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

# Quote Bounds

> Read the current top-up bounds and payment requirements for a buyer

Free, read-only preview of what a top-up for `buyer` would look like right now: merchant-side balance, credit limit, remaining headroom, the accepted amount range, and the exact x402 payment requirements that a subsequent `POST` would challenge with.

## Path

<ParamField path="merchant" type="string" required>
  Merchant id. Currently `antseed`.
</ParamField>

## Query

<ParamField query="buyer" type="string" required>
  Address to quote for (checksummed or lowercase).
</ParamField>

<ParamField query="amount" type="string">
  Optional gross amount in USDC base units. When present, the quote validates
  it against the bounds (`400 amount_too_low` / `amount_too_high` /
  `409 credit_limit_reached` on violation).
</ParamField>

<ParamField query="network" type="string">
  Optional payment source: `base`, `optimism`, or `ink`. Defaults to Base.
  Unknown sources return `400 wrong_network`.
</ParamField>

## Response fields

All amounts are USDC base-unit decimal strings.

| Field                     | Meaning                                                                                                                                     |
| ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| `minAmount` / `maxAmount` | Accepted gross range for the selected source. Cross-chain minimums include a buffered Across fee quote (or the configured static fallback). |
| `balance`                 | Buyer's current merchant-side balance (available + reserved).                                                                               |
| `creditLimit`             | Merchant-side credit limit for the buyer.                                                                                                   |
| `headroom`                | Remaining credit capacity (`creditLimit − balance`).                                                                                        |
| `minBuyerDeposit`         | Merchant-side minimum applying to this top-up (`"0"` once the buyer has a balance).                                                         |
| `requirements`            | The x402 payment requirements a `POST` would return in `accepts[0]`.                                                                        |
| `sources`                 | All eligible sources as `{ network, evmChainId, minAmount, maxAmount }`.                                                                    |

<RequestExample>
  ```bash Request theme={"system"}
  curl "https://antseed.mrdn.finance/v1/antseed/topups/quote?buyer=0xYourAddress&amount=5000000&network=optimism"
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={"system"}
  {
    "buyer": "0xYourAddress",
    "amount": "5000000",
    "minAmount": "1250000",
    "maxAmount": "10000000",
    "balance": "0",
    "creditLimit": "10000000",
    "headroom": "10000000",
    "minBuyerDeposit": "1000000",
    "requirements": {
      "scheme": "exact",
      "network": "optimism",
      "extra": { "destinationChainId": 8453, "…": "…" },
      "…": "…"
    },
    "sources": [
      { "network": "base", "evmChainId": 8453, "minAmount": "1250000", "maxAmount": "10000000" },
      { "network": "optimism", "evmChainId": 10, "minAmount": "1750000", "maxAmount": "10000000" },
      { "network": "ink", "evmChainId": 57073, "minAmount": "1750000", "maxAmount": "10000000" }
    ]
  }
  ```
</ResponseExample>