microfrontends

# Vercel Microfrontends Split a large application into independently deployable units that render as one cohesive app. Vercel handles routing on its global network using `microfrontends.json`. **Core concepts:** default app (has `microfrontends.json`, serves unmatched requests) · child apps (have `routing` path patterns) · asset prefix (prevents static-asset collisions) · independent deployments. **Frameworks:** Next.js (App Router + Pages Router), SvelteKit, React Router, Vite — all via `@vercel/microfrontends`. **CLI (`vercel microfrontends` / `vercel mf`):** - `create-group` — create a new group; interactive by default, or fully non-interactive with `--non-interactive` (options: `--name`, `--project` (repeatable), `--default-app`, `--default-route`, `--project-default-route` (repeatable, format: `<project>=<route>`, required for each non-default project in non-interactive mode), `--yes` to skip confirmation prompt); note: `--non-interactive` is blocked if adding the projects would exceed the free tier limit — the user must confirm billing changes interactively - `add-to-group` — add the current project to an existing group; always asks for confirmation (there is no `--yes`), so it needs an interactive terminal, and it refuses to run with `--non-interactive` when adding would go past the free project limit (options: `--group` and `--default-route` pre-fill the prompts) - `remove-from-group` — remove the current project from its group; without `--yes` it needs an interactive terminal (option: `--yes` skips the project-link prompt and removal confirmations, including the warning for projects still referenced in `microfrontends.json`) - `delete-group` — delete a group and all its settings, irreversible; without `--yes` it needs an interactive terminal (options: `--group` to pre-select group, `--yes` skips the deletion confirmation; pass both to delete without prompts) - `inspect-group` — retrieve group metadata (project names, frameworks, git repos, root dirs); useful for automating setup (options: `--group`, `--format=json`, `--config-file-name`) - `pull` — pull remote `microfrontends.json` for local development (option: `--deployment`; needs Vercel CLI 65+, older CLIs use `--dpl`) - `microfrontends proxy` — local dev proxy · `microfrontends port` — print auto-assigned port ## Finding Detailed Information This skill includes detailed reference docs in the `references/` directory. **Do not read all references upfront.** Instead, search or grep the relevant file when the user asks about a specific topic: | Topic | Reference file | |---|---| | Getting started, quickstart, framework setup, `microfrontends.json` schema, fields, naming, examples | `references/configuration.md` | | Path expressions, asset prefixes, flag-controlled routing, middleware | `references/path-routing.md` | | Local proxy setup, polyrepo config, Turborepo, ports, deployment protection | `references/local-development.md` | | Inspecting groups (`inspect-group`), adding/removing projects, fallback environments, navigation, observability | `references/managing-microfrontends.md` | | Testing utilities (`validateMiddlewareConfig`, `validateRouting`, etc.), debug headers, common issues | `references/troubleshooting.md` | | Deployment protection, Vercel Firewall, WAF rules for microfrontends | `references/security.md` | When the user asks about a specific topic, use grep or search over the relevant reference file to find the answer without loading all references into context.