Simulate New Order (Pre-trade Risk)

Preview what opening a new position would do to the caller's uniMMR. Useful for front-ends that want to surface "safe leverage" or "this trade will put you into margin-call territory" UX before the user clicks submit.

This endpoint is a pure calculation — no order is placed, no state changes.

HTTP Request

POST /api/v1/unified/risk/simulate (HMAC SHA256)

Request Body

Name	Type	Required	Description
symbol	STRING	YES	e.g. "BTCUSDT"
side	STRING	NO	"long" / "short" — informational only in the current release
size_usd	DECIMAL	YES	Notional USD value the trade would open (positive)
leverage	INT	YES	Leverage (≥ 1, ≤ symbol max)

Response Example

{
    "current_uni_mmr": "3.50",
    "simulated_uni_mmr": "2.80",
    "new_initial_margin": "2500.00",
    "new_maint_margin": "250.000000",
    "available_after": "42500.00",
    "can_open": true,
    "reason": null
}

Field semantics

Field	Meaning
current_uni_mmr	uniMMR before the hypothetical trade
simulated_uni_mmr	uniMMR after the hypothetical fill at mark price
new_initial_margin	size_usd / leverage
new_maint_margin	Tier-aware MM contribution of the new position
available_after	total_equity − (current_initial_margin + new_initial_margin)
can_open	true when all gates pass (see below)
reason	When can_open == false, short English string explaining which gate failed

Gating rules

The order would be rejected (can_open == false) if any of:

• account_status is reduce_only → "account in reduce_only mode"
• account_status is liquidating → "account is liquidating"
• available_after < 0 → "insufficient available balance after opening"
• simulated_uni_mmr < 1.10 → "simulated uniMMR would fall below 1.10"

Error Codes

HTTP	Code	Meaning
400	INVALID_LEVERAGE	leverage < 1
400	INVALID_SIZE	size_usd <= 0

Code Examples

curl

API_KEY="your_api_key"
API_SECRET="your_api_secret"
TIMESTAMP=$(date +%s%3N)
BODY='{"symbol":"BTCUSDT","side":"long","size_usd":"5000","leverage":10}'
PAYLOAD="timestamp=${TIMESTAMP}${BODY}"
SIGNATURE=$(echo -n "${PAYLOAD}" | openssl dgst -sha256 -hmac "${API_SECRET}" | awk '{print $2}')
curl -s -X POST \
  -H "X-MBX-APIKEY: ${API_KEY}" \
  -H "Content-Type: application/json" \
  --data "${BODY}" \
  "https://api.ztdx.io/api/v1/unified/risk/simulate?timestamp=${TIMESTAMP}&signature=${SIGNATURE}"

Python

import time, hmac, hashlib, json, requests

API_KEY = "your_api_key"
API_SECRET = "your_api_secret"

ts = int(time.time() * 1000)
body = json.dumps({"symbol": "BTCUSDT", "size_usd": "5000", "leverage": 10},
                  separators=(",", ":"))
payload = f"timestamp={ts}{body}"
sig = hmac.new(API_SECRET.encode(), payload.encode(), hashlib.sha256).hexdigest()
r = requests.post(
    f"https://api.ztdx.io/api/v1/unified/risk/simulate?timestamp={ts}&signature={sig}",
    headers={"X-MBX-APIKEY": API_KEY, "Content-Type": "application/json"},
    data=body,
)
print(r.json())