### Install Dependencies and Start Dev Server

Source: https://github.com/hugorcd/evlog/blob/main/apps/nitro-v2-playground/README.md

Install project dependencies and start the development server.

```bash
pnpm install
pnpm run dev
```

--------------------------------

### Clone and Run TanStack Start Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/05.tanstack-start.md

Clone the evlog repository, navigate to the tanstack-start example directory, install dependencies, and run the development server. Access the demo at http://localhost:3000.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog/examples/tanstack-start
pnpm install
pnpm run dev
```

--------------------------------

### Run Fastify Example

Source: https://github.com/hugorcd/evlog/blob/main/examples/fastify/README.md

Execute this command from the monorepo root to start the Fastify example.

```bash
# From the monorepo root
bun run example:fastify
```

--------------------------------

### Install Dependencies and Start Development Server

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/README.md

Use these npm commands to install project dependencies and start the local development server. The site will be accessible at http://localhost:3000.

```bash
npm install

# Start development server
npm run dev
```

--------------------------------

### Install and Run TanStack Start Project

Source: https://github.com/hugorcd/evlog/blob/main/examples/tanstack-start/README.md

Use these commands to install project dependencies and start the development server.

```bash
pnpm install
pnpm dev
```

--------------------------------

### Install Dependencies and Run Dev Server

Source: https://github.com/hugorcd/evlog/blob/main/examples/browser/README.md

Install project dependencies using bun install and start the development server with bun run dev.

```bash
bun install
bun run dev
```

--------------------------------

### Clone and Run Fastify Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/09.fastify.md

Clone the Evlog repository, navigate to the directory, install dependencies, and run the Fastify example.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:fastify
```

--------------------------------

### Run SvelteKit Example

Source: https://github.com/hugorcd/evlog/blob/main/examples/sveltekit/README.md

Execute this command from the monorepo root to start the SvelteKit example application. Access the interactive UI at http://localhost:5173.

```bash
# From the monorepo root
bun run example:sveltekit
```

--------------------------------

### Clone and Run Hono Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/08.hono.md

Clone the Evlog repository and run the Hono example to explore the interactive test UI. This involves installing dependencies and starting the example server.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:hono
```

--------------------------------

### Run evlog Express Example

Source: https://github.com/hugorcd/evlog/blob/main/examples/express/README.md

Execute this command from the monorepo root to start the Express example application.

```bash
bun run example:express
```

--------------------------------

### Run Development Server

Source: https://github.com/hugorcd/evlog/blob/main/examples/orpc/README.md

Starts the development server for the oRPC example.

```bash
bun run dev
```

--------------------------------

### Run oRPC Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/15.orpc.md

Clone the repository, install dependencies, and run the oRPC example to test your integration. Access the interactive UI at http://localhost:3000.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:orpc
```

--------------------------------

### Run SvelteKit Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/03.sveltekit.md

Clone the Evlog repository, install dependencies, and run the SvelteKit example to explore the interactive test UI.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:sveltekit
```

--------------------------------

### Full Setup Example for Next.js

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/5.enrichers.md

Shows how to set up the Evlog logger with multiple enrichers, including trace context, within a Next.js application.

```typescript
// lib/evlog.ts
import { createEvlog } from 'evlog/next'
import {
  createUserAgentEnricher,
  createGeoEnricher,
  createRequestSizeEnricher,
  createTraceContextEnricher,
} from 'evlog/enrichers'

const enrichers = [
  createUserAgentEnricher(),
  createGeoEnricher(),
  createRequestSizeEnricher(),
  createTraceContextEnricher(),
]

export const { withEvlog, useLogger, log, createError } = createEvlog({
  service: 'my-app',
  enrich: (ctx) => {
    for (const enricher of enrichers) enricher(ctx)
  },
})
```

--------------------------------

### Full Setup Example for Standalone

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/5.enrichers.md

Demonstrates initializing the Evlog logger with a set of enrichers, including trace context, in a standalone Node.js application.

