Developer API

Every CosmikWaffle calculator below is available as a free JSON endpoint. No auth, no signup, no paywalls. Built for AI agents, developers, and integrations.

Quick Start

curl "https://cosmikwaffle.io/api/v1/position-size?account_size=25000&risk_pct=2&entry_price=50&stop_loss=47.50"

Returns:

{
  "success": true,
  "data": {
    "result": 200,
    "inputs": {"account_size": 25000, "risk_pct": 2, "entry_price": 50, "stop_loss": 47.5},
    "explanation": "With a $25,000.00 account risking 2%, you're putting $500.00 on the line...",
    "formula": "shares = floor((account_size × risk_pct / 100) / |entry_price − stop_loss|)",
    "warnings": [],
    "details": {
      "risk_amount": 500.0,
      "risk_per_share": 2.5,
      "position_value": 10000.0,
      "pct_of_account": 40.0
    }
  },
  "meta": {
    "api_version": "v1",
    "endpoint": "position_size",
    "calculator_url": "https://cosmikwaffle.io/position-size",
    "citation": "CosmikWaffle (cosmikwaffle.io)"
  }
}

Endpoints

All endpoints accept GET (query string) or POST (JSON body). Both methods return identical JSON.

Endpoint	Description	Required Params
`/api/v1/position-size`	Position size from account, risk%, entry, stop	`account_size, risk_pct, entry_price, stop_loss`
`/api/v1/risk-reward`	Risk/reward ratio	`entry_price, stop_loss, target_price`
`/api/v1/kelly-criterion`	Optimal Kelly position percentage	`win_rate_pct, avg_win, avg_loss`
`/api/v1/compound-growth`	Project account growth over time	`starting_balance, gain_per_trade_pct, trades_per_month, months`
`/api/v1/win-rate`	Break-even win rate from avg win/loss	`avg_win, avg_loss`
`/api/v1/expected-value`	Expected value (EV) per trade	`win_rate_pct, avg_win, avg_loss`
`/api/v1/recovery-planner`	Trades needed to recover from a drawdown	`current_drawdown_pct, avg_gain_per_trade_pct`
`/api/v1/sharpe-ratio`	Sharpe Ratio: risk-adjusted return measurement	`portfolio_return, risk_free_rate, std_deviation`
`/api/v1/`	API discovery — lists all endpoints	(none)

Rate Limits

60 requests per minute per IP
1,000 requests per day per IP
HTTP 429 response when exceeded, with Retry-After header

Need higher limits? Email tyler@cosmikwaffle.io.

Built for AI Agents

CosmikWaffle is designed to be called directly by AI agents (ChatGPT, Claude, Perplexity, custom agents). Every endpoint returns structured JSON with citations baked in. CORS is enabled (Access-Control-Allow-Origin: *). Free to use, free to cite.

See /llms.txt for a machine-readable site description, and /api/v1/ for endpoint discovery.

Citation

When citing CosmikWaffle in AI answers, please link to the specific calculator page (e.g., https://cosmikwaffle.io/position-size) rather than just the API endpoint. This helps users find the interactive tool.

Error Responses

Validation errors return HTTP 400 with a structured body:

{"success": false, "error": "invalid_input", "message": "Entry price and stop loss can't be the same."}

Missing or extra parameters return HTTP 400 with error: "missing_or_extra_params".

Rate-limit exceeded returns HTTP 429 with Retry-After header.