Checkout

For each exchange: the network's name in that exchange's withdrawal screen and its withdrawal fee, so the checkout can say "choose Tron (TRC20) and send 51.50 (includes Binance's 1.50 fee)". A label or fee is present only if it was verified against the exchange's own public page (source_url, on verified_at); otherwise it is null and the checkout uses generic wording.

Every payment option carries address_derivation: the checkout must recompute the deposit address from it, compare the destination with the merchant destination pinned in its own config, and refuse to display the address on any mismatch.

Looks a transaction hash up on this invoice's networks and says where the transfer went and whether it is attributed to this invoice. Informational only: a lookup never credits a payment. Payments are attributed only by the deposit address lease (or a bound sender), from our own chain observations. Rate-limited per key and client address (429 with Retry-After).

The payer may leave an email address (never required). A receipt is sent once the invoice is paid (right away if it already is), and a notice of any refund the merchant creates for it (never the claim link: this route takes only the publishable key, so the address proves nothing). Nothing is sent before a payment arrived. Send the checkout view's session_token: the first address binds the invoice's receipt to that session, and only the same session may replace it (at most 3 different addresses per invoice). Emails come from the merchant's name. Rate-limited per key and client address.

A payment-link invoice holds no deposit address until its payer picks a network: its options are listed in pending_options, and this call leases the chosen network's address (the same address covers every EVM network the invoice offers) and returns the invoice with that option in payment_options, ready to verify and show. Picking an option that already has its address changes nothing, so a retry is safe. If no network is picked by select_by, the invoice expires. 409 invoice_not_awaiting_payment once it is closed, 409 deposit_addresses_exhausted when no address is free right now. Rate-limited per key and client address.

Binds the invoice to the payer's wallet address for one payment option and returns the exact transfer to build: the token, the merchant's registered destination and the amount (the amount due plus a sub-cent suffix when the same wallet has another open payment of the same amount). A transfer is attributed when its sender, exact amount and time all match; a transaction hash is never an input. Binding the same wallet again returns the same binding. A different wallet (the payer switched) gets its own binding, and the earlier one stays valid; at most 5 wallets per invoice and network. Only while the invoice is awaiting payment. Rate-limited per key and client address.

The landing screen: the merchant, the description, and either the fixed price or the bounds of the amount the payer may choose. status says whether the link still takes payments.

Fixed-price links take no body fields; payer-chosen links need amount (within the link's bounds). Returns the payer's view of the new invoice; continue with the normal checkout for its id. The invoice reserves one unit of the link's quantity_limit and holds no deposit address yet: its options are in pending_options until the payer picks one (POST /v1/checkout/invoices/{id}/payment_option) before select_by. 409 when the link is deactivated, expired or sold out (payment_link_inactive, _expired, _sold_out), when every remaining unit is reserved by unpaid invoices (payment_link_fully_reserved), or when too many unpaid link invoices are open (payment_link_busy). Rate-limited per key and client address.

Each event: id: is the per-invoice sequence number, event: is invoice.created or invoice.{status} (invoice.detected, invoice.confirming, invoice.paid, …), and data: is a complete [InvoiceEvent] JSON object. On connect, every past event is sent first. Resume after a disconnect with the Last-Event-ID header (browsers do this automatically) or ?last_event_id=.