# GET /api/mcp/data/chain-at-time/{ticker}

> How was SPY's 21 August chain priced at the close on 14 August?

Returns calls and puts for one expiration as they were priced at the close of a past trading day, with quotes, IV, Greeks, volume and open interest.

- **Family:** Options chain (https://apexvol.com/developers/options-chain-api)
- **Plan:** Pro and above. Every call needs `Authorization: Bearer avmcp_<token>`; tokens are issued to paid and trial accounts under Account, then API Access.
- **Units:** Prices in dollars; implied_vol as a decimal; Greeks per share.
- **Basis:** End-of-day snapshot from the historical feed. Both the expiration and the trade date must be past dates.
- **MCP tools:** `get_historical_chain`
- **Background:** https://apexvol.com/learn/how-to-read-options-chain

## Parameters

| Name | In | Default | Range | Meaning |
|---|---|---|---|---|
| `ticker` (required) | path |  | any covered symbol | The underlying, upper case. Use /search to check coverage. |
| `expiration` (required) | query |  | YYYY-MM-DD | The expiration to fetch. |
| `trade_date` (required) | query |  | YYYY-MM-DD, a past trading day | The day whose close to use. |

## Request

```bash
curl -H "Authorization: Bearer avmcp_YOUR_TOKEN" \
     "https://apexvol.com/api/mcp/data/chain-at-time/SPY?expiration=2026-08-21&trade_date=2026-08-14"
```

## Response (captured 2026-09-08)

Real response, lists cut to the rows nearest the money. The envelope is `{"success": true, "data": ...}`.

```json
{
  "success": true,
  "data": {
    "calls": [
      {
        "ask": 4.75,
        "bid": 4.69,
        "delta": 0.5747,
        "epsilon": -0.0857,
        "expiration": "2026-08-21",
        "gamma": 0.0436,
        "implied_vol": 0.0895,
        "open_interest": 54326,
        "rho": 0.0848,
        "right": "C",
        "strike": 775,
        "theta": -0.3008,
        "underlying_price": 776.07,
        "vega": 0.4203,
        "volume": 6045
      },
      {
        "ask": 4.14,
        "bid": 4.12,
        "delta": 0.5315,
        "epsilon": -0.0792,
        "expiration": "2026-08-21",
        "gamma": 0.0452,
        "implied_vol": 0.0885,
        "open_interest": 5227,
        "rho": 0.0785,
        "right": "C",
        "strike": 776,
        "theta": -0.2954,
        "underlying_price": 776.07,
        "vega": 0.4277,
        "volume": 8446
      },
      {
        "ask": 3.59,
        "bid": 3.57,
        "delta": 0.486,
        "epsilon": -0.0724,
        "expiration": "2026-08-21",
        "gamma": 0.0462,
        "implied_vol": 0.0874,
        "open_interest": 5722,
        "rho": 0.0718,
        "right": "C",
        "strike": 777,
        "theta": -0.2877,
        "underlying_price": 776.07,
        "vega": 0.427,
        "volume": 15012
      }
    ],
    "expiration": "2026-08-21",
    "puts": [
      {
        "ask": 3.13,
        "bid": 3.12,
        "delta": -0.4253,
        "epsilon": -0.0857,
        "expiration": "2026-08-21",
        "gamma": 0.0436,
        "implied_vol": 0.09,
        "open_interest": 6989,
        "rho": -0.0637,
        "right": "P",
        "strike": 775,
        "theta": -0.3008,
        "underlying_price": 776.07,
        "vega": 0.4203,
        "volume": 17977
      },
      {
        "ask": 3.55,
        "bid": 3.53,
        "delta": -0.4685,
        "epsilon": -0.0792,
        "expiration": "2026-08-21",
        "gamma": 0.0452,
        "implied_vol": 0.0889,
        "open_interest": 1969,
        "rho": -0.0702,
        "right": "P",
        "strike": 776,
        "theta": -0.2954,
        "underlying_price": 776.07,
        "vega": 0.4277,
        "volume": 8064
      },
      {
        "ask": 4.0,
        "bid": 3.98,
        "delta": -0.514,
        "epsilon": -0.0724,
        "expiration": "2026-08-21",
        "gamma": 0.0462,
        "implied_vol": 0.0877,
        "open_interest": 2999,
        "rho": -0.0771,
        "right": "P",
        "strike": 777,
        "theta": -0.2877,
        "underlying_price": 776.07,
        "vega": 0.427,
        "volume": 8247
      }
    ],
    "ticker": "SPY",
    "time_of_day": "EOD",
    "trade_date": "2026-08-14",
    "underlying_price": 776.07
  }
}
```

## Fields

- `calls[], puts[]`: One row per strike per side.
- `strike, bid, ask, implied_vol`: The quote and IV that day.
- `delta, gamma, theta, vega, rho`: Greeks at the close.
- `underlying_price, trade_date, time_of_day`: Context.

## Errors

- `401`: no or revoked token
- `429`: Retry-After seconds
- `403`: Pro plan required
- `424`: data feed unavailable, retry
- Full list: https://apexvol.com/developers/errors

## Ask it in an MCP client

- Show the SPY chain for 21 August as it was priced on 14 August.
- What was the IV of the NVDA 200 call on the day before earnings?
- Pull the AAPL chain snapshot from last Friday.

Conventions for units, bases and timestamps: https://apexvol.com/developers/conventions