```typescript
// index.ts
import { initLogger } from 'evlog'
import {
  createUserAgentEnricher,
  createGeoEnricher,
  createRequestSizeEnricher,
  createTraceContextEnricher,
} from 'evlog/enrichers'

initLogger({
  enrichers: [
    createUserAgentEnricher(),
    createGeoEnricher(),
    createRequestSizeEnricher(),
    createTraceContextEnricher(),
  ],
})
```

--------------------------------

### Run Next.js Evlog Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/02.nextjs.md

Clone the Evlog repository, navigate to the Next.js example directory, install dependencies, and run the development server to test the integration.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog/examples/nextjs
pnpm install
pnpm run dev
```

--------------------------------

### Run NestJS Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/06.nestjs.md

Clone the evlog repository, install dependencies, and run the NestJS example using pnpm.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:nestjs
```

--------------------------------

### Run Evlog React Router Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/11.react-router.md

Clone the Evlog repository, install dependencies, and run the React Router example to explore the interactive test UI.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:react-router
```

--------------------------------

### Run Express Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/07.express.md

Clone the Evlog repository, install dependencies, and run the Express example using pnpm. Access the interactive test UI at http://localhost:3000.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:express
```

--------------------------------

### Clone and Run Evlog Elysia Example Locally

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/10.elysia.md

Clone the Evlog repository, navigate to the project directory, install dependencies, and run the Elysia example. Access the interactive UI at http://localhost:3000.

```bash
git clone https://github.com/hugorcd/evlog.git
cd evlog
pnpm install
pnpm run example:elysia
```

--------------------------------

### Install evlog AI Skill

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/1.start/3.installation.md

Install the evlog skill for your AI assistant to enable guided setup and code review. This command should be run in your terminal.

```bash
npx skills add https://www.evlog.dev
```

--------------------------------

### Start Documentation Site

Source: https://github.com/hugorcd/evlog/blob/main/AGENTS.md

Starts the documentation site, typically accessible on port 3000.

```bash
pnpm run docs
```

--------------------------------

### Full Setup Example for Hono / Express / Fastify / Elysia / NestJS

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/5.enrichers.md

Provides integration examples for using multiple enrichers, including trace context, with various Node.js frameworks like Hono, Express, Fastify, Elysia, and NestJS.

```typescript
import {
  createUserAgentEnricher,
  createGeoEnricher,
  createRequestSizeEnricher,
  createTraceContextEnricher,
} from 'evlog/enrichers'

const enrichers = [
  createUserAgentEnricher(),
  createGeoEnricher(),
  createRequestSizeEnricher(),
  createTraceContextEnricher(),
]

app.use(evlog({ enrichers })) // Hono / Express / Elysia
// await app.register(evlog, { enrichers }) // Fastify
// EvlogModule.forRoot({ enrichers }) // NestJS
```

--------------------------------

### Start Development Server

Source: https://github.com/hugorcd/evlog/blob/main/AGENTS.md

Starts the development server for the playground environment.

```bash
pnpm run dev
```

--------------------------------

### Install Evlog and Run Wrangler

Source: https://github.com/hugorcd/evlog/blob/main/examples/workers/README.md

Install the evlog package and start the Cloudflare Workers development server.

```bash
pnpm add evlog
pnpm dlx wrangler dev
```

--------------------------------

### Install and Run Tests

Source: https://github.com/hugorcd/evlog/blob/main/examples/community-framework-skeleton/README.md

Install dependencies and run the tests for the evlog-community-framework-skeleton.

```bash
pnpm install
pnpm --filter evlog-community-framework-skeleton test
```

--------------------------------

### Install and Run Tests

Source: https://github.com/hugorcd/evlog/blob/main/examples/community-adapter-skeleton/README.md

Installs project dependencies and runs the test suite for the adapter skeleton.

```bash
pnpm install
pnpm --filter evlog-community-adapter-skeleton test
```

--------------------------------

### Full Setup Example for Nuxt / Nitro

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/5.enrichers.md

Demonstrates how to integrate multiple enrichers, including trace context, into a Nuxt/Nitro application by hooking into the 'evlog:enrich' event.

