Documentation Index
Fetch the complete documentation index at: https://docs.kalshi.com/llms.txt
Use this file to discover all available pages before exploring further.
For the general overview of fixed-point pricing and contract quantities across REST and WebSocket APIs, see Fixed-Point Migration.
Technical Specification
To enable subpenny precision, include tag 21005 in your Logon message:
| Tag | Name | Description | Value |
|---|
| 21005 | UseDollars | Enable dollar-based price format | Y |
- Legacy Format (Cents): Prices given in whole cents. E.g. 72 cents =
72.
- New Format (Dollars): Prices normalized to dollars with fixed precision (up to 4 decimal places).
Examples:
| Cents | FIX Decimal | String Representation |
|---|
| 1.23¢ | Decimal(123, -4) | 0.0123 |
| 72.5¢ | Decimal(7250, -4) | 0.725 |
| 99¢ | Decimal(9900, -4) | 0.99 |
| Tag | Field Name | Description |
|---|
| 6 | AvgPx | Average price of fills |
| 31 | LastPx | Price of last fill |
| 44 | Price | Order limit price |
| 132 | BidPx | Quote bid price |
| 133 | OfferPx | Quote ask price |
Sample Messages
8=FIXT.1.1|9=300|35=A|34=1|52=20250926-21:54:07.001|
96=QhA8659Mhygcm+xE/wb1m...|21005=Y|
^^ Enable dollar format
8=FIXT.1.1|9=200|35=D|34=2|52=20250926-21:54:16.040|
38=100.0|40=2|44=0.7500|54=1|60=20250926-21:54:16.040|
^^ price
10=092|
8=FIXT.1.1|9=400|35=8|34=4|52=20250926-21:54:16.159|
6=0.6600|14=100|31=0.7000|32=60|38=100.0000|39=2|44=0.7500|
^^ avgPx ^^ lastPx ^^ price
