Vite Plugin

The evlog/vite plugin adds build-time DX features to any Vite-based project. It works with SvelteKit, Hono, Express, Fastify, Elysia, and any framework using Vite as its build tool.

Quick Start

1. Install

bun add evlog

2. Add to vite.config.ts

import { defineConfig } from 'vite'
import evlog from 'evlog/vite'

export default defineConfig({
  plugins: [
    evlog({
      service: 'my-api',
      environment: 'production',
    }),
  ],
})

That's it. The plugin automatically:

• Initializes the logger at compile time (no initLogger() call needed)
• Strips log.debug() calls from production builds

Features

Auto-initialization

The plugin injects logger configuration at compile time via Vite's define hook. Your code can use log, createLogger(), and createRequestLogger() immediately — no initLogger() call required.

// Before (manual setup)
import { initLogger, createLogger } from 'evlog'
initLogger({ env: { service: 'my-api' } })
const log = createLogger()

// After (with Vite plugin)
import { createLogger } from 'evlog'
const log = createLogger()

The service, environment, pretty, silent, enabled, and sampling options are serialized and injected at build time.

Debug stripping

By default, all log.debug() calls are removed from production builds. This is a compile-time transformation — the calls are completely eliminated from the output, not just silenced.

evlog({
  service: 'my-api',
  // Default: strip debug logs in production builds
  // strip: ['debug'],

  // Strip debug and info in production:
  // strip: ['debug', 'info'],

  // Disable stripping:
  // strip: [],
})

Stripping only activates during vite build (not vite dev).

Source location injection

When enabled, the plugin injects __source: 'file:line' into object-form log calls. This tells you exactly which file and line produced each log entry.

evlog({
  service: 'my-api',
  sourceLocation: true,      // Always inject
  // sourceLocation: 'dev',  // Only in development
})

Before transform:

log.info({ action: 'checkout', total: 99 })

After transform:

log.info({ action: 'checkout', total: 99, __source: 'src/checkout.ts:42' })

Auto-imports (opt-in)

Automatically detect and import evlog symbols (log, createEvlogError, parseError, etc.) without manual import statements. Disabled by default.

evlog({
  service: 'my-api',
  autoImports: true,
})

When enabled, the plugin:

1. Scans your code for evlog symbols
2. Adds the correct import statements automatically
3. Generates a .d.ts file for TypeScript support

Client-side injection

When the client option is provided, the plugin injects a <script> tag into HTML pages that initializes the client-side logger. This enables log.info(), log.error(), etc. in browser code.

evlog({
  service: 'my-api',
  client: {
    console: false,
    transport: {
      enabled: true,
      endpoint: '/api/_evlog/ingest',
    },
  },
})

Configuration

Nuxt Integration

The Nuxt module exposes strip and sourceLocation directly in nuxt.config.ts:

export default defineNuxtConfig({
  modules: ['evlog/nuxt'],
  evlog: {
    env: { service: 'my-app' },
    strip: ['debug'],           // Default
    sourceLocation: 'dev',      // Inject in dev only
  },
})

Vite Compatibility

The plugin supports Vite 7+ and is optimized for Vite 8 (Rolldown). On Vite 8, transform hooks use Rolldown-native filter and moduleType for maximum performance — non-matching files are skipped entirely on the Rust side without crossing the JS bridge.