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

# Fleack: Mobile A/B testing without an SDK

> Fleack lets you run A/B tests on your mobile app by intercepting API traffic at the edge. No SDK, no rebuild, no app store review.

Fleack sits between your mobile app and your backend. By pointing one DNS record at Fleack, your team can test prices, ad frequencies, reward amounts, copy, and feature toggles on every live app version — instantly, without touching client code or waiting for a store release.

<CardGroup cols={2}>
  <Card title="Quick Start" icon="rocket" href="/quickstart">
    Get your first A/B test live in 5 minutes. One DNS record is all it takes.
  </Card>

  <Card title="Core Concepts" icon="book-open" href="/core-concepts/overview">
    Learn about endpoints, levers, tests, segments, and the results engine.
  </Card>

  <Card title="Integration" icon="plug" href="/integration/how-it-works">
    Understand how Fleack intercepts traffic and what the fail-open guarantee means.
  </Card>

  <Card title="Recipes" icon="flask" href="/recipes/ab-test-interstitial-frequency">
    Step-by-step guides for the most common mobile growth tests.
  </Card>
</CardGroup>

## How Fleack works

Fleack intercepts every API call your app makes through a single CNAME on the hostname you already use. It forwards requests unchanged to your real backend, and on the way back it rewrites the targeted JSON value for each user's assigned variant. When no test is running, the response is byte-identical to what your backend sent.

<Steps>
  <Step title="Point DNS at Fleack">
    Add a CNAME on `api.your-game.com` pointing to your Fleack tenant hostname. No code changes in the app.
  </Step>

  <Step title="Traffic flows through the edge">
    Fleack captures request/response samples and automatically classifies which endpoints are safe to test.
  </Step>

  <Step title="Pick a lever and launch a test">
    Choose a parameter from the Levers catalog — AI finds them automatically. Set variants, allocations, and a segment, then click Launch.
  </Step>

  <Step title="Read results and promote the winner">
    The Bayesian results engine shows win probability per variant. Promote the winner with one click — no engineering required.
  </Step>
</Steps>

<Note>
  Fleack is designed to be **fail-open**: if anything goes wrong on Fleack's side, your end users always see the original backend response. Fleack never breaks your app.
</Note>