Skip to main content
GET
/
v1
/
{merchant}
/
topups
/
quote
curl "https://antseed.mrdn.finance/v1/antseed/topups/quote?buyer=0xYourAddress&amount=5000000&network=optimism"

{
  "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" }
  ]
}
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

​
merchant
string
required
Merchant id. Currently antseed.

​
Query

​
buyer
string
required
Address to quote for (checksummed or lowercase).
​
amount
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).
​
network
string
Optional payment source: base, optimism, or ink. Defaults to Base. Unknown sources return 400 wrong_network.

​
Response fields

All amounts are USDC base-unit decimal strings.
FieldMeaning
minAmount / maxAmountAccepted gross range for the selected source. Cross-chain minimums include a buffered Across fee quote (or the configured static fallback).
balanceBuyer’s current merchant-side balance (available + reserved).
creditLimitMerchant-side credit limit for the buyer.
headroomRemaining credit capacity (creditLimit − balance).
minBuyerDepositMerchant-side minimum applying to this top-up ("0" once the buyer has a balance).
requirementsThe x402 payment requirements a POST would return in accepts[0].
sourcesAll eligible sources as { network, evmChainId, minAmount, maxAmount }.
curl "https://antseed.mrdn.finance/v1/antseed/topups/quote?buyer=0xYourAddress&amount=5000000&network=optimism"

{
  "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" }
  ]
}