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

# Introduction to the Vouch Trust Infrastructure SDK

> Discover how Vouch's identity verification, fraud detection, and escrow modules help you build safer, more trusted digital marketplaces.

Vouch is a trust infrastructure SDK built for developers who are tired of stitching together three separate vendors every time they launch a marketplace or B2B platform. Instead of managing a KYC provider, a fraud-scoring service, and a payments escrow layer independently, you get all three as first-class modules in a single TypeScript package — each backed by the same AI engine, sharing the same user context, and accessed through one consistent API.

## Why Vouch exists

Every marketplace faces the same trust problems: you need to know your users are who they claim to be, you need to catch bad actors before they cause damage, and you need a neutral way to hold funds until both sides of a transaction are satisfied. Solving these problems individually means multiple integration projects, multiple compliance reviews, and multiple failure surfaces. Vouch collapses that complexity into a single SDK so you can focus on your product instead of your plumbing.

## Core capabilities

Vouch exposes three modules that cover the full lifecycle of a trusted transaction.

<CardGroup cols={3}>
  <Card title="Identity Verification" icon="id-card" href="/docs/sdk/identity">
    Launch a zero-click KYC modal or submit documents directly. Vouch runs liveness checks, document authentication, and AI-powered review — and returns a structured verification result.
  </Card>

  <Card title="Fraud Detection" icon="shield-halved" href="/docs/sdk/fraud">
    Score any user action or transaction in real time. Vouch returns a GREEN, AMBER, or RED flag along with the signals that drove the decision, so you can act immediately.
  </Card>

  <Card title="Escrow Management" icon="vault" href="/docs/sdk/escrow">
    Create milestone-based escrow accounts, track their status, assess release readiness, and confirm payouts — all programmatically, without touching a payments dashboard.
  </Card>
</CardGroup>

## How it works

When you call any Vouch SDK method, the SDK serialises your request and sends it to the Vouch backend at `https://vouch-fmql.onrender.com/v1` over HTTPS, authenticated with your API key. The backend routes the request to the appropriate AI engine — identity, fraud, or escrow — processes it, and returns a structured JSON response. You never communicate with the AI engine directly; the SDK and backend handle all of that on your behalf.

```
Your app  →  vouch-sdk  →  Vouch API  →  AI engine
                ↑                             |
                └─────── JSON response ───────┘
```

The SDK is stateless on the client side. Every method call is an independent HTTPS request, which means you can call Vouch from serverless functions, long-running servers, or edge runtimes without managing sessions or background workers.

## Requirements

Before you integrate Vouch, make sure your environment meets these prerequisites.

| Requirement           | Minimum version                                        |
| --------------------- | ------------------------------------------------------ |
| Node.js (server-side) | 18.0 or later                                          |
| TypeScript            | 5.0 or later                                           |
| Browser (client-side) | Any modern browser with `fetch` and `FormData` support |
| `vouch-sdk` package   | 1.3.0                                                  |

<Note>
  The `vouch-sdk` package is published as pure ESM. If your project uses CommonJS, configure your bundler (esbuild, Webpack, Rollup) to transpile ESM dependencies, or use a dynamic `import()` call.
</Note>

Ready to integrate? Head to the [Quickstart](/docs/quickstart) to install the SDK and make your first API call in under five minutes.