# Per-contract bid/ask/mid distribution

`GET https://flow-api.skylit.ai/v1/contract-ratio/{symbol}`

API: Flowseeker. Credits: 1.

Single-contract counterpart to `/v1/chain-ratio/{ticker}`. Returns
`askRatio`, `bidRatio`, `midRatio`, `aggressionRatio`, and a
`bias`/`aggression`/`confidence` interpretation for one specific
OPRA option symbol.

## Authentication

Send your Skylit API key as a bearer token: `Authorization: Bearer <key>`. No other header is accepted.

## Parameters

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `symbol` | path | string | yes | OPRA option symbol in URL-safe form: `{ticker}__{YYMMDD}{C\|P}{strike×1000, 8 digits}` — the ticker and the 15-character contract block are joined by a **double underscore** (`__`). For example, an AAPL $250 call expiring 2026-01-17 is `AAPL__260117C00250000`. (A space-padded 21-char OCC form such as `AAPL 260117C00250000` is also accepted on some endpoints, but the `__` form is canonical and works across all contract routes.) |
| `date` | query | string (date) | no |  |
| `timeframe` | query | string | no |  (one of `5m`, `15m`, `1h`, `4h`, `1d`; default `1d`) |
| `min_premium` | query | integer | no |  (min 0) |

## Example request

```bash
curl "https://flow-api.skylit.ai/v1/contract-ratio/SPY__250516C00580000" \
  -H "Authorization: Bearer $SKYLIT_API_KEY"
```

## Responses

### 200

Contract ratio analysis with interpretation.

Shape (placeholder values):

```json
{
  "data": {
    "symbol": "SPY 250516C00580000",
    "ticker": "string",
    "optionType": "CALL",
    "date": "string",
    "timeframe": "string",
    "tradeCount": 0,
    "totalVolume": 0,
    "totalPremium": 0,
    "contractRatios": {
      "askRatio": 0,
      "bidRatio": 0,
      "midRatio": 0,
      "aggressionRatio": 0
    },
    "interpretation": {
      "bias": "BULLISH",
      "aggression": "HIGH",
      "confidence": "HIGH",
      "description": "string"
    }
  },
  "meta": {
    "timestamp": "string",
    "requestId": "d7574836"
  }
}
```

### 400

Request validation failed.

invalidParam:

```json
{
  "error": {
    "code": "BAD_REQUEST",
    "message": "Invalid parameter 'timeframe': must be one of [1m, 5m, 15m, 1h, 4h, 1d, 1w, 1M]"
  }
}
```

### 401

Missing or invalid API key.

missingKey:

```json
{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "Authentication required"
  }
}
```

### 402

The account's shared Skylit credit balance is lower than this route's cost. Top up to continue. Carries `X-Credits-Remaining: 0`.

Headers: `X-Credits-Remaining`.

outOfCredits:

```json
{
  "error": {
    "code": "insufficient_credits",
    "message": "Out of credits. Top up to continue making requests."
  }
}
```

### 403

API key invalid, revoked or expired, or the account's API access is suspended (`account_suspended`).

accountSuspended:

```json
{
  "error": {
    "code": "account_suspended",
    "message": "API access has been suspended for this account. Contact support."
  }
}
```

### 404

Unknown resource (ticker / sector / window with no data).

noData:

```json
{
  "error": {
    "code": "NOT_FOUND",
    "message": "No trades found for AAPL on 2026-05-27 with timeframe 1d"
  }
}
```

### 429

Per-minute rate limit exceeded.

Headers: `Retry-After`.

tooFast:

```json
{
  "error": {
    "code": "RATE_LIMITED",
    "message": "Rate limit of 100 req/min exceeded. Retry after 18s."
  }
}
```

### 503

Underlying data source temporarily unavailable, or the credit balance could not be verified (`credit_check_failed`). Safe to retry.

ingestionLag:

```json
{
  "error": {
    "code": "UNAVAILABLE",
    "message": "Live feed is degraded; please retry in a few seconds."
  }
}
```

creditCheckFailed:

```json
{
  "error": {
    "code": "credit_check_failed",
    "message": "Could not verify credit balance. Please retry."
  }
}
```