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

# Core concepts

> The building blocks of Wallets as a Service.

A handful of concepts cover almost everything you'll do with WAAS: you create **deposit addresses** to receive stablecoins, confirmed deposits credit your **merchant USD balance**, and you pay out with a **quote** followed by a **transfer** to a **whitelisted recipient**.

## Deposit address

A **deposit address** is an on-chain address you create to receive stablecoins on a supported **chain** (e.g. `BASE`). Each address has a stable `id` — store it as your reference. Yara manages the underlying keys; you never handle private keys.

Share the `address` with whoever is paying you, or display it in your app.

<Warning>
  An address is tied to its **chain**. Sending funds on a different network can result in lost funds. Always show the chain alongside the address.
</Warning>

## Deposit

A **deposit** is an incoming stablecoin transfer to one of your addresses. Yara watches the chain, waits for confirmations, and records the deposit. Once `CONFIRMED`, the USD value is credited to your merchant balance and a `deposit.confirmed` [webhook](/wallets/guides/webhooks) fires.

## Merchant USD balance

Confirmed deposits roll up into a single **merchant USD balance** — your spendable ledger balance. It has three parts:

| Field              | Meaning                                                      |
| ------------------ | ------------------------------------------------------------ |
| `available`        | Spendable now.                                               |
| `reserved`         | Held against in-flight transfers.                            |
| `pending_deposits` | Deposits seen but not yet confirmed — **not** spendable yet. |

## Whitelisted recipient

A **recipient** is a payout destination you approve in the [dashboard](https://dashboard.yara.cash) before sending funds — a bank account or a crypto address. You reference it by `recipient_id` when quoting a transfer. Funds can only ever leave to whitelisted recipients. See [Whitelist an address](/wallets/guides/whitelist-an-address).

## Quote

A **quote** prices a payout to a recipient. You send an `amount`, a `currency` (e.g. `NGN`), and a `recipient_id`; you get back the gross amount, fee, net amount, the USD that will be debited, the destination rail, and an `expires_at`. Quotes are short-lived — initiate the transfer before it expires.

## Transfer

A **transfer** is the payout itself. You create it from a valid `quote_id`; Yara reserves the funds and processes it asynchronously. Track its `status` (e.g. `RESERVED` → completed) via [webhooks](/wallets/guides/webhooks) or by fetching the transfer.

## How they fit together

<Steps>
  <Step title="Create an address">
    Provision a deposit address on a supported chain.
  </Step>

  <Step title="Receive a deposit">
    Stablecoins arrive, confirm, and credit your merchant USD balance.
  </Step>

  <Step title="Whitelist a recipient">
    Approve the payout destination in the dashboard.
  </Step>

  <Step title="Quote, then transfer">
    Quote the payout, then initiate the transfer from the quote.
  </Step>
</Steps>

<Card title="Next: create an address" icon="arrow-right" href="/wallets/guides/create-an-address" horizontal>
  Put these concepts to work.
</Card>