Get started
Your software changes. Its promises shouldn't.
Find the few things your software must always keep true. Install IZ4, distil your promises, and keep them beside your code.
1 Install
curl -fsSL https://raw.githubusercontent.com/nige123/cli.iz4.you/main/install | sh
irm https://raw.githubusercontent.com/nige123/cli.iz4.you/main/install.ps1 | iex
No account, no payment, nothing to set up. Install by hand · Trouble?
2 Distil your promises
I have software already
In your repository:
iz4 init
It works with the coding agent you already use. It reads your code and docs, drafts what your software is for and who it serves, then suggests a few promises worth keeping.
No agent to hand? It asks you instead, one question at a time.
I'm starting something new
In the new repository, the same:
iz4 init
Say what it is for and who it is for, then what must always stay true for them.
For ideas, a starter pack: SaaS Essentials.
You keep, change or leave out each suggestion. Nothing is added without your yes. Keep only what really matters: two strong promises beat ten vague ones, and leaving a weak one out is a good decision.
3 Keep your promises
Your IZ4 now sits beside your code: what your software is for, who it serves, and the promises you chose. That was the hard part.
Give a promise a test and a rule for changing it, and it becomes an invariant: something your software keeps. iz4 test writes a test for each one that has none.
Every coding agent that opens the repository reads it before it works. iz4 init set that up. Next:
iz4 check
It says what holds in the file, and what is left to do. It never claims more than it checked.
A new invariant is exploring: reword its promise as often as you like, and a failing test only warns. When the promise is agreed, iz4 establish NAME. From then on, a change to it waits for your signed yes, and a failing test stops the commit.
Put your IZ4 on the record
When you're ready, register it. Your project gets a public card, an IZ4 badge like this one, and a status badge for your README.
Put your IZ4 on the record Optional. Everything above works without an account.
More: the full guide · the foundation every IZ4 carries · pricing