# Supported FIX messages

Here is the list of the **Market Data FIX API** messages supported by Revolut FIX Gateway.

## Session-level messages

For [session-level messages](https://www.onixs.biz/fix-protocol.html#:~:text=The%20FIX%20Session%20layer), Revolut FIX Gateway follows the [FIX 4.4](https://www.onixs.biz/fix-dictionary/4.4/index.html) specification.
This means that all messages are supported.

| Code   | Description                                                                                                                                                |
| ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `A`    | [Logon](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-A-logon)                               |
| `0`    | [Heartbeat](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-0-heartbeat)                       |
| `1`    | [Test Request](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-1-test-request)                 |
| `2`    | [Resend Request](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-2-resend-request)             |
| `3`    | [Session Level Reject](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-3-session-level-reject) |
| `4`    | [Sequence Reset](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-4-reset-sequence)             |
| `5`    | [Logout](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-5-logout)                             |

## Application-level messages

For [application-level messages](https://www.onixs.biz/fix-protocol.html#:~:text=The%20FIX%20Application%20level%20messaging), only the messages listed below are supported.

### Requests

| Code   | Description                                                                                                                                                  |
| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `V`    | [Market Data Request](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-application-level-messages/message-v-market-data-request) |

### Responses

| Code   | Description                                                                                                                                                                |
| ------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `W`    | [Full Refresh](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-application-level-messages/message-w-full-refresh)                             |
| `X`    | [Incremental Refresh](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-application-level-messages/message-x-incremental-refresh)               |
| `Y`    | [Market Data Request Reject](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-application-level-messages/message-y-market-data-request-reject) |

Any other message will be rejected with the [**`3` (Session Level Reject**)](/docs/guides/exchange-fix-api/market-data-fix-api/supported-fix-messages/fix-session-level-messages/message-3-session-level-reject) message.

## External resources

For more information, see the [FIX 4.4 documentation](https://www.onixs.biz/fix-dictionary/4.4/msgs_by_category.html).