---
title: "Exploring the API"
description: "This section introduces testing GraphQL endpoint queries using tools like GraphiQL and Postman, and details the POST request structure with a “GetCustomers” query example."
lang: en
languages:
  en: https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/index.md
lastmod: 2026-07-10
---

> Documentation index: https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/llms.txt


# Exploring the API

Last modified July 10, 2026

> This section introduces testing GraphQL endpoint queries using tools like GraphiQL and Postman, and details the POST request structure with a “GetCustomers” query example.


For testing, you can run requests to the GraphQL endpoint with your preferred tools. We recommend:

- [GraphiQL](https://github.com/graphql/graphiql) - a web-based GraphQL IDE
- [Postman](https://www.postman.com/) - the widely used collaboration platform for API development, with built-int GraphQL support
- [Insomnia](https://insomnia.rest/) - similar to Postman, also with built-in support for GraphQL
- [Curl](https://curl.se/) - a widely used command line tool for transfering data using a variety of network protocols, including HTTP/HTTPs

The general form of a GraphQL query is as follows:

- the request is a POST
- the content type is `application/json`
- the body is a JSON with the form shown below, where the value of `query` is a serialized JSON (properly escaped) and `variables` is a JSON object. The `variables` property can be skipped or could be set to `null` if there are no GraphQL variables in the query.

```json
{
  "query" : "...",
  "variables" : {}
}
```

The following snippet shows a query example:

```json
{
   "query":"query GetCustomers($companyNo: Int, $pageSize: Int, $after :String)\n{\n  useCompany(no: $companyNo)\n  {\n    associate(first: $pageSize, after: $after)\n    {\n      totalCount\n      pageInfo\n      {\n        hasNextPage\n        hasPreviousPage\n        startCursor\n        endCursor\n      }\n      items\n      {\n        associateNo\n        customerNo\n        name\n      }\n    }\n  }\n}",
   "variables":{"companyNo":9112233,"pageSize":5},
   "operationName":"GetCustomers"
}
```

In this example, you can also see the property `operationName` that contains the name of the operation (that follows the `query` or `mutation` keyword).

> [!NOTE]
>
> The topic of GraphQL variables is addressed later in the tutorial in section [Named queries and parameters](https://docs.vismasoftware.no/businessnxtapi/apireference/features/parameters/index.md).


---

[View this page](https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/)


## In this section


- [GraphiQL](https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/graphiql/index.md): Explore and test GraphQL queries using GraphiQL, a web IDE with features like schema auto-fetch, query auto-complete, and documentation exploration.

- [Postman](https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/postman/index.md): Postman supports GraphQL requests with built-in tools or raw POST requests, using application/json content type for queries and variables.

- [Insomnia](https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/insomnia/index.md): Insomnia offers superior GraphQL support with schema fetching, autocomplete, and an interactive schema explorer for efficient API management.

- [Making requests from code](https://docs.vismasoftware.no/businessnxtapi/intro/exploring_api/code/index.md): Learn how to make programmatic requests in C#/.NET 5 to execute GraphQL queries and deserialize JSON responses.