![](\"https://visual-recognition-demo.ng.bluemix.net/images/samples/5.jpg\")
\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n api_key: '\n
\n\n## Installation\n\n```sh\nnpm install watson-developer-cloud\n```\n\n## Getting the service credentials\n\nYou will need the `username`, `password`, and `url` (`api_key` for Visual Recognition) for each service. Service credentials are different from your IBM Cloud account username and password.\n\nTo get your service credentials, follow these steps:\n\n1. Log in to IBM Cloud at https://console.bluemix.net/catalog/?category=watson.\n1. In the IBM Cloud **Catalog**, select the service you want to use.\n1. Type a unique name for the service instance in the **Service name** field. For example, type `my-service-name`. Leave the default values for the other options.\n1. Click **Create**.\n1. From the service dashboard, click **Service credentials**.\n1. Click **View credentials** under **Actions**.\n1. Copy `username`, `password` (or `api_key` for Visual Recognition), and `url`.\n\n## Usage\n\nThe examples below assume that you already have service credentials. If not,\nyou will have to create a service in [IBM Cloud][ibm_cloud].\n\nIf you are running your application in IBM Cloud, you don't need to specify the\ncredentials; the library will get them for you by looking at the `VCAP_SERVICES` environment variable.\n\nCredentials are checked for in the following order:\n\n1. Hard-coded or programatic credentials passed to the service constructor\n\n2. `SERVICE_NAME_USERNAME` and `SERVICE_NAME_PASSWORD` environment properties (or `SERVICE_NAME_API_KEY` when appropriate) and, optionally, `SERVICE_NAME_URL`\n\n3. IBM-Cloud-supplied credentials (via the `VCAP_SERVICES` JSON-encoded environment property)\n\n### Client-side usage\n\nSee the `examples/` folder for [Browserify](http://browserify.org/) and [Webpack](http://webpack.github.io/) client-side SDK examples (with server-side generation of auth tokens.)\n\nNote: not all services currently support CORS, and therefore not all services can be used client-side.\nOf those that do, most require an auth token to be generated server-side via the [Authorization Service](#authorization).\n\n### Data collection opt-out\n\nBy default, [all requests are logged](https://console.bluemix.net/docs/services/watson/getting-started-logging.html). This can be disabled of by setting the `X-Watson-Learning-Opt-Out` header when creating the service instance:\n\n```js\nvar myInstance = new watson.WhateverServiceV1({\n /* username, password, version, url, etc... */\n headers: {\n \"X-Watson-Learning-Opt-Out\": true\n }\n});\n```\n\n## Documentation\n\nYou can find links to the documentation at https://console.bluemix.net/developer/watson/documentation. Find the service that you're interested in, click **API reference**, and then select the **Node** tab.\n\nThere are also auto-generated JSDocs available at http://watson-developer-cloud.github.io/node-sdk/master/\n\n\n## Questions\n\nIf you are having difficulties using the APIs or have a question about the Watson services, please ask a question at [dW Answers](https://developer.ibm.com/answers/questions/ask/?topics=watson) or [Stack Overflow](http://stackoverflow.com/questions/ask?tags=ibm-watson-cognitive).\n\n## Examples\n\nThe [examples][examples] folder has basic and advanced examples.\n\n### Authorization\n\nThe Authorization service can generate auth tokens for situations where providing the service username/password is undesirable.\n\nTokens are valid for 1 hour and may be sent using the `X-Watson-Authorization-Token` header or the `watson-token` query param.\n\nNote that the token is supplied URL-encoded, and will not be accepted if it is double-encoded in a querystring.\n\n```javascript\nvar watson = require('watson-developer-cloud');\n\nvar authorization = new watson.AuthorizationV1({\n username: 'Table of Contents
