AI Builders
Digest

Anthropic's Boris Cherny and Cat Wu shared the evolution from Claude Code to Claude Tag. Claude Tag is unlocking productivity across the entire org: engineering, product, data, sales, and marketing. Their internal version lands 65% of product PRs. Claude Fable 5 is now available in Claude Tag. Anthropic is granting credits for Claude Enterprise and Team orgs to use Claude Tag through September 1st.

Valar Atomics founder Isaiah Taylor discussed reviving nuclear energy through hardware iteration and manufacturing on No Priors. They recently powered an NVIDIA Blackwell AI chip with their nuclear reactor - the first ever. The company focuses on simple, safe, mass-manufacturable reactors to unlock energy abundance.

The Takeaway: By focusing on manufacturing over traditional construction, rapid hardware iteration, and passive safety designs, Valar Atomics is proving nuclear fission can have its Ford or Tesla moment, making energy 10x cheaper.

Valar Atomics founder and CEO Isaiah Taylor, with Manhattan Project family roots, started the company out of frustration with nuclear stagnation. They recently brought online the first advanced reactor built by a startup in Utah and powered an AI chip with it. Taylor highlights the importance of the DOE testing pathway, opened by a Trump executive order.

"We believe this is a hardware execution problem," Taylor explains, prioritizing simplicity and scalability over complex designs. Key innovations include modular concrete bioshields and TRISO fuel with passive cooling that prevents meltdown even when all active safety systems are off.

Taylor predicts that accelerating "tick rate" exponentially (time between new reactors) will enable massive deployment, ushering in hyper techno-industrialism where cheap energy makes almost everything free.

Guillermo Rauch introduced new rules for Vercel AI Gateway that allow dynamic rewriting of model routes, e.g., redirecting Claude Fable 5 to Opus 5. This helps maintain production workloads when models are retired or GPU capacity is contested. AI Gateway is positioned as a CDN for AI models.

Boris Cherny noted that Artifacts in Claude Code have been life-changing and is excited for expansion to Pro and Max users.

Peter Yang shared tips for getting the most out of Fable before July 7th: prep context with cheaper models, plan with Fable then execute with another, and babysit lower effort modes. Thariq confirmed Fable will come off subscriptions after July 7th but aims to restore it soon.

Box CEO Aaron Levie emphasized that deploying AI in the enterprise beyond chatbots requires real work: cleaning data, modernizing systems, evals, and change management. The FDE role will be one of the most critical jobs in tech going forward.

OpenAI CEO Sam Altman said watching the USA win in the USA during USA birthday week was incredible.

Swyx invited everyone to the Latent Space live pod at AIE Expo and highlighted normalizing men talking about mental health in hypergrowth.

YC CEO Garry Tan shared thoughts on building and politics, encouraging time in SF. Other notes: Peter Yang created stickers with his daughter using Codex; Zara Zhang on AI teaching better than professors and using groups for agents.

Nan Yu (Head of Product at Linear) on systems coordinating work. Guillermo Rauch on private backend connectivity. Peter Steinberger on daily calls with AT&T rep using OpenClaw. Dan Shipper on needing better AI storytelling for long tasks like Fable.

Nikunj Kothari advises against judging SF as a tourist and on the fulfillment of connecting people to opportunities. Zara Zhang: root of AI slop is no substance. Matt Turck shared conversation with NVIDIA's Bryan Catanzaro on Nemotron.