# Vite Impl Javascript Api

> >

- **Type:** Skill
- **Install:** `agentstack add skill-impertio-studio-vite-claude-skill-package-vite-impl-javascript-api`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Impertio-Studio](https://agentstack.voostack.com/s/impertio-studio)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Impertio-Studio](https://github.com/Impertio-Studio)
- **Source:** https://github.com/Impertio-Studio/Vite-Claude-Skill-Package/tree/main/skills/source/vite-impl/vite-impl-javascript-api

## Install

```sh
agentstack add skill-impertio-studio-vite-claude-skill-package-vite-impl-javascript-api
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# vite-impl-javascript-api

## Quick Reference

### Core API Functions

| Function | Return Type | Purpose |
|----------|------------|---------|
| `createServer(inlineConfig?)` | `Promise` | Start a programmatic dev server |
| `build(inlineConfig?)` | `Promise` | Run a production build |
| `preview(inlineConfig?)` | `Promise` | Start a preview server for built output |
| `resolveConfig(inlineConfig, command, ...)` | `Promise` | Resolve and merge all config sources |
| `mergeConfig(defaults, overrides, isRoot?)` | `Record` | Deep-merge two Vite configs |
| `loadConfigFromFile(configEnv, ...)` | `Promise` | Load config from a file path |
| `loadEnv(mode, envDir, prefixes?)` | `Record` | Load `.env` files for a given mode |

### Utility Functions

| Function | Purpose |
|----------|---------|
| `searchForWorkspaceRoot(current, root?)` | Find monorepo workspace root directory |
| `normalizePath(id)` | Convert Windows backslashes to forward slashes |
| `createFilter(include, exclude)` | Create a picomatch-based file filter |
| `transformWithOxc(code, filename, options?, inMap?)` | Transform code with OXC (Vite 8+) |
| `transformWithEsbuild(code, filename, options?, inMap?)` | Transform code with esbuild (DEPRECATED) |
| `preprocessCSS(code, filename, config)` | Preprocess CSS (experimental) |

### Version Constants

| Constant | Description |
|----------|-------------|
| `version` | Current Vite version string |
| `rolldownVersion` | Rolldown version used (Vite 8+) |
| `esbuildVersion` | Backward compatibility only |
| `rollupVersion` | Backward compatibility only |

### Critical Warnings

**NEVER** use `createServer()` and `build()` in the same Node.js process without setting `process.env.NODE_ENV` or the `mode` config option consistently. Inconsistent modes cause unpredictable behavior.

**NEVER** call `mergeConfig()` with `isRoot=true` (the default) when merging nested config subsections like `build` or `server`. ALWAYS pass `isRoot=false` for nested option merging.

**NEVER** use `transformWithEsbuild()` in new projects targeting Vite 8+. ALWAYS use `transformWithOxc()` instead -- `transformWithEsbuild` is deprecated.

**ALWAYS** call `server.close()` in cleanup/shutdown handlers when using `createServer()` programmatically. Failing to close leaks file watchers, HTTP connections, and WebSocket handles.

**ALWAYS** call `server.listen()` after `createServer()` -- the server is NOT listening by default. `createServer()` only creates the server instance.

---

## Decision Tree: Which API Function?

