What is mfe-architecture-boundary-design?

Rules for designing micro-frontends around business areas. A micro-frontend is an independently deployable part of a web application that one team owns from development through operation.

Use it when choosing micro-frontend boundaries, assigning ownership, reducing dependencies, and checking whether teams can release parts independently.

It helps teams avoid splitting an application into overly small or tightly connected pieces that require constant coordination. It also distinguishes a business-owned micro-frontend from a reusable interface component.

mfe-architecture-boundary-design — Cursor rule for Cursor by lucamezza

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.

README.md

[![agentmods](https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design/github.svg)](https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design)

Your own site

<a href="https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design"><img src="https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design/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.

Your own site · 80×15

<a href="https://agentmods.dev/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design"><img src="https://agentmods.dev/badge/rules/lucamezzalira/mfe-skills/mfe-architecture-boundary-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 1,734 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.

Model	Per session	Once invoked
Fable 5.1	$0.00022	$0.01734
Opus 5	$0.00011	$0.00867
Sonnet 5	$0.00004	$0.00347
Haiku 4.5	$0.00002	$0.00173

Measured 12d ago against content hash d0ed9760e2fa, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

mfe-architecture-boundary-design 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-boundary-design.mdc · 120 lines

How it starts

The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Boundary design

Version: 1.2 | Skill: understanding-mfe-architecture | Source: Building Micro-Frontends (O'Reilly) and the Micro-Frontend Canvas

The canonical definition

A micro-frontend represents a business subdomain that is autonomous, independently deliverable, with the same or different technology, with a low degree of coupling, and owned by a single team.

Six characteristics follow directly from this definition:

Business domain representation — models a subdomain, not a technical layer or UI component type
Autonomous codebase — built and maintained without coordinating with other teams
Independent deployment — shipped without requiring other teams to act
Low coupling — minimal external dependencies; changes inside do not cascade outside
Optimised for fast flow — team can iterate and release at its own cadence
Single-team ownership — one team owns design, development, deployment, and operations end-to-end

The critical distinction from components: a component addresses a technical challenge through abstraction and reusability. A micro-frontend completely owns a business domain and is not designed for reuse. If you can reuse it everywhere, it is probably a component. If it represents a domain and can live on its own, it is a micro-frontend.

The seven principles

Adapted from microservices architecture. When reviewing or generating architecture, check it against each one.

1. Modelled around business domains — identify boundaries by user journey steps (checkout, search, profile) or business capabilities, not by technical framework types or component categories. DDD event storming is the recommended technique for identifying subdomains.

2. Culture of automation — a poor automation culture makes micro-frontends a nightmare. Every independent unit needs solid CI/CD pipelines with a fast feedback loop. Automation also enforces guardrails: bundle size limits, dependency alignment, design system version enforcement, and architecture fitness functions (for example no cross-MFE imports except explicit shared allowlists).

Read the full file on GitHub · 120 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.

12d ago First seen · 120 lines · 1,734 tokens per session scan A d0ed9760e2fa

Subscribe to this mod's changes

mfe-architecture-boundary-design is a cursor rule published in the GitHub repository lucamezzalira/mfe-skills (51 stars, last pushed 17d ago), licensed MIT. It adds 22 tokens to every session and 1,734 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.

Frontend

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Source: docs/agents/pages.md Regenerate: npm run agents:sync -w packages/openbridge-webcomponents -->.

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mfe-architecture-boundary-design