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

# Advanced Usage

> Learn advanced techniques and best practices for getting the most out of the StealthGPT API, including optimization strategies and advanced configuration options

## Writing Mode

When generating content (`rephrase: false`), choose how the model interprets your prompt:

<Card title="Writing Mode Options" icon="pen-nib">
  <CardGroup cols={2}>
    <Card title="default" icon="file-lines">
      Follows your prompt as written. Use for emails, lists, product copy, summaries, or any format you specify — does not force essay structure.
    </Card>

    <Card title="essay" icon="graduation-cap">
      Default for the API. Structures the output as an academic essay. Pair with `tone` (Standard, HighSchool, College, PhD) to set education level.
    </Card>
  </CardGroup>
</Card>

```json theme={null}
{
  "prompt": "Write a product description for a premium leather wallet",
  "rephrase": false,
  "writingMode": "default"
}
```

## Optimizing Tone Selection

Tone applies when `writingMode` is `essay`. StealthGPT offers several tone options to match your content needs:

<Card title="Tone Options" icon="sliders">
  <CardGroup cols={2}>
    <Card title="Standard" icon="pen">
      Default tone for general-purpose content. Balanced readability and formality.
    </Card>

    <Card title="HighSchool" icon="graduation-cap">
      Simpler style with occasional grammatical errors. High on Flesch-Kincaid Readability.
    </Card>

    <Card title="College" icon="book">
      Semi-complex style with occasional minor errors. Medium Flesch-Kincaid score.
    </Card>

    <Card title="PhD" icon="user-graduate">
      Complex, sophisticated style. No grammatical errors. Low Flesch-Kincaid score.
    </Card>
  </CardGroup>
</Card>

Choose the tone that best matches your target audience and content requirements.

## Detector Parameter (Deprecated)

The `detector` parameter is **deprecated** and kept only for backward compatibility.

<Card title="Detector Parameter" icon="shield-check">
  <CardGroup cols={1}>
    <Card title="Unified Stealth Engine" icon="shield">
      All requests now use a single stealth model optimized for general AI detection avoidance.
      The `detector` value (e.g. `"turnitin"` or `"gptzero"`) no longer changes model behavior and can be safely omitted.
    </Card>
  </CardGroup>
</Card>

## Humanizer Model Selection

Use the `model` parameter to choose between the full stealth pipeline and a faster cleanup pass:

<Card title="Model Options" icon="cpu">
  <CardGroup cols={2}>
    <Card title="heavy" icon="shield">
      Default. Runs the full StealthGPT humanizer pipeline and is designed for AI detector bypass. The structural rewrite also strips invisible text watermarks such as Claude's mark and Gemini's SynthID.
    </Card>

    <Card title="lite" icon="zap">
      Fast AI-smell cleanup that keeps the text mostly unchanged. This mode is not designed to bypass AI detectors.
    </Card>
  </CardGroup>
</Card>

```json theme={null}
{
  "prompt": "Your text here",
  "rephrase": true,
  "model": "heavy"
}
```

## Humanize Input (Rephrase Mode)

When humanizing existing text (`rephrase: true` on `/api/stealthify`, or `text` on `/api/stealthify/runs`), send **only the source text**. Do not wrap it with model instructions.

| Do                                                          | Don't                                                                                  |
| ----------------------------------------------------------- | -------------------------------------------------------------------------------------- |
| `"prompt": "Renewable energy offers several advantages..."` | `"prompt": "Humanize the following text: Renewable energy offers..."`                  |
| `"prompt": "Students should sleep eight hours..."`          | `"prompt": "Rewrite this to sound more human and undetectable:\n\nStudents should..."` |

Instruction prefixes like "Humanize the following", "Make this undetectable", or "Rewrite in a natural tone" confuse the humanizer and degrade results. Use API parameters (`tone`, `model`, `qualityMode`, `outputFormat`) for control instead.

The prompt-crafting tips below apply to **generation** (`rephrase: false`), not to humanize/rephrase requests.

