# OBV & Volume Screener (Multi-Asset) API
> Which markets are under accumulation or distribution and where volume is surging, computed live from Yahoo Finance (no key, nothing stored). Price tells you what is happening; volume tells you whether to believe it. On-Balance Volume adds the day's volume when a market closes up and subtracts it when it closes down, so a rising OBV means buyers are in control (accumulation) and a falling OBV means sellers are (distribution) — and a divergence between OBV and price is an early warning of a turn. A volume surge — today's volume well above its recent average — flags conviction behind a move. For a cross-asset, cross-sector universe — equity indices and sectors, gold, oil, commodities, bonds and crypto — this computes each asset's OBV trend over the last month, its latest volume versus the 20-day average, and tags it accumulation, distribution or neutral. The screener endpoint returns the markets under accumulation and distribution and the ones with a volume surge. The asset endpoint returns one market's OBV/volume card. The universe endpoint lists what is covered. The cross-asset volume / OBV screener cut — distinct from the bring-your-own-candle volume-indicator API and the crypto volume-profile API; it adds the volume dimension the price-only screeners miss.

## Authentication
All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys.

```bash
curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/obv-api/..."
```

## Pricing
- **Free** (Free) — 840 calls/Mo, 2 req/s
- **Starter** ($10/Mo) — 18,600 calls/Mo, 6 req/s
- **Pro** ($31/Mo) — 92,500 calls/Mo, 16 req/s
- **Business** ($73/Mo) — 502,000 calls/Mo, 40 req/s

## Endpoints

### Screener

#### `GET /v1/screener` — Cross-asset board with accumulation/distribution and volume surges

**Parameters:**
- `class` (query, optional, string) — Filter by class: equities, sector, commodities, bonds, crypto Example: `sector`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/obv-api/v1/screener?class=sector"
```

### Asset

#### `GET /v1/asset` — One market OBV / volume card

**Parameters:**
- `asset` (query, required, string) — Asset key (see /v1/universe) Example: `sp500`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/obv-api/v1/asset?asset=sp500"
```

### Universe

#### `GET /v1/universe` — Supported instruments

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/obv-api/v1/universe"
```

### Meta

#### `GET /v1/meta` — Service metadata

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/obv-api/v1/meta"
```


---
Marketplace page: https://www.oanor.com/api/obv-api
OpenAPI spec: https://www.oanor.com/api/obv-api/openapi.json