Skip to main content
A payment link is a short URL — https://pay.kibble.sh/pay/{slug} — paired with a QR code and a deposit address. When you create one, Kibble generates an 8-character slug, stores the expected amount, and begins monitoring the deposit address for USDC transfers on Base. The payer opens the link, scans the QR code with their crypto wallet, sends USDC, and the status updates automatically. You can create a payment link interactively via the CLI or programmatically via the REST API.
Run npx create-kibble and select kibble charge when prompted. See the Quickstart for the full walkthrough.

​
Request fields

FieldTypeRequiredDescription
business_namestringYesShown on the payment page
emailstringYesYour merchant email
expected_amountstringYesAmount in USDC, up to 2 decimal places (e.g. "49.00")
wallet_typestringYesprivy or byo
wallet_addressstringIf byoYour USDC address on Base (0x…)
product_descriptionstringNoOptional description shown on the payment page

​
The merchant portal

Every payment link has a corresponding merchant portal at https://pay.kibble.sh/merchant/{slug}. The portal shows:
  • The current payment status
  • The expected amount and any amount received
  • The on-chain transaction hash once a transfer is detected
Bookmark the merchant portal URL immediately after creating a link — Kibble does not send it by email.

​
Embedding a payment widget

The API response includes two embed options you can drop directly into a webpage.

​
iframe

<iframe
  src="https://pay.kibble.sh/pay/{slug}"
  width="400"
  height="600"
  frameborder="0">
</iframe>

​
JavaScript widget

<script
  src="https://pay.kibble.sh/w.js"
  data-slug="{slug}">
</script>
The JS widget renders a self-contained checkout component. Replace {slug} with the actual slug returned when you created the link.

​
Payment statuses

Kibble monitors the deposit address using Alchemy webhooks. When a USDC transfer arrives on Base, the status transitions based on how the received amount compares to the expected amount.
The payment link has been created and the deposit address is being monitored. No on-chain transfer has been detected yet. This is the initial status for every new link.
The received amount exactly matches the expected amount. The payment is complete.
The received amount is less than the expected amount. The link remains open — additional transfers can bring it to confirmed.
The received amount exceeds the expected amount. You can view the overpaid amount in the merchant portal. Kibble does not automatically refund the difference.
Only USDC on Base is accepted. Transfers of any other token — or USDC on a different chain — are not detected and will not update the payment status. The USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on chain ID 8453.

​
How detection works

When you create a payment link, Kibble begins monitoring the deposit address on Base for incoming USDC transfers. When a transfer is detected, Kibble:
  1. Confirms the received token is USDC on Base.
  2. Compares the transferred amount to the expected amount.
  3. Updates the payment link status to confirmed, partial, or excess.
Status updates are reflected in the merchant portal and via the status polling endpoint within seconds of the on-chain transfer. The deposit address is dedicated to this payment link and is not shared with other links.