\n\n * [Installation](#installation)\n * [Getting the Service Credentials](#getting-the-service-credentials)\n * [Usage](#usage)\n * [Client-side usage](#client-side-usage)\n * [Data collection opt-out](#data-collection-opt-out)\n * [Questions](#questions)\n * [Examples](#examples)\n * [IBM Watson Services](#ibm-watson-services)\n * [Authorization](#authorization)\n * [Conversation](#conversation)\n * [Discovery](#discovery)\n * [Language Translator](#language-translator)\n * [Natural Language Classifier](#natural-language-classifier)\n * [Natural Language Understanding](#natural-language-understanding)\n * [Personality Insights](#personality-insights)\n * [Speech to Text](#speech-to-text)\n * [Text to Speech](#text-to-speech)\n * [Tone Analyzer](#tone-analyzer)\n * [Visual Recognition](#visual-recognition)\n * [Composing Services](#composing-services)\n * [Debug](#debug)\n * [Tests](#tests)\n * [License](#license)\n * [Contributing](#contributing)\n\n\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n api_key: '\n
\n\n## Installation\n\n```sh\nnpm install watson-developer-cloud\n```\n\n## Getting the service credentials\n\n## Visual Recognition\n\nThe process for authenticating with Visual Recognition has changed:\n\n- For new service instances, authenticate by using IAM. See [IAM Authentication](#iam-authentication). Also set the service URL by passing in `url` in the service constructor. \n- For service instances created before May 23, 2018, authenticate by providing the basic auth `api_key` for the service instance.\n\n### Basic Auth\nYou will need the `username`, `password`, and `url` for each service. Visual Recognition instances created before May 23, 2018 use `api_key`. Service credentials are different from your IBM Cloud account username and password.\n\nTo get your service credentials, follow these steps:\n\n1. Log in to IBM Cloud at https://console.bluemix.net/catalog/?category=watson.\n1. In the IBM Cloud **Catalog**, select the service you want to use.\n1. Type a unique name for the service instance in the **Service name** field. For example, type `my-service-name`. Leave the default values for the other options.\n1. Click **Create**.\n1. From the service dashboard, click **Service credentials**.\n1. Click **View credentials** under **Actions**.\n1. Copy `username`, `password` (or `api_key` for Visual Recognition), and `url`.\n\n### IAM Authentication\n\nWhen authenticating with IAM, you have the option of passing in:\n- the IAM API key and, optionally, the IAM service URL\n- an IAM access token\n\n**Be aware that passing in an access token means that you're assuming responsibility for maintaining that token's lifecycle.** If you instead pass in an IAM API key, the SDK will manage it for you.\n\n```js\n// in the constructor, letting the SDK manage the IAM token\nconst discovery = new DiscoveryV1({\n url: 'Table of Contents
\n\n * [Installation](#installation)\n * [Getting the Service Credentials](#getting-the-service-credentials)\n * [Usage](#usage)\n * [Client-side usage](#client-side-usage)\n * [Sending Request Headers](#sending-request-headers)\n * [Parsing HTTP Response](#parsing-http-response)\n * [Data collection opt-out](#data-collection-opt-out)\n * [Questions](#questions)\n * [Examples](#examples)\n * [IBM Watson Services](#ibm-watson-services)\n * [Authorization](#authorization)\n * [Assistant](#assistant)\n * [Discovery](#discovery)\n * [Language Translator](#language-translator)\n * [Natural Language Classifier](#natural-language-classifier)\n * [Natural Language Understanding](#natural-language-understanding)\n * [Personality Insights](#personality-insights)\n * [Speech to Text](#speech-to-text)\n * [Text to Speech](#text-to-speech)\n * [Tone Analyzer](#tone-analyzer)\n * [Visual Recognition](#visual-recognition)\n * [Composing Services](#composing-services)\n * [Debug](#debug)\n * [Tests](#tests)\n * [License](#license)\n * [Contributing](#contributing)\n\n\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n url: '\n
