@aws-sdk/smithy-client

Client Creation

This feature allows you to create a custom client by extending the base Client class provided by the @aws-sdk/smithy-client package. This is useful for creating service-specific clients.

const { Client } = require('@aws-sdk/smithy-client');

class MyServiceClient extends Client {
  constructor(config) {
    super(config);
  }
}

const client = new MyServiceClient({ region: 'us-west-2' });

Command Creation

This feature allows you to create custom commands by extending the base Command class. Commands encapsulate the input and middleware logic for making API calls.

const { Command } = require('@aws-sdk/smithy-client');

class MyCommand extends Command {
  constructor(input) {
    super();
    this.input = input;
  }

  resolveMiddleware(clientStack, configuration, options) {
    // Middleware logic here
  }
}

const command = new MyCommand({ key: 'value' });

Middleware Stack

This feature allows you to create and manage a stack of middleware functions that can be used to modify the behavior of commands and clients. Middleware can be added at various stages of the request lifecycle.

const { MiddlewareStack } = require('@aws-sdk/smithy-client');

const stack = new MiddlewareStack();
stack.add((next, context) => async (args) => {
  console.log('Before request');
  const result = await next(args);
  console.log('After request');
  return result;
}, {
  step: 'initialize',
  name: 'loggingMiddleware',
});