Invar — a terminal IDE built on ivue

Invar is ivue at full scale: a complete terminal IDE — editor, file tree, workspace search, find/replace, git, tasks, terminals, LSP, and agent integration — built entirely on ivue classes, running under Bun in a terminal with no DOM and no Vue components. The same Reactive() and Static() that drive the browser examples on this site drive every keystroke of it; only the paint target changed.

Invar is an alpha, experimental project — a proving ground for ivue beyond the web, and an experiment in agentic development: AI agents wrote almost all of it, using the ivue skill as their base discipline, with every module governed by explicit invariant contracts and a merge gate that enforces them. The story of how that worked is a series on the blog, starting with Introducing Invar and AI agents built an editor.

A look inside

The editor — file tree, syntax-highlighted source, structure outline.

Workspace search streaming ripgrep results — click a match, land on the line.

In-file find — live match highlighting, case, whole-word, and regex toggles.

Quick Open — fuzzy go-to-file with exact-basename ranking.

The agent fleet's task dashboard — one shared renderer for pane and CLI.

The numbers

Counted from the open repository, 2026-09-03 (its own deterministic census script, scripts/census.sh, plus AST checkers; source excludes tests):

source lines               107,670   across 412 files, 41 modules
classes                        384   100% namespace-pattern conforming
Reactive() classes              91
Static() capability classes    211
invariant contracts             39   (~19,000 lines)
value-import cycles              0   (Tarjan over the import graph)
computed() calls                12   (memoization is opt-in)
module-level variables           0

Those zeros are not tidiness — they are the ivue discipline holding at scale, mechanically enforced on every merge. How each one is achieved has its own deep dive: zero import cycles, zero module-level state, twelve computed() in 108k lines.

What to study in the source

Invar is open as a study-scale example of ivue architecture — the patterns from this site's guides, applied at three orders of magnitude:

• The namespace pattern everywhere — 384 classes, one export shape, cross-module references that resolve at first access.
• 91 Reactive() classes, 211 Static() capability classes — file system, subprocesses, PTY file descriptors, and native library handles behind $-cached static getters.
• The flyweight pattern rendering editor text at O(viewport) — the same architecture as the 20-million-cell grid, driving a real editor.
• Reactivity as resource governor — SQLite connections, LSP servers, and timers that exist only while observed.
• Invariant contracts — every module ships a *.invariants.md stating what must hold, what is impossible if it does, and how it is verified: uniformity as an instrument.

github.com/infinite-system/invar — clone it, run bun start, and read the modules with the guides open beside them.

Related guide pages

• Backend ivue — ivue with no DOM, under Bun.
• Static() — Capability Classes — capability classes, $-cached statics, the anchor.
• Caches, Registries & self — shared stores, LazyShared, reading statics through self.
• Namespace Pattern — $Class, Class, and the types derived from them.
• Node class HMR — class hot-swap on the backend.