```typescript
// server/plugins/evlog-enrich.ts
import {
  createUserAgentEnricher,
  createGeoEnricher,
  createRequestSizeEnricher,
  createTraceContextEnricher,
} from 'evlog/enrichers'

export default defineNitroPlugin((nitroApp) => {
  const enrichers = [
    createUserAgentEnricher(),
    createGeoEnricher(),
    createRequestSizeEnricher(),
    createTraceContextEnricher(),
  ]

  nitroApp.hooks.hook('evlog:enrich', (ctx) => {
    for (const enricher of enrichers) enricher(ctx)
  })
})
```

--------------------------------

### Install and Run Tests

Source: https://github.com/hugorcd/evlog/blob/main/examples/community-enricher-skeleton/README.md

Installs project dependencies and runs the tests for the evlog-community-enricher-skeleton using pnpm.

```bash
pnpm install
pnpm --filter evlog-community-enricher-skeleton test
```

--------------------------------

### Install Evlog and Fastify

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/09.fastify.md

Install the necessary packages for Evlog and Fastify using your preferred package manager.

```bash
pnpm add evlog fastify
```

```bash
bun add evlog fastify
```

```bash
yarn add evlog fastify
```

```bash
npm install evlog fastify
```

--------------------------------

### Build TanStack Start Project for Production

Source: https://github.com/hugorcd/evlog/blob/main/examples/tanstack-start/README.md

Run this command to create a production-ready build of your application.

```bash
pnpm build
```

--------------------------------

### Install Dependencies

Source: https://github.com/hugorcd/evlog/blob/main/AGENTS.md

Installs all project dependencies using pnpm.

```bash
pnpm install
```

--------------------------------

### Install NuxtHub and Evlog Adapters

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/adapters/self-hosted/02.nuxthub.md

Install both the NuxtHub core and the evlog NuxtHub adapter. This is the first step to integrating evlog with NuxtHub for log storage.

```bash
pnpm add @nuxthub/core @evlog/nuxthub
```

--------------------------------

### Initialize Evlog Client

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/1.client-logging.md

Call initLog({ service: 'web' }) once at the application's start to initialize the Evlog client. This setup is framework-agnostic.

```typescript
import { initLog } from '@evlog/client'

initLog({
  service: 'web'
})
```

--------------------------------

### Run NestJS Example

Source: https://github.com/hugorcd/evlog/blob/main/examples/nestjs/README.md

Execute the NestJS example from the monorepo root using the provided bun command. Access the interactive UI at http://localhost:3000 to test routes.

```bash
# From the monorepo root
bun run example:nestjs
```

--------------------------------

### Install Nuxthub and Evlog Adapter

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/adapters/self-hosted/02.nuxthub.md

Install the necessary packages for Nuxthub core and the Evlog adapter using your preferred package manager.

```bash
pnpm add @nuxthub/core @evlog/nuxthub
```

```bash
bun add @nuxthub/core @evlog/nuxthub
```

```bash
yarn add @nuxthub/core @evlog/nuxthub
```

```bash
npm install @nuxthub/core @evlog/nuxthub
```

--------------------------------

### Install Evlog and Express

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/07.express.md

Install the necessary packages for Evlog and Express using your preferred package manager.

```bash
pnpm add evlog express
```

```bash
bun add evlog express
```

```bash
yarn add evlog express
```

```bash
npm install evlog express
```

--------------------------------

### Add AI Observability with evlog

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/2.ai-sdk/01.overview.md

Install the AI SDK, import and create an AI logger, and wrap your model to automatically capture AI metrics. This setup provides insights into token usage, tool calls, and streaming performance.

```bash
pnpm add ai
```

--------------------------------

### Direct OTLP API Usage Examples

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/adapters/cloud/02.otlp.md

Examples demonstrating how to send single or batch events using the OTLP adapter. Also shows how to convert an event to OTLP format for inspection. Ensure the endpoint is correctly configured.

