# Per-contract bid/ask/mid distribution

`GET https://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://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",
    "nextCursor": "string",
    "nextEndTime": "string"
  }
}
```

### 400

Request validation failed.

invalidParam:

```json
{
  "error": {
    "code": "INVALID_PARAMETER",
    "message": "Invalid value 'bogus' for 'timeframe'. Allowed: 5m, 15m, 1h, 4h, 1d."
  }
}
```

### 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

Unknown, revoked or expired API key (the gateway's `forbidden`), the account's API access is suspended (`account_suspended`) or blocked (`account_blocked`). Not retryable.

badKey:

```json
{
  "error": {
    "code": "FORBIDDEN",
    "message": "Access to this API has been disallowed"
  }
}
```

accountSuspended:

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

### 404

Unknown ticker or contract (`SYMBOL_NOT_FOUND`), or no data for the requested window. Not charged.

unknownSymbol:

```json
{
  "error": {
    "code": "SYMBOL_NOT_FOUND",
    "message": "Unknown ticker 'ZZZZQ'."
  }
}
```

noData:

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

### 429

Either the key exceeded its requests-per-minute limit (`X-RateLimit-Limit`; no `Retry-After`, wait until `X-RateLimit-Reset`), or the account is over one of the API's own limits, such as the query budget (queries running at once, fresh queries per second): `TOO_MANY_CONCURRENT_QUERIES` or `RATE_LIMITED` with `Retry-After`. Not charged; retry after the wait.

tooFast:

```json
{
  "error": {
    "code": "RATE_LIMITED",
    "message": "Rate limit exceeded."
  }
}
```

queryBudget:

```json
{
  "error": {
    "code": "TOO_MANY_CONCURRENT_QUERIES",
    "message": "This account already has 16 queries running on the shared query engine across all servers (limit ch.concurrent.customer). Cached answers are not affected. Retry after Retry-After; to backfill a day, follow meta.nextCursor instead of splitting time windows. See https://www.skylit.ai/docs/api-reference/rate-limits-and-retries",
    "retry_after": 1,
    "docs_url": "https://www.skylit.ai/docs/api-reference/errors#too_many_concurrent_queries"
  }
}
```

### 500

Unexpected server error (`INTERNAL_ERROR`, `DATABASE_ERROR`). Not charged; safe to retry with exponential backoff.

internal:

```json
{
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "Internal server error"
  }
}
```

### 503

Underlying data source temporarily unavailable, the credit balance could not be verified (`credit_check_failed`), or the API is paused for maintenance (`api_paused`, with a `Retry-After` header and a `retry_after` field in seconds). Not charged; 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."
  }
}
```

### 504

The request did not complete within 25 seconds. Not charged; narrow the window or retry.

tooSlow:

```json
{
  "error": {
    "code": "GATEWAY_TIMEOUT",
    "message": "The request took too long and was not completed. It was not charged; narrow the request or retry."
  }
}
```