mfe-architecture-rules-ref

mfe-architecture-rules-ref is a cursor rule for Cursor from lucamezzalira/mfe-skills. It costs 27 tokens per session (714 once invoked), scanned A, original, MIT.

A quick reference for checking whether micro-frontend boundaries follow seven design rules. Micro-frontends are independently deployable parts of a larger web application.

In plain words
What is it for?
Use it during reviews of existing or planned micro-frontends, especially when checking ownership, deployment independence, API size, fallback behavior, and coordination needs.
Why use it?
It provides a short checklist for spotting boundaries that are too large, too coupled, poorly owned, or unable to work independently before implementation starts.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it during reviews of existing or planned micro-frontends, especially when checking ownership, deployment independence, API size, fallback behavior, and coordination needs.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/lucamezzalira/mfe-skills

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mfe-architecture-rules-ref

README.md
[![agentmods](https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref/github.svg)](https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref)
Your own site
<a href="https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref"><img src="https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mfe-architecture-rules-ref

Your own site · 80×15
<a href="https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref"><img src="https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-rules-ref.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 714 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00714
Opus 5 $0.00014 $0.00357
Sonnet 5 $0.00005 $0.00143
Haiku 4.5 $0.00003 $0.00071

Measured 12d ago against content hash e1dbbbae7a67, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

mfe-architecture-rules-ref scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/mfe-architecture-rules-ref.mdc · 51 lines

How it starts

The opening of the file, as written. The whole thing — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MFE boundary rules — quick reference

Version: 1.2 | Skill: understanding-mfe-architecture | Full rules: load reviewing-mfe-boundaries skill

For full rule definitions, violation signals, and code-checkable patterns across all toolchains (React, Angular/Native Federation, Module Federation v1/v2, Single SPA), load reviewing-mfe-boundaries skill.

Boundary health check

Use this checklist when reviewing whether existing boundaries are well-formed. A well-formed boundary satisfies all seven:

  1. Is the API surface minimal — fewer than 5 props to the container?
  2. Is the micro-frontend context-aware — does it retrieve its own data given minimal input?
  3. Is it less extensible than a component — not designed for reuse across domains?
  4. Is it coarse-grained — not fine enough to require constant coordination with its container?
  5. Can it deploy without coordinating with other teams?
  6. Does it have a graceful fallback if it fails to load?
  7. Does a single team own it end-to-end?

If any answer is no, the boundary needs to be revisited before implementation begins.

Rule summary

Rule Core principle Primary violation signal
1 — Business subdomain Represents a domain, not a UI element Named after UI element; reused across domains
2 — Minimal API surface Fewer than 5 props; identifiers not objects Domain objects passed as props; container fetches data for the MFE
3 — Hide implementation details API contract agreed upfront; internals hidden Direct import from another MFE's package
4 — Events not shared state Event emitter or storage only; no shared state managers Redux/Zustand/MobX shared across MFE boundaries
5 — Independent deployment No versioned URL pinning; no build-time coupling Shell hard-codes versioned remote URL; CI needs: coupling
6 — Isolate failure Fallback in shell for every remote mount No fallback at mount point in the shell
7 — Coarse-grained Max 3 MFEs per view; shell first segment via manifest; MFE hardcodes sub-routes Shell owning /catalog/product/:id; shell hard-coded MFE routes; shell catalog:* handlers
8 — Single-team ownership One team owns full lifecycle Multiple teams in CODEOWNERS for same MFE

Read the full file on GitHub · 51 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 51 lines · 714 tokens per session scan A e1dbbbae7a67

Subscribe to this mod's changes

mfe-architecture-rules-ref is a cursor rule published in the GitHub repository lucamezzalira/mfe-skills (51 stars, last pushed 17d ago), licensed MIT. It adds 27 tokens to every session and 714 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.