Crypto futures calculator API
for exact trading math

Every calculator on TradingCalc is available as a REST API call. Position size, liquidation price, funding cost, PnL — deterministic results from verified formulas. Same inputs always produce the same outputs.

POST https://tradingcalc.io/api/mcp

Why a deterministic calculation API?

For risk-sensitive trading math, approximations fail. LLMs give plausible-looking numbers that change between calls. TradingCalc is the computation layer that AI calls — not AI itself.

Quickstart — position size API

Calculate position size from account balance and max risk %. No API key required for the free tier.

curl -X POST https://tradingcalc.io/api/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0", "id": 1,
    "method": "tools/call",
    "params": {
      "name": "workflow.run_position_sizing",
      "arguments": {
        "side": "long",
        "entryPrice": 83000,
        "stopLoss": 81000,
        "riskUsdt": 100,
        "leverage": 5
      }
    }
  }'

{
  "result": {
    "sizeBase": 0.04861,
    "sizeQuote": 4034.56,
    "margin": 806.91,
    "stopDistPct": 2.41
  }
}

Liquidation price API

Calculate the exact liquidation price for a futures position. Isolated and cross margin, long and short.

curl -X POST https://tradingcalc.io/api/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer tc_your_key" \
  -d '{
    "jsonrpc": "2.0", "id": 1,
    "method": "tools/call",
    "params": {
      "name": "workflow.run_liquidation_safety",
      "arguments": {
        "side": "long",
        "entryPrice": 83000,
        "leverage": 10,
        "marginType": "isolated"
      }
    }
  }'

{
  "result": {
    "liquidationPrice": 75155.00,
    "liquidationDistPct": 9.45,
    "initialMarginPct": 10.0,
    "maintenanceMarginPct": 0.5
  }
}

API endpoints — full inventory

Full reference at tradingcalc.io/docs — includes all parameters, response schemas, and error codes.

Authentication

No API key required for free tier usage (20 calls/day). For higher limits, pass your key via Authorization header.

// Free tier — no key required
curl -X POST https://tradingcalc.io/api/mcp \
  -H "Content-Type: application/json" \
  -d '{ "jsonrpc": "2.0", ... }'

// Authenticated — bearer token
curl -X POST https://tradingcalc.io/api/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer tc_your_api_key" \
  -d '{ "jsonrpc": "2.0", ... }'

Pricing

Primitive = 1 credit · Workflow = 5 credits · Pre-trade check = 10 credits