# API Documentation

## Overview

Vault Dashboard exposes a small read-only HTTP API plus a WebSocket stream.

Base capabilities:

- health monitoring
- portfolio snapshot retrieval
- options chain retrieval
- strategy analysis retrieval
- periodic real-time portfolio updates over WebSocket

Unless noted otherwise, all responses are JSON.

---

## Conventions

### Base URL

Examples:

```text
http://localhost:8000
https://vault.example.com
```

### Content type

Responses use:

```http
Content-Type: application/json
```

### Authentication

There is currently **no application-layer authentication** on these endpoints.

If the deployment requires restricted access, enforce it at the network or reverse-proxy layer.

### Errors

The app currently relies mostly on framework defaults. Typical failures may include:

- `422 Unprocessable Entity` for invalid query parameters
- `500 Internal Server Error` for unexpected runtime issues

---

## HTTP endpoints

## 1. Health

### `GET /health`

Deployment and uptime check.

#### Query parameters

None.

#### Response schema

```json
{
  "status": "ok",
  "environment": "production",
  "redis_enabled": false
}
```

#### Field definitions

- `status` (`string`): expected value is currently `"ok"`
- `environment` (`string`): runtime environment from `APP_ENV` or `ENVIRONMENT`
- `redis_enabled` (`boolean`): `true` when Redis is configured and connected

#### Example request

```bash
curl -fsS http://localhost:8000/health
```

#### Example response

```json
{
  "status": "ok",
  "environment": "development",
  "redis_enabled": false
}
```

---

## 2. Portfolio

### `GET /api/portfolio`

Returns a portfolio snapshot derived from the current quote for a symbol.

#### Query parameters

| Name | Type | Required | Default | Description |
|---|---|---:|---|---|
| `symbol` | string | no | `GLD` | Ticker symbol to analyze |

#### Response schema

```json
{
  "symbol": "GLD",
  "spot_price": 215.0,
  "portfolio_value": 215000.0,
  "loan_amount": 600000.0,
  "ltv_ratio": 2.7907,
  "updated_at": "2026-03-21T12:34:56.000000+00:00",
  "source": "fallback"
}
```

#### Field definitions

- `symbol` (`string`): requested ticker, uppercased
- `spot_price` (`number`): latest spot/quote price
- `portfolio_value` (`number`): current modeled collateral value, currently `spot_price * 1000`
- `loan_amount` (`number`): modeled loan balance, currently fixed at `600000.0`
- `ltv_ratio` (`number`): `loan_amount / portfolio_value`
- `updated_at` (`string`, ISO 8601): response generation timestamp
- `source` (`string`): quote source such as `yfinance` or `fallback`

#### Example request

```bash
curl "http://localhost:8000/api/portfolio?symbol=GLD"
```

#### Example response

```json
{
  "symbol": "GLD",
  "spot_price": 215.0,
  "portfolio_value": 215000.0,
  "loan_amount": 600000.0,
  "ltv_ratio": 2.7907,
  "updated_at": "2026-03-21T12:34:56.000000+00:00",
  "source": "fallback"
}
```

---

## 3. Options chain

### `GET /api/options`

Returns a simplified options chain snapshot for the symbol.

#### Query parameters

| Name | Type | Required | Default | Description |
|---|---|---:|---|---|
| `symbol` | string | no | `GLD` | Ticker symbol to analyze |

#### Response schema

```json
{
  "symbol": "GLD",
  "updated_at": "2026-03-21T12:34:56.000000+00:00",
  "calls": [
    {
      "strike": 225.75,
      "premium": 6.45,
      "expiry": "2026-06-19"
    }
  ],
  "puts": [
    {
      "strike": 204.25,
      "premium": 6.02,
      "expiry": "2026-06-19"
    }
  ],
  "source": "fallback"
}
```

#### Array item schema

Each option row in `calls` or `puts` has:

- `strike` (`number`)
- `premium` (`number`)
- `expiry` (`string`, `YYYY-MM-DD`)

#### Field definitions

- `symbol` (`string`): requested ticker, uppercased
- `updated_at` (`string`, ISO 8601): response generation timestamp
- `calls` (`array<object>`): example call rows derived from spot
- `puts` (`array<object>`): example put rows derived from spot
- `source` (`string`): upstream quote source used to derive the chain

#### Notes

The current options chain is synthetic. It is not yet a full broker-grade chain feed.

