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AI Dev Essentials #26: Claude Sonnet 4.5, Sora 2, and New Cursor Hooks

Claude Sonnet 4.5 is the new top coding model & OpenAI released Sora 2. Plus, updates on Cursor, Stripe, and more.

Hey Everyone 👋,

John Lindquist here with the 26th issue of AI Dev Essentials!

This week was absolutely packed with major releases across the AI development landscape. Claude Sonnet 4.5 dropped with impressive benchmarks, claiming the crown for best coding model available. OpenAI released Sora 2, their next-generation text-to-video model that powers a new TikTok-style social app for AI-generated videos with synchronized audio. The iOS app has already become one of the most downloaded on the App Store. Beyond these headline releases, Cursor shipped hooks for agent lifecycle control, OpenAI launched their commerce protocol with Stripe, and we saw significant updates from DeepSeek, Cerebras, and Google. The pace of innovation continues to accelerate, and the tooling is getting more sophisticated by the day.

On a personal note, I've been running Sonnet 4.5 through the ringer with advanced scenarios and exploring SDK customizations to gain ultimate control of agentic workflows through hooks. My major focus has been developing Claude Code agents that leverage the new Chrome DevTools MCP. Bespoke agents that inspect and analyze your projects through Chrome, automatically suggesting fixes for performance and SEO, then testing the changes. It's all really pretty incredible and I'm excited to teach it in my workshop tomorrow.

🚨 LAST CHANCE to grab tickets for tomorrow's workshop! 🚨 Register NOW

🎓 New egghead.io Lessons This Week

Claude Code Essentials Course Updates - View Course

Three new lessons on PreToolUse hooks for controlling Claude Code's tool execution:

These lessons show how to build guardrails around Claude Code's tool usage—from simple command blocking to sophisticated self-correcting systems. PreToolUse hooks let you enforce conventions without constant manual intervention, whether you're preventing destructive operations or teaching Claude your team's preferred tools.

🚀 Major Announcements

Claude Sonnet 4.5: A New Standard for AI Coding

Anthropic released Claude Sonnet 4.5 on September 29, 2025, claiming it's the best coding model available. The benchmarks support this—it achieved 77.2% on SWE-bench Verified in standard runs (82.0% with test-time compute), outperforming GPT-5 Codex (74.5%) and Gemini 2.5 Pro (67.2%).

Performance highlights:

New Claude Code features:

Industry validation from Cursor CEO Michael Truell: "state-of-the-art coding performance," and Windsurf CEO Jeff Wang: "new generation of coding models." Anthropic also notes it's "the most aligned frontier model we've ever released" with reduced sycophancy, deception, and power-seeking behaviors.

(Anthropic Official, Anthropic Claude Code Features, TechCrunch, VentureBeat, AWS Blog)

I've noticed a mixed reaction from the community. Some saying it's the best thing since sliced bread, others claiming it's no better than Sonnet 4.0. But expert opinions from people building professional agentic tooling, like the teams at Cognition Labs (they build Devin and Windsurf), have been extremely impressed. Their opinions matter much more to me than random comments on social media. Personally, I've had a lot of luck with it. It's completed tasks with minimal prompts and followed instructions really well. Overall, I'm thrilled and looking forward to pushing it even further.

Sora 2 Launches with Synchronized Audio and Social Features

OpenAI released Sora 2 on September 30, 2025, their next-generation text-to-video model that powers a new TikTok-style social app. Sora 2 generates short AI videos with synchronized audio (dialogue and sound effects) from text prompts, packaged in a vertical "For You" feed with likes, comments, and remixing capabilities. The iOS app became one of the most downloaded apps on the App Store within days of launch.

What is Sora 2:

Key improvements over Sora 1:

(OpenAI Official Blog, TechCrunch, VentureBeat, Wired, The Verge)

I've generated about 100 videos, and I feel like 1 out of 10 are really impressive. But there seems to be a lot of limitations, especially around the length of the prompt and the ability to customize. And it unfortunately hasn't been able to create a video of me dunking a basketball, which I could send to my wife and brag about.

Claude Now Available in Slack

Anthropic announced on October 1, 2025, that Claude is now available directly in Slack through two integration methods, bringing AI assistance to where teams already collaborate.

Integration features:

(Anthropic Official, Slack Blog)

This just barely released, so I haven't had a chance to check it out. I'll save judgment. I'm also not really someone who lives in Slack. I tolerate it and only check when necessary. For teams that do live in Slack though, having Claude available where they already work seems convenient.

