> ## 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 enums & encodings

> Enumerations, primitive and composite encodings of the market data schema (ID 34)

<div className="api-banner">
  <span className="api-protocol ws">SBE</span>
  <span className="api-detail">schema 34 · market data</span>
  <span className="api-tag">types</span>
</div>

## Enumerations

### OrderUpdateAction

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `New` | `1` | |
| `Change` | `2` | |
| `Delete` | `3` | |

### InstrumentUpdateAction

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Add` | `1` | |
| `Modify` | `2` | |
| `Delete` | `3` | |

### ProductType

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Spot` | `1` | |
| `Future` | `2` | |
| `Option` | `3` | |

### MarketSector

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Crypto` | `1` | |
| `Equity` | `2` | |
| `Fx` | `3` | |
| `TokenizedEquity` | `4` | |
| `Index` | `5` | |

### MaturityType

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Monthly` | `1` | |
| `Quarterly` | `2` | |
| `Irregular` | `3` | |
| `Perpetual` | `4` | |
| `Semiannual` | `5` | |

### Side

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Buy` | `1` | |
| `Sell` | `2` | |

### AggressorSide

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Buy` | `1` | |
| `Sell` | `2` | |

### InstrumentTradingStatus

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Hidden` | `1` | |
| `Online` | `2` | |
| `Maintenance` | `3` | |
| `CancelOnly` | `4` | |
| `PostOnly` | `5` | |
| `LimitOnly` | `6` | |
| `Delisted` | `7` | |
| `ReduceOnly` | `8` | |
| `SystemMaintenance` | `9` | |
| `Halted` | `10` | |
| `Closed` | `11` | Instrument is outside its scheduled trading session |

### TradingSessionStatusCode

Applies to Spot and Futures only. US Perps does not expose a global trading session status; it provides the status per instrument (see `InstrumentTradingStatus`).

Encoding: `uint8`

| Name | Value | Description |
| :- | :- | :- |
| `Halted` | `1` | |
| `Open` | `2` | |
| `CancelOnly` | `101` | |
| `PostOnly` | `102` | |
| `LimitOnly` | `103` | |

### OrdTypeMD

Encoding: `char`

| Name | Value | Description |
| :- | :- | :- |
| `Market` | `1` | Taker order was a market order \[Kraken emits: Yes] |
| `Limit` | `2` | Taker order was a limit order \[Kraken emits: Yes] |

## Primitive and composite encodings

### messageHeader

Composite of: `blockLength:uint16`, `templateId:uint16`, `schemaId:uint16`, `version:uint16`.

### groupSizeEncoding

Composite of: `blockLength:uint16`, `numInGroup:uint16`.

### InstrumentId

Primitive `uint64`, length 1, required.

Opaque, globally unique instrument identifier assigned by Instrument Registry.

### OrderId

Composite of: `low:uint64`, `high:uint64`.

### TradeId

Composite of: `low:uint64`, `high:uint64`.

### TimestampNs

Primitive `int64`, length 1, required.

Positive UTC timestamp in nanoseconds since the Unix epoch.

### Scale

Primitive `uint8`, length 1, required. Maximum value 36.

Number of supported decimal places.

### Decimal

Composite of: `mantissa:int64`, `exponent:int8`.

`exponent` ranges from -36 to 0.

### Price

Composite of: `decimal:ref`.

### Quantity

Composite of: `decimal:ref`.

### SymbolEncoding

Composite of: `length:uint16`, `varData:char`.

`length` is the number of UTF-8 encoded bytes, up to 128. Used by `symbol` and `underlyingSymbol`.

### CurrencyEncoding

Composite of: `length:uint8`, `varData:char`.

`length` is the number of UTF-8 encoded bytes, up to 12.

### DescriptionEncoding

Composite of: `length:uint16`, `varData:char`.

`length` is the number of UTF-8 encoded bytes, up to 512.

### StatusReasonEncoding

Composite of: `length:uint16`, `varData:char`.

`length` is the number of UTF-8 encoded bytes, up to 1024. An empty value means no reason was supplied.

<Note>
  Kraken constrains these values to the limits above before publishing and does not truncate identifiers.
</Note>