From SaaS to API Powerhouse 🚀 – Day 45 of LLM.txt Mastery

TL;DR: Turned LLM.txt Mastery into a fully API-callable platform, unlocking new B2B possibilities and tackled some tricky type and import glitches along the way.

🎯 Today's Focus

Today was all about leveling up LLM.txt Mastery’s backend to support external integrations. Instead of just being a standalone app, it’s now a platform other tools and businesses can call programmatically — a big step toward scaling and adding new revenue streams.

✨ Key Wins

I finally flipped the switch on the API endpoints powering LLM.txt Mastery. That means partners like AImpactScanner can now automatically analyze websites and generate those handy LLMs.txt files without any manual clicking. This is huge because it opens the door for usage-based pricing—clients pay for what they actually use, which feels fairer and more scalable.

To keep things enterprise-ready, I built in robust security layers: API key authentication to make sure only authorized users get in, plus rate limiting and usage tracking so I can monitor and protect the system from abuse or overload. It’s like turning a cozy workshop into a well-guarded factory line.

💡 What I Learned

One interesting wrinkle today was dealing with TypeScript’s type system when I added a custom apiKey property to the Express request object. Express doesn’t know about this extra property by default, so I had to extend its interface properly. It reminded me how important it is to plan for these extensions early on — it saves headaches later when your codebase grows and types get stricter.

🔧 Challenge of the Day

I hit a couple of small but annoying snags. First, I was importing the relations function from the wrong part of Drizzle ORM. It’s a subtle mistake—Drizzle splits its exports across packages, so grabbing it from drizzle-orm/pg-core instead of drizzle-orm threw errors. Took about 15 minutes to track down, but it was a good reminder to double-check docs when something feels off.

Then, the TypeScript type errors popped up in my API routes because the apiKey I injected via middleware wasn’t declared in the Express Request type. After extending the interface, those errors vanished. Both fixes were little puzzles that slowed down the flow but ultimately made the platform stronger.

📊 Progress Snapshot

• Completed: 0 new features but 2 critical fixes
• Momentum: 📈 Steady

🔮 Tomorrow's Mission

Next up is generating a production API key for AImpactScanner and starting to monitor how the API performs in the wild. I’m also thinking about building an SDK (@llmtxtmastery/sdk) to make integration even smoother for partners, plus creating an OpenAPI/Swagger spec so developers have clear docs to follow.

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Part of my build-in-public journey with LLM.txt Mastery. Follow along for daily updates!