feat: add missing API fields and endpoints from v3.8.0 audit

Audit against the latest Kalshi Python SDK (v3.8.0) revealed two gaps:

- Add yes_bid_size_fp and yes_ask_size_fp to REST Market struct (already
  present in WebSocket ticker messages, added to API Feb 24, 2026)
- Add subaccount netting endpoints: GET and PUT
  /portfolio/subaccounts/netting (added to API Feb 23, 2026)
- Update API README: total endpoint count 84 -> 86, add netting to
  subaccounts section

Author: pbeets

src/api/README.md

@@ -24,7 +24,7 @@ Complete reference for all Kalshi REST API endpoints supported by this library.
 | Order Groups | 7 | 100% |
 | Account | 1 | 100% |
 | Portfolio | 5 | 100% |
-| Subaccounts | 5 | 100% |
+| Subaccounts | 7 | 100% |
 | Markets | 6 | 100% |
 | Events | 6 | 100% |
 | Series | 2 | 100% |
@@ -38,7 +38,7 @@ Complete reference for all Kalshi REST API endpoints supported by this library.
 | Incentive Programs | 1 | 100% |
 | FCM | 2 | 100% |
 | Historical | 6 | 100% |
-| **Total** | **84** | **100%** |
+| **Total** | **86** | **100%** |
 
 ---
 
@@ -123,6 +123,8 @@ Complete reference for all Kalshi REST API endpoints supported by this library.
 | 🔲 | POST | `/portfolio/subaccounts/transfer` | `transfer_between_subaccounts()` | |
 | 🔲 | GET | `/portfolio/subaccounts/balances` | `get_subaccount_balances()` | |
 | 🔲 | GET | `/portfolio/subaccounts/transfers` | `get_subaccount_transfers()` | |
+| 🔲 | GET | `/portfolio/subaccounts/netting` | `get_subaccount_netting()` | Netting config for all subaccounts |
+| 🔲 | PUT | `/portfolio/subaccounts/netting` | `update_subaccount_netting()` | Enable/disable netting per subaccount |
 | 🔲 | GET | `/portfolio/summary/total_resting_order_value` | `get_resting_order_value()` | FCM members only |
 
 **Source**: `src/api/subaccounts.rs`

src/api/subaccounts.rs

@@ -8,8 +8,9 @@ use crate::{
     error::Result,
     models::{
         CreateSubaccountRequest, CreateSubaccountResponse, GetSubaccountTransfersParams,
-        RestingOrderValueResponse, SubaccountBalancesResponse, SubaccountTransfersResponse,
-        TransferBetweenSubaccountsRequest, TransferResponse,
+        RestingOrderValueResponse, SubaccountBalancesResponse, SubaccountNettingResponse,
+        SubaccountTransfersResponse, TransferBetweenSubaccountsRequest, TransferResponse,
+        UpdateSubaccountNettingRequest,
     },
 };
 
@@ -46,6 +47,20 @@ pub async fn get_subaccount_transfers(
     http.get(&path).await
 }
 
+/// Returns netting configuration for all subaccounts.
+pub async fn get_subaccount_netting(http: &HttpClient) -> Result<SubaccountNettingResponse> {
+    http.get("/portfolio/subaccounts/netting").await
+}
+
+/// Updates the netting configuration for a specific subaccount.
+pub async fn update_subaccount_netting(
+    http: &HttpClient,
+    request: UpdateSubaccountNettingRequest,
+) -> Result<()> {
+    http.put_no_response("/portfolio/subaccounts/netting", &request)
+        .await
+}
+
 /// Returns the total value in cents of all resting orders (primarily for FCM members).
 pub async fn get_resting_order_value(http: &HttpClient) -> Result<RestingOrderValueResponse> {
     http.get("/portfolio/summary/total_resting_order_value")

src/client.rs

@@ -44,9 +44,9 @@ use crate::{
         PositionsResponse, QueuePositionsResponse, QuoteResponse, RestingOrderValueResponse,
         RfqResponse, SeriesListResponse, SeriesResponse, SettlementsResponse,
         StructuredTargetResponse, StructuredTargetsResponse, SubaccountBalancesResponse,
-        SubaccountTransfersResponse, TagsByCategoriesResponse, TradesResponse,
-        TransferBetweenSubaccountsRequest, TransferResponse, UpdateOrderGroupLimitRequest,
-        UserDataTimestampResponse,
+        SubaccountNettingResponse, SubaccountTransfersResponse, TagsByCategoriesResponse,
+        TradesResponse, TransferBetweenSubaccountsRequest, TransferResponse,
+        UpdateOrderGroupLimitRequest, UpdateSubaccountNettingRequest, UserDataTimestampResponse,
     },
 };
 
