> For the complete documentation index, see [llms.txt](https://help.nightfall.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.nightfall.ai/developer-api/key-concepts.md).

# Key Concepts

- [Entities and Terms to Know](https://help.nightfall.ai/developer-api/key-concepts/key_terms.md)
- [Setting Up Nightfall](https://help.nightfall.ai/developer-api/key-concepts/setup.md)
- [Creating API Key](https://help.nightfall.ai/developer-api/key-concepts/setup/api_key.md)
- [Creating Policies](https://help.nightfall.ai/developer-api/key-concepts/setup/policies.md)
- [Alerting](https://help.nightfall.ai/developer-api/key-concepts/alerting.md)
- [Scanning Text](https://help.nightfall.ai/developer-api/key-concepts/text_scan.md)
- [Scanning Files](https://help.nightfall.ai/developer-api/key-concepts/file_scan.md)
- [Supported File Types](https://help.nightfall.ai/developer-api/key-concepts/file_scan/supported_file_types.md)
- [File Scanning and Webhooks](https://help.nightfall.ai/developer-api/key-concepts/file_scan/webhooks.md)
- [Uploading and Scanning API Calls](https://help.nightfall.ai/developer-api/key-concepts/file_scan/scan_api_calls.md)
- [Special File Types](https://help.nightfall.ai/developer-api/key-concepts/file_scan/special_file_types.md)
- [Specialized File Detectors](https://help.nightfall.ai/developer-api/key-concepts/file_scan/special_file_detectors.md)
- [Webhooks and Asynchronous Notifications](https://help.nightfall.ai/developer-api/key-concepts/file_scan/webhooks_async_notifications.md)
- [Accessing Your Webhook Signing Key](https://help.nightfall.ai/developer-api/key-concepts/file_scan/webhooks_async_notifications/webhook_signing_key.md)
- [Creating a Webhook Server](https://help.nightfall.ai/developer-api/key-concepts/file_scan/webhooks_async_notifications/webhook_server.md)
- [Scanning Features](https://help.nightfall.ai/developer-api/key-concepts/scanning_features.md)
- [Using Pre-Configured Detection Rules](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/pre_configured_detection_rules.md)
- [Scanning Images for patterns using Custom Regex Detectors](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/pre_configured_detection_rules/scanning-images-for-patterns-using-custom-regex-detectors.md)
- [Creating an Inline Detection Rule](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/inline_detection_rules.md)
- [Using Exclusion Rules](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/exclusion_rules.md)
- [Using Context Rules](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/context_rules.md)
- [Using Redaction](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/redaction.md)
- [Using Policies to Send Alerts](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/send_alerts_using_policies.md)
- [Detecting Secrets](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/secrets_detection.md)
- [PHI Detection Rules](https://help.nightfall.ai/developer-api/key-concepts/scanning_features/phi_detection_rules.md)
- [Test Datasets](https://help.nightfall.ai/developer-api/key-concepts/test_datasets.md)
- [Errors](https://help.nightfall.ai/developer-api/key-concepts/errors.md)
- [Nightfall Playground](https://help.nightfall.ai/developer-api/key-concepts/nightfall_playground.md)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.nightfall.ai/developer-api/key-concepts.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.