Documentation

TypeScript SDK Middlewares

Middleware is used to add functionality to the request object in the TypeScript SDK.

You can add middleware when creating the TypeScript SDK client. Multiple middlewares can be added using a chain of middleware builder methods.

const client = new ClientBuilder()
  .withClientCredentialsFlow(authMiddlewareOptions)
  .withHttpMiddleware(httpMiddlewareOptions)
  .withLoggerMiddleware()
  // Chain additional middleware here
  .build();

HttpMiddleware

Handles sending the HTTP request to the Composable Commerce API.

type HttpMiddlewareOptions = {
  host: string;
  credentialsMode?: 'omit' | 'same-origin' | 'include';
  includeHeaders?: boolean;
  includeResponseHeaders?: boolean;
  includeOriginalRequest?: boolean;
  includeRequestInErrorResponse?: boolean;
  maskSensitiveHeaderData?: boolean;
  timeout?: number;
  enableRetry?: boolean;
  retryConfig?: {
    maxRetries?: number;
    retryDelay?: number;
    backoff?: boolean;
    maxDelay?: number;
    retryOnAbort?: boolean;
    retryCodes?: Array<number | string>;
  };
  fetch?: any;
  abortController?: AbortController; // deprecated
  getAbortController?: () => AbortController;
};


const options: HttpMiddlewareOptions = {
  host: 'https://api.europe-west1.gcp.commercetools.com',
  includeResponseHeaders: true,
  maskSensitiveHeaderData: true,
  includeOriginalRequest: false,
  includeRequestInErrorResponse: false,
  enableRetry: true,
  retryConfig: {
    maxRetries: 3,
    retryDelay: 200,
    backoff: false,
    retryCodes: [503],
  },
  fetch: fetchFn,
};


const client = new ClientBuilder()
  .withHttpMiddleware(options)
  // ...
  .build();

AuthMiddleware

Handles generating, authenticating, and refreshing auth tokens used when making authenticated requests to the Composable Commerce API.

The auth token lifecycle is managed by the SDK and there is usually no need to directly interact or access the authentication token. Expired tokens are automatically discarded and new tokens are generated (or refreshed if using withRefreshTokenFlow) for new requests.

The following authentication flows can be used. The main difference in the authentication flows is the options that can be passed to each of the middlewares.

withClientCredentialsFlow

Handles authentication for the client credentials flow of the Composable Commerce API.

type AuthMiddlewareOptions = {
  host: string
  projectKey: string
  credentials: Credentials
  scopes?: Array<string>
  oauthUri?: string
  fetch?: any
  tokenCache?: TokenCache
}


const options: AuthMiddlewareOptions {
  host: 'https://auth.europe-west1.gcp.commercetools.com',
  projectKey: 'test-project-key',
  credentials: {
    clientId: process.env.CTP_CLIENT_ID,
    clientSecret: process.env.CTP_CLIENT_SECRET
  },
  scopes: [`manage_project:${projectKey}`],
  fetch: fetchFn
}




const client = new ClientBuilder()
  .withClientCredentialsFlow(options)
  // ...
  .build()

withPasswordFlow

Handles authentication for the password flow of the Composable Commerce API.

type PasswordAuthMiddlewareOptions = {
  host: string;
  projectKey: string;
  credentials: {
    clientId: string;
    clientSecret: string;
    user: {
      username: string;
      password: string;
    };
  };
  scopes?: Array<string>;
  tokenCache?: TokenCache;
  oauthUri?: string;
  fetch?: any;
};


const options: PasswordAuthMiddlewareOptions = {
  host: 'https://auth.europe-west1.gcp.commercetools.com',
  projectKey: 'test-project-key',
  credentials: {
    clientId: process.env.CTP_CLIENT_ID,
    clientSecret: process.env.CTP_CLIENT_SECRET,
    user: {
      username: process.env.USERNAME,
      password: process.env.PASSWORD,
    },
  },
  scopes: [`manage_project:${projectKey}`],
  fetch: fetchFn,
};


const client = new ClientBuilder()
  .withPasswordFlow(options)
  // ...
  .build();

withAnonymousSessionFlow

Handles authentication for the anonymous session flow of the Composable Commerce API.

