> ## Documentation Index
> Fetch the complete documentation index at: https://docs.maesn.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Introduction to Maesn Unified API for ERP and Accounting software.The documentation helps you to get started with the maesn API.

The maesn API provides a single API to integrate with a range of systems with similar capabilties. By providing a set of generic resources and standardized operations that are mapped and transformed to the resources and operations of the respective target systems, an integrator can implement a single integration workflow toward the unified API to integrate to all the supported target systems.

Resources are modeled after important concepts in the target systems, such as Accounts, Customers, Invoices, Suppliers, Transactions and others. They are exposed in the API through representations, where each representation provides the most useful way to interact with the resource within a certain use case.

We conform to the HTTP/1.1 protocol as described in the IETF RFCs 7230-7235 unless otherwise stated.

## Getting started with the API

Follow our [quick start guide](/guides/quick-start) to started right away.

## Calling conventions

When calling the API, the client should select a resource and HTTP method matching the expected operation result. The client then sends a request to the API and it replies with the response or returns an error.

The general convention for choosing an HTTP method is:

`POST` results in the creation of a new resource of a given type.

`GET` returns the given resource’s representation without any side effects.

`PATCH` partially or fully changes the state of the given resource.

`PUT` replaces a given resource or creates (upserts) a new resource if the given resource does not already exist.

`DELETE` removes or hides a given resource making it inaccessible.

## Responses

All responses are returned as JSON documents and will contain at least one of the top-level keys:

```json theme={null}
{
    "meta": {},
    "data": {},
    "errors": {}
}
```

The keys have the following purposes:

* `meta`: A meta object that contains non-standard information (pagination, warnings, etc.). Including the meta key is optional.
* `data`: Contains the actual response information (requested resource representation). The document's "primary data".
* `errors`: An array of error objects.

The keys `data` and `errors` will never coexist in the same response.

The primary data is either:

* a single resource object, a single resource identifier object, or null, for requests that target single resources.
* an array of resource objects, an array of resource identifier objects, or an empty array (\[]), for requests that target resource collections.

## Standardized Data

Maesn uses internationally standardized formats for values such as country codes, currencies, and date formats to ensure consistency across all integrations.
See our [Standardized Data](/standardization) section to learn more.

## Feedback

If you have feedback or questions, don’t hesitate to [reach out](https://www.maesn.com/contact/) to us. Access to the API can be generated on our [website](https://app.maesn.dev).