Claude 4.5, One Week Later: A Glimpse of What’s Coming

Video Description

I’ve been kicking the tires on Anthropic’s new Claude 4.5 Sonnet for about a week, and this is my honest first look. I’m not here to parade charts—I wanted to see what it does on a real build. So I asked it to take on a surprisingly complex PRD: a Kanban/whiteboard system with image-to-list import, keyboard-centric input, Firebase backend (multi-user + OAuth), indices, settings, icons/colors, and tests. What stood out: it’s faster, it tackles a lot of concerns at once, and the new context editing + externalized memory approach feels like a genuine step toward long-running, solution-level agents. Checkpoints/rollback were actually useful (double-escape FTW). I also tried the native Claude Code panel in VS Code/Cursor—nice performance bump, though I still hop into the CLI to watch it “cook.” Not all roses: it wrote a save hook that recursively hammered Firebase and burned my quota—twice. Debouncing/queues fixed it, but it’s a good reminder these models still need guardrails and tests (it did generate solid Playwright + unit coverage after). Big picture: this release looks like the first real glimpse of “build a solution, not just a file.” I still wouldn’t jump ship if you’re happy with your current stack (Codex/Cursor users, you’re fine), but it’s absolutely worth a week of experiments. References you might want: Sonnet 4.5 Announcement: https://www.anthropic.com/news/claude-sonnet-4-5 Anthropic (Claude): https://www.anthropic.com Claude Code VS Code extension: https://code.visualstudio.com/docs/editor/extension-marketplace Firebase: https://firebase.google.com Keywords: Claude 4.5, Sonnet 4.5, Anthropic, Claude Code, VS Code, Cursor, Agents, Computer Use, Context Editing, RAG, Firebase, OAuth, Playwright, Long Context, First Impressions, AI Engineering Hashtags: #Claude45 #Anthropic #AIEngineering #Agents #VSCode #Cursor #Firebase #RAG #ContextEditing #FirstImpressions 00:00 - Intro 01:14 - What is 4.5 04:41 - The PRD 06:12 - The App 09:33 - Our Change 10:13 - Yes. It spent all my money 11:53 - Change completed 12:11 - Checkpoints 12:52 - VS Code Extension 14:36 - What this all means 19:33 - Conclusion