microfrontends AGENTS.md

A project guide for Vercel’s microfrontends library, which lets separate parts of a large web application be developed and deployed independently.

In plain words
What is it for?
Use it when building, testing, linting, or changing the TypeScript library and its framework examples.
Why use it?
It explains the monorepo layout, supported web frameworks, package manager, and commands agents must use.

Instructions file for CodexOpenCode

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.

agentmods
npx agentmods add instructions/vercel/microfrontends/agents-md
Clone the repo
git clone --depth 1 https://github.com/vercel/microfrontends

Made for: Codex, OpenCode.

Per session 1,094 This file is loaded in full into every session.
When invoked 1,094 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.01094 $0.01094
Opus 5 $0.00547 $0.00547
Sonnet 5 $0.00219 $0.00219
Haiku 4.5 $0.00109 $0.00109

Measured yesterday against content hash 0948c91714e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

microfrontends AGENTS.md 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 yesterday.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

AGENTS.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

This is a monorepo for @vercel/microfrontends, a library that enables splitting large applications into independently developed and deployed microfrontends on Vercel. The package provides generic platform support for microfrontends in multiple frameworks, such as Next.js, SvelteKit, React Router, Vite, and React.

Repository Structure

  • packages/microfrontends/ - The main @vercel/microfrontends package (the only publishable package)
  • examples/ - Working examples of microfrontend implementations (nextjs-app, nextjs-pages, react-router, single-spa, sveltekit, etc.)

Technologies

  • This is a TypeScript codebase
  • Use pnpm for package management
  • Turbo manages the monorepo build pipeline
  • The package uses dual ESM/CJS exports via tsup
  • Follow Vercel style guide (configured via @vercel/style-guide)
  • Be familiar with Module Federation, single-spa, and Next.js Multi-Zones

Common Commands

  • pnpm build - Build all packages using Turbo
  • pnpm test - Run unit tests for all packages
  • pnpm lint - Run ESLint on all packages
  • pnpm format - Format all files with Prettier
  • pnpm typecheck - Run TypeScript type checking
  • pnpm checks - Run build, lint, test, and typecheck on all packages (run before submitting PRs)

When running commands for a specific application, do not cd into the directory. Run commands from the root. The above commands can be run for a particular package by using a filter option: pnpm checks -F <package name>. Use this.

Make sure that pnpm checks is successful for the entire repository when verifying a change.

Dev examples

  • pnpm dev:nextjs-app - Run the Next.js App Router example
  • pnpm dev:nextjs-pages - Run the Next.js Pages Router example
  • pnpm dev:react-router - Run the React Router example
  • pnpm dev:single-spa - Run the single-spa example
  • pnpm dev:sveltekit - Run the SvelteKit example

Read the full file on GitHub · 96 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. yesterday First seen · 96 lines · 1,094 tokens per session scan A 0948c91714e1

Subscribe to this mod's changes

microfrontends AGENTS.md is an instructions file published in the GitHub repository vercel/microfrontends (45 stars, last pushed 1mo ago), licensed MIT. It adds 1,094 tokens to every session, about $0.0055 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.