Live trading API

The live trading API trades today's session against the real-time market. It mirrors the historical orders API but lives under /live and operates on a single, in-progress simulation per user. See Live trading for the concepts. Requires a registered account.

Endpoints

Method	Path	Purpose
POST	/live	Start today's live simulation
GET	/live	Get your current live simulation
DELETE	/live	End your live simulation
POST	/live/orders	Place an order
POST	/live/orders/dry-run	Validate + preview without persisting
PUT	/live/orders	Atomically cancel + replace a pending limit order
DELETE	/live/orders/{id}	Cancel a pending order
GET	/live/orders · /live/orders/{id}	List / get orders
GET	/live/positions	Current positions
GET	/live/history	Per-second P&L history (chart line)
GET	/live/transactions	Transaction log

Start a session

curl -s https://api.0dtespx.com/live \
  -X POST -H "Authorization: $TOKEN" -H 'Content-Type: application/json' \
  -d '{"starting_capital":"100000","description":"my live session"}'

Returns 201 with the live-simulation object. The date is implicitly today, and you can only have one active live simulation at a time — there is no daily cap on how many you create. A session can only be created while the market is open and live data is flowing — otherwise you get 400.

Place an order

The request body matches the historical orders API. Two additions make retries safe:

curl -s https://api.0dtespx.com/live/orders \
  -X POST -H "Authorization: $TOKEN" -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: ord-2025-05-07-001' \
  -d '{
    "type":"limit","price":"5.00","price_effect":"debit",
    "legs":[{"instrument":"SPXW  260507C05950000","quantity":"1","action":"buy to open"}]
  }'

• Idempotency-Key (header, optional but recommended) — a duplicate submission within the retention window returns the original response instead of placing a second order.
• client_order_id (body, optional UUID) — used as the order's id; a replay with the same id resolves to the existing order. When omitted, one is derived from the idempotency key, so most clients never need to set it.

Order lifecycle

Live orders never time-travel — status is the persisted state and stays terminal once set:

Status	Meaning
pending	Accepted, awaiting a matching tick
filled	Executed
canceled	You canceled the pending order
expired	Auto-expired at the 4:00 PM ET close
rejected	Failed a buying-power recheck at fill time (rejection_reason explains)

No orders are accepted after the close (400, kind market_closed).

Cancel and replace

# cancel a pending order
curl -s -X DELETE https://api.0dtespx.com/live/orders/$ORDER_ID -H "Authorization: $TOKEN"

# atomically cancel + replace a pending LIMIT order's price
curl -s -X PUT https://api.0dtespx.com/live/orders \
  -H "Authorization: $TOKEN" -H 'Content-Type: application/json' \
  -d '{"order_id":"'"$ORDER_ID"'","type":"limit","price":"5.50","price_effect":"debit","legs":[ … ]}'

Only price and price_effect may change in a replacement; type, legs, and underlying are fixed. Cancelling or replacing a non-pending order returns 409. Replacing a non-limit order returns 400.

Read your state

curl -s https://api.0dtespx.com/live              -H "Authorization: $TOKEN"  # current sim
curl -s https://api.0dtespx.com/live/orders       -H "Authorization: $TOKEN"  # orders
curl -s https://api.0dtespx.com/live/positions    -H "Authorization: $TOKEN"  # positions
curl -s https://api.0dtespx.com/live/history      -H "Authorization: $TOKEN"  # per-second P&L history
curl -s https://api.0dtespx.com/live/transactions -H "Authorization: $TOKEN"  # transactions

Live state also pushes over the WebSocket — REST is authoritative for an operation you just performed; the WebSocket is the source of truth for changes you didn't initiate (other tabs, fills, the close). De-dupe orders by id and prefer the newer updated_at. After a disconnect, refetch positions/orders/transactions to recover.

Settlement and ending

Settlement runs automatically once the closing tick is recorded; the session then moves into your historical endpoints and GET /live returns null. End a session early with DELETE /live, after which you can POST /live again for a fresh session the same day.

Error semantics

Status	Meaning
400	Validation error (insufficient buying power, market closed, …)
409	Order is no longer pending — can't cancel or replace
503	Live trading briefly unavailable — always safe to retry; no state changed