\n\n## Before you begin\n* You need an [IBM Cloud][ibm-cloud-onboarding] account.\n\n## Installation\n\n```sh\nnpm install watson-developer-cloud\n```\n\n## Usage\n\nThe [examples][examples] folder has basic and advanced examples. The examples within each service assume that you already have [service credentials](#getting-credentials). \n\nCredentials are checked for in the following order:\n\n1. Hard-coded or programatic credentials passed to the service constructor\n\n2. Environment variables:\n- `SERVICE_NAME_USERNAME` and `SERVICE_NAME_PASSWORD` environment properties (or `SERVICE_NAME_API_KEY` when appropriate) and, optionally, `SERVICE_NAME_URL`\n- If using IAM: `SERVICE_NAME_IAM_APIKEY` and optionally `SERVICE_NAME_IAM_URL`, or `SERVICE_NAME_IAM_ACCESS_TOKEN`\n\n3. IBM-Cloud-supplied credentials (via the `VCAP_SERVICES` JSON-encoded environment property)\n\nIf you run your app in IBM Cloud, the SDK gets credentials from the [`VCAP_SERVICES`][vcap_services] environment variable. \n\n### Client-side usage\n\nSee the `examples/` folder for [Browserify](http://browserify.org/) and [Webpack](http://webpack.github.io/) client-side SDK examples (with server-side generation of auth tokens.)\n\nNote: not all services currently support CORS, and therefore not all services can be used client-side.\nOf those that do, most require an auth token to be generated server-side via the [Authorization Service](#authorization).\n\n## Authentication\nWatson services are migrating to token-based Identity and Access Management (IAM) authentication.\n\n- With some service instances, you authenticate to the API by using **[IAM](#iam)**.\n- In other instances, you authenticate by providing the **[username and password](#username-and-password)** for the service instance.\n\n### Getting credentials\n\nTo find out which authentication to use, view the service credentials. You find the service credentials for authentication the same way for all Watson services:\n\n1. Go to the IBM Cloud [Dashboard](https://cloud.ibm.com/) page.\n2. Either click an existing Watson service instance in your [resource list](https://cloud.ibm.com/resources) or click [**Create resource > AI**](https://cloud.ibm.com/catalog?category=ai) and create a service instance.\n3. Click on the **Manage** item in the left nav bar of your service instance.\n\nOn this page, you should be able to see your credentials for accessing your service instance.\n\nIn your code, you can use these values in the service constructor or with a method call after instantiating your service.\n\n### Supplying credentials\n\nThere are two ways to supply the credentials you found above to the SDK for authentication:\n\n#### Credentials file (easier!)\n\nWith a credentials file, you just need to put the file in the right place and the SDK will do the work of parsing it and authenticating. You can get this file by clicking the **Download** button for the credentials in the **Manage** tab of your service instance.\n\nThe file downloaded will be called `ibm-credentials.env`. This is the name the SDK will search for and **must** be preserved unless you want to configure the file path (more on that later). The SDK will look for your `ibm-credentials.env` file in the following places (in order):\n\n- Directory provided by the environment variable `IBM_CREDENTIALS_FILE`\n- Your system's home directory\n- Your current working directory (the directory Node is executed from)\n\nAs long as you set that up correctly, you don't have to worry about setting any authentication options in your code. So, for example, if you created and downloaded the credential file for your Discovery instance, you just need to do the following:\n\n```js\nconst DiscoveryV1 = require('watson-developer-cloud/discovery/v1');\nconst discovery = new DiscoveryV1({ version: '2019-02-01' });\n```\n\nAnd that's it!\n\nIf you're using more than one service at a time in your code and get two different `ibm-credentials.env` files, just put the contents together in one `ibm-credentials.env` file and the SDK will handle assigning credentials to their appropriate services.\n\nIf you would like to configure the location/name of your credential file, you can set an environment variable called `IBM_CREDENTIALS_FILE`. **This will take precedence over the locations specified above.** Here's how you can do that:\n\n```bash\nexport IBM_CREDENTIALS_FILE=\"Table of Contents