#### Example request

```bash
curl "http://localhost:8000/api/options?symbol=GLD"
```

---

## 4. Strategies

### `GET /api/strategies`

Returns strategy comparison data, recommendations by risk profile, and sensitivity analysis.

#### Query parameters

| Name | Type | Required | Default | Description |
|---|---|---:|---|---|
| `symbol` | string | no | `GLD` | Ticker symbol to analyze |

#### Top-level response schema

```json
{
  "symbol": "GLD",
  "updated_at": "2026-03-21T12:34:56.000000+00:00",
  "paper_parameters": {},
  "strategies": [],
  "recommendations": {},
  "sensitivity_analysis": {}
}
```

#### Top-level field definitions

- `symbol` (`string`): requested ticker, uppercased
- `updated_at` (`string`, ISO 8601): response generation timestamp
- `paper_parameters` (`object`): engine inputs used for the analysis
- `strategies` (`array<object>`): detailed strategy comparison rows
- `recommendations` (`object`): recommendation results keyed by risk profile
- `sensitivity_analysis` (`object`): recommendation changes across parameter shifts

### 4.1 `paper_parameters` schema

```json
{
  "portfolio_value": 1000000.0,
  "loan_amount": 600000.0,
  "margin_call_threshold": 0.75,
  "spot_price": 460.0,
  "volatility": 0.16,
  "risk_free_rate": 0.045
}
```

Fields:

- `portfolio_value` (`number`)
- `loan_amount` (`number`)
- `margin_call_threshold` (`number`)
- `spot_price` (`number`)
- `volatility` (`number`)
- `risk_free_rate` (`number`)

### 4.2 `strategies[]` schema

Each element in `strategies` is produced by `StrategySelectionEngine.compare_all_strategies()`:

```json
{
  "name": "protective_put_atm",
  "cost": {},
  "protection": {},
  "scenarios": [],
  "score_inputs": {
    "annual_cost": 0.0,
    "hedged_ltv_at_threshold": 0.0
  }
}
```

Fields:

- `name` (`string`): internal strategy identifier
- `cost` (`object`): strategy-specific cost payload
- `protection` (`object`): strategy-specific protection payload
- `scenarios` (`array<object>`): scenario analysis rows
- `score_inputs` (`object`): normalized inputs used for recommendation scoring

#### Protective put cost schema

Typical `cost` object for `protective_put_*`:

```json
{
  "strategy": "protective_put_atm",
  "label": "ATM",
  "strike": 460.0,
  "strike_pct": 1.0,
  "premium_per_share": 21.1234,
  "total_cost": 45920.43,
  "cost_pct_of_portfolio": 0.04592,
  "term_months": 12,
  "annualized_cost": 45920.43,
  "annualized_cost_pct": 0.04592
}
```

#### Protective put protection schema

```json
{
  "strategy": "protective_put_atm",
  "threshold_price": 368.0,
  "strike": 460.0,
  "portfolio_floor_value": 1000000.0,
  "unhedged_ltv_at_threshold": 0.75,
  "hedged_ltv_at_threshold": 0.652174,
  "payoff_at_threshold": 200000.0,
  "maintains_margin_call_buffer": true
}
```

#### Protective put scenario row schema

```json
{
  "price_change_pct": -0.2,
  "gld_price": 368.0,
  "gold_value": 800000.0,
  "option_payoff": 200000.0,
  "hedge_cost": 45920.43,
  "net_portfolio_value": 954079.57,
  "unhedged_ltv": 0.75,
  "hedged_ltv": 0.6,
  "margin_call_without_hedge": true,
  "margin_call_with_hedge": false
}
```

#### Laddered put cost schema

Typical `cost` object for `laddered_put_*`:

```json
{
  "strategy": "laddered_put_50_50_atm_otm95",
  "label": "50_50_ATM_OTM95",
  "legs": [
    {
      "weight": 0.5,
      "strike": 460.0,
      "premium_per_share": 21.1234,
      "weighted_cost": 22960.22
    }
  ],
  "blended_premium_per_share": 18.4567,
  "blended_cost": 40123.45,
  "cost_pct_of_portfolio": 0.040123,
  "annualized_cost": 40123.45,
  "annualized_cost_pct": 0.040123
}
```

#### Laddered put protection schema

```json
{
  "strategy": "laddered_put_50_50_atm_otm95",
  "threshold_price": 368.0,
  "portfolio_floor_value": 975000.0,
  "payoff_at_threshold": 175000.0,
  "unhedged_ltv_at_threshold": 0.75,
  "hedged_ltv_at_threshold": 0.615385,
  "maintains_margin_call_buffer": true,
  "legs": [
    {
      "weight": 0.5,
      "strike": 460.0,
      "weighted_payoff_at_threshold": 100000.0
    }
  ]
}
```

