Open Interest

Type: NONE

Weight: 1

GET /fapi/v1/openInterest

Status: Implemented.

Aggregates open interest from ledger.positions — the sum of all positive (long) qty for the symbol. In a closed system with no external counterparty, sum(longs) == sum(abs(shorts)), so summing just the long side is sufficient and avoids double-counting.

Request

Param	Type	Required
symbol	string	yes

Response

Field	Type	Notes
openInterest	string	Sum of long qty in base units, as a decimal string; "0" when there are no open positions.
time	int64	Server time (ms) when the response was built.

{
  "symbol": "BTCUSDT",
  "openInterest": "12.500000000000000000",
  "time": 1782899500075
}

Errors

HTTP	code	msg
400	-1100	Unknown symbol.
400	—	symbol missing or malformed: plain-text axum rejection (Failed to deserialize query string: …), not the {code,msg} JSON shape.
500	-1000	Database error.

Source: rocky-backend/services/api-gateway/src/fapi/routes_market.rs (open_interest handler).