## Crafting Effective Prompts

The quality of generated content depends significantly on your prompt. Here are some techniques to improve your prompts when `rephrase` is `false`:

<AccordionGroup>
  <Accordion title="Be Specific">
    Instead of: "Write about cars"

    Try: "Write about the environmental impact of electric vehicles compared to traditional combustion engines"
  </Accordion>

  <Accordion title="Include Context">
    Instead of: "Write a product description"

    Try: "Write a product description for a premium leather wallet targeted at young professionals who value both style and functionality"
  </Accordion>

  <Accordion title="Specify Format">
    Instead of: "Write about climate change"

    Try: "Create a 5-point listicle about practical steps individuals can take to reduce their carbon footprint"
  </Accordion>

  <Accordion title="Define Voice and Tone">
    Instead of: "Write about cryptocurrency"

    Try: "Explain cryptocurrency concepts in a conversational tone as if speaking to someone with no technical background"
  </Accordion>
</AccordionGroup>

## Output Format

Control the formatting of the returned content with the `outputFormat` parameter:

<Card title="Output Format Options" icon="file-text">
  <CardGroup cols={2}>
    <Card title="text" icon="type">
      Default format. Returns plain text without markdown formatting.
    </Card>

    <Card title="markdown" icon="markdown">
      Returns formatted content with markdown syntax (headings, lists, bold, etc.).
    </Card>
  </CardGroup>
</Card>

```json theme={null}
{
  "prompt": "Write a summary of quantum computing",
  "rephrase": false,
  "outputFormat": "markdown"
}
```

## Content Length Optimization

For optimal performance, we recommend keeping responses under 2,000 characters. When you need longer content:

1. Break down your content needs into smaller, focused requests
2. Use the `/api/stealthify/articles` endpoint for complete blog articles
3. Chain multiple requests together, using the output of one as input for another

## Using Templates

You can include templates in your prompts to guide the structure of generated content:

```json theme={null}
{
  "prompt": "Please write an email following this template:\n\nSubject: [Product] - New Features\n\nHello [Name],\n\nI'm excited to share the latest updates to [Product]...\n\nBest regards,\n[Your Name]",
  "rephrase": false
}
```

## Iterative Rephrasing

For maximum undetectability, consider an iterative approach:

<Steps>
  <Step title="Generate Initial Content">
    Create the first version of your content with `rephrase: false`
  </Step>

  <Step title="First Rephrasing">
    Submit the generated content with `rephrase: true`
  </Step>

  <Step title="Second Rephrasing">
    For even higher undetectability, submit the rephrased content for another round
  </Step>
</Steps>

<Warning>
  Too many rephrasing iterations may affect content coherence or meaning. Test and find the optimal balance.
</Warning>

## Multilingual Support

StealthGPT automatically detects the language of your input and routes it through a unified language engine:

* For English input, content is processed directly with no additional translation.
* For non-English input, the text is first translated to English, humanized, then:
  * If `isMultilingual` is `true` (default), translated back into the original language.
  * If `isMultilingual` is `false`, returned in humanized English.

To use this effectively, keep `isMultilingual` at its default (`true`) unless you specifically want English-only output for non-English prompts.

## Premium Quality with Stealth Agent

<Warning>
  Business mode has been **removed** from `/api/stealthify` and replaced by the [Stealth Agent](/api-reference/endpoints/stealthify-agent) endpoint. The `business` field is still accepted in request bodies for backward compatibility, but it has no effect: all `/api/stealthify` requests run on the standard engine and are billed at the standard rate.
</Warning>

When undetectability and quality are paramount, send the prompt to `POST /api/stealthify/agent` instead. The Stealth Agent runs a multi-step pipeline (research → draft → optional fact-check → humanize → optional images) that consistently produces higher-quality, more grounded, and harder-to-detect long-form content than a single-pass humanizer can.

<CardGroup cols={3}>
  <Card title="Academic preset" icon="graduation-cap" href="/api-reference/stealth-agent/use-cases#academic">
    Essays, literature reviews, and research-style writing with auto-formatted citations.
  </Card>

  <Card title="SEO preset" icon="magnifying-glass-chart" href="/api-reference/stealth-agent/use-cases#seo">
    Long-form blog posts grounded in keyword research and competitor analysis.
  </Card>

  <Card title="Social preset" icon="share-nodes" href="/api-reference/stealth-agent/use-cases#social">
    LinkedIn or Medium posts that match each platform's voice and structure.
  </Card>
</CardGroup>

See the [Stealth Agent overview](/api-reference/stealth-agent/overview), [usage guide](/api-reference/stealth-agent/guide), and [use cases](/api-reference/stealth-agent/use-cases) for details. Billing is `ceil(outputWords × 10)` Stealth API words per successful run; see [Pricing](/api-reference/pricing).