fill

privatechannel: fillwss://api.staging.sphx.io/v1/ws

The authenticated account's own fills, within ~10 ms of the match (p99). Carries the account's own-leg fee (signed µUSDC) and the fill tag (normal / liquidation / adl). If two of your accounts cross, each receives its own frame. Requires bearer auth on the upgrade. No subscribe params (auto-scoped).

Subscribe

{ "op": "subscribe", "channel": "fill" }

No params — the channel auto-scopes to the authenticated account.

Requires a bearer token on the upgrade request.

Events

fill

One of your orders traded.

Field	Type	Required	Description
event_seq	integer · int64	✓	Cluster sequence number — monotonic; drives gap detection and REST/WS joins.
ts_ns	integer · int64	✓	Aeron Cluster timestamp — MILLISECONDS despite the name.
instrument_id	integer · int64	✓
maker_order_id	integer · uint64	✓
taker_order_id	integer · uint64	✓
account_id	integer · int64	✓	Always the connection's authenticated account.
side	maker · taker	✓	Which side of the match this account was on.
price_pips	integer	✓
count	integer	✓
maker_side	buy · sell	✓
fee_uusdc	integer · int64	✓	This account's own leg fee, signed µUSDC (negative = rebate).
tag	normal · liquidation · adl	✓	Liquidation fills carry the tag here only — never on the public tape.

Example frame

{
  "channel": "fill",
  "event": "fill",
  "data": {
    "event_seq": 1057,
    "ts_ns": 1779111582959,
    "instrument_id": 1000,
    "maker_order_id": 41,
    "taker_order_id": 42,
    "account_id": 7,
    "side": "taker",
    "price_pips": 3900,
    "count": 100,
    "maker_side": "buy",
    "fee_uusdc": 0,
    "tag": "normal"
  }
}