\n\n * [Before you begin](#before-you-begin)\n * [Installation](#installation)\n * [Usage](#usage)\n * [Client-side usage](#client-side-usage)\n * [Authentication](#authentication)\n * [IAM](#iam)\n * [Username and password](#username-and-password)\n * [API key](#api-key)\n * [Callbacks vs Promises](#callbacks-vs-promises)\n * [Sending request headers](#sending-request-headers)\n * [Parsing HTTP response](#parsing-http-response)\n * [Data collection opt-out](#data-collection-opt-out)\n * [Documentation](#documentation)\n * [Questions](#questions)\n * [IBM Watson services](#ibm-watson-services)\n * [Authorization](#authorization)\n * [Assistant v2](#assistant-v2)\n * [Assistant v1](#assistant-v1)\n * [Discovery](#discovery)\n * [Language Translator](#language-translator)\n * [Natural Language Classifier](#natural-language-classifier)\n * [Natural Language Understanding](#natural-language-understanding)\n * [Personality Insights](#personality-insights)\n * [Speech to Text](#speech-to-text)\n * [Text to Speech](#text-to-speech)\n * [Tone Analyzer](#tone-analyzer)\n * [Visual Recognition](#visual-recognition)\n * [Composing Services](#composing-services)\n * [Debug](#debug)\n * [Tests](#tests)\n * [License](#license)\n * [Contributing](#contributing)\n\n\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n url: '\n
\n\n## Before you begin\n* You need an [IBM Cloud][ibm-cloud-onboarding] account.\n\n## Installation\n\n```sh\nnpm install watson-developer-cloud\n```\n\n## Usage\n\nThe [examples][examples] folder has basic and advanced examples. The examples within each service assume that you already have [service credentials](#getting-credentials).\n\nCredentials are checked for in the following order:\n\n1. Hard-coded or programatic credentials passed to the service constructor\n\n2. Environment variables:\n- `SERVICE_NAME_USERNAME` and `SERVICE_NAME_PASSWORD` environment properties (or `SERVICE_NAME_API_KEY` when appropriate) and, optionally, `SERVICE_NAME_URL`\n- If using IAM: `SERVICE_NAME_IAM_APIKEY` and optionally `SERVICE_NAME_IAM_URL`, or `SERVICE_NAME_IAM_ACCESS_TOKEN`\n\n3. IBM-Cloud-supplied credentials (via the `VCAP_SERVICES` JSON-encoded environment property)\n\nIf you run your app in IBM Cloud, the SDK gets credentials from the [`VCAP_SERVICES`][vcap_services] environment variable.\n\n### Client-side usage\n\nSee the `examples/` folder for [Browserify](http://browserify.org/) and [Webpack](http://webpack.github.io/) client-side SDK examples (with server-side generation of auth tokens.)\n\nNote: not all services currently support CORS, and therefore not all services can be used client-side.\nOf those that do, most require an auth token to be generated server-side via the [Authorization Service](#authorization).\n\n## Authentication\nWatson services are migrating to token-based Identity and Access Management (IAM) authentication.\n\n- With some service instances, you authenticate to the API by using **[IAM](#iam)**.\n- In other instances, you authenticate by providing the **[username and password](#username-and-password)** for the service instance.\n\n### Getting credentials\n\nTo find out which authentication to use, view the service credentials. You find the service credentials for authentication the same way for all Watson services:\n\n1. Go to the IBM Cloud [Dashboard](https://cloud.ibm.com/) page.\n2. Either click an existing Watson service instance in your [resource list](https://cloud.ibm.com/resources) or click [**Create resource > AI**](https://cloud.ibm.com/catalog?category=ai) and create a service instance.\n3. Click on the **Manage** item in the left nav bar of your service instance.\n\nOn this page, you should be able to see your credentials for accessing your service instance.\n\nIn your code, you can use these values in the service constructor or with a method call after instantiating your service.\n\n### Supplying credentials\n\nThere are two ways to supply the credentials you found above to the SDK for authentication:\n\n#### Credentials file (easier!)\n\nWith a credentials file, you just need to put the file in the right place and the SDK will do the work of parsing it and authenticating. You can get this file by clicking the **Download** button for the credentials in the **Manage** tab of your service instance.