### Basic Fastify Application

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/otel/metrics.md

A foundational Fastify application structure. No specific setup is required beyond installing Fastify.

```js
'use strict'

const server = require('fastify')({
  logger: {
    level: 'info'
  }
})

server.route({
  path: '/',
  method: 'GET',
  handler (req, res) {
    res.send({ hello: 'world' })
  }
})

server.listen({ port: 8080 })
```

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

### Install Git via Homebrew

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/developer-setup.md

Installs Git using Homebrew. After installation, configure your SSL key/certificate and username.

```bash
brew install git
```

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

### Core Instrumentation Configuration Example

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/module-instrumentations.md

Example configuration for a core instrumentation module, specifying its type and filename.

```javascript
http: {
  type: MODULE_TYPE.TRANSACTION,
  file: 'http.js'
}
```

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

### Install Node.js Agent Dependencies

Source: https://github.com/newrelic/node-newrelic/blob/main/README.md

Install the project's dependencies using npm after cloning the repository.

```bash
$ npm install
```

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

### Install Node.js via NVM

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/developer-setup.md

Installs Node.js version 20 using NVM. You can replace '20' with any other desired version.

```bash
nvm install 20
```

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

### Configure Multiple Application Names

Source: https://github.com/newrelic/node-newrelic/blob/main/NEWS.md

This example shows how to use the identifier override to uniquely identify agent instances on the same host when they have multiple application names.

```javascript
app_name['myName', 'unique1']
app_name['myName', 'unique2']
```

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

### Install Node Version Manager (NVM)

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/developer-setup.md

Installs NVM, a tool for managing multiple Node.js versions. Ensure you check the repository for the latest version number.

```bash
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
```

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

### First Party External Instrumentation Example

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/module-instrumentations.md

Configures an external first-party instrumentation by providing the npm package identifier. No module type is needed for external instrumentations.

```javascript
'koa': {module: '@newrelic/koa'}
```

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

### Install New Relic Node.js Agent

Source: https://github.com/newrelic/node-newrelic/blob/main/README.md

Install the `newrelic` package using npm. This is the first step in instrumenting your Node.js application.

```sh
$ npm install newrelic
```

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

### Start a Web Transaction

Source: https://github.com/newrelic/node-newrelic/blob/main/Migration Guide.md

Use `newrelic.startWebTransaction()` to initiate a web transaction. The callback is invoked immediately and works with promises.

```javascript
const newrelic = require('newrelic');

// Example using a callback
newrelic.startWebTransaction('my-web-transaction', () => {
  // Transaction logic here
  // Call newrelic.endTransaction() when done if not using promises
});

// Example with promises
newrelic.startWebTransaction('my-promise-transaction', async () => {
  await someAsyncOperation();
  // Transaction will end automatically when the promise resolves
});
```

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

### Install npm 2.0.0 or higher

Source: https://github.com/newrelic/node-newrelic/blob/main/Migration Guide.md

Use this command to install npm version 2.0.0 or higher if you are using an earlier version of Node.js 0.10.

```sh
$ npm install --global npm@2
```

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

### Basic Shim.wrap Example

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/function-wrapping.md

This example demonstrates the most basic usage of shim.wrap to replace the 'helloWorld' method on 'testObject'. The wrapper function returns a new function that logs a custom message, effectively overriding the original method's behavior.

```javascript
// our wrappers will go here
// ...

shim.wrap(testObject, 'helloWorld', function wrapCreator(){
    return function wrappedHelloWorld(console) {
        console.log("I am the new method!");
    }
});
```

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

### First Party Internal Instrumentation Example

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/module-instrumentations.md

Configures an internal first-party instrumentation by specifying its module type. The agent automatically loads the instrumentation file based on the module name.

```javascript
'express': {type: MODULE_TYPE.WEB_FRAMEWORK}
```

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

### Start a Background Transaction

Source: https://github.com/newrelic/node-newrelic/blob/main/Migration Guide.md

Use `newrelic.startBackgroundTransaction()` for background tasks. The callback is invoked immediately and supports promises.

```javascript
const newrelic = require('newrelic');

// Example using a callback
newrelic.startBackgroundTransaction('my-background-task', () => {
  // Background task logic here
  // Call newrelic.endTransaction() when done if not using promises
});

// Example with promises
newrelic.startBackgroundTransaction('my-promise-background-task', async () => {
  await processQueue();
  // Transaction will end automatically when the promise resolves
});
```

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

### Convert .proto to .json using protobufjs-cli

Source: https://github.com/newrelic/node-newrelic/blob/main/lib/grpc/endpoints/infinite-tracing/Readme.md

Use this command to convert a .proto file to a JSON descriptor file. Ensure protobufjs-cli is installed.

```sh
npx --package=protobufjs-cli -c 'pbjs --keep-case v1.proto' > v1.json
```

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

### External Instrumentation Setup Function

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/module-instrumentations.md

The export function for external instrumentation modules. It receives a shim object and the module to instrument.

```javascript
module.exports = function instrument(shim, moduleToInstrument) {
  //wrap your methods and do your newrelic-y things here
}
```

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

### Enable Prerelease Feature Flag

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/feature-flags.md

To enable a prerelease feature flag, add a `feature_flags` property to your agent configuration. This example shows how to enable a hypothetical `example_new_instrumentation` behavior.

```javascript
{
  feature_flag: {
    example_new_instrumentation: true
  }
}
```

