Request limits

Every hard bound the API enforces on a request. Exceeding one is a 400 with { "error": "Invalid request data" } unless the table says otherwise.

Limit	Value
Request body	8 MiB (8,388,608 bytes) — exceeded gives `413 { "error": "Payload too large" }`
Order line items	1 to 20
Order item quantity	1 to 1,000,000
Invoice line items	1 to 100
Invoice item quantity	1 to 1,000,000
`Idempotency-Key`	1 to 255 characters
`successUrl` / `cancelUrl`	2048 characters, `http` or `https` only
`memo`	5000 characters
Invoice item `description`	2000 characters
Stock append `text`	5,000,000 characters, and at most 10,000 lines per call — counted after repeats within the batch are collapsed
List `limit`	1 to 100, defaults to 20
Fiat decimal places	3

The 8 MiB cap is on encoded bytes, not characters. A stock-append text well under its 5,000,000-character limit can still 413 once non-ASCII content is UTF-8 encoded. See Appending stock.

Expiry windows

Window	Default	Range	Set by
Order	30 minutes	10 minutes – 90 days	`expiresIn` on `POST /v1/orders`
Invoice	24 hours	10 minutes – 90 days	`expiresIn` on `POST /v1/invoices`, or a template
Payment attempt (quote)	30 minutes	—	Not settable

Invoice email limits

Emailing an invoice is rate-limited at three levels — per invoice, per store over a rolling 24 hours, and platform-wide. A refusal is a 429 carrying retryAfterSeconds and a matching Retry-After header when the block is a cooldown you can wait out. Check email.canSend on the invoice rather than probing. Details in Emailing an invoice.

Get started

Charging a customer

Getting paid

Reference

Expiry windows

Invoice email limits

​Expiry windows

​Invoice email limits

Expiry windows

Invoice email limits