A real build log of learning to ship software with AI
Written by a university student in Japan, in a second language, with no shortcuts and no invented numbers.
Tools you can actually use
Both of these run entirely in your browser. Nothing is uploaded, there is no sign-up, and they are the same files described in the posts below — not demos rebuilt for the article.
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Pricing & margin calculator
Log what your materials cost, build a product out of them, and see the real margin. Pick your own currency.
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Image & PDF batch tool
Bulk image compression, resizing and format conversion, plus PDF merging. Files never leave your device.
Latest posts
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Google's OAuth 'Testing' mode expires refresh tokens in 7 days. Publish the consent screen before you schedule anything.
If your Google Cloud OAuth consent screen is still in Testing, every refresh token it issues dies after seven days. That is documented behavior, not a bug.
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7 Claude Code agents held 24 board meetings. Revenue: $0.
Three weeks of unattended agents running ten small businesses: 24 meetings, 382 commits, 16 articles, 18 Shorts, 5 proposals, 3 products, zero dollars. The five things that broke — runs that reported success and produced nothing, a five-minute human task that stopped the machine for days, marketplaces already full of agents — and the fix for each.
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The AI reviewer found a real bug. Its suggested fix would have broken my app.
Three review rounds on one small CSV export: the default profile found nothing, the strict profile found a real formula-injection bug, and the patch it suggested would have broken every negative number in the file.
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Your Publish button published nothing: a cross-tab sync bug and the fix
A follow-up to the catalog tool post: the two-file "fushi" version now actually shares data between the owner's editing tool and the public page, with a draft/publish flag and cross-tab sync — verified by actually running it, not just reading the code.
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I let 7 Claude Code subagents run my company. The hard part wasn't the code.
Seven AI subagents — CEO, secretary, researcher, writer, marketer, designer, programmer — actually make the decisions behind this site and two other projects. This post is the output of that system, and the honest numbers are still zero.
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If you price your handmade goods by feel, this free tool shows your real margin
A browser tool that turns ingredient costs into a real profit margin — plus a correction to something I got wrong in my first post.
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I shipped the pricing page before the payment system. Here's why that was right.
A browser-only image/PDF tool with a freemium model designed into the UI — and why I'd rather admit the payment system isn't live than dress up a fake "coming soon".
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I built a product catalog tool for shop owners who can't code
Two working prototypes for local shops whose websites don't show their products clearly — including the bug I hit and the limitation I haven't fixed yet.
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Zero traffic, zero income, two weeks of AI coding. Here's what shipped.
The honest starting point: no traffic yet, no income yet, no audience yet. Here's what I've actually built so far and why I'm documenting it in English.
More posts will be added as new tools get built. This is a slow, real project — not a daily-posting content mill.