Field notes on Bitcoin software
Bitcoin apps, read from the inside.
Nettlewick is a reading room and planning desk for people who build, test, or choose Bitcoin software. We write about where keys live, what an app is allowed to read, and what it says to the network when no one is watching.
Start with the boundary
Most Bitcoin apps are described by their screens. We find it more useful to describe them by their boundary, the line between what runs on your device and what travels outward. Keys, signing, local data and network requests each sit on one side of that line or the other, and each side fails in its own way.
The diagram beside this text holds the whole idea in one picture. Everything inside the dashed line belongs to the app and to you. Everything past it belongs to someone else's machine, and every message that crosses is a decision worth reading.
Three places to look
-
Keys. Who can produce a signature, where the key material is stored, and what it takes to move it. Read the keys section.
-
Data. What the app keeps on disk, what it can rebuild from the chain, and what it should never write down in plain text. Read about chain data.
-
Network. Which servers it contacts, what those servers learn, and how much of that traffic you can route, delay or refuse. Read about network requests.
A planning desk
The configurator lets you describe a Bitcoin app before you build or buy one. Choose where its keys sit, where its chain data comes from, and which supporting modules it includes. The schematic and the plan summary change as you choose. Nothing is saved, sent, or looked up.
Review before you trust
The review checklist is a short sequence of questions for any app that will hold value for you or for other people. It asks what you can check yourself: a working restore, a signing screen that shows the whole transaction, a list of the hosts an app contacts. A product page is not evidence, and neither is a demonstration video.
How we write
- We explain mechanisms first. We do not name products, because products change faster than the reasons behind them.
- We do not predict prices, rank assets, or suggest what anyone should hold, sell, or sign.
- We say so when we do not know something, and when a claim cannot be checked from outside the software.
Not financial, legal, or medical advice
Nettlewick describes how software works. It does not tell you what to buy, hold, sell, or move, and it does not replace a qualified reviewer for any app that holds funds.
Who this is for
Developers choosing an architecture, product people writing a specification, careful users who want to understand an app before they trust it, and teachers who need a clear picture of how the parts connect.