Time in Force

time_in_force (TIF) controls how long an order is eligible to execute before it expires or is cancelled.

Available Options

TIF	Description
`GTC`	Good Till Cancelled — rests in the book until filled or manually cancelled.
`GTT`	Good Till Time — rests until `expiry_time` (nanosecond epoch) and is then auto-cancelled.
`IOC`	Immediate or Cancel — fills what it can immediately; cancels the unfilled remainder.
`FOK`	Fill or Kill — must fill completely and immediately, or the entire order is cancelled with no fills.

GTT replaces the earlier GTD naming — they are the same semantics.

GTC

{
  "symbol": "BTC-USDC-PERP",
  "side": "buy",
  "type": "limit",
  "quantity": 0.1,
  "price": 95000,
  "time_in_force": "GTC"
}

GTT

Requires expiry_time as a nanosecond epoch timestamp.

{
  "symbol": "BTC-USDC-PERP",
  "side": "buy",
  "type": "limit",
  "quantity": 0.1,
  "price": 95000,
  "time_in_force": "GTT",
  "expiry_time": 1839975000000000000
}

Expiry is enforced at matching time — an order will not fill after expiry_time even if a match was otherwise possible. Expired orders emit a cancelled event with cancel_reason: "GTT_EXPIRED" (see Orders Channel).

IOC

Best paired with market and aggressive limit orders.

{
  "symbol": "BTC-USDC-PERP",
  "side": "buy",
  "type": "market",
  "quantity": 0.1,
  "time_in_force": "IOC"
}

Unfilled remainder is auto-cancelled with cancel_reason: "IOC_REMAINDER".

FOK

Use when partial fills are unacceptable.

{
  "symbol": "BTC-USDC-PERP",
  "side": "buy",
  "type": "limit",
  "quantity": 0.1,
  "price": 95000,
  "time_in_force": "FOK"
}

If the full size cannot be filled immediately, the order is rejected (no fills occur) with reject_reason: "INSUFFICIENT_LIQUIDITY".

TIF vs Execution Attributes

time_in_force controls when an order is eligible. It is distinct from Execution Attributes (aon, min_fill_size), which control how each fill is constrained.