What hiiu is

hiiu reads a frontend repository and builds a copy of the app that runs with no backend and no real data. The routes, the components and the design system are the ones already in the repo. Every request the app makes is intercepted and answered locally, so the copy runs on a laptop with nothing else switched on.

That copy is meant for the people who cannot run the real one. A designer opens it, describes a change to a coding agent, and watches the change render in the actual product rather than in a drawing of it.

The shape of it #

Four commands carry the whole loop, and each one is documented in the reference:

Step	Command	What it leaves behind
Set it up once	hiiu init	A built, verified base for this repo
Open a copy	hiiu dev	The app's own dev server, on loopback, intercepted
Give one to a designer	hiiu fork	A git workspace with an AGENTS.md in it

Everything else is a piece of that pipeline you can run on its own: analyze reads the repo, ir compiles what it found into a contract, decisions proposes the answers analysis cannot compute, overlay prints the interception files, build makes the base, and verify crawls a running copy and reports what it saw.

What to expect on your own repo #

The copy never talks to a real service, so no customer data can reach it. Requests the interception layer does not recognise are denied and recorded rather than guessed at, which means an app that talks to something unusual produces a list of gaps instead of a page that is quietly wrong. That list is the useful output: it says exactly what hiiu could not stand in for.

Two readers #

Every page here has a markdown twin at the same path with .md on the end, and the twin is the same file the page was rendered from. /llms.txt lists them all, and /llms-full.txt is the whole site as one document.

curl https://hiiu.eu/docs/cli/build.md
curl https://hiiu.eu/llms-full.txt

The CLI is built for the same reader. Every command takes --json, puts exactly one document on stdout and sends everything else to stderr, so an agent can parse a command a human ran:

hiiu analyze --json | jq '.framework, .router'

Driving hiiu from an agent is the page about that.

Where to go next #

• Install, which is honest about the fact that the CLI is not published yet.
• Quickstart: analyze, build, dev, verify, on your own repo.
• The CLI contract: global flags, the JSON document, exit codes.