```
Need to run Vite programmatically?
├── Development server → createServer()
│   ├── Custom middleware → server.middlewares.use()
│   ├── SSR rendering → server.ssrLoadModule()
│   ├── Transform a file → server.transformRequest()
│   └── Transform HTML → server.transformIndexHtml()
├── Production build → build()
├── Preview built output → preview()
├── Read resolved config → resolveConfig()
├── Combine configs → mergeConfig()
├── Load config file → loadConfigFromFile()
├── Load env variables → loadEnv()
├── Transform code standalone → transformWithOxc() (v8+) / transformWithEsbuild() (v5-v7)
└── Find workspace root → searchForWorkspaceRoot()
```

---

## ViteDevServer Interface

The `ViteDevServer` object returned by `createServer()` provides full programmatic control:

### Properties

| Property | Type | Purpose |
|----------|------|---------|
| `config` | `ResolvedConfig` | Fully resolved Vite configuration |
| `middlewares` | `Connect.Server` | Connect-compatible middleware stack |
| `httpServer` | `http.Server \| null` | Underlying Node HTTP server (null in middleware mode) |
| `watcher` | `FSWatcher` | Chokidar file system watcher |
| `ws` | `WebSocketServer` | WebSocket server for HMR communication |
| `pluginContainer` | `PluginContainer` | Runs plugin hooks programmatically |
| `moduleGraph` | `ModuleGraph` | Tracks import relationships and HMR state |
| `resolvedUrls` | `ResolvedServerUrls \| null` | Resolved local and network URLs (available after `listen()`) |

### Methods

| Method | Signature | Purpose |
|--------|-----------|---------|
| `transformRequest` | `(url, options?) → Promise` | Transform a module by URL |
| `transformIndexHtml` | `(url, html, originalUrl?) → Promise` | Apply HTML transforms |
| `ssrLoadModule` | `(url, options?) → Promise>` | Load a module for SSR |
| `ssrFixStacktrace` | `(e: Error) → void` | Fix SSR error stack traces |
| `reloadModule` | `(module: ModuleNode) → Promise` | Trigger HMR reload for a module |
| `listen` | `(port?, isRestart?) → Promise` | Start listening on a port |
| `restart` | `(forceOptimize?) → Promise` | Restart the dev server |
| `close` | `() → Promise` | Shut down the server and clean up |
| `bindCLIShortcuts` | `(options?) → void` | Enable keyboard shortcuts (r, u, c, q) |
| `waitForRequestsIdle` | `(ignoredId?) → Promise` | Wait until all pending requests complete |

---

## PreviewServer Interface

The `PreviewServer` object returned by `preview()`:

| Member | Type | Purpose |
|--------|------|---------|
| `config` | `ResolvedConfig` | Resolved configuration |
| `middlewares` | `Connect.Server` | Connect middleware stack |
| `httpServer` | `http.Server` | HTTP server (ALWAYS present, unlike dev server) |
| `resolvedUrls` | `ResolvedServerUrls \| null` | Resolved URLs |
| `printUrls()` | method | Print server URLs to console |
| `bindCLIShortcuts(options?)` | method | Enable keyboard shortcuts |

---

## Key Types

### InlineConfig

Extends `UserConfig` with:
- `configFile`: Set to a path to specify config file, or `false` to disable auto-resolving. ALWAYS set `configFile: false` when you want zero config file influence.

### ResolvedConfig

All `UserConfig` properties resolved (no undefined values), plus:
- `config.assetsInclude(id)`: Function to check if an ID is an asset
- `config.logger`: Internal logger object

### resolveConfig Signature

```typescript
async function resolveConfig(
  inlineConfig: InlineConfig,
  command: 'build' | 'serve',  // 'serve' for dev AND preview
  defaultMode?: string,        // default: 'development'
  defaultNodeEnv?: string,     // default: 'development'
  isPreview?: boolean,         // default: false
): Promise
```

**ALWAYS** pass `command: 'serve'` for both dev and preview scenarios. The `command` parameter is `'build'` ONLY for production builds.

---

## Version Differences

| Feature | Vite 5.x / 6.x | Vite 8.x+ |
|---------|----------------|-----------|
| Transform API | `transformWithEsbuild()` | `transformWithOxc()` |
| Bundler engine | Rollup-based | Rolldown-based |
| Version constants | `version` only | `version`, `rolldownVersion`, `esbuildVersion` (compat), `rollupVersion` (compat) |
| Filter utility | `@rollup/pluginutils` | `createFilter()` re-exported from Vite directly |

---

## Reference Links

- [references/api-reference.md](references/api-reference.md) -- Complete API signatures for all programmatic functions
- [references/examples.md](references/examples.md) -- Working code examples for dev server, build, preview, and utilities
- [references/anti-patterns.md](references/anti-patterns.md) -- Common programmatic API mistakes and how to avoid them

### Official Sources

- https://vite.dev/guide/api-javascript
- https://vite.dev/guide/api-environment
- https://vite.dev/guide/ssr

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Impertio-Studio](https://github.com/Impertio-Studio)
- **Source:** [Impertio-Studio/Vite-Claude-Skill-Package](https://github.com/Impertio-Studio/Vite-Claude-Skill-Package)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** yes
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** yes
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-impertio-studio-vite-claude-skill-package-vite-impl-javascript-api
- Seller: https://agentstack.voostack.com/s/impertio-studio
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.