> For AI agents: the complete documentation index is available at https://mfdoctor.kevinbeier.com/llms.txt, the full documentation bundle is available at https://mfdoctor.kevinbeier.com/llms-full.txt.

# Vite integration notes

The Vite plugin is not a thin copy of the Rspack plugin. mfdoctor keeps its
Vite-only facts under the `vite` section of `project.json`.

## Rolldown and Vite Plus

Module Federation on Rolldown-integrated Vite and Vite Plus uses the **same**
mfdoctor entry as classic Vite:

```ts
import { federation } from "@module-federation/vite";
import { federationDoctor } from "@tonoizer/mfdoctor/vite";
```

| Flavor                    | How mfdoctor detects it                                                         | Emit engine |
| ------------------------- | ------------------------------------------------------------------------------- | ----------- |
| Classic Vite              | Default when no strong Rolldown / Vite Plus markers                             | `rollup`    |
| `rolldown-vite` / Vite 8+ | Declared `rolldown-vite`, `vite→rolldown-vite` alias, or `meta.rolldownVersion` | `rolldown`  |
| Vite Plus                 | `vite-plus` / `@voidzero-dev/vite-plus-core` (including `vite` alias overrides) | `rolldown`  |

Bare `rolldown` in `package.json` is weak evidence only (common in monorepo
tooling roots) and does **not** reclassify classic Vite by itself.

mfdoctor records `bundler.lifecycle` (`flavor`, `engine`, `postEmitHook`,
`evidence`) on `project.json`. Emit analysis prefers **on-disk** `dist/**` /
`build/**` assets over the in-memory Rollup `bundle` object, because Rolldown
does not share that object across hooks. When Rolldown has not finished writing
on `writeBundle`, mfdoctor defers to `closeBundle`. If emit facts are still
missing, it leaves `capabilities.emittedAssets` false so
[`doctor/partial-analysis`](https://mfdoctor.kevinbeier.com/rules/doctor/partial-analysis.md) reports the gap
honestly.

Direct Rolldown **without** `@module-federation/vite` is unsupported, Rolldown
dropped built-in Module Federation in favor of the Vite plugin.

A copyable production smoke lives in
[`examples/compatibility/rolldown`](https://github.com/tonoizer/module-federation-doctor/tree/main/examples/compatibility/rolldown).
It aliases `vite` to Vite Plus and registers the same `@tonoizer/mfdoctor/vite`
entry. The matrix cell stays **partial** (`partial-bundler` on `report.status`)
until emit evidence is enough to promote.

## Vite-only options

| Option                                       | Risk or opportunity                                     | mfdoctor guidance                                                                                                                   |
| -------------------------------------------- | ------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| `publicPath`                                 | Wrong base breaks remote chunks and CSS                 | Compare with manifest output                                                                                                        |
| `bundleAllCSS`                               | Full CSS set can repeat for every expose                | Warn for multi-expose producers                                                                                                     |
| `ignoreOrigin`                               | Proxy entry origin without a tested base                | Info when true without `server.origin` ([`vite/ignore-origin`](https://mfdoctor.kevinbeier.com/rules/vite/ignore-origin.md))        |
| `virtualModuleDir`                           | Nested virtual folder collides                          | Warn when the name contains slashes ([`vite/virtual-module-dir`](https://mfdoctor.kevinbeier.com/rules/vite/virtual-module-dir.md)) |
| `hostInitInjectLocation`                     | HTML and entry injection serve different app shapes     | SSR needs `entry` ([`vite/host-init-inject-ssr`](https://mfdoctor.kevinbeier.com/rules/vite/host-init-inject-ssr.md))               |
| `moduleParseTimeout`                         | Fixed timer can end a busy large parse                  | Prefer idle timeout                                                                                                                 |
| `moduleParseIdleTimeout`                     | Resets while modules are active                         | Better for large builds                                                                                                             |
| `varFilename`                                | Adds a synchronous global-format entry                  | Verify filename and deployment; intentional mixed-bundler escape hatch                                                              |
| `target` / `ssrExternals` / `ssrEntryLoader` | Changes server remote output / React instance ownership | Keep SSR contracts aligned ([`vite/ssr-nitro-externals`](https://mfdoctor.kevinbeier.com/rules/vite/ssr-nitro-externals.md))        |
| `disableRemote/shared/snapshot`              | Removes runtime capabilities                            | Reject config that still uses them                                                                                                  |