#### Lease duration analysis cost schema

Typical `cost` object for `lease_duration_analysis`:

```json
{
  "strategy": "lease_duration_analysis",
  "comparison": [
    {
      "months": 3,
      "strike": 460.0,
      "premium_per_share": 9.1234,
      "total_cost": 19833.48,
      "annualized_cost": 79333.92,
      "annualized_cost_pct": 0.079334,
      "rolls_per_year": 4.0,
      "recommended_roll_month": 2
    }
  ],
  "optimal_duration_months": 12,
  "lowest_annual_cost": 45920.43,
  "lowest_annual_cost_pct": 0.04592
}
```

#### Lease duration analysis protection schema

```json
{
  "strategy": "lease_duration_analysis",
  "threshold_price": 368.0,
  "durations": [
    {
      "months": 12,
      "payoff_at_threshold": 200000.0,
      "hedged_ltv_at_threshold": 0.6,
      "maintains_margin_call_buffer": true
    }
  ]
}
```

### 4.3 `recommendations` schema

The object contains keys:

- `conservative`
- `balanced`
- `cost_sensitive`

Each recommendation object has this shape:

```json
{
  "risk_profile": "balanced",
  "recommended_strategy": "laddered_put_50_50_atm_otm95",
  "rationale": {
    "portfolio_value": 1000000.0,
    "loan_amount": 600000.0,
    "margin_call_threshold": 0.75,
    "spot_price": 460.0,
    "volatility": 0.16,
    "risk_free_rate": 0.045
  },
  "comparison_summary": [
    {
      "name": "protective_put_atm",
      "annual_cost": 45920.43,
      "hedged_ltv_at_threshold": 0.6
    }
  ]
}
```

### 4.4 `sensitivity_analysis` schema

```json
{
  "volatility": [
    {
      "volatility": 0.12,
      "recommended_strategy": "protective_put_otm_95"
    }
  ],
  "spot_price": [
    {
      "spot_price": 414.0,
      "recommended_strategy": "protective_put_otm_95"
    }
  ]
}
```

---

## WebSocket API

## Endpoint

### `WS /ws/updates`

Used for server-pushed real-time updates.

### Connection lifecycle

1. Client opens a WebSocket connection to `/ws/updates`
2. Server accepts the connection
3. Server immediately sends a `connected` event
4. Server periodically broadcasts `portfolio_update` events
5. Client may keep the connection alive by sending text frames
6. Server removes the connection when disconnected or on send failure

### Event: `connected`

Sent once after successful connection.

#### Schema

```json
{
  "type": "connected",
  "message": "Real-time updates enabled"
}
```

Fields:

- `type` (`string`): event name
- `message` (`string`): human-readable confirmation

### Event: `portfolio_update`

Broadcast on an interval controlled by `WEBSOCKET_INTERVAL_SECONDS`.

#### Schema

```json
{
  "type": "portfolio_update",
  "connections": 2,
  "portfolio": {
    "symbol": "GLD",
    "spot_price": 215.0,
    "portfolio_value": 215000.0,
    "loan_amount": 600000.0,
    "ltv_ratio": 2.7907,
    "updated_at": "2026-03-21T12:34:56.000000+00:00",
    "source": "fallback"
  }
}
```

Fields:

- `type` (`string`): event name
- `connections` (`integer`): current number of connected WebSocket clients
- `portfolio` (`object`): same schema as `GET /api/portfolio`

### Example JavaScript client

```js
const ws = new WebSocket('ws://localhost:8000/ws/updates');

ws.onmessage = (event) => {
  const payload = JSON.parse(event.data);
  console.log(payload.type, payload);
};

ws.onopen = () => {
  // optional keepalive or ping surrogate
  setInterval(() => {
    if (ws.readyState === WebSocket.OPEN) {
      ws.send('ping');
    }
  }, 10000);
};
```

---

## OpenAPI

Because the app is built on FastAPI, interactive docs are typically available at:

- `/docs`
- `/redoc`

This file is the human-oriented reference for payload semantics and current behavior.

## Notes and limitations

- Endpoints are read-only today
- There are no POST/PUT/DELETE endpoints yet
- The options chain is currently synthetic
- Strategy outputs are paper-analysis results, not execution instructions
- Symbol validation is minimal and currently delegated to downstream quote behavior