```typescript
import { sendToOTLP, sendBatchToOTLP, toOTLPLogRecord } from 'evlog/otlp'

// Send a single event
await sendToOTLP(event, {
  endpoint: 'http://localhost:4318',
})

// Send multiple events
await sendBatchToOTLP(events, {
  endpoint: 'http://localhost:4318',
})

// Convert event to OTLP format (for inspection)
const otlpRecord = toOTLPLogRecord(event)
```

--------------------------------

### Install Evlog and React Router Packages

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/11.react-router.md

Install the necessary Evlog and React Router packages using your preferred package manager.

```bash
pnpm add evlog react-router @react-router/node @react-router/serve
```

```bash
bun add evlog react-router @react-router/node @react-router/serve
```

```bash
yarn add evlog react-router @react-router/node @react-router/serve
```

```bash
npm install evlog react-router @react-router/node @react-router/serve
```

--------------------------------

### Hono / Express / Fastify / Elysia / NestJS Evlog Setup

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/5.extend/9.drain-pipeline.md

Configures the Evlog drain pipeline for various Node.js frameworks. Includes examples for Hono, Express, Elysia, Fastify, and NestJS. Remember to flush the pipeline on SIGTERM.

```typescript
import type { DrainContext } from 'evlog'
import { createDrainPipeline } from 'evlog/pipeline'
import { createAxiomDrain } from 'evlog/axiom'

const pipeline = createDrainPipeline<DrainContext>()
const drain = pipeline(createAxiomDrain())

app.use(evlog({ drain })) // Hono / Express / Elysia
// await app.register(evlog, { drain }) // Fastify
// EvlogModule.forRoot({ drain }) // NestJS

process.on('SIGTERM', () => drain.flush())
```

--------------------------------

### Install Evlog and ORPC Server

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/15.orpc.md

Install the necessary packages for Evlog and the ORPC server using your preferred package manager.

```bash
pnpm add evlog @orpc/server
```

```bash
bun add evlog @orpc/server
```

```bash
yarn add evlog @orpc/server
```

```bash
npm install evlog @orpc/server
```

--------------------------------

### Example Wide Event Log Output

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/01.nuxt.md

This is an example of the consolidated log output for a single request after using `useLogger` to set various context fields.

```bash
10:23:45 INFO [my-app] POST /api/checkout 200 in 145ms
  ├─ user: id=usr_123 plan=enterprise
  ├─ cart: items=3 total=14999
  ├─ payment: method=card cardLast4=4242
  └─ requestId: a1b2c3d4-...
```

--------------------------------

### Install Evlog Package

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/04.nitro.md

Install the Evlog package using your preferred package manager.

```bash
pnpm add evlog
```

```bash
bun add evlog
```

```bash
yarn add evlog
```

```bash
npm install evlog
```

--------------------------------

### Install Evlog and Elysia

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/10.elysia.md

Install the necessary packages for Evlog and Elysia using your preferred package manager.

```bash
pnpm add evlog elysia
```

```bash
bun add evlog elysia
```

```bash
yarn add evlog elysia
```

```bash
npm install evlog elysia
```

--------------------------------

### Install Evlog and Hono Dependencies

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/08.hono.md

Install the necessary packages for Evlog and Hono using your preferred package manager.

```bash
pnpm add evlog hono @hono/node-server
```

```bash
bun add evlog hono @hono/node-server
```

```bash
yarn add evlog hono @hono/node-server
```

```bash
npm install evlog hono @hono/node-server
```

--------------------------------

### Install AI SDK

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/2.ai-sdk/01.overview.md

Add the AI SDK as a dependency using your preferred package manager.

```bash
pnpm add ai
```

```bash
bun add ai
```

```bash
yarn add ai
```

```bash
npm install ai
```

--------------------------------

### TanStack Start Configuration with Evlog

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/skills/review-logging-patterns/SKILL.md

Set up Evlog for TanStack Start by configuring `nitro.config.ts` and adding error handling middleware.