type AnonymousAuthMiddlewareOptions = {
  host: string;
  projectKey: string;
  credentials: {
    clientId: string;
    clientSecret: string;
    anonymousId?: string;
  };
  scopes?: Array<string>;
  oauthUri?: string;
  fetch?: any;
  tokenCache?: TokenCache;
};


const options: AnonymousAuthMiddlewareOptions = {
  host: 'https://auth.europe-west1.gcp.commercetools.com',
  projectKey: 'test-project-key',
  credentials: {
    clientId: process.env.CTP_CLIENT_ID,
    clientSecret: process.env.CTP_CLIENT_SECRET,
    anonymousId: process.env.CTP_ANONYMOUS_ID, // a unique id
  },
  scopes: [`manage_project:${projectKey}`],
  fetch: fetchFn,
};


const client = new ClientBuilder()
  .withAnonymousSessionFlow(options)
  // ...
  .build();

withRefreshTokenFlow

Handles authentication for the refresh token flow of the Composable Commerce API.

type RefreshAuthMiddlewareOptions = {
  host: string;
  projectKey: string;
  credentials: {
    clientId: string;
    clientSecret: string;
  };
  refreshToken: string;
  tokenCache?: TokenCache;
  oauthUri?: string;
  fetch?: any;
};


const options: RefreshAuthMiddlewareOptions = {
  host: 'https://auth.europe-west1.gcp.commercetools.com',
  projectKey: 'test-project-key',
  credentials: {
    clientId: process.env.CTP_CLIENT_ID,
    clientSecret: process.env.CTP_CLIENT_SECRET,
  },
  refreshToken: 'bXvTyxc5yuebdvwTwyXn==',
  tokenCache: TokenCache,
  scopes: [`manage_project:${projectKey}`],
  fetch: fetchFn,
};


const client = new ClientBuilder()
  .withRefreshTokenFlow(options)
  // ...
  .build();

withExistingTokenFlow

Attaches an access token Authorization header.

type ExistingTokenMiddlewareOptions = {
  force?: boolean;
};


const authorization: string = 'Bearer G8GLDqrUMYzaOjhdFGfK1HRIOAtj7qQy';
const options: ExistingTokenMiddlewareOptions = {
  force: true,
};


const client = new ClientBuilder()
  .withExistingTokenFlow(authorization, options)
  // ...
  .build();

CorrelationIdMiddleware

CorrelationIdMiddleware adds the X-Correlation-ID entry to the request headers.

type CorrelationIdMiddlewareOptions = {
  generate: () => string;
};


const options: CorrelationIdMiddlewareOptions = {
  generate: () => 'cd260fc9-c575-4ba3-8789-cc4c9980ee4e', // Replace with your own UUID or a generator function
};


const client = new ClientBuilder()
  .withCorrelationIdMiddleware(options)
  // ...
  .build();

UserAgentMiddleware

UserAgentMiddleware adds a customizable User-Agent header to every request. By default it adds the SDK (and its version) and the running process (and its version) to the request. For example:

'User-Agent': 'commercetools-sdk-javascript-v2/2.1.4 node.js/18.13.0'

type HttpUserAgentOptions = {
  name?: string;
  version?: string;
  libraryName?: string;
  libraryVersion?: string;
  contactUrl?: string;
  contactEmail?: string;
  customAgent?: string;
};


const options: HttpUserAgentOptions = {
  name: 'test-client-agent',
  version: '2.9.0',
};


const client = new ClientBuilder()
  .withUserAgentMiddleware(options)
  // ...
  .build();

QueueMiddleware

Use QueueMiddleware to reduce concurrent HTTP requests.

type QueueMiddlewareOptions = {
  concurrency: number;
};


const options: QueueMiddlewareOptions = {
  concurrency: 20,
};


const client = new ClientBuilder()
  .withQueueMiddleware(options)
  // ...
  .build();

withTelemetryMiddleware

Allows integrating analytics and monitoring services (such as New Relic or Dynatrace) into your TypeScript SDK applications. For more information, see Observability.

withTelemetryMiddleware requires the @commercetools/ts-sdk-apm package, which can be installed using one of the following commands.

