# Composition data

### What is this endpoint for?

This endpoint retrieves the historical compositions of our Reference Rates, determined by our periodic rate rebalances. You can learn more about our Reference Rates [here](https://www.kaiko.com/indices/reference-rates).

### Endpoint

```
https://us.market-api.kaiko.io/v2/data/index.v1/digital_asset_rates_compo
```

### Request parameters

<table><thead><tr><th width="170">Parameter</th><th width="131">Required</th><th width="356">Description</th><th>Example</th></tr></thead><tbody><tr><td><code>index_code</code></td><td>Yes</td><td>The desired rate <a data-footnote-ref href="#user-content-fn-1"><code>ticker</code></a></td><td><code>KK_BRR_BTCUSD</code></td></tr><tr><td><code>start_time</code></td><td>No</td><td>Starting time in ISO 8601 (inclusive).</td><td><code>2023-01-25T00:00:00.000Z</code></td></tr><tr><td><code>end_time</code></td><td>No</td><td>Ending time in ISO 8601 (exclusive).</td><td><code>2023-04-25T00:00:00.000Z</code></td></tr></tbody></table>

### Response Fields

| Field               | Description                                       |
| ------------------- | ------------------------------------------------- |
| `index_code`        | The ticker of the rate                            |
| `start_period`      | Start of the composition period                   |
| `end_period`        | End of the composition period                     |
| `exchanges`         | Exchanges used during the composition period \*\* |
| `window_seconds`    | Calculation window in seconds for the period      |
| `partition_seconds` | Partition size in seconds for the period          |
| `result`            | Status of the query                               |

{% hint style="info" %}
\*\* \
\
These are the exchanges that constitute the eligible universe of trading venues for the queried rate and time.

For each publication of a rate, the methodology will use trade data from these source exchanges based on actual trading activity.

Being listed as a source exchange does not guarantee that trades from exchange will be included in any given rate calculation. For the specific exchanges used for each publication, use the [replication data endpoint](https://docs.kaiko.com/kaiko-indices/reference-rates/replication-data).
{% endhint %}

### Request example

{% tabs %}
{% tab title="cURL" %}
{% code overflow="wrap" %}

```url
curl -H "X-Api-Key: $KAIKO_API_KEY" \
     -H 'Accept: application/json' \
    "https://us.market-api.kaiko.io/v2/data/index.v1/digital_asset_rates_compo?index_code=KK_BRR_BTCUSD&start_time=2025-06-01T00:00:00Z"
```

{% endcode %}
{% endtab %}
{% endtabs %}

### Response example

{% tabs %}
{% tab title="JSON" %}
{% code fullWidth="false" %}

```json
{
  "query": {
    "data_version": "v1",
    "request_time": "2025-09-22T12:39:25.097Z",
    "start_time": "2025-02-01T00:00:00Z",
    "end_time": "2025-04-01T00:00:00Z"
  },
  "time": "2025-09-22T12:39:25.107Z",
  "timestamp": 1758544765107,
  "data": [
    {
      "index_code": "KK_BRR_BTCUSD",
      "start_period": "2025-03-24T21:04:22.523Z",
      "end_period": "2025-06-23T21:06:13.244716Z",
      "exchanges": [
        "cbse",
        "gmni",
        "krkn",
        "lmax",
        "stmp"
      ],
      "window_seconds": 15,
      "partition_seconds": 3
    },
    {
      "index_code": "KK_BRR_BTCUSD",
      "start_period": "2025-01-07T22:00:58.271494Z",
      "end_period": "2025-03-24T21:29:22.526544Z",
      "exchanges": [
        "cbse",
        "gmni",
        "krkn",
        "lmax",
        "stmp"
      ],
      "window_seconds": 15,
      "partition_seconds": 3
    },
    {
      "index_code": "KK_BRR_ETHUSD",
      "start_period": "2025-03-24T21:04:22.523Z",
      "end_period": "2025-06-23T21:06:13.244716Z",
      "exchanges": [
        "cbse",
        "crco",
        "krkn",
        "lmax",
        "stmp"
      ],
      "window_seconds": 15,
      "partition_seconds": 3
    },
    {
      "index_code": "KK_BRR_ETHUSD",
      "start_period": "2025-01-07T22:00:58.271494Z",
      "end_period": "2025-03-24T21:29:22.526544Z",
      "exchanges": [
        "cbse",
        "crco",
        "krkn",
        "lmax",
        "stmp"
      ],
      "window_seconds": 15,
      "partition_seconds": 3
    }
  ],
  "result": "success"
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

[^1]: You can get a full list of our tickers using the [reference data endpoint](https://docs.kaiko.com/kaiko-indices/reference-rates/reference-data).