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

### Configure MySQL Docker Container

Source: https://github.com/newrelic/node-newrelic/blob/main/docker/Readme.md

Example Docker Compose configuration for a MySQL container. Mounts local configuration files and sets up environment variables and health checks.

```yaml
  mysql:
    container_name: nr_node_mysql
    platform: ${DOCKER_PLATFORM:-linux/amd64}
    image: mysql:8.3
    volumes:
      - "./docker/mysql:/etc/mysql/conf.d"
    ports:
      - "3306:3306"
    environment:
      MYSQL_ALLOW_EMPTY_PASSWORD: 1
    healthcheck:
      test: ["CMD", "mysql" ,"-h", "mysql", "-P", "3306", "-u", "root", "-e", "SELECT 1"]
      interval: 1s
      timeout: 10s
      retries: 30
```

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

### Configuring URL Obfuscation with Regex

Source: https://github.com/newrelic/node-newrelic/blob/main/NEWS.md

Enable and configure URL obfuscation using regular expressions in your New Relic configuration. This example shows how to mask numerical IDs in URLs.

```javascript
url_obfuscation: {
  enabled: true,
  regex: {
    pattern: /(\/api\/v1\/users\/)([\[\d\]]+)(\/.*$)/,
    flags: "i",
    replacement: '$1**$3'
  }
}
```

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

### Example of Route and Query Parameters in Express

Source: https://github.com/newrelic/node-newrelic/blob/main/NEWS.md

Illustrates how route and query parameters are captured as attributes on Transactions, Segments, and Spans in an Express.js application. Route parameters are prefixed with `request.parameters.route.*` and query parameters with `request.parameters.*`.

```javascript
app.get('/api/users/:id', myMiddleware, myController)
```

```bash
curl http://localhost:3000/api/users/abc123?id=true
```

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

### Bootstrap New Relic ESM Loader

Source: https://github.com/newrelic/node-newrelic/blob/main/README.md

To use the New Relic Node.js agent with ES Modules, start your program using the `node` command with the `--import` flag pointing to the `esm-loader.mjs` file. This example also includes the `-r newrelic` flag to require the agent.

```sh
node --import newrelic/esm-loader.mjs -r newrelic your-program.js
```

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

### Setting up a Test Program for Shim Wrapping

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/function-wrapping.md

This script sets up a mock environment to test the Shim.wrap functionality. It manually requires the Shim library and creates a test object with methods to be wrapped. The agent and Shim are mocked to isolate the wrapping logic.

```javascript
//File: test.js

const newrelic = require('newrelic');

// grab the agent instance from cache and manually
// require the shim library -- normally the agent
// will handle this for you
const agent = require.cache.__NR_cache.agent;
const Shim = require('newrelic/lib/shim/shim');

// do the same fnApply/apply shenanigans as the shim library
// https://github.com/newrelic/node-newrelic/blob/v7.1.3/lib/shim/shim.js#L17-L19
const fnApply = Function.prototype.apply

// create a simple test object that
// will stand in for our module
const testObject = {};
testObject.helloWorld = function helloWorld(console) {
    console.log("Hello World! :)");
}
testObject.goodbyeWorld = function goodbyeWorld(console) {
    console.log("Goodbye World! :(");
}

// create an instance of a Shim, passing in fake
// values for the module name and module path,
// again, the agent normally takes care of
// this for you
shim = new Shim(agent, 'fake', '/path/to/fake.js')

// our wrappers will go here
// ...

// call our methods
testObject.helloWorld(console);
testObject.goodbyeWorld(console);
console.log("Done")

// exit early to avoid harvest loop
process.exit(1)
```

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

### Install Homebrew Package Manager

Source: https://github.com/newrelic/node-newrelic/blob/main/documentation/developer-setup.md

Installs the Homebrew package manager on macOS. This is a prerequisite for installing other development tools.

```bash
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
```

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

### Run All Benchmarks with npm

Source: https://github.com/newrelic/node-newrelic/blob/main/test/benchmark/Readme.md

Use this command to execute all available benchmark tests via the npm script.

```zsh
npm run bench
```

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

### Get Current Transaction Reference

Source: https://github.com/newrelic/node-newrelic/blob/main/Migration Guide.md

Use `newrelic.getTransaction()` to get a reference to the current transaction. Useful with callback-based consumers or when needing explicit transaction control.

```javascript
const newrelic = require('newrelic');

newrelic.startWebTransaction('get-transaction-example', () => {
  const transaction = newrelic.getTransaction();
  console.log('Current transaction:', transaction.name);
  // Use transaction object for further operations if needed
  newrelic.endTransaction();
});
```

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

### Run Benchmarks with New Relic Metrics and .env File

Source: https://github.com/newrelic/node-newrelic/blob/main/test/benchmark/Readme.md

Execute benchmarks and send metrics to New Relic using an ingest license key specified in a .env file. This method also allows for configuring the metrics host if sending to production instead of staging.

```zsh
# Starting at node-newrelic (root directory)
cd bin
touch .env
# Fill out NEW_RELIC_LICENSE_KEY=YOUR_INGEST_LICENSE_KEY
# If you are sending metrics to production instead of staging (default), also include: NEW_RELIC_METRICS_HOST=otlp.nr-data.net
node --env-file .env ./run-bench.js
```