Caffeine AI lets you build real applications on the Internet Computer just by chatting — and because they run directly on the blockchain, you get the security and verifiability that comes with it, plus built-in crypto features like depositing ICP and CKUSDC. This is a hands-on walkthrough of how I actually use it, based on the two sites I've built: jerrybanfield.com and jerrybanfield.net.
What I've built with it
jerrybanfield.com is a clean one-page site I built mostly from a single prompt — perfect for coaching or consulting traffic you want to convert. jerrybanfield.net was far more advanced: a platform where advertisers pay creators to make content, with fully integrated crypto payments. Every user gets a unique deposit address, can swap ICP to CKUSDC in one click, and withdraw — plus campaigns, submissions, messages, and an admin dashboard. That one took 70-plus versions and a lot of learning to get working.
Start with a detailed first prompt
The single biggest lesson: get crystal clear on what you want before your first prompt. I dictate everything I want in detail, run it through ChatGPT or Gemini to turn it into a clean, specific prompt, and only then paste that into Caffeine AI. The more clearly you describe and visualize what you want, the faster and cleaner the output. When I rushed jerrybanfield.net with a vague prompt, I paid for it later in bug-fixing sloppy code.
Iterate with screenshots
After the first build, you iterate. The best way to communicate changes is screenshots — screenshot a layout you don't like, or a site you do like, paste it in, and tell it what to adjust. For a static one-page site that's straightforward. It gets more involved when you build something with logins and back-end logic.
Pricing, page speed, and publishing
Get the $29/month plan — the starter 40-credit plan isn't enough, and you really
want a custom domain because it's what makes a site look legitimate. Redoing
jerrybanfield.com several times only cost about 50 credits; jerrybanfield.net burned
~150. If your site loads slowly, run it through Google PageSpeed, screenshot the
results, and paste them in — that's how I got mobile page speed up around 89. To
publish, open the version panel in the top right, pick the version you want live,
and hit publish; give the canisters a few minutes to upgrade. Note the
*.caffeine.xyz draft is only a live preview — anything you sign into
there won't appear on the live site.
Security audits and a few hard-won lessons
Any time, you can simply tell it to run a security audit and it will find and fix high- and medium-severity issues — do this intermittently. You can also drop the code into another AI like Claude for a second check. A few things I learned the hard way: skip the admin dashboard unless someone else is managing the app for you, and be aware that Internet Identity sign-in can noticeably slow your whole site. The crypto bugs took the most patience — figuring out it was using a CKUSDC test canister instead of the real one, and that I needed a plain ICP deposit address (no memo) before swapping. I tested one thing at a time, fixed each broken piece, and gave it exact screenshots and error messages. If something hangs, tell it to add visible error output so you can diagnose it.
Marketplace, custom domains, and credits
If someone else has already built something that works, you probably can too —
browse the app marketplace and remix an existing app to move much faster. Start from
scratch only when you have a very clear vision. To map a custom domain, buy the
domain (or bring your own), add the CNAME and TXT records — I use Cloudflare — and
set a permanent 301 redirect from the top-level domain to the www
version, since the attachment uses www. Get a real domain; the default
subdomain looks unprofessional.
On cost: 100 credits is $25, so one credit is about 25 cents. Canister top-ups are essentially your hosting bill, and across hundreds of visitors and all my builds I've drained only around $5 in top-ups so far. Fire off as much as you can in a single prompt to conserve credits, since you're charged per prompt. When you're happy, you can publish to the marketplace with a thumbnail, description, and tags — a great way for people to discover you. Honestly, this is the best website I've ever had, and it was built by chatting. If you want to talk through your own app, you can record a video with me at jerrybanfield.com, and you can follow more of my ICP work on my ICP playlist.