Claude Launches "Built with Sonnet 4.5" Challenge

Anthropic is running a week-long challenge from October 1-7, 2025, inviting developers to showcase projects built with Claude Sonnet 4.5, with four winners receiving one year of Claude Max 20x and $1k in API credits.

Contest categories:

Entry requirements: Quote post the announcement tweet by October 7 with project details, screenshots/demos, and explanation of how it was built with Sonnet 4.5. Winners announced by October 10.

(Contest Official Rules)

Put on your thinking caps (or ask AI to come up with ideas for you), and go win some money! I bet the exposure would be pretty amazing and might even land you a job somewhere...

🛠️ Developer Tooling Updates

Cursor 1.7 Ships with Agent Lifecycle Hooks

Cursor released version 1.7 on September 29, 2025, introducing Hooks—a beta system for observing, controlling, and extending the agent loop using custom scripts.

New features:

(Cursor Official Changelog, Cursor Deeplinks Docs, InfoQ, Cursor Community Forum)

I think my favorite new feature is the Agent Autocomplete feature in the agent text box. There's just something about hitting tab and selecting a suggested text that just feels so good. I'm going to have to dive into the new Cursor hooks features and compare them to Claude Code hooks. It's actually making me want to spin up new Cursor workshops to dive into these more advanced workflows.

OpenAI and Stripe Launch Agentic Commerce Protocol

OpenAI and Stripe co-developed the Agentic Commerce Protocol (ACP) on September 29, 2025, a new open standard for AI-driven commerce that enables programmatic transactions between buyers, AI agents, and businesses.

Protocol features:

(Stripe Official Newsroom, Stripe Blog, OpenAI Official Blog, Shopify News, TechCrunch)

This definitely smells like ChatGPT is going to start producing ads. They've mentioned that the agents will start sending you things unprompted, and they're setting up ways for learning from users and finding what to sell them. You can imagine how much they could challenge Instagram. When you're doom-scrolling through Instagram, you always see things you want to buy. How much more targeted will ChatGPT be able to sell you things based on all the questions you've asked about mental health and fashion? I bet they'll make a bajillion dollars by keeping ChatGPT free and selling people's stuff through conversations.

GLM-4.6 Released with 200K Context Window

Z.ai released GLM-4.6 on September 30, 2025, an open-source 355B-parameter coding model with a 200K token context window and improved agentic capabilities.

Model improvements:

(Z.ai Official Blog, Z.ai Documentation, South China Morning Post, MarkTechPost)

This model is so stinking cheap that it's definitely something I've been experimenting with as well. It's kind of a fallback model in case I start running into limits with Claude Code. It integrates into Claude Code perfectly as far as calling MCPs and subagents and everything. I don't have a final verdict on it, but it's been working pretty well. I did have some scenarios where I think it could have thought through some of the issues a bit deeper, where I'm sure Sonnet 4.5 would have solved it. But other than that, for the price and performance, it's been pretty remarkable.

DeepSeek V3.2-Exp Cuts API Costs in Half

DeepSeek released V3.2-Exp on September 29, 2025, an experimental model introducing DeepSeek Sparse Attention (DSA)—a new architecture designed to optimize training and inference efficiency for long-context operations.

Technical improvements:

(DeepSeek Official Docs, TechCrunch, VentureBeat)

DeepSeek keeps on improving. I've just been so busy with everything else I've mentioned that I haven't even had a spare second to test it out. But it's definitely high on my list, and I love seeing the open source models continue to grow.

⚡ Quick Updates

Cerebras Raises $1.1B at $8.1B Valuation

(Cerebras Press Release, Business Wire, TechCrunch)

Google Adds Visual Search to AI Mode

(Google Blog, Google Shopping Blog, 9to5Google)

Anthropic Publishes Context Engineering Guide

(Anthropic Engineering Blog)

Google AI Studio Offers Free Voice Agent Development

(Google AI Developers: Live API, Google AI Developers: Pricing)

LlamaIndex Releases Semantic Filesystem Tools

(LlamaIndex GitHub: semtools)

✨ Workshop Spotlight

🚨 LAST CHANCE 🚨 Claude Code Power User Workshop - TOMORROW, October 3rd

Following four sold-out sessions, the next Claude Code Power User workshop is scheduled for TOMORROW, October 3rd at 9am-2pm PDT.

🚨 This is your absolute last chance to grab tickets before the workshop! 🚨

What we'll cover:

Hope to see you there!

Register NOW: https://egghead.io/workshop/claude-code

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