# Tracker Indexer Reference Manual

for tracker-indexer &version;

## Overview

The tracker-indexer is responsible for indexing all content it is given. The indexer is completely modular, this means that there are modules or 'backends' which are used for indexing specific content types. This reference manual attempts to help developers write 3rd party modules to extract content not commonly supported by Tracker.

## Modules

&tracker-module-file; &tracker-module-iteratable;

## Metadata

&tracker-module-metadata; &tracker-module-metadata-utils;

## Integrating Applications

This part describes how you can add your own application categories and extractors to Tracker to be able to index (and ultimately track) your content.

&adding-categories-and-properties; &writing-an-extractor; &writing-an-indexer-module;