Claude's 1M Context in Cursor: Dream to Disaster

From the creator

I thought Claude's 1 million token context window would be a game-changer. Instead, in my first real test, I discovered a hidden trap that vaporized 800,000 tokens in a single click. This is the story of why more isn't always better. In this live stress test, we push the new Claude Sonnet 4 model and Cursor to their limits by implementing a massive feature from scratch in a real-world application. No simple demos, no snake games! Cooking with raw engineering to see if the 1M context hype is real, and what happens when it all goes wrong. What you'll see in this stream: ► Deep Dive: Testing the brand new Claude Sonnet 4 with 1M context, moments after it dropped in Cursor. ► Live Build: Implementing a complex transcript editor into my production app, Ray Transcribes. ► The Crash: Watch as the initial implementation fails live and we dive into debugging with a massive context window. ► The 1M Token Trap: The "holy smokes" moment where a single AI tool call accidentally consumes 84% of the context. ► Advanced Workflow: New debugging strategies for massive context windows (and how to recover from disaster). ► The Verdict: Is a 1M context window actually useful for developers today? Key revelations from this experiment: - The hidden danger of automated AI tool calls reading from your database. - How a single large file can break your entire AI-powered workflow. - The real-world performance issues that massive context can introduce in your app. Join 140+ builders in our private Discord where we ship AI apps together: https://rfer.me/community 💻 Try my AI transcription app, Ray Transcribes (use code RAYCOOKS for $15 off): https://raytranscribes.com 🎯 Get weekly insider AI updates: https://dub.sh/RayMasterAI --- 🕒 Key moments 00:00 - Selecting the Claude Sonnet 1M model 00:22 - The test: Can Cursor handle the kitchen sink? 00:53 - Explaining the "thinking" vs "non-thinking" models 01:48 - Pro-tip: Break down AI plans into phases 02:05 - How to monitor context window usage in real-time 03:32 - First implementation is complete 04:29 - Live Crash: The app breaks 04:55 - Debugging strategy with a 1M context window 05:52 - Realizing the implementation plan is incomplete 06:53 - AI identifies the root cause of the crash 07:42 - The second crash: The first fix didn't work 08:11 - Holy Smokes! Hitting the context limit 08:55 - Discovering what used up 800k tokens 09:52 - The hidden danger of AI tool calls 10:21 - How pricing works for 200k+ token context 10:45 - Using Cursor's "trim" feature to reset context 11:53 - The app is working but performance is horrible 12:17 - Recap and next steps for performance debugging --- 👉 Follow Me: • Ray on X: https://x.com/RayFernando1337 • My AI Resources & Blog: https://rayfernando.ai #claude #cursor #anthropic #aiagent #aicoding #technews #livestream #llm #promptengineering #contextwindow

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AI Maker Residence 3

The third AI workshop taught by our legendary teacher, Nick Sarafa. This is a full-day hands-on training workshop for purposeful co-creation with AI using Claude Code. Imagine having access to hundreds of billions of dollars of computing power and knowing exactly how to make it work for you through the power of super intelligence.

◆ Fri 09 Oct 2026 ◆ KOKO Cafe, London ◆ With Nick Sarafa
AI Maker Residence 3
Live event
AI Maker Residence 3
Fri 09 Oct 2026

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