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

# Overview

> See the full spectrum of every diff.

<span id="what-is-diffraction" />

Diffraction reviews UI-affecting changes to web applications. It plans important
user journeys for a pull request, executes them in browsers, and records evidence
so reviewers can understand what changed and what went wrong.

A problem found during a review is called an **aberration**: a departure from the
expected behavior or appearance of the application.

<Note>
  Diffraction is under active development. The local review workflow is
  available for trusted checkouts. Production adapters are implemented, but
  hosted reviews require operator configuration, credentials, and model
  selection. Installing the GitHub App alone does not activate review execution.
</Note>

<span id="what-it-reviews" />

## What a review covers

* Flows selected from the pull request's change context and repository guidance.
* A separate execution for each selected browser and viewport.
* Recorded steps, DOM replay events, screenshots, traces, and diagnostic evidence.
* Findings linked to evidence, with reproduction where available.

Existing end-to-end tests help ground a review. Brand findings must come from
repository-supplied rules or references, rather than a model's aesthetic preference.

<span id="where-to-start" />

## Start with your workflow

<ul className="docs-route-list">
  <li>
    <a href="/docs/site/local-development">
      <strong>Run a local review</strong>

      <span>
        Use Codex and Playwright to review a trusted application checkout.
      </span>
    </a>
  </li>

  <li>
    <a href="/docs/site/github">
      <strong>Connect a GitHub repository</strong>

      <span>
        Set up selected repositories on a configured Diffraction deployment.
      </span>
    </a>
  </li>
</ul>

<span id="read-next" />

## Find the right guide

| You want to…                                          | Start here                                           |
| ----------------------------------------------------- | ---------------------------------------------------- |
| Define commands, routes, browser targets, and budgets | [Repository configuration](/docs/site/configuration) |
| Understand what happens during a run                  | [Review lifecycle](/docs/site/lifecycle)             |
| Interpret findings and coverage                       | [Read a review](/docs/site/reviews)                  |
| Understand artifacts and workspace access             | [Evidence and access](/docs/site/evidence)           |
| Diagnose an incomplete or unavailable review          | [Troubleshooting](/docs/site/troubleshooting)        |