Install with npmTerminal
npm install @commercetools/ts-sdk-apm
Install with yarnTerminal
yarn add @commercetools/ts-sdk-apm
// Required import
import {
  createTelemetryMiddleware,
  TelemetryMiddlewareOptions,
} from '@commercetools/ts-sdk-apm';


const telemetryOptions: TelemetryMiddlewareOptions = {
  createTelemetryMiddleware,
  apm: () => typeof require('newrelic'), // installed npm `newrelic` package
  tracer: () => typeof require('/absolute-path-to-a-tracer-module'),
};


const client = new ClientBuilder()
  .withTelemetryMiddleware(telemetryOptions)
  // ...
  .build();

LoggerMiddleware

Logs incoming requests and response objects. You can include an optional options parameter which takes in a custom logger function and optional parameter that can be used within the logger function.

import {
  type Next,
  type Client,
  type MiddlewareRequest,
  type LoggerMiddlewareOptions,
  type MiddlewareResponse,
  ClientBuilder,
} from '@commercetools/sdk-client-v2';


function logger(options?: LoggerMiddlewareOptions) {
  return (next: Next): Next => {
    return (req: MiddlewareRequest, res: MiddlewareResponse) => {
      console.log(options); // Logs all included options except the logger function output -> { level: 'debug', name: 'custom-logger-fn' }
      console.log(req, res);
      next(req, res);
    };
  };
}


const client: Client = new ClientBuilder()
  .withProjectKey('projectKey')
  .withLoggerMiddleware({
    level: 'debug',
    name: 'custom-logger-fn',
    logger,
  })
  // ...
  .build();

BeforeExecutionMiddleware

This middleware runs before a call is made to the Composable Commerce API, and is useful for preprocessing requests. This middleware has access to the request and response object as well as the options included in .withBeforeExecutionMiddleware().

import {
  type Next,
  type Client,
  type MiddlewareRequest,
  type BeforeExecutionMiddlewareOptions,
  type MiddlewareResponse,
  ClientBuilder,
} from '@commercetools/sdk-client-v2';


function before(options: BeforeExecutionMiddlewareOptions) {
  return (next: Next): Next => {
    return (req: MiddlewareRequest, res: MiddlewareResponse) => {
      // Logic to be executed goes here
      // option will contain { name: 'before-middleware-fn' }
      console.log(options); // { name: 'before-middleware-fn' }
      next(req, res);
    };
  };
}


const client: Client = new ClientBuilder()
  .withProjectKey('projectKey')
  .withBeforeExecutionMiddleware({
    name: 'before-middleware-fn',
    middleware: before,
  })
  // ...
  .build();

AfterExecutionMiddleware

This middleware runs after a call is made to the Composable Commerce API, and is useful when the response from the API needs to be checked for further actions (for example, custom retry implementations and post-response processing). This middleware has access to the request and response object as well as the options included in .withAfterExecutionMiddleware().

import {
  type Next,
  type Client,
  type MiddlewareRequest,
  type AfterExecutionMiddlewareOptions,
  type MiddlewareResponse,
  ClientBuilder,
} from '@commercetools/sdk-client-v2';


function aftere(options: AfterExecutionMiddlewareOptions) {
  return (next: Next): Next => {
    return (req: MiddlewareRequest, res: MiddlewareResponse) => {
      // Logic to be executed goes here
      // option will contain { name: 'after-middleware-fn' }
      console.log(options); // { name: 'after-middleware-fn' }
      next(req, res);
    };
  };
}


const client: Client = new ClientBuilder()
  .withProjectKey('projectKey')
  .withAfterExecutionMiddleware({
    name: 'after-middleware-fn',
    middleware: aftere,
  })
  // ...
  .build();

Custom middleware

Certain use cases, such as adding headers to API requests, may require you to create custom middleware.

The following code example demonstrates how to create custom middleware that includes a value for the header X-External-User-ID.

function customHeaderMiddleware() {
  return (next) => (request, response) => {
    const newRequest = {
      ...request,
      headers: {
        ...request.headers,
        'X-External-User-ID': 'custom-header-value',
      },
    };


    next(newRequest, response);
  };
}

This custom middleware can then be added using the .withMiddleware() method.

const client = new ClientBuilder()
  .withMiddleware(customHeaderMiddleware())
  // ...
  .build();