\n\nThe file downloaded will be called `ibm-credentials.env`. This is the name the SDK will search for and **must** be preserved unless you want to configure the file path (more on that later). The SDK will look for your `ibm-credentials.env` file in the following places (in order):\n\n- Directory provided by the environment variable `IBM_CREDENTIALS_FILE`\n- Your system's home directory\n- Your current working directory (the directory Node is executed from)\n\nAs long as you set that up correctly, you don't have to worry about setting any authentication options in your code. So, for example, if you created and downloaded the credential file for your Discovery instance, you just need to do the following:\n\n```js\nconst DiscoveryV1 = require('watson-developer-cloud/discovery/v1');\nconst discovery = new DiscoveryV1({ version: '2019-02-01' });\n```\n\nAnd that's it!\n\nIf you're using more than one service at a time in your code and get two different `ibm-credentials.env` files, just put the contents together in one `ibm-credentials.env` file and the SDK will handle assigning credentials to their appropriate services.\n\nIf you would like to configure the location/name of your credential file, you can set an environment variable called `IBM_CREDENTIALS_FILE`. **This will take precedence over the locations specified above.** Here's how you can do that:\n\n```bash\nexport IBM_CREDENTIALS_FILE=\"Table of Contents
\n\n * [Before you begin](#before-you-begin)\n * [Installation](#installation)\n * [Usage](#usage)\n * [Client-side usage](#client-side-usage)\n * [Authentication](#authentication)\n * [IAM](#iam)\n * [Username and password](#username-and-password)\n * [API key](#api-key)\n * [Callbacks vs Promises](#callbacks-vs-promises)\n * [Sending request headers](#sending-request-headers)\n * [Parsing HTTP response](#parsing-http-response)\n * [Data collection opt-out](#data-collection-opt-out)\n * [Documentation](#documentation)\n * [Questions](#questions)\n * [IBM Watson services](#ibm-watson-services)\n * [Authorization](#authorization)\n * [Assistant v2](#assistant-v2)\n * [Assistant v1](#assistant-v1)\n * [Discovery](#discovery)\n * [Language Translator](#language-translator)\n * [Natural Language Classifier](#natural-language-classifier)\n * [Natural Language Understanding](#natural-language-understanding)\n * [Personality Insights](#personality-insights)\n * [Speech to Text](#speech-to-text)\n * [Text to Speech](#text-to-speech)\n * [Tone Analyzer](#tone-analyzer)\n * [Visual Recognition](#visual-recognition)\n * [Composing Services](#composing-services)\n * [Debug](#debug)\n * [Tests](#tests)\n * [License](#license)\n * [Contributing](#contributing)\n\n\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n url: '\n
\n\n## Before you begin\n* You need an [IBM Cloud][ibm-cloud-onboarding] account.\n\n## Installation\n\n```sh\nnpm install watson-developer-cloud\n```\n\n## Usage\n\nThe [examples][examples] folder has basic and advanced examples. The examples within each service assume that you already have [service credentials](#getting-credentials).\n\nCredentials are checked for in the following order:\n\n1. Hard-coded or programatic credentials passed to the service constructor\n\n2. Environment variables:\n- `SERVICE_NAME_USERNAME` and `SERVICE_NAME_PASSWORD` environment properties\n- If using IAM: `SERVICE_NAME_IAM_APIKEY` and optionally `SERVICE_NAME_IAM_URL`, or `SERVICE_NAME_IAM_ACCESS_TOKEN`\n- Optionally, `SERVICE_NAME_URL`\n\n3. IBM-Cloud-supplied credentials (via the `VCAP_SERVICES` JSON-encoded environment property)\n\nIf you run your app in IBM Cloud, the SDK gets credentials from the [`VCAP_SERVICES`][vcap_services] environment variable.\n\n### Client-side usage\n\nSee the `examples/` folder for [Browserify](http://browserify.org/) and [Webpack](http://webpack.github.io/) client-side SDK examples (with server-side generation of auth tokens.)\n\nNote: not all services currently support CORS, and therefore not all services can be used client-side.\nOf those that do, most require an auth token to be generated server-side via the [Authorization Service](#authorization).\n\n## Authentication\nWatson services are migrating to token-based Identity and Access Management (IAM) authentication.\n\n- With some service instances, you authenticate to the API by using **[IAM](#iam)**.