```typescript
// nitro.config.ts
import { defineConfig } from 'nitro'
import evlog from 'evlog/nitro/v3'

export default defineConfig({
  experimental: { asyncContext: true },
  modules: [evlog({ env: { service: 'my-app' } })],
})
```

```typescript
// src/routes/__root.tsx
import { createMiddleware } from '@tanstack/react-start'
import { evlogErrorHandler } from 'evlog/nitro/v3'

export const Route = createRootRoute({
  server: {
    middleware: [createMiddleware().server(evlogErrorHandler)],
  },
})
```

--------------------------------

### Install Axiom Drain Adapter

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/adapters/cloud/01.axiom.md

Import the createAxiomDrain function from the evlog/axiom package to set up the Axiom adapter.

```typescript
import { createAxiomDrain } from 'evlog/axiom'
```

--------------------------------

### Traditional logging example

Source: https://github.com/hugorcd/evlog/blob/main/apps/just-use-evlog/content/landing.md

Demonstrates a typical, unhelpful logging output from a server handler. This example shows multiple INFO, WARN, and ERROR messages that lack context and narrative.

```bash
$ node server.js
INFO  Starting handler
INFO  user loaded
INFO  db query ok
WARN  slow???
ERROR  Payment failed
ERROR  Error: undefined
INFO  done
```

--------------------------------

### Install Better Auth

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/3.better-auth/01.overview.md

Install the Better Auth dependency for your project using your preferred package manager.

```bash
pnpm add better-auth
```

```bash
bun add better-auth
```

```bash
yarn add better-auth
```

```bash
npm install better-auth
```

--------------------------------

### Install evlog with bun

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/1.start/3.installation.md

Use this command to add evlog to your project if you are using bun as your package manager.

```bash
bun add evlog
```

--------------------------------

### HTTP Drain Quick Start

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/5.extend/9.drain-pipeline.md

Quick start example for setting up the HTTP transport for client-side logs. It initializes the logger with a pre-configured HTTP drain that sends logs to a specified endpoint.

```typescript
import { initLogger, log } from 'evlog'
import { createHttpLogDrain } from 'evlog/http'

const drain = createHttpLogDrain({ drain: { endpoint: 'https://logs.example.com/v1/ingest' } })
initLogger({ drain })

log.info({ action: 'page_view', path: location.pathname })
```

--------------------------------

### Run Development Server (Monorepo Root)

Source: https://github.com/hugorcd/evlog/blob/main/apps/just-use-evlog/README.md

Start the development server for the 'just-use-evlog' app from the monorepo root directory.

```bash
pnpm run dev:just-use-evlog
```

--------------------------------

### Create an API Route with TanStack Start

Source: https://github.com/hugorcd/evlog/blob/main/examples/tanstack-start/README.md

Define API routes by specifying the 'server' property in route definitions. This example creates a '/api/hello' route that responds with a JSON message.

```tsx
import { createFileRoute } from '@tanstack/react-router'
import { json } from '@tanstack/react-start'

export const Route = createFileRoute('/api/hello')({
  server: {
    handlers: {
      GET: () => json({ message: 'Hello, World!' }),
    },
  },
})
```

--------------------------------

### Multi-hook Plugin Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/5.extend/4.plugins.md

Define a plugin that hooks into multiple event lifecycle stages for comprehensive tracking, such as request metrics. Ensure `statsd` is initialized and available in the `setup` hook.

```typescript
import { definePlugin } from 'evlog/toolkit'

export const requestMetricsPlugin = definePlugin({
  name: 'request-metrics',

  setup({ env }) {
    statsd.init({ service: env.service })
  },

  enrich({ event }) {
    event.tier = event.duration && event.duration > 1000 ? 'slow' : 'fast'
  },

  drain({ event }) {
    statsd.timing('http.request', event.duration as number, { path: event.path as string })
  },

  onRequestStart({ logger, request }) {
    logger.set({ trace: { startedAt: Date.now() } })
  },

  onRequestFinish({ event, durationMs }) {
    if (event && (event.level === 'error' || durationMs > 5000)) {
      // alert / forward / etc.
    }
  },
})
```

--------------------------------

### Create a Server Function with TanStack Start

Source: https://github.com/hugorcd/evlog/blob/main/examples/tanstack-start/README.md

Define server functions using createServerFn to handle server-side logic that can be seamlessly called from client components. This example fetches the current server time.

