Pagination, limits and errors

The rules every list endpoint and every error follows.

Formats

Requests and responses are JSON, in UTF-8. Responses are never cached (Cache-Control: no-store).
Field names are snake_case.
Dates and times are ISO 8601 in UTC, for example 2026-10-29T14:30:00.000Z.
Money amounts are decimal strings with two places, such as "1348.00", so no precision is lost. Currency is given alongside where it applies.

Pagination

List endpoints return one page at a time, newest first:

List response

{
  "data": [ ... ],
  "has_more": true,
  "next_cursor": "cm2abc123"
}

Parameter	Type	Description
limit	integer	Items per page, 1 to 100. Default 25. A missing or invalid value falls back to the default instead of failing.
cursor	string	Pass the previous response's `next_cursor` to get the next page. Stop when `has_more` is `false`.

Getting the next page

curl -H "Authorization: Bearer zlx_live_YOUR_KEY" \
  "https://api.zargologix.com/v1/shipments?limit=50&cursor=cm2abc123"

Staying in sync

To mirror ZargoLogix data in your own system, poll with updated_since (shipments) or created_since (invoices and quotes) and de-duplicate by id. A record that changes while you are paging can appear on two pages, so always upsert by id rather than inserting. For instant updates instead of polling, use webhooks.

Rate limits

Each key has a per-minute request limit (120 by default; ZargoLogix can set a different limit for a particular key). The limit that applies to you is always in the response headers:

Header	Type	Meaning
X-RateLimit-Limit	integer	Requests allowed per one-minute window.
X-RateLimit-Remaining	integer	Requests left in the current window.
X-RateLimit-Reset	integer	Seconds until the window resets (not a timestamp).

Over the limit you get 429 rate_limited with a Retry-After header (seconds). Wait that long, then retry. Counts are shared across all of a key's requests, however many servers send them.

Errors

Every error has the same shape:

400 Bad Request

{
  "error": {
    "code": "invalid_parameter",
    "message": "status must be one of: DRAFT, PENDING_APPROVAL, APPROVED, ..."
  }
}

Use code in your program. The message is for people and may change.

Code	Status	Meaning
invalid_parameter	400	A filter value is not valid, for example an unknown status or a date that is not ISO 8601.
unauthorized	401	Missing or invalid API key.
key_revoked	401	The key was revoked.
key_expired	401	The key has expired.
insufficient_scope	403	The key does not have the scope this endpoint needs.
not_found	404	No record matches the id you asked for.
rate_limited	429	Too many requests. See Retry-After.
internal_error	500	Something went wrong on our side. Retry after a moment; if it persists, check the system status page.

Retry 429 and 5xx responses with a growing delay. Do not retry 4xx responses other than 429 without changing the request.
The public tracking endpoint uses a simpler error shape. See the Tracking page.