant is another person's variable.Alan Perlis
Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war
