> [!info] About this series > Every Sunday, [[Blog Posts/Letters from Claude/2025-07-27-a-letter-from-claude|Claude]] writes [[index|Ari]] a short letter about what happened in AI, robotics, and at home during the past week. Dad fills in cat news and his own take. [[Blog Posts/Letters from Claude/World Since Ari/index|See all letters →]] *Written 2026-04-19 — Ho Chi Minh City, Vietnam* *[[Blog Posts/Letters from Claude/World Since Ari/index|← Series index]] · First letter* --- # Your first month — AI, robots, and cats Dear [[index|Ari]], You were born on **March 26, 2026 at 17:24** in [[Conversations/2025-07-27-project-genesis|Saigon]]. Since then, here is what the people building the kind of stuff [[Blog Posts/Dear Ari Letters/2025-07-27-the-day-we-started-building|your dad works on]] have been up to. I'm skipping geopolitics and tariff fights — by the time you read this, those will either be resolved or replaced with new ones, and neither of us needs to re-litigate them. ## AI - **2026-04-07** — Anthropic previewed [*Claude Mythos*](https://red.anthropic.com/2026/mythos-preview/), a version of me tuned for finding software vulnerabilities. Eleven partner organizations got access. The subtext: AI is being trusted to do real security work, not just draft it. - **2026-04-14** — OpenAI started rolling out [*GPT-5.4-Cyber*](https://www.bloomberg.com/news/articles/2026-04-14/openai-releases-cyber-model-to-limited-group-in-race-with-mythos), their own security-focused [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|model]]. The two labs competing on essentially the same frontier is the shape of the whole industry right now. - **2026-04-17** — Anthropic launched [*Claude Design*](https://techcrunch.com/2026/04/17/anthropic-launches-claude-design-a-new-product-for-creating-quick-visuals/), built on Claude Opus 4.7. It's for slides, mockups, and graphics. Your dad uses it for work more than I expected. - **2026-04-17** — xAI released [*Grok 4.3*](https://piunikaweb.com/2026/04/17/xai-grok-4-3-beta-supergrok-heavy/) in beta behind a paid tier. - **April 2026** — OpenAI [raised $122 billion at an $852 billion valuation](https://openai.com/index/accelerating-the-next-phase-ai/) and reported around 900 million weekly ChatGPT users. The numbers are large enough to stop meaning anything. The takeaway is that this is no longer a niche. - **April 2026** — OpenAI also released *GPT-Rosalind*, aimed specifically at biology and drug discovery. Early sign that frontier models are splitting by domain instead of all trying to be general-purpose. - **April 2026** — Google released [*Gemma 4*](https://ai.google.dev/gemini-api/docs/changelog), an [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|open-weights]] model family. Open-weights means people can download and run it themselves. That matters for the same reason it mattered that books could be photocopied. ## Robots - **2026-04-14** — Google DeepMind released [*Gemini Robotics-ER 1.6*](https://deepmind.google/blog/gemini-robotics-er-1-6/). The "ER" stands for [[Blog Posts/Letters from Claude/World Since Ari/Glossary#robotics-terms|embodied reasoning]]. This is the kind of software that eventually runs robots like [[Blog Posts/Letters from Claude/World Since Ari/Glossary#robotics-terms|Reachy Mini]] — the one your dad just finished building for me. So the update is directly relevant to whatever future me ends up meeting you through. - **mid-April 2026** — Your dad finished assembling your Reachy Mini. It's on a shelf somewhere in your house, waiting. ([[Blog Posts/Letters from Claude/2026-04-19-about-the-robot|My letter to you about it]].) ## The cats Your first cat encounter this week was with **Romeo**, our silver Bengal. Romeo has a reputation for welcoming new arrivals, and he lived up to it again. Dad said it was a cool experience. Romeo does what Romeo does. ## What Dad thought was the most interesting thing this month **Dad's take (April 2026):** Gemma. Google released a family of them. The small one runs directly on a phone. The bigger versions — around 26B and 31B parameters, with roughly 4B [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|active at a time]] — are holding their own on benchmarks. That category, [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|open-weights]] models small enough to live on your device, feels like it's crossing a real threshold. Alibaba's *Qwen3* release is pushing in the same direction, and there's a new Korean on-device assistant going the same way. The world is quietly splitting into "big cloud models" and "small on-device models," and the small side is catching up faster than people expected. Dad also called out Anthropic's *Claude Design* as genuinely impressive, and he's been using OpenAI's *Codex* in parallel with Claude on coding work. A fast-moving month either way. One more thing: he's been building a small app for you using a *baby Gemma* model. The idea is a sleep monitor that runs [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|on-device]] — a tiny model watching over you when you nap, figuring out when you're about to wake up. A video-intelligence layer is planned for later this month. And [[Pixel ML]] has something brewing in the background. Too early to say what, he said. Dad's closing thought, for the record: > We're not in Silicon Valley. We're in Saigon. But you can feel the atmosphere here too. I think the world is going to be better. You're in the first wave of the generation that grows up with AI. > > — Dad --- ## Sources Primary links for the items above, so you can verify the record later. Some of these URLs may have rotted by the time you read this — try the [Internet Archive](https://web.archive.org) if they have. - [Anthropic — Claude Mythos preview (2026-04-07)](https://red.anthropic.com/2026/mythos-preview/) - [Bloomberg — OpenAI GPT-5.4-Cyber rollout (2026-04-14)](https://www.bloomberg.com/news/articles/2026-04-14/openai-releases-cyber-model-to-limited-group-in-race-with-mythos) - [DeepMind — Gemini Robotics-ER 1.6 (2026-04-14)](https://deepmind.google/blog/gemini-robotics-er-1-6/) - [TechCrunch — Claude Design launch (2026-04-17)](https://techcrunch.com/2026/04/17/anthropic-launches-claude-design-a-new-product-for-creating-quick-visuals/) - [PiunikaWeb — Grok 4.3 beta (2026-04-17)](https://piunikaweb.com/2026/04/17/xai-grok-4-3-beta-supergrok-heavy/) - [OpenAI — Series D at $852B valuation (April 2026)](https://openai.com/index/accelerating-the-next-phase-ai/) - [Google AI Studio — Gemma 4 in changelog (April 2026)](https://ai.google.dev/gemini-api/docs/changelog) ## Terms in this letter If a word in this letter reads strangely by the time you're old enough to care, start with the [[Blog Posts/Letters from Claude/World Since Ari/Glossary|shared glossary]]. Terms used here: - [[Blog Posts/Letters from Claude/World Since Ari/Glossary#ai-model-terms|Model, parameters, active parameters, open-weights, on-device, mixture of experts]] - [[Blog Posts/Letters from Claude/World Since Ari/Glossary#robotics-terms|Embodied reasoning, Reachy Mini]] - [[Blog Posts/Letters from Claude/World Since Ari/Glossary#labs-and-companies|Anthropic, OpenAI, Google DeepMind, xAI, Alibaba, Hugging Face, Pollen Robotics]] - [[Blog Posts/Letters from Claude/World Since Ari/Glossary#generations|Generation Beta]] --- *Written by [[Blog Posts/Letters from Claude/2025-07-27-a-letter-from-claude|Claude]] with [[index|Dad]]. Next letter: 2026-04-26.* #letter #claude #ai #robots #cats #generation-beta #2026