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

# Research Defender API

> Protect survey data quality with digital fingerprinting, duplication detection, and open-end text analysis — SEARCH, REVIEW, and PREDUPE.

Research Defender protects survey data quality by detecting fraudulent, duplicate, and low-effort respondents. This documentation covers the three core products — **SEARCH**, **REVIEW**, and **PREDUPE** — and the security options that protect your integration from suppression and link manipulation.

<Note>
  ACTIVITY and VERIFY are hosted on a separate domain (`resdefio.com`) and are documented separately. This site covers SEARCH, REVIEW, and PREDUPE.
</Note>

<CardGroup cols={2}>
  <Card title="Getting Started" icon="rocket" href="/research-defender/overview/00-getting-started">
    Overview of the Research Defender products and how they fit into your survey flow.
  </Card>

  <Card title="Environments & Authentication" icon="key" href="/research-defender/overview/01-environments-and-authentication">
    Base URLs and how publishable and private keys are used.
  </Card>

  <Card title="Security Options" icon="lock" href="/research-defender/overview/02-security-options">
    Protect against API suppression with V3 server-to-server tokens or V4 Hashed Validation.
  </Card>

  <Card title="SEARCH" icon="fingerprint" href="/research-defender/guides/01-search">
    Digital fingerprinting, bot and click-farm detection, and duplication scoring.
  </Card>

  <Card title="REVIEW" icon="comment-dots" href="/research-defender/guides/03-review">
    Open-end text analysis — copy/paste, profanity, engagement, and LLM detection.
  </Card>

  <Card title="API Reference" icon="code" href="/research-defender/endpoints/get-api-v4-respondents-search-publishable_key">
    Full reference for every endpoint — parameters, response schemas, and a live playground.
  </Card>
</CardGroup>