API Objects

Payment

The core object representing one customer-facing payment intent.

Field	Type	Notes
id	string	pi_...
amount	integer	Smallest unit
currency	string	USDT, USDC, ETH, SOL
network	string	POLYGON, ETHEREUM, SOLANA
status	enum	pending, processing, succeeded, failed, expired, canceled
pay_address	string	Address customer should send funds to
expires_at	timestamp	After this, status → expired if unpaid
settlement	object	See Settlement below
metadata	object	Arbitrary key/value (max 50 keys, 500 chars/value)

Status transitions

pending ──────► processing ──────► succeeded
   │                                    │
   ├──► canceled                        ├──► refunded (via Refund)
   └──► expired                         └──► failed (chargeback / reversal)

Checkout Session

A hosted payment page session. cs_....

QR Session

An in-store / POS QR-code-based payment. qrs_....

Refund

A full reversal of a succeeded Payment. re_.... v1 supports full refunds only.

Webhook Event

A delivery record of a server-side event. evt_.... See Webhooks → Event types.

Webhook Endpoint

A merchant-registered URL receiving event deliveries. we_....

Error codes

Each error response carries a code field. The catalog below lists codes by error.type.

authentication_error (401)

Code	Meaning
api_key_missing	No Authorization header was sent
api_key_invalid	The API key is malformed or has been revoked
api_key_expired	The API key has been rotated and the old key is no longer accepted

permission_error (403)

Code	Meaning
publishable_key_not_allowed	A pk_* key was used for an endpoint that requires a secret key (e.g., refunds, list operations)
livemode_mismatch	A test-mode key was used against live-mode resources, or vice versa

invalid_request_error (400)

Code	Meaning
parameter_missing	A required parameter is absent
parameter_invalid	A parameter has the wrong type or format
amount_too_small	amount is below the minimum for the chosen currency
network_unsupported	network is not one of POLYGON, ETHEREUM, SOLANA
currency_unsupported	currency is not one of USDT, USDC, ETH, SOL
currency_network_mismatch	The token does not exist on the chosen network (e.g., SOL on POLYGON)
settlement_invalid	settlement.mode is invalid, or splits percentages do not sum to 100

not_found_error (404)

Code	Meaning
resource_not_found	The object referenced by id does not exist (Payment, Checkout Session, QR Session, Refund, Webhook Endpoint)

idempotency_error (409)

Code	Meaning
idempotency_key_in_use	The Idempotency-Key was previously used with a different request body
payment_not_cancelable	The Payment is in a terminal state (succeeded, failed, expired, canceled) and cannot be canceled
payment_already_refunded	The Payment has already been refunded

rate_limit_error (429)

Code	Meaning
rate_limit_exceeded	More than 100 req/sec on this API key — see Rate Limits

payment_error (402)

Code	Meaning
insufficient_balance	Refund cannot proceed because the account’s balance in the source token is too low
network_rejected	On-chain transaction was rejected (gas, nonce, etc.)

network_error (502 / 504)

Code	Meaning
rpc_unavailable	Blockchain RPC is unreachable. Retry with an Idempotency-Key.
rpc_timeout	Blockchain RPC did not respond within the deadline. Retry.

api_error (5xx)

Code	Meaning
internal_error	Unhandled ParaSta server error. Report with request_id.