For AI agents: the complete documentation index is available at https://mfeflow.github.io/mfeflow/llms.txt, the full documentation bundle is available at https://mfeflow.github.io/mfeflow/llms-full.txt, and this page is available as Markdown at https://mfeflow.github.io/mfeflow/reference/mfeflow-app-json.md.
mfeflow

    mfeflow.app.json reference

    This page lists every field of mfeflow.app.json, the file in each app's folder. For why it exists, read Ownership.

    The project has one mfeflow.json at its root. Each app has one mfeflow.app.json next to its code.

    The JSON Schema is published at https://mfeflow.github.io/mfeflow/schema/mfeflow-app.json.

    Example

    apps/checkout/mfeflow.app.json
    {
  "name": "checkout",
  "owner": "team-payments",
  "contact": "#payments",
  "shells": ["shell"],
  "routes": ["/checkout", "/checkout/*"],
  "exposes": ["./App"],
  "events": {
    "publishes": ["checkout.order-completed.v1"],
    "consumes": ["cart.item-added.v1"]
  },
  "budgets": { "initialJsKb": 10 },
  "platform": { "react": "^19" }
}

    Fields

    FieldTypeRequiredMeaning
    $schematextNoSchema URL for editors
    nametextYesModule Federation name. Must match the app in mfeflow.json
    ownertextYesThe owning team, such as team-payments
    contacttextNoA Slack channel, email or URL
    shellslist of namesYesShells the remote runs in. Empty for a shell
    routeslist of pathsYesPaths the remote claims. No duplicates
    exposeslist of pathsYesModules the remote offers
    eventsobjectNoEvents the app publishes and consumes
    analyticsEventslistNoAnalytics event names the app sends
    budgetsobjectNoLimits for this app
    platformobjectNoPackage ranges the remote needs from its shell

    Rules for values

    FieldRuleExample
    nameLowercase words of letters and digits joined by single _checkout, order_status
    shellsEach item is a shell name, with the same ruleshell
    routesStarts with /. Letters, digits and / _ : * . -/cart, /shop/:id, /checkout/*
    exposesStarts with ././App
    events.*<domain>.<event>.v<major>cart.item-added.v1
    analyticsEvents<domain>_<object>_<action>checkout_order_completed

    events

    FieldTypeMeaning
    publisheslist of event namesEvents the app emits
    consumeslist of event namesEvents the app listens to

    Both are required inside events. The names use the same pattern as the event-bus package.

    budgets

    FieldTypeMeaning
    initialJsKbnumber, at least 1Gzip JavaScript budget for the remote's routes. mfeflow budget checks it
    lcpMsnumber, at least 1An LCP target for the app. Recorded for your perf job; the CLI does not measure it

    platform

    An object from package name to a semver range, such as { "react": "^19", "@mfeflow/runtime": "^0.4" }. mfeflow check-compat compares each range with the version the shell has (E302).

    Checks

    The validate and doctor commands check every app file against this format and against the project file. A bad file is E113.

    A name that disagrees with the project file, or overlapping routes, is E116. See Error codes.

    Moving from mfe.json

    Before version 0.6 this file was called mfe.json. The old name still works.

    If an app has only mfe.json, the CLI reads it and prints one notice for the command. Nothing else changes.

    If an app has both files, the CLI stops with E122. Keep mfeflow.app.json and delete mfe.json.

    To move by hand, rename the file and change $schema to the new address above. The upgrade engine has a migration that does the same for you; it runs once the upgrade command ships.

    The old schema address keeps working, so existing $schema lines still resolve in your editor.