From f3a30ec4b49f078ef95595787252469e56943d9e Mon Sep 17 00:00:00 2001
From: Zihao Xue <zx278@cornell.edu>
Date: Sun, 22 Mar 2026 14:12:47 -0700
Subject: [PATCH 1/4] refactor: handle error in fetch_order_book() in the same
 way

---
 sdks/python/pmxt/client.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sdks/python/pmxt/client.py b/sdks/python/pmxt/client.py
index 835ade4..0c468fc 100644
--- a/sdks/python/pmxt/client.py
+++ b/sdks/python/pmxt/client.py
@@ -622,6 +622,9 @@ def fetch_order_book(self, id: str) -> OrderBook:
             data = self._handle_response(json.loads(response.data))
             return _convert_order_book(data)
         except Exception as e:
+            from pmxt.errors import OrderNotFound
+            if isinstance(e, OrderNotFound):
+                return OrderBook(bids=[], asks=[])
             raise self._parse_api_exception(e) from None
 
     def cancel_order(self, order_id: str) -> Order:

From ad31ed0e58fb09e4d82df3f85ecd3242aca9bec1 Mon Sep 17 00:00:00 2001
From: Zihao Xue <zx278@cornell.edu>
Date: Sun, 22 Mar 2026 14:49:33 -0700
Subject: [PATCH 2/4] refactor: add 'watchAddress' into SKIP_GENERATE

---
 sdks/python/scripts/generate-client-methods.js     | 1 +
 sdks/typescript/scripts/generate-client-methods.js | 1 +
 2 files changed, 2 insertions(+)

diff --git a/sdks/python/scripts/generate-client-methods.js b/sdks/python/scripts/generate-client-methods.js
index 62b1343..51b0d5c 100644
--- a/sdks/python/scripts/generate-client-methods.js
+++ b/sdks/python/scripts/generate-client-methods.js
@@ -34,6 +34,7 @@ const SKIP_GENERATE = new Set([
     'fetchTrades',               // special parameter handling
     'watchOrderBook',            // streaming
     'watchTrades',               // streaming
+    'watchAddress',              // streaming
     'createOrder',               // outcome shorthand logic
     'buildOrder',                // complex args format
     'submitOrder',               // complex args format
diff --git a/sdks/typescript/scripts/generate-client-methods.js b/sdks/typescript/scripts/generate-client-methods.js
index 60765c4..3ff8d83 100644
--- a/sdks/typescript/scripts/generate-client-methods.js
+++ b/sdks/typescript/scripts/generate-client-methods.js
@@ -33,6 +33,7 @@ const SKIP_GENERATE = new Set([
     'fetchTrades',               // resolution parameter handling
     'watchOrderBook',            // streaming
     'watchTrades',               // streaming
+    'watchAddress',              // streaming
     'createOrder',               // outcome shorthand logic
     'buildOrder',                // complex args format, returns BuiltOrder
     'getExecutionPrice',         // delegates to getExecutionPriceDetailed

From d5a820ed8032bbcc038a858789809eccc80712da Mon Sep 17 00:00:00 2001
From: "Samuel EF. Tinnerholm" <samuel.tinnerholm@gmail.com>
Date: Mon, 23 Mar 2026 09:19:32 +0200
Subject: [PATCH 3/4] Revert "refactor: handle error in fetch_order_book() in
 the same way"

This reverts commit f3a30ec4b49f078ef95595787252469e56943d9e.
---
 sdks/python/pmxt/client.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/sdks/python/pmxt/client.py b/sdks/python/pmxt/client.py
index 0c468fc..835ade4 100644
--- a/sdks/python/pmxt/client.py
+++ b/sdks/python/pmxt/client.py
@@ -622,9 +622,6 @@ def fetch_order_book(self, id: str) -> OrderBook:
             data = self._handle_response(json.loads(response.data))
             return _convert_order_book(data)
         except Exception as e:
-            from pmxt.errors import OrderNotFound
-            if isinstance(e, OrderNotFound):
-                return OrderBook(bids=[], asks=[])
             raise self._parse_api_exception(e) from None
 
     def cancel_order(self, order_id: str) -> Order:

