> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kraken.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Market Data Request

> Subscribe to market data streams via FIX

<div className="api-banner">
  <span className="api-protocol fix">FIX</span>
  <span className="api-detail">session: market-data</span>
  <span className="api-tag">35=V</span>
</div>

The MarketDataRequest message is used by the client system to request a market data stream for the order book and/or trades.

In response, the FIX Server will begin sending out a [MarketDataSnapshot](/exchange/api-reference/unified-fix/mdsfr) if it is a valid request. Otherwise, the FIX Server will send out a [MarketDataRequestReject](/exchange/api-reference/unified-fix/mdrr) with the Text tag containing the reason for the rejection.

Each subscription request needs to have a unique identifier set via tag MDReqID, which will be used to refer back to the client. It is also used to unsubscribe from market data.

Market data updates are sent to clients using a [MarketDataSnapshotFullRefresh](/exchange/api-reference/unified-fix/mdsfr) message and then [MarketDataIncrementalRefresh](/exchange/api-reference/unified-fix/mdir) message. A full empty market data snapshot may be sent in case no more prices are received.
These prices will stream continuously until the client requests to unsubscribe using a MarketDataRequest with the SubscriptionRequestType set to Unsubscribe (263=2).

For the OrderBook, the client can request Level 2 or Level 3 depending on the value of the AggregatedBook tag.

In case of a disconnection, the subscription will be cancelled. The Client will need to subscribe again after the reconnection.

***

<ResponseField name="header" type="" required>35=`V`</ResponseField>

<ResponseField name="262 - MDReqID" type="string" required>
  Unique request identifier.
</ResponseField>

<ResponseField name="263 - SubscriptionRequestType" type="integer" required>
  **Possible values:**

  * `1` : Snapshot + Updates
  * `2` : Disable previous snapshot + Update request
</ResponseField>

<ResponseField name="264 - MarketDepth" type="integer" required>
  **Possible values:**

  * `0` : Full depth of book (limited to 1000 for Level 2)
  * `1` : Top of Book
  * `10`, `25`, `100`, `500` and `1000`
</ResponseField>

<ResponseField name="265 - MDUpdateType" type="integer">
  **Possible values:**

  * `1` : Incremental Refresh

  Only incremental Refresh is supported.
</ResponseField>

<ResponseField name="266 - AggregatedBook" type="boolean">
  Specify if the request is for Level 2 or Level 3.

  **Possible values:**

  * `Y` : one book entry per side per price. Aka Level 2.
  * `N` : Multiple entries per side per price allowed. Aka Level 3. Only Available for Derivatives.

  **Default value:** `Y`

  Level 3 is only available for MDEntryType BID and OFFER. Request will get rejected if used with MDEntryType TRADE.
</ResponseField>

<ResponseField name="267 - NoMDEntryTypes" type="integer" required>
  Repeating Group. Number of MDEntryTypes.

  <Expandable title="repeating group" defaultOpen>
    <ResponseField name="269 - MDEntryType" type="integer" required>
      Client can subscribe to bid/offer and/or trades. It is not possible to subscribe to only bid or only offer.

      **Possible values:**

      * `0` : Bid
      * `1` : Offer
      * `2` : Trade
    </ResponseField>

    <ResponseField name="146 - NoRelatedSym" type="integer" required>
      Number of pairs to subscribe to.

      <Expandable title="repeating group">
        <ResponseField name="55 - Symbol" type="string" required>
          Asset Pair listed on the exchange.
        </ResponseField>
      </Expandable>
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="trailer" type="" required />

<CodeGroup>
  ```text Spot Subscribe BTC/USD L2 (bid+ask, depth 10) theme={null}
  8=FIX.4.4|9=117|35=V|34=2|49=CLIENT|56=KRAKEN-MD|52=20260407-14:32:01.000|262=MDSUB1|263=1|264=10|265=1|267=2|269=0|269=1|55=BTC/USD|10=244|
  ```

  ```text Spot Unsubscribe theme={null}
  8=FIX.4.4|9=111|35=V|34=3|49=CLIENT|56=KRAKEN-MD|52=20260407-14:32:10.000|262=MDSUB1|263=2|264=10|265=1|267=1|269=0|55=BTC/USD|10=223|
  ```

  ```text Futures L2 Subscribe theme={null}
  8=FIX.4.4|9=133|35=V|34=2|49=CLIENT-DRV|56=KRAKEN-DRV-MD|52=20260407-14:32:01.000|146=1|55=PF_ETHUSD|262=MDSUB2|263=1|264=0|265=1|267=3|269=0|269=1|269=2|10=197|
  ```

  ```text Futures L3 Subscribe theme={null}
  8=FIX.4.4|9=133|35=V|34=3|49=CLIENT-DRV|56=KRAKEN-DRV-MD|52=20260407-14:32:01.000|146=1|55=PF_ETHUSD|262=MDSUB3|263=1|264=0|265=1|266=N|267=2|269=0|269=1|10=121|
  ```
</CodeGroup>