Tommkruix/archprint

**Mine the architecture rules your repo already enforces, with the evidence attached.**
**Try it in your browser**, nothing to install ·
Quick start · Use in CI · Use with AI agents · Docs
What it does, in plain words
Every codebase has unwritten rules. "Pages never talk to the database directly." "Shared code never reaches back
into the app." Nobody wrote them down, but the code follows them, until one day someone (or an AI assistant)
breaks one without noticing.
Archprint reads a TypeScript project, finds the rules its code already follows, and shows you the proof for each
one: how many files follow it, which files break it, and how sure it is. The rules you trust become automatic
checks in the tools your team already runs, so a break is caught the next time lint runs (in your editor, a
pre-commit hook or CI), not weeks later in review.
Think of it as a building inspector who surveys the house first and writes down how it was actually built,
instead of handing you a rulebook from somewhere else.
- **For developers and tech leads:** inferred, evidence-backed lint rules for ESLint and dependency-cruiser,
generated with init, connected with wire, and removed with eject.
- **For reviewers:** archprint check flags only the rule breaks a pull request introduces, inline on GitHub,
never the existing backlog.
- **For teams using AI coding agents:** Claude Code, Cursor and other agents can ask Archprint for the project's
rules, with the evidence, before they write code.
- **For anyone evaluating a codebase:** a quick, honest picture of how a project is actually structured.
Your CLAUDE.md is guidance. Your lint rules are enforcement. Archprint closes the gap by generating the
enforcement from patterns your codebase already demonstrates, so you adopt rules you can trust instead of
authoring them by hand.
See it in action
The recordings below use archprint-demo, a small Next.js API whose
routes reach the database only through a service layer.
**1. Find the rules your code already follows.** Each rule comes with its evidence.
**2. See why one rule is trusted.** The confidence check, step by step.
**3. Turn the rules on, watch a break get caught, and remove it all again.** Archprint writes its files, adds one
line to your ESLint config, lint flags a route that imports the database directly, and eject restores your
project exactly.
**Try it yourself, nothing to install:** open the demo in StackBlitz.
The scan runs as soon as it opens, and the demo's README
walks through enforcing a rule in ESLint, breaking it, and asking for the rules over MCP.
Use it with AI coding agents
AI coding agents can ask Archprint for a project's rules through
MCP, an open standard that lets agents use outside tools. You ask in plain
words; the agent calls Archprint on its own and answers with the evidence. Archprint only reports. Enforcement
still runs in your linter.
**Claude Code** lists the rules with what is enforced and what is held for review, then adds a route and checks
its own change with archprint before it reports back:
**Cursor works the same way.** In these recordings Cursor was set to Grok 4.7, not Claude. In the desktop app's
chat, its agent called Archprint's scan tool on its own; this screenshot shows the tool result and the answer:
In the terminal (cursor-agent), it does the same: lists the rules, then adds the route and checks it with
archprint_check:
Measured: the same question with and without Archprint
We asked Claude Code (Opus 5.5) "What architecture rules does this repo already follow?" on the demo app (70
files), five runs each way. Median [range]:
| | Without Archprint | With Archprint |
| ----------------- | ------------------------- | ------------------------- |
| Tokens read | 81k [58k to 96k] | 52k [52k to 52k] |
| Tokens written | 1.1k [1.1k to 1.4k] | 0.6k [0.6k to 0.6k] |
| Cost per question | $0.083 [$0.078 to $0.153] | $0.037 [$0.032 to $0.076] |
| Time | 17 s [15 to 19] | 10 s [9 to 31] |
| Tool calls | 5 [4 to 10] | 2 [2 to 2] |
What the answers showed:
- Both found the main rule: routes reach the database only through lib/services/.
- With Archprint, every run gave the evidence for each rule and named the one file that breaks one (lib/db.ts
reads process.env outside the config layer). No run without it noticed that.
- Without Archprint, Claude also described naming conventions Archprint does not check.
Read these numbers with care: about 50k of the tokens read in both columns are Claude Code's own system prompt,