⚛️ Cursor ditched Solid for React and blamed the agents

Hey guys,

Welcome to another edition of Import React by Cosden Solutions!

Thanks to reactCon Berlin for sponsoring today's edition.

Cursor just mass-migrated from Solid to React, and the reason isn't what you'd expect. Someone forked TanStack Router, claimed it was 19x faster, and Tanner wrote a 3,000-word audit with receipts. And Lovable moved 850,000 lines of code off Next.js onto TanStack Start, mostly using agents, with one eleven-minute incident along the way.

Let's get into it.

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🔁 Cursor Migrated From Solid to React and Blamed the Agents
Cursor's pretty much done migrating from Solid to React, and the new agents window is 99% React. The big motivation was perf and maintainability, they found that signal-based reactivity made it "actually quite easy to create perf footguns" when reactivity caused accidental fan-out in large, complex apps. Also, apparently non-React frameworks that look like React just confuse coding agents, and agents were "quite bad at writing good Solid code" because everything ended up being accidentally tracked. React Compiler handles most over-rendering now, and they've built an in-house framework called Dune that bans useEffect outright.

🔥 Someone Forked TanStack Router, Claimed 19x Faster — Tanner Brought Receipts
A developer announced a drop-in replacement for TanStack Router that was "up to 19x faster," claiming PRs had been ignored for two months. Tanner Linsley dropped a full audit of the fork, and the benchmarks fell apart: the 19x headline came from repeatedly calling router.load() on an already loaded server router that skipped all loader work TanStack actually runs. The "drop-in replacement" had 197 failing test cases at launch. And the "ignored PRs" narrative? One was merged the next day, others were superseded by broader work, and authorship was preserved. The fork's been fixed since, the current benchmarks do show real gains on equal loader counts, but the original claims didn't hold up.

🏗 Lovable Moved 850K Lines From Next.js to TanStack Start
42 million monthly visitors, 400 routes, and 850K lines of code migrated from Next.js on Vercel to TanStack Start on Lovable's own infra, route by route, mostly by agents, over six months. The DX numbers are wild: local dev server startup dropped from 70 seconds and 8GB RAM on Next.js to 10 seconds and 1.5GB on TanStack Start. One developer ran the whole migration by telling agents "move component X to shared web code" and getting production-ready PRs back. The one bad moment: an OOM incident that took the site to 50% error rate for 11 minutes when a static JSON import pushed their Cloudflare isolate over its 128MB memory limit.

🧭 Inside a TanStack Router Navigation
A single router.navigate() call looks like one async operation. Under the hood, TanStack Router now coordinates four independent lifetimes, a current transaction (which navigation may publish), private lanes (what one route attempt decided), loader flights (shared work with lease-counted abort control), and framework render receipts (proof React actually committed). The rewrite fixed dozens of bugs across preloading, redirects, caching, and pending UI that all traced back to the same root cause: the router was compressing too many facts into too few variables.

Quick Links

💸 Who Are the Token Brokers?
Startups are sitting on unused AI API credits from accelerator programs, and a whole grey market has popped up to resell them. There are now dedicated credit marketplaces listing Anthropic and OpenAI tokens at 30–80% off, bulk-discount "routers" offering a flat 40% discount, and Telegram channels where supply changes hands. One broker offered $100K in spend per day.

🎨 The Case for Software Craftsmanship in the Era of Vibes
Zed's founder Nathan Sobo on why quality should matter more now that cranking out code isn't the bottleneck. His point: measure what you ship by how reliable and changeable the system is, not lines touched. A messy codebase doesn't just slow you down — it tanks your AI tools too.

🧱 The "Full Stack Builder" Is a Terrible Idea
AI lets anyone on a product team build almost anything. That doesn't make the team obsolete — it makes it more important. The old handoff process was slow, but it was also a quality check that forced collaboration. Now a PM can ship a prototype without a designer ever seeing it, and AI will happily hallucinate features that don't exist.

🎮 "Is Agentic AI Making You Procrastinate?"
r/webdev gets honest about what working with coding agents actually feels like. One dev's company mandated AI tools while requiring manual approval for every command, "approving an ls is such a time sink." Another describes approval fatigue: you start rubber-stamping, then realize you just let the agent add an account-wide GitHub key. The best comment compares not using AI to playing off-meta in a ranked game.

See you next week,

Darius