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

# Introduction

> Overview of the GPTHuman REST API

# Welcome to the GPTHuman API

The GPTHuman API enables you to **transform AI-generated text into natural, human-sounding prose**. This documentation covers everything you need to integrate GPTHuman into your application, including authentication, credit usage, and the `POST /v1/humanize` response fields returned by the live API.

<Callout icon="rocket">
  Looking for a quick start? Jump straight to the <a href="/api-reference/v1/humanize/post">`POST /v1/humanize`</a> endpoint or experiment in the interactive playground on the right.
</Callout>

## Usage

### Credits & pricing

• **1 word = 1 credit.** The number of credits consumed equals the word count of the `text` field in your request.

• **Credit packages.** Credits are purchased as packages from the API dashboard: <a href="https://app.gpthuman.ai/api" target="_blank">API Dashboard</a>.

The API Dashboard displays your remaining credits and the available credit packages.

## Versions

Current stable version: **1.0.0** (see the [Changelog](/api-reference/changelog)). Future releases will follow semantic versioning.

## Authentication

All requests require an **API key** passed as a Bearer token in the `Authorization` header:

```http theme={null}
Authorization: Bearer YOUR_API_KEY
```

You can create and manage keys from your GPTHuman API dashboard.

## Request defaults

If you omit optional request settings, the API applies the following defaults:

* `tone`: `College`
* `mode`: `Balanced`

## Response metadata

Successful `POST /v1/humanize` responses include the rewritten output together with usage and analysis metadata such as:

* detected `language`
* `similarity` and `readability`
* `humanScore` when available
* input and output counts
* `creditUsage` and remaining `creditBalance`