From 4c71a18403eebb8e919f20bd319bfa4f1f73c2e3 Mon Sep 17 00:00:00 2001
From: "Samuel EF. Tinnerholm" <samuel.tinnerholm@gmail.com>
Date: Mon, 23 Mar 2026 09:22:48 +0200
Subject: [PATCH 4/4] fix: throw errors for non-existing orderbooks across all
 exchanges

Closes #66
---
 core/src/exchanges/baozi/normalizer.ts  | 5 +++--
 core/src/exchanges/kalshi/fetcher.ts    | 5 +++++
 core/src/exchanges/limitless/fetcher.ts | 2 +-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/core/src/exchanges/baozi/normalizer.ts b/core/src/exchanges/baozi/normalizer.ts
index 6afc42f..fdb24c4 100644
--- a/core/src/exchanges/baozi/normalizer.ts
+++ b/core/src/exchanges/baozi/normalizer.ts
@@ -1,5 +1,6 @@
 import { MarketFetchParams } from '../../BaseExchange';
 import { UnifiedMarket, UnifiedEvent, PriceCandle, OrderBook, Trade, Position, Balance } from '../../types';
+import { NotFound } from '../../errors';
 import { IExchangeNormalizer } from '../interfaces';
 import {
     LAMPORTS_PER_SOL,
@@ -88,12 +89,12 @@ export class BaoziNormalizer implements IExchangeNormalizer<BaoziRawMarket, Baoz
 
     normalizeOrderBook(raw: BaoziRawMarket | null, outcomeId: string): OrderBook {
         if (!raw) {
-            throw new Error(`Market not found for outcome: ${outcomeId}`);
+            throw new NotFound(`Market not found for outcome: ${outcomeId}`, 'Baozi');
         }
 
         const market = this.normalizeMarket(raw);
         if (!market) {
-            throw new Error(`Could not parse market for outcome: ${outcomeId}`);
+            throw new NotFound(`Could not parse market for outcome: ${outcomeId}`, 'Baozi');
         }
 
         const outcome = market.outcomes.find(o => o.outcomeId === outcomeId);
diff --git a/core/src/exchanges/kalshi/fetcher.ts b/core/src/exchanges/kalshi/fetcher.ts
index 1922424..f4746a6 100644
--- a/core/src/exchanges/kalshi/fetcher.ts
+++ b/core/src/exchanges/kalshi/fetcher.ts
@@ -1,6 +1,7 @@
 import { MarketFilterParams, EventFetchParams, OHLCVParams, TradesParams, MyTradesParams } from '../../BaseExchange';
 import { IExchangeFetcher, FetcherContext } from '../interfaces';
 import { kalshiErrorMapper } from './errors';
+import { NotFound } from '../../errors';
 import { validateIdFormat } from '../../utils/validation';
 import { mapIntervalToKalshi } from './utils';
 
@@ -253,6 +254,10 @@ export class KalshiFetcher implements IExchangeFetcher<KalshiRawEvent, KalshiRaw
         validateIdFormat(id, 'OrderBook');
         const ticker = id.replace(/-NO$/, '');
         const data = await this.ctx.callApi('GetMarketOrderbook', { ticker });
+        const book = data.orderbook_fp;
+        if (!book || (!book.yes_dollars?.length && !book.no_dollars?.length)) {
+            throw new NotFound(`Order book not found: ${id}`, 'Kalshi');
+        }
         return data;
     }
 
diff --git a/core/src/exchanges/limitless/fetcher.ts b/core/src/exchanges/limitless/fetcher.ts
index 1d413cb..929b79f 100644
--- a/core/src/exchanges/limitless/fetcher.ts
+++ b/core/src/exchanges/limitless/fetcher.ts
@@ -170,7 +170,7 @@ export class LimitlessFetcher implements IExchangeFetcher<LimitlessRawMarket, Li
                 timestamp: data.timestamp,
             };
         } catch (error: any) {
-            return { bids: [], asks: [] };
+            throw limitlessErrorMapper.mapError(error);
         }
     }