`hostInitInjectLocation` is a `@module-federation/vite` control.
[`vite/host-init-inject-ssr`](https://mfdoctor.kevinbeier.com/rules/vite/host-init-inject-ssr.md) does **not**
run on Rsbuild, Modern.js, Rspack, or Webpack. Those SSR hosts inject
federation bootstrap through different public APIs, and mfdoctor does not invent
a sibling finding without a documented option and fixture. Copied Vite keys on
webpack-family configs are
[`config/copied-vite-options-on-webpack`](https://mfdoctor.kevinbeier.com/rules/config/copied-vite-options-on-webpack.md).
See [Limitations](https://mfdoctor.kevinbeier.com/limitations.md#ssr-host-init-inject-vite-only).

### Remotes typing

Vite string remotes and object remotes without `type` default to **`var`**. mfdoctor warns via
[`vite/remotes-prefer-module`](https://mfdoctor.kevinbeier.com/rules/vite/remotes-prefer-module.md) unless you set explicit
`type: 'module'` (Vite↔Vite ESM), another explicit type such as `global` for webpack/rspack
remotes, or configure producer `varFilename` for var-host interop
([`vite/var-filename-interop`](https://mfdoctor.kevinbeier.com/rules/vite/var-filename-interop.md)).

## Dialect fact matrix (config-only vs plugin-resolved)

| Check                                   | CLI config-only            | Plugin `configResolved`                 |
| --------------------------------------- | -------------------------- | --------------------------------------- |
| Remotes typing / `varFilename`          | Yes                        | Yes                                     |
| `hostInitInjectLocation` / SSR          | Yes (MF options + deps)    | Yes (+ builds when `targetKind=ssr`)    |
| `manualChunks` / `codeSplitting.groups` | Skip                       | Yes (`bundler.viteConfig`)              |
| Hashed `filename`                       | Yes                        | Yes                                     |
| `remoteHmr`                             | Yes when set on MF options | Yes                                     |
| `virtualModuleDir` slashes              | Yes                        | Yes                                     |
| `ignoreOrigin` without `server.origin`  | Skip                       | Yes (info when origin observed missing) |
| `resolve.alias` ∩ shared                | Skip                       | Yes                                     |
| `server.origin`                         | Skip                       | Yes                                     |
| `publicPath` kind (manifest skip)       | Skip                       | Yes (`bundler.outputPublicPathKind`)    |

The full current surface is in the official
[normalizer](https://github.com/module-federation/vite/blob/321d7db8a4b2a1764b3a7cdc16246222d97231ac/src/utils/normalizeModuleFederationOptions.ts).

## Chunk ownership

The plugin replaces user `manualChunks` and `codeSplitting.groups` choices
where needed. This is intentional: federation bootstrap depends on isolated
runtime-init and `loadShare` chunks. A custom group can create an init-order
cycle.

Fix: move general chunk tuning outside the federation runtime graph. Do not
fight the plugin by reapplying manual chunks after it.

Source:
[Vite plugin config hook](https://github.com/module-federation/vite/blob/321d7db8a4b2a1764b3a7cdc16246222d97231ac/src/index.ts).

## Manifest asset analysis

`manifest.disableAssetsAnalyze` is not the same as
`dev.disableAssetsAnalyze`. The manifest option can speed a development
consumer, but on a producer it omits shared/expose asset detail. The official
`mf` skill currently describes this under `dev`; mfdoctor follows the actual
plugin type and implementation.

Fix: keep full asset analysis for production producer manifests. If it is
disabled for local speed, do not use that manifest as release evidence.