Orders

Limit and market orders on the Capital AI exchange, in whole contracts.

Place an order

POST /api/v1/compute/commands · scope trade

The body is an envelope with your request_id and one command. Use a fresh UUID per request.

Field	Type	Description
request_id	string	Your ID for this request, echoed back.
command.type	place_order
command.instrument_id	string	The contract, e.g. H100SXM-11-26.
command.side	buy | sell	Direction.
command.lots	string	Whole contracts, at least 1.
command.order_type	limit | market	Optional, default limit. A market order takes no price and never rests.
command.price_cents	string	Limit orders: cents per contract, a whole number of dollars ("140000").
command.price_micros	string	Limit orders, instead of price_cents: micro-dollars per GPU-hour ("1950000"), taken to the contract’s cent. Send one or the other, not both.
command.time_in_force	GTC | IOC | FOK	Optional, default GTC: rest until filled or cancelled. IOC fills what it can and cancels the rest; FOK fills in full or not at all. A market order is always IOC.

A sell is refused before it reaches the exchange when it exceeds what you hold free: contracts in a resting sell or locked by a deployment don’t count.

REST

curl -X POST "$CAPITALAI_API_URL/api/v1/compute/commands" \
  -H "Authorization: Bearer $CAPITALAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_id": "0b1f0a4e-7c1e-4a44-9b1a-0a1e3c2d4f55",
    "command": {
      "type": "place_order",
      "instrument_id": "H100SXM-11-26",
      "side": "sell",
      "lots": "10",
      "price_cents": "145000",
      "time_in_force": "GTC"
    }
  }'

Results

200 with the exchange’s answer, whatever it was:

{ "request_id": "0b1f0a4e-…", "status": "COMMITTED", "object_id": "8123" }

status	Meaning
COMMITTED	Accepted. object_id is the order ID; a limit order is now on the book, a market or IOC order has already filled what it could.
REJECTED	Refused. message says why.
RECEIVED, CHECKING	In flight. Rare; the order’s fate shows in your activity.

Rejection messages you may see:

message	Meaning
unknown instrument	No such contract.
invalid lots	lots is missing, zero or not a whole number.
price must be a whole number of dollars per contract	A resting limit must be on the $1 grid.
invalid price or lots	The price is missing or malformed.
give price_cents or price_micros, not both
… contracts are free to sell …	A sell for more than you hold free. The message names how many are free and how many a deployment has locked.
insufficient funds and other exchange reasons	The exchange’s own wording.

HTTP errors: 400 with code: invalid_command when the body is not an object; 401/403 as in Authentication; 503 when the exchange is unreachable.

Cancel an order

Same endpoint, a different command:

Field	Type	Description
command.type	cancel_order
command.order_id	string	The object_id from the place result.

REST

curl -X POST "$CAPITALAI_API_URL/api/v1/compute/commands" \
  -H "Authorization: Bearer $CAPITALAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"request_id": "5c3b…", "command": {"type": "cancel_order", "order_id": "8123"}}'

REJECTED with order is not open when the order has filled, was cancelled, or isn’t yours.

Reading the book and your orders

The order book, your positions, open orders and fills are what the app’s Markets, contract and Home pages show. These reads are session-only today and are coming to the API. Your fills show on the app’s Transactions page as Buy and Sell rows on the Exchange rail, and Home’s Orders tab lists what is resting. GET /api/v1/transactions covers money movements only.