Let the buyer pick the coin

Opt in when creating the invoice

{
  "usd_amount": "25.00",
  "allow_asset_selection": true,
  "asset": "USDC_BASE"
}

• Requires usd_amount (we reprice from dollars when they switch).
• Fixed coin amount cannot use asset selection.
• Controlled by you on the API call — the buyer only sees the picker if you enabled it.

Which coins appear

The picker only lists coins you enabled under Settings → Accepted coins. All platform coins are on by default. Disabling a coin hides it from new invoices, payment links, and the checkout picker — and the create API rejects that asset with a clear error.

What happens on switch

1. Same USD quote stays (metadata.usd_amount).
2. Live price of the new coin is fetched.
3. expected_amount_atomic updates.
4. A new deposit address / QR is minted.
5. Previous addresses are archived in metadata for manual tracing.

Selection locks after any payment is detected or the invoice leaves pending.

Card purchases

Untouched card payments still default to USDC on Base. If the buyer picks a coin first, card buys that coin. See Buy with card.