@@ -1888,6 +1888,47 @@ impl KalshiClient {
         subaccounts::get_resting_order_value(&self.http).await
     }
 
+    /// Get netting configuration for all subaccounts.
+    ///
+    /// Returns the netting enabled/disabled setting for each subaccount.
+    ///
+    /// # Example
+    ///
+    /// ```ignore
+    /// let netting = client.get_subaccount_netting().await?;
+    /// for config in &netting.netting_configs {
+    ///     println!("Subaccount {}: netting {}",
+    ///         config.subaccount_number,
+    ///         if config.enabled { "enabled" } else { "disabled" }
+    ///     );
+    /// }
+    /// ```
+    pub async fn get_subaccount_netting(&self) -> Result<SubaccountNettingResponse> {
+        subaccounts::get_subaccount_netting(&self.http).await
+    }
+
+    /// Update the netting configuration for a specific subaccount.
+    ///
+    /// # Arguments
+    ///
+    /// * `request` - The netting update request specifying subaccount and enabled state
+    ///
+    /// # Example
+    ///
+    /// ```ignore
+    /// use kalshi_trade_rs::models::UpdateSubaccountNettingRequest;
+    ///
+    /// // Enable netting for the primary account
+    /// let request = UpdateSubaccountNettingRequest::new(0, true);
+    /// client.update_subaccount_netting(request).await?;
+    /// ```
+    pub async fn update_subaccount_netting(
+        &self,
+        request: UpdateSubaccountNettingRequest,
+    ) -> Result<()> {
+        subaccounts::update_subaccount_netting(&self.http, request).await
+    }
+
     // =========================================================================
     // Live Data API
     // =========================================================================

src/models.rs

@@ -110,6 +110,7 @@ pub use structured_target::{
 pub use subaccount::{
     CreateSubaccountRequest, CreateSubaccountResponse, GetSubaccountTransfersParams,
     RestingOrderValueResponse, Subaccount, SubaccountBalance, SubaccountBalancesResponse,
-    SubaccountTransfer, SubaccountTransfersResponse, TransferBetweenSubaccountsRequest,
-    TransferResponse,
+    SubaccountNettingConfig, SubaccountNettingResponse, SubaccountTransfer,
+    SubaccountTransfersResponse, TransferBetweenSubaccountsRequest, TransferResponse,
+    UpdateSubaccountNettingRequest,
 };

src/models/market.rs

@@ -189,10 +189,16 @@ pub struct Market {
     pub yes_bid: i64,
     /// Best YES bid price in dollars.
     pub yes_bid_dollars: String,
+    /// Size at best YES bid (fixed-point decimal string).
+    #[serde(default)]
+    pub yes_bid_size_fp: Option<String>,
     /// Best YES ask price in cents.
     pub yes_ask: i64,
     /// Best YES ask price in dollars.
     pub yes_ask_dollars: String,
+    /// Size at best YES ask (fixed-point decimal string).
+    #[serde(default)]
+    pub yes_ask_size_fp: Option<String>,
     /// Best NO bid price in cents.
     pub no_bid: i64,
     /// Best NO bid price in dollars.

src/models/subaccount.rs

@@ -257,6 +257,42 @@ pub struct SubaccountTransfersResponse {
     pub cursor: Option<String>,
 }
 
+/// Netting configuration for a single subaccount.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SubaccountNettingConfig {
+    /// Subaccount number (0 for primary, 1-32 for subaccounts).
+    pub subaccount_number: i32,
+    /// Whether netting is enabled for this subaccount.
+    pub enabled: bool,
+}
+
+/// Response from GET /portfolio/subaccounts/netting.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SubaccountNettingResponse {
+    /// Netting configurations for all subaccounts.
+    pub netting_configs: Vec<SubaccountNettingConfig>,
+}
+
+/// Request body for PUT /portfolio/subaccounts/netting.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct UpdateSubaccountNettingRequest {
+    /// Subaccount number (0 for primary, 1-32 for subaccounts).
+    pub subaccount_number: i32,
+    /// Whether to enable netting for the subaccount.
+    pub enabled: bool,
+}
+
+impl UpdateSubaccountNettingRequest {
+    /// Create a new netting update request.
+    #[must_use]
+    pub fn new(subaccount_number: i32, enabled: bool) -> Self {
+        Self {
+            subaccount_number,
+            enabled,
+        }
+    }
+}
+
 /// Response from GET /portfolio/summary/total_resting_order_value.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct RestingOrderValueResponse {