```tsx
import { createServerFn } from '@tanstack/react-start'

const getServerTime = createServerFn({
  method: 'GET',
}).handler(async () => {
  return new Date().toISOString()
})

// Use in a component
function MyComponent() {
  const [time, setTime] = useState('')
  
  useEffect(() => {
    getServerTime().then(setTime)
  }, [])
  
  return <div>Server time: {time}</div>
}
```

--------------------------------

### Hono/Express/Fastify/Standalone Stream Server Setup

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/5.extend/1.stream.md

For frameworks like Hono, Express, Fastify, or standalone Node.js applications, start the stream server manually and register its drain hook. Ensure it's only enabled in development environments.

```typescript
import { startStreamServer } from 'evlog/stream'

if (process.env.NODE_ENV !== 'production' && process.env.EVLOG_STREAM === '1') {
  const { drain } = await startStreamServer()
  // Plug `drain` into the evlog drain hook for your framework
}
```

--------------------------------

### Build for Production

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/README.md

Run this npm command to build the project for production. The output will be placed in the '.output' directory, ready for deployment.

```bash
npm run build
```

--------------------------------

### Build for Deployment

Source: https://github.com/hugorcd/evlog/blob/main/apps/nitro-v2-playground/README.md

Build the project for deployment.

```bash
pnpm run build
```

--------------------------------

### Terminal Output Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/13.standalone.md

Example of how structured logs appear in the terminal after processing.

```bash
14:58:15 INFO [migrate] user-migration
  ├─ migrated: 1250
  ├─ found: 1250
  ├─ status: complete
  └─ task: user-migration
```

--------------------------------

### Initialize Evlog Logger with Global Options

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/6.reference/1.configuration.md

Configure Evlog globally at application startup using `initLogger`. This example sets essential options like enabling logging, defining environment context, disabling pretty printing, and configuring sampling and drains.

```typescript
import { initLogger } from 'evlog'
import { createAxiomDrain } from 'evlog/axiom'

initLogger({
  enabled: true,
  env: { service: 'my-api', environment: 'production' },
  pretty: false,
  silent: false,
  stringify: true,
  minLevel: 'info',
  sampling: { rates: { info: 10 }, keep: [{ status: 400 }] },
  drain: createAxiomDrain(),
})
```

--------------------------------

### Basic AI SDK Logging Setup

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/skills/review-logging-patterns/SKILL.md

Use `createAILogger` to wrap your logger and `ai.wrap` to transparently capture LLM calls from the AI SDK. This is suitable for basic token usage and model info logging.

```typescript
import { createAILogger } from 'evlog/ai'

const log = useLogger(event) // or any RequestLogger
const ai = createAILogger(log)

const result = streamText({
  model: ai.wrap('anthropic/claude-sonnet-4.6'),  // accepts string or model object
  messages,
})
```

--------------------------------

### AI SDK Cost Estimation Setup

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/skills/review-logging-patterns/SKILL.md

Provide a pricing map to `createAILogger` to enable `ai.estimatedCost` logging. This helps in tracking the cost associated with AI model usage.

```typescript
const ai = createAILogger(log, {
  cost: {
    'claude-sonnet-4.6': { input: 3, output: 15 },
    'gpt-4o': { input: 2.5, output: 10 },
  },
})
```

--------------------------------

### Install Evlog for NestJS

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/06.nestjs.md

Install the evlog package along with necessary NestJS dependencies using your preferred package manager.

