Only What Runs Gets Published
Six pieces on a server becoming an app, two real boards, and the earlier claims paid back in code. From this month on, nothing runs in the magazine that did not run on a machine.
Vol. 7
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- What You Do Not Expose Protects the App — Every Server Is an App, and What Comes AfterA server becoming an app does not mean putting every capability on a screen. What you never turn into a tool is the shape of that app, and its safety. We made that argument in 2026-04 and deferred it with "the next pieces will show you". This time we do not defer — that a capability absent from the tool list really cannot be reached is paid back in execution logs and a real board's answers.FREE
- Sitting Down Without an Interpreter — Where One Piece of Judgment Becomes a RuleIn 2026-03 we wrote that "eight tenths of a tool is judgment, and that judgment is already in your hands". How those eight tenths sit down on a screen without an interpreter was stated only in prose. This time we pay it in real things — a farmer's piece of judgment was seven lines, and the verification stops the foreman's checklist from having a single character changed.FREE
- Only the Screen Thaws — Install-less Apps, and What Compiling FrozeThe two vision pieces from 2026-01 and 02 are merged into one, and every number written back then without measuring has been replaced with a measurement. Is a screen definition really small — 656 bytes. Does an edit really arrive immediately — 83 milliseconds, zero builds. And what still has to stay frozen.FREE
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- Attach to One Chip and the Attached Device Becomes the Terminal — POS, Kiosk and Kitchen Screen at OnceOne server stood up beside the payment terminal already in the shop, with a tablet, a PC and a kitchen screen attached. No app was built for any of the three, and each became a kiosk, a POS and a kitchen display. The card authorisation path was not touched by a single line. Full code, run log, and the three screens exactly as rendered.DEV
- Boards Hand Over Their Screens — Two Real Devices, Two Transports, One ClientThe STM32H723 over USB serial, the ESP32 discovered by mDNS and attached over Wi-Fi TCP. Each board hands over its own screen definition, and pressing a button turns a real LED on. The client code does not differ by a character between the two. No simulator — in this piece alone, verification fails without hardware.DEV
- The Screen That Never Asks — What Is Bolted to a Wall Must Not AskEvery screen in this series learned by asking. A screen in your hand can do that; a kitchen screen bolted to a wall cannot — it either asks constantly or is late. After subscribing, the screen made zero tool calls while three orders arrived.DEV
- What Retrying Costs — Not the Side Calling, the Side ReceivingWriting about retries is mostly written from the caller's side. This piece counts from the receiving side. Four callers got through a 700-millisecond outage two different ways, and both eventually succeeded. What differed is how many times the gateway was hit meanwhile — 64 and 25.DEV
- Told Yes Twice — What One await DecidesTwo people take the same slot at the same moment. Described in words, the two handlers do exactly the same thing — look whether it is free, and if it is, take it. One of them confirms to both people; the other does not. The difference is one await in the middle.DEV
- Who May Press This — Hiding a Button Is Not AuthorisationTwo people open the same screen. The void button is visible to both. When the assistant presses it the server refuses, and the refusal goes into the ledger. The screen file is the same file, and we printed its hash into the log.DEV
- The Screen Arrives from the Server — When the Client Holds No Screens at AllEvery sample in this series so far kept its screen files next to the app. This client has not a single screen. It asks the server what to draw, draws it, and asks again when the server says it changed. No reinstall, no restart, no build.DEV
- A First MCP Server — My Code Runs Inside the Chat WindowType "save that to my notes" into Claude Desktop and a few-dozen-line server on my laptop executes. No store, no deployment — one line of config. We build that round trip from beginning to end and make it check itself with dart test.DEV
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- The Tool That Refuses to Read — Keeping Judgment Outside a Clinic FlowIn 2026-04 we ran a piece about a doctor building a clinic flow tool. That piece stated in prose what the tool does not do. This time we drew it in code — this server has no tool that produces a judgement, and it throws if it tries to emit a word that sounds like a verdict.DEV
- The Standard Stays Yours — What a Grading Tool Does Not DoIn 2026-03 we ran a piece about a teacher building a grading tool. That piece never said what the tool based its marks on. This time we built it — every mark comes out carrying which branch of the rubric produced it, and "they slip on question three" is counted out of the papers.DEV
- A Log You Can Ask — What Thirty Notebooks Could Not ShowIn 2026-04 we ran a piece about a farmer moving thirty years of handwritten notebooks onto one screen. At the heart of that piece — "say it and it becomes a screen" — there was nothing real. We constructed the situation to its real shape and built the whole thing ourselves — and "eighteen days" appears nowhere in the source. It is computed from the records.DEV
- Forty-Five Lines — The Actual Size of the Little Thing Built on a WeekendIn 2026-01 we ran a piece about a non-developer building a club dues tool on a weekend afternoon. That piece had no screen, no definition, no process. This time we built it, and counted how many lines the maker actually touches — forty-five. And if that number grows, the verification fails.DEV