====== Prices, Volumes & Data Types ======

[[developers:apiv2|◀ WebSocket API (V2)]]

===== Prices and Decimals are Represented as Strings =====

Two wrapper types carry exact numbers as strings:

  * [[https://github.com/CTS-Futures/t4-api-tools/blob/main/proto/t4/v2/common/price.proto#L12|Price]]
  * [[https://github.com/CTS-Futures/t4-api-tools/blob/main/proto/t4/v2/common/price.proto#L6|Decimal]]

<code>
message Price   { string value = 1; }   // e.g. "4200.50"
message Decimal { string value = 1; }   // e.g. "1.50"
</code>

T4 uses text to avoid binary floating-point rounding. **Parse them into your language's native decimal type**, not a ''double''. ''Price'' is used for market/order prices; ''Decimal'' is used for order volumes and cash values.

===== Volumes =====

  * **Order routing** — volumes (''volume'', ''max_show'', ''max_volume'', fill volumes) are ''Decimal''. This allows the API to support fractional exchange quantities (e.g. Kalshi).
  * **Market data** — depth and trade volumes are plain integers (''int32'').

===== System Price format =====

T4 publishes prices in different formats. The setting controls how prices are formatted in the trading and all other platform API's (chart's, etc.)

<note>If you expect ES to look like ''5954.75'' instead of ''595475'', choose **Real**.</note>

Set [[https://github.com/CTS-Futures/t4-api-tools/blob/main/proto/t4/v2/common/enums.proto#L35|PriceFormat]] on [[https://github.com/CTS-Futures/t4-api-tools/blob/main/proto/t4/v2/auth/auth.proto#L9|LoginRequest]] to choose how ''Price'' strings are formatted:

<WRAP 75%>
^ PriceFormat ^ Description ^ Example (ES) ^
| ''PRICE_FORMAT_REAL'' | Human-readable decimal placement used by most trading UIs. | <code>5954.75</code> |
| ''PRICE_FORMAT_DECIMAL'' | Raw exchange representation, without UI-friendly decimal placement. | <code>595475</code> |
| ''PRICE_FORMAT_CLEARING_DECIMAL'' | Typically used for data imports and exports only. | <code>595475</code> |
</WRAP>

See [[developers:systempricing|System Price Format]] for more information.