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

# Arga

> Real-world sandboxes for apps and agents

Arga gives apps and agents a production-like place to act. Run code changes, browser tests, or autonomous agents against twins of third-party APIs, MCPs, and CLIs, seeded from your stack and reset between runs.

Use Arga when production is too risky, static fixtures are too shallow, and you need to know how your software behaves across the real tools your users depend on.

Under the hood, Arga is built on three primitives:

* **API twins.** Compatible stand-ins for third-party APIs, MCPs, and CLIs so tests can read, write, retry, and fail safely without touching production services.
* **Isolated sandboxes.** Run in staging, preview, localhost, or an Arga-hosted sandbox with your app, agents, and twins wired together for each validation.
* **Production-informed scenarios.** Seed sandboxes from mock data or scoped production data pulled through [integrations](/integrations), then reset them between runs.

That same infrastructure validates code changes and AI agents. Use it to test PRs before merge, exercise frontend and backend workflows, or observe an agent taking actions without real-world side effects.

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Start testing in under a minute.
  </Card>

  <Card title="How it works" icon="gears" href="/concepts/how-it-works">
    How sandboxes, twins, scenarios, and validation runs fit together.
  </Card>

  <Card title="Digital twins" icon="clone" href="/concepts/digital-twins">
    Stateful replicas of external services, APIs, MCPs, and CLIs.
  </Card>

  <Card title="Integrations" icon="plug" href="/integrations">
    Connect production tools so Arga can seed realistic twins.
  </Card>
</CardGroup>

## What you can build on Arga

<CardGroup cols={2}>
  <Card title="Validate modes" icon="list-check" href="/features/validate-modes">
    Compare URL runs, PR runs, and sandbox runs.
  </Card>

  <Card title="Per-PR sandboxes" icon="code-pull-request" href="/features/pr-validation">
    Deploy changed services into a deterministic sandbox with API twins on every PR.
  </Card>

  <Card title="Agent & security testing" icon="shield-halved" href="/features/agent-security-testing">
    Red-team software and AI agents in safe, sandboxed environments.
  </Card>

  <Card title="Custom scenarios" icon="database" href="/features/custom-scenarios">
    Pin reusable scenarios with pre-configured digital twin data.
  </Card>

  <Card title="CLI" icon="terminal" href="/cli-and-mcp">
    Authenticate locally and kick off validation workflows from the terminal.
  </Card>

  <Card title="MCP" icon="plug" href="/mcp">
    Wire Arga context and validation tools into your IDE agent.
  </Card>
</CardGroup>