Magento 2: How to login as Customer and place new order via REST APIs

In order to place a new order as a logged in customer using REST APIs in Magento 2, please follow below steps:

You can Download the Postman Tool from here: www.postman.com
Now, Open Post man and create below Requests: MAGENTO 2 REST APIs:

CUSTOMER LOGIN:

	Request Type: POST
	Request URL: {{baseUrl}}/{{storecode}}/V1/integration/customer/token
	Body:
	{
	"username": {{customerNumber}},
	"password": {{customerPassword}}
	}
	Headers:
	Content-Type: application/json
	Authorization: Bearer {{token}}
	Response:
	CustomerToken

view raw Login hosted with ❤ by GitHub

CREATING CUSTOMER QUOTE:

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine
	Request Type: POST
	Headers:
	Authorization: Bearer {{customerToken}}
	Response:
	Quote ID

view raw MAGENTO 2 REST API FOR CREATING CUSTOMER QUOTE: hosted with ❤ by GitHub

ADD ITEMS TO CART

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine/items
	Request Type: GET
	Headers:
	Content-Type: application/json
	Authorization: Bearer {{customerToken}}
	Body:
	{
	"cartItem": {
	"sku": "item-sku-1",
	"qty": 1,
	"quote_id": {{cartId}}
	}
	}

view raw gistfile1.txt hosted with ❤ by GitHub

COLLECT CART TOTALS

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine/totals
	Request Type: GET
	Headers:
	Content-Type: application/json
	Authorization: Bearer {{customerToken}}
	Authorization Type: Inherit Auth from Parent

view raw gistfile1.txt hosted with ❤ by GitHub

GET AVAILABLE SHIPPING METHODS & ESTIMATING SHIPPING CHARGES

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine/estimate-shipping-methods
	Request Type: POST
	Headers:
	Content-Type: application/json
	Authorization: Bearer {{customerToken}}
	Body:
	{
	"cartId": {{cartId}},
	"address": {
	"region": {{region_title}},
	"region_id": {{region_id}},
	"region_code": {{region_code}},
	"country_id": {{country_id}},
	"street": [
	"123 Oak Ave"
	],
	"postcode": "10577",
	"city": {{city_id}},
	"firstname": "Reena",
	"lastname": "Parekh",
	"customer_id": {{customerNumber}},
	"email": {{customerEmail}},
	"telephone": {{customerNumber}},
	"same_as_billing": 1
	}
	}

view raw test.txt hosted with ❤ by GitHub

SET BILLING AND SHIPPING ADDRESS OF ORDER

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine/shipping-information
	Request Type: POST
	Body:
	{
	"addressInformation": {
	"shipping_address": {
	"region": {{region_title}},
	"region_id": {{region_id}},
	"region_code": {{region_code}},
	"country_id": {{country_code}},
	"street": [
	"123 Oak Ave"
	],
	"postcode": "10577",
	"city": {{city_code}},
	"firstname": "Reena",
	"lastname": "Parekh",
	"email": {{customerEmail}},
	"telephone": {{customerNumber}}
	},
	"billing_address": {
	"region": {{region_title}},
	"region_id": {{region_id}},
	"region_code": {{region_code}},
	"country_id": {{country_code}},
	"street": [
	"123 Oak Ave"
	],
	"postcode": "10577",
	"city": {{city_code}},
	"firstname": "Reena",
	"lastname": "Parekh",
	"email": {{customerEmail}},
	"telephone": {{customerNumber}}
	},
	"shipping_carrier_code": "freeshipping",
	"shipping_method_code": "freeshipping"
	}
	}

view raw test.txt hosted with ❤ by GitHub

PLACE ORDER

	Request URL: {{baseUrl}}/{{storecode}}/V1/carts/mine/payment-information
	Request Type: POST
	Headers:
	Content-Type: application/json
	Authorization: Bearer {{customerToken}}
	Body:
	{
	"paymentMethod": {
	"method": "cashondelivery"
	},
	"billing_address": {
	"region": {{region_title}},
	"region_id": {{region_id}},
	"region_code": {{region_code}},
	"country_id": {{country_id}},
	"street": [
	"123 Oak Ave"
	],
	"postcode": "10577",
	"city": {{city_id}},
	"firstname": "Reena",
	"lastname": "Parekh",
	"email": {{customerEmail}},
	"telephone": {{customerNumber}}
	}
	}

view raw test.txt hosted with ❤ by GitHub

Now check your admin panel and there will be a new COD order placed.