Introduction to REST

ShipStation is a REST (REpresentational State Transfer) API, which means that it follows certain HTTP conventions for things like URLs, methods, headers, and status codes. If you're not yet familiar with REST, then this page is for you. It'll explain the basics you need to know to get started with ShipStation API.

Resources

REST APIs are centered around the concept of resources. Resources are data on which you can perform operations. For example, one of the resources in ShipStation is a label, and the operations that you can perform on a label include creating a label, querying labels, and voiding labels.

JSON

REST allows resources to be represented in any format, such as JSON, XML, CSV, binary, etc. Almost all resources in ShipStation are in JSON format. One notable exception to this is label images, which can be downloaded in a variety of formats.

JSON is a convenient format to represent REST resources because it's human-readable, compresses well, and is supported by all modern programming languages. In addition, JSON is fairly easy to understand because it only has a few data types:

JSON Data Types

HTTP

REST APIs communicate using HTTP (HyperText Transfer Protocol) or its more secure sibling, HTTPS (HTTP Secure), which uses TLS (Transport Layer Security) to encrypt request and response data.

ShipStation requires HTTPS and TLS v1.1 or higher for all API calls. This means that all API calls must be made to https://api.shipstation.com, not http://.

Requests & Responses

To call a REST API, you need to send an HTTP request to the server. The request contains all the information necessary to tell the server (i.e., ShipStation) what you want it to do. When the server is finished performing the operation you requested, it sends an HTTP response back to you, which contains all the information necessary to let you know whether the operation was successful or not and includes any data that you requested.

• All HTTP requests consist of four parts: method, endpoint, headers, and JSON data.
• HTTP responses consist of just three parts: a status code, headers, and JSON data.

Methods

The HTTP protocol includes many different "methods" (also called "verbs"), such as GET, POST, PUT, PATCH, OPTIONS, and more. Each of these methods instructs the server to perform a certain operation on a resource. To keep things simple, ShipStation only uses the following methods:

Endpoints

To call our API you have to know its endpoint, which is a combination of a URL (Uniform Resource Locator) and an HTTP method. For example, to create a shipping label, you need to use the POST method to call the v2/labels endpoint: POST https://api.shipstation.com/v2/labels. In this case, the POST method tells the server that you want to create a new resource and the /v2/labels URL path tells the server what kind of resource you want to create (a label).

URL Query Parameters

Some HTTP requests may also include URL query parameters, which are used by the server to filter the data returned in the response. A query parameter consists of a key-value pair, such as carrier_id=se-28529731.

You specify query parameters by including them directly in the URL using a ? to indicate that query parameters follow.

For example:

https://api.shipstation.com/v2/labels?carrier_id=se-28529731.

This example tells ShipStation to return all the labels from the specified carrier ID. If we did not include this portion in the URL, ShipStation would have returned all the labels ever created regardless of carrier ID.

If you wish to include multiple parameters in the URL, simply separate each set of parameters with an &.

For example:

https://api.shipstation.com/v2/labels?carrier_id=se-28529731&warehouse_id=se-1234.

This example tells ShipStation to return all labels with the specified Carrier ID and the specified warehouse ID.

Example Request with Query Parameters

GET /v2/labels?created_at_start=2020-11-09T00:37:54.14212Z&created_at_end=2020-11-09T22:37:54.14212Z HTTP/1.1
Host: https://api-stage.shipstation.com
API-Key: __YOUR_API_KEY_HERE__
Content-Type: application/json

Headers

HTTP requests and responses have a data section and a headers section. The data section contains a REST resource, such as a label in JSON format. The headers section contains metadata about the request or response.

There are many different types of headers, but these are the main ones that are relevant for ShipStation: request headers and response headers.

Request Headers

Response Headers

Status Codes

HTTP response status codes let you know whether your API request was processed successfully or if an error occurred. ShipStation uses the following status codes: