# API Introduction

The Red Flag Alert API provides advanced search capabilities and access to detailed information on millions of UK businesses. With full integration into the Companies House filing history document API, PDFs of submitted documentation can also be obtained from one easy point.

This documentation site provides an introduction on how to use it and details of its capabilities.

#### Versions

At this present time, the current version of the API is **`v4`**. As new features are added, any that have the potential to break backwards compatibility will always be introduced on a new version number of the API, leaving the existing API version untouched.

However, any new features introduced in this way will only be available in the new version of the API, i.e. version **`v5`**.


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# Agent Instructions: 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://developer.redflagalert.net/master.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.