```bash
pnpm add evlog @nestjs/common @nestjs/core @nestjs/platform-express
```

```bash
bun add evlog @nestjs/common @nestjs/core @nestjs/platform-express
```

```bash
yarn add evlog @nestjs/common @nestjs/core @nestjs/platform-express
```

```bash
npm install evlog @nestjs/common @nestjs/core @nestjs/platform-express
```

--------------------------------

### Install Nuxthub and Evlog Adapter with Nuxi

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/adapters/self-hosted/02.nuxthub.md

Alternatively, use the nuxi command to add the Nuxthub core and Evlog adapter modules to your project.

```bash
npx nuxi module add @nuxthub/core @evlog/nuxthub
```

--------------------------------

### Access Logger in TanStack Start Request Context

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/skills/review-logging-patterns/SKILL.md

Retrieve the logger instance in TanStack Start using `useRequest()` from `nitro/context`.

```typescript
import { useRequest } from 'nitro/context'
import type { RequestLogger } from 'evlog'

const req = useRequest()
const log = req.context.log as RequestLogger
log.set({ user: { id: 'user_123' } })
```

--------------------------------

### Build Package

Source: https://github.com/hugorcd/evlog/blob/main/AGENTS.md

Builds the main evlog package.

```bash
pnpm run build:package
```

--------------------------------

### Example Event with Trace Context

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/5.enrichers.md

Illustrates an example event output that includes the 'traceContext' object, along with top-level 'traceId' and 'spanId' fields.

```json
{
  "traceContext": {
    "traceparent": "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01",
    "traceId": "4bf92f3577b34da6a3ce929d0e0e4736",
    "spanId": "00f067aa0ba902b7"
  },
  "traceId": "4bf92f3577b34da6a3ce929d0e0e4736",
  "spanId": "00f067aa0ba902b7"
}
```

--------------------------------

### Run Tests in TanStack Start Project

Source: https://github.com/hugorcd/evlog/blob/main/examples/tanstack-start/README.md

Execute this command to run all defined tests using Vitest.

```bash
pnpm test
```

--------------------------------

### Wide Event Log Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/4.use-cases/2.ai-sdk/01.overview.md

Example of a wide event log entry, including AI-specific details like model, tokens, and performance metrics.

```json
{
  "method": "POST",
  "path": "/api/chat",
  "status": 200,
  "duration": "4.5s",
  "ai": {
    "calls": 1,
    "model": "claude-sonnet-4.6",
    "provider": "anthropic",
    "inputTokens": 3312,
    "outputTokens": 814,
    "totalTokens": 4126,
    "reasoningTokens": 225,
    "finishReason": "stop",
    "msToFirstChunk": 234,
    "msToFinish": 4500,
    "tokensPerSecond": 180
  }
}
```

--------------------------------

### Cloudflare Worker Log Output Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/3.integrate/frameworks/12.cloudflare-workers.md

Example of structured log output from a Cloudflare Worker using Evlog, showing request details and context.

```bash
14:58:15 INFO [my-worker] GET /api/users 200 in 12ms
  ├─ orders: count=5
  ├─ user: id=usr_123 plan=pro
  ├─ route: /api/users
  └─ requestId: 4a8ff3a8-...
```

--------------------------------

### Run evlog Benchmarks in Terminal

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/6.reference/2.performance.md

Commands to execute all benchmarks, compare against alternatives, or measure bundle size.

```bash
cd packages/evlog

pnpm run bench                          # all benchmarks
pnpm exec vitest bench bench/comparison/ # vs alternatives only
pnpm exec tsx bench/scripts/size.ts     # bundle size
```

--------------------------------

### Wide Event Output Example

Source: https://github.com/hugorcd/evlog/blob/main/apps/docs/content/2.learn/2.wide-events.md

Demonstrates the consolidated output of a wide event, showing all set context, operation details, and status in a single, readable log entry.

```bash
[INFO] POST /api/checkout (234ms)
  user: { id: 1, plan: 'pro' }
  cart: { id: 42, items: 3, total: 9999 }
  payment: { method: 'card', status: 'success' }
  status: 200
```