> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sx.bet/llms.txt
> Use this file to discover all available pages before exploring further.
# Order Lifecycle
> How order status, fill amounts, and pending fills transition during an order's lifetime.
## Overview
Once an order is on the book, its `status`, `fillAmount`, and `pendingFillAmount` fields tell you where it is in its lifecycle. This page is the reference for what each combination means and how transitions are reported on the [`active_orders`](/api-reference/centrifugo-active-order-updates) and [`order_book`](/api-reference/centrifugo-order-book-updates) WebSocket channels.
## Order status reference
Orders can have one of three statuses:
| Status | Meaning |
| ---------- | --------------------------------------------------- |
| `ACTIVE` | Order is live and available to be filled |
| `INACTIVE` | Order has been cancelled and is no longer available |
| `FILLED` | Order has been fully filled |
## Order fill precision
When an order is fully filled, `fillAmount` may be slightly less than `totalBetSize` due to on-chain arithmetic rounding. An order is considered fully filled — and will receive `status: "FILLED"` — when the remaining unfilled amount is within a small precision tolerance (\~0.001% of `totalBetSize`).
Do not use `fillAmount === totalBetSize` to detect a fully filled order. Use `status === "FILLED"` instead.
## WebSocket order update sequence
When a taker fills your order, you'll receive the following sequence of updates on the [`active_orders`](/api-reference/centrifugo-active-order-updates) and [`order_book`](/api-reference/centrifugo-order-book-updates) channels.
**1. Fill in progress**
```json theme={null}
{
"status": "INACTIVE",
"fillAmount": "0",
"pendingFillAmount": "2681511700",
"totalBetSize": "2681520865"
}
```
When a fill that exhausts the remaining order size has been submitted but not yet confirmed on-chain, the order temporarily shows `status: "INACTIVE"` with a non-zero `pendingFillAmount`. This does **not** mean the order was cancelled. The order is being held — no further fills will be accepted against it while it is pending.
**2. Fill confirmed**
```json theme={null}
{
"status": "FILLED",
"fillAmount": "2681511700",
"pendingFillAmount": "0",
"totalBetSize": "2681520865"
}
```
Once the fill is confirmed on-chain, the order transitions to `FILLED`. Note that `fillAmount` may be marginally less than `totalBetSize` (see [Order fill precision](#order-fill-precision)).
Rarely, a pending fill is rejected on-chain. You'll see a final update where `pendingFillAmount` returns to `0` without `fillAmount` increasing.
## Order states
Read `status` and `pendingFillAmount` together to understand an order's current state.
| `status` | `pendingFillAmount` | Meaning |
| ---------- | ------------------- | -------------------------------------------------------------------------------------------------------- |
| `ACTIVE` | `"0"` | Live, no fill in progress |
| `ACTIVE` | `> "0"` | Live, fill in progress |
| `INACTIVE` | `"0"` | Cancelled, no fill in progress |
| `INACTIVE` | `> "0"` | Fill in progress — either being held mid-confirmation, or the maker cancelled while a fill was in flight |
| `FILLED` | `"0"` | Fully filled |
`INACTIVE` with a non-zero `pendingFillAmount` does not by itself tell you whether the maker cancelled or a fill is simply in flight. Both can be true at once — see below.
## Cancelling an order with a pending fill
A maker can cancel an order *after* the [betting delay](/developers/betting-delays) has elapsed and the fill has been submitted to chain, but *before* the fill is confirmed. When this happens:
* The order shows `status: "INACTIVE"` (because you cancelled it) **and** `pendingFillAmount > 0` (because the fill is still in flight).
* The pending fill may still confirm on-chain. If it does, the next update will show an updated `fillAmount` — so a cancelled order can end up with a non-zero final `fillAmount`.
* Once the pending fill resolves on-chain, `pendingFillAmount` returns to `"0"` and `fillAmount` reflects whatever the on-chain settlement ended up being (which may be zero in the rare case that the pending fill was rejected). The order remains `INACTIVE`.
The [cancel endpoints](/api-reference/post-cancel-orders) also return a `pendingFills` array on their response, listing any fills awaiting confirmation against the orders you just cancelled. Use this to know upfront which cancelled orders still have in-flight work.
## Order auto-cancellation
Orders may be automatically cancelled (set to `INACTIVE`) by the exchange when the remaining unfilled size drops below the minimum taker amount. This can occur after a partial fill. The resulting `INACTIVE` update is indistinguishable in structure from a maker-initiated cancellation — both have `pendingFillAmount: "0"` once resolved.
## Related
Subscribing to order updates, cancelling, and the heartbeat safety mechanism.
WebSocket channel reference for a maker's own orders.
WebSocket channel reference for a market's full order book.
Why there's a delay between fill submission and on-chain confirmation.