How to get all addresses of a customer using rest Magento2? Is there any out of the box API?
Yes there is, given you have the customer ID:
GET /V1/customers/{customerId}
this will return all the customer addresses
"customer":
{
"id": 0,
"default_billing": "string",
"default_shipping": "string",
"addresses": [
{
"id": 0,
"customer_id": 0,
"region": {
"region_code": "string",
"region": "string",
"region_id": 0,
"extension_attributes": {}
},
"region_id": 0,
"country_id": "string",
"street": [
"string"
]
}
]
}