The Foundation Is Already There
Making a tool isn't starting from bare ground. Most already hold the hard foundation; what's missing is just one axis — the screen.
Vol. 3
build
- What Can It Do — Write the List Down and the Client Belongs to One ServerSecond in the mcp_client course. Ask for the tool and resource lists. Two lines, and whether they exist decides between "a client for that server" and "a client that stands in front of any server."DEV
- It Connects — the Transport Is a Command to Run, Not a SettingFirst in the mcp_client course. The client attaches to the server. What to notice is not the connection code but what the transport turns out to be — not a socket to open but a command to launch, which is why changing transports later becomes changing one line.DEV
- Say Only That It Changed — Why the Value Must Not Ride AlongLast in the mcp_server course. The screen stops asking every second. The server tells it, and the notification carries the uri and no value. And nothing at all goes to a client that did not subscribe.DEV
- When the Instrument Has No Dedicated SoftwareInstruments already know how to talk. The problem is that three vendors answer three ways — exponent notation, a carriage return, a value with the unit glued on. Those three were made one shape and put on one screen. And the screen shows the number the meter said, not the number the knob was set to.DEV
- It Survives the Process — by the Least Clever MethodFifth in the mcp_server course. A waiting count in a variable dies with the process. It gets written to a file — the whole file, every time. Slower than a partial update, and it never leaves a half-written record.DEV