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

> ## Agent Instructions
> API requests use the base URL https://api.unusualwhales.com and require a bearer token in the `Authorization` header (`Authorization: Bearer <API_KEY>`). Create and manage API tokens at https://unusualwhales.com/dashboard/api.
> For live market data inside an AI tool, use the Unusual Whales MCP server at https://unusualwhales.com/public-api/mcp.
> Instructions for agents using Unusual Whales tools: https://unusualwhales.com/skill.md

# FlexOptionState

> Daily open interest and mark state for a FLEX option contract.

Message
fields**8**
topic[flex-options](/docs/kafka/topics/flex-options.md)

**Proto definition**

```protobuf schema.proto theme={null}
message FlexOptionState {
  FlexOption flex_option = 1;
  Date date = 2;
  int32 open_interest = 3;
  optional int32 previous_open_interest = 4;
  optional int32 open_interest_change = 5;
  Decimal mark = 6;
  optional Decimal previous_mark = 7;
  FlexTickerState ticker_state = 8;
}
```

## Fields

The number on the right of each row is the protobuf field number.

flex\_option
[FlexOption](/docs/kafka/types/FlexOption.md)
1

FLEX option contract metadata.

date
[Date](/docs/kafka/types/Date.md)
2

The date this data represents

open\_interest
int32
3

Open interest reported for the contract.

previous\_open\_interest
int32
optional
4

Open interest reported on the previous trading day. Missing when it is the first day this contract trades and there is no previous trading day.

open\_interest\_change
int32
optional
5

Change in open interest from the previous trading day. Missing when it is the first day this contract trades and there is no previous trading day.

mark
[Decimal](/docs/kafka/types/Decimal.md)
6

Mark price reported for the contract.

previous\_mark
[Decimal](/docs/kafka/types/Decimal.md)
optional
7

Mark price reported on the previous trading day. Missing when it is the first day this contract trades and there is no previous trading day.

ticker\_state
[FlexTickerState](/docs/kafka/types/FlexTickerState.md)
8

Aggregate FLEX option state for the contract's underlying ticker.