\n- In other instances, you authenticate by providing the **[username and password](#username-and-password)** for the service instance.\n\n### Getting credentials\n\nTo find out which authentication to use, view the service credentials. You find the service credentials for authentication the same way for all Watson services:\n\n1. Go to the IBM Cloud [Dashboard](https://cloud.ibm.com/) page.\n2. Either click an existing Watson service instance in your [resource list](https://cloud.ibm.com/resources) or click [**Create resource > AI**](https://cloud.ibm.com/catalog?category=ai) and create a service instance.\n3. Click on the **Manage** item in the left nav bar of your service instance.\n\nOn this page, you should be able to see your credentials for accessing your service instance.\n\nIn your code, you can use these values in the service constructor or with a method call after instantiating your service.\n\n### Supplying credentials\n\nThere are two ways to supply the credentials you found above to the SDK for authentication:\n\n#### Credentials file (easier!)\n\nWith a credentials file, you just need to put the file in the right place and the SDK will do the work of parsing it and authenticating. You can get this file by clicking the **Download** button for the credentials in the **Manage** tab of your service instance.\n\nThe file downloaded will be called `ibm-credentials.env`. This is the name the SDK will search for and **must** be preserved unless you want to configure the file path (more on that later). The SDK will look for your `ibm-credentials.env` file in the following places (in order):\n\n- Directory provided by the environment variable `IBM_CREDENTIALS_FILE`\n- Your system's home directory\n- Your current working directory (the directory Node is executed from)\n\nAs long as you set that up correctly, you don't have to worry about setting any authentication options in your code. So, for example, if you created and downloaded the credential file for your Discovery instance, you just need to do the following:\n\n```js\nconst DiscoveryV1 = require('watson-developer-cloud/discovery/v1');\nconst discovery = new DiscoveryV1({ version: '2019-02-01' });\n```\n\nAnd that's it!\n\nIf you're using more than one service at a time in your code and get two different `ibm-credentials.env` files, just put the contents together in one `ibm-credentials.env` file and the SDK will handle assigning credentials to their appropriate services.\n\nIf you would like to configure the location/name of your credential file, you can set an environment variable called `IBM_CREDENTIALS_FILE`. **This will take precedence over the locations specified above.** Here's how you can do that:\n\n```bash\nexport IBM_CREDENTIALS_FILE=\"Table of Contents
\n\n * [Before you begin](#before-you-begin)\n * [Installation](#installation)\n * [Usage](#usage)\n * [Client-side usage](#client-side-usage)\n * [Authentication](#authentication)\n * [IAM](#iam)\n * [Username and password](#username-and-password)\n * [API key](#api-key)\n * [Callbacks vs Promises](#callbacks-vs-promises)\n * [Sending request headers](#sending-request-headers)\n * [Parsing HTTP response](#parsing-http-response)\n * [Data collection opt-out](#data-collection-opt-out)\n * [Documentation](#documentation)\n * [Questions](#questions)\n * [IBM Watson services](#ibm-watson-services)\n * [Authorization](#authorization)\n * [Assistant v2](#assistant-v2)\n * [Assistant v1](#assistant-v1)\n * [Discovery](#discovery)\n * [Language Translator](#language-translator)\n * [Natural Language Classifier](#natural-language-classifier)\n * [Natural Language Understanding](#natural-language-understanding)\n * [Personality Insights](#personality-insights)\n * [Speech to Text](#speech-to-text)\n * [Text to Speech](#text-to-speech)\n * [Tone Analyzer](#tone-analyzer)\n * [Visual Recognition](#visual-recognition)\n * [Composing Services](#composing-services)\n * [Debug](#debug)\n * [Tests](#tests)\n * [License](#license)\n * [Contributing](#contributing)\n\n\n\n```js\nvar VisualRecognitionV3 = require('watson-developer-cloud/visual-recognition/v3');\nvar fs = require('fs');\n\nvar visualRecognition = new VisualRecognitionV3({\n url: '