fix: properly support note prefix as bytes or string

docs/subscriptions.md

@@ -75,7 +75,7 @@ class TransactionFilter(TypedDict):
     receiver: NotRequired[str | list[str]]
     """Filter to transactions being received by the specified address(es)."""
 
-    note_prefix: NotRequired[str]
+    note_prefix: NotRequired[str | bytes]
     """Filter to transactions with a note having the given prefix."""
 
     app_id: NotRequired[int | list[int]]

src/algokit_subscriber/subscriber.py

@@ -84,7 +84,7 @@ def poll_once(self) -> TransactionSubscriptionResult:
                 matched_transactions = [
                     t
                     for t in poll_result["subscribed_transactions"]
-                    if filter_name in t.get("filters_matched", [])
+                    if filter_name in (t.get("filters_matched") or [])
                 ]
                 mapped_transactions = (
                     mapper(matched_transactions) if mapper else matched_transactions

src/algokit_subscriber/subscription.py

@@ -186,7 +186,7 @@ def extract_arc28_events(
     return emitted_events if emitted_events else []
 
 
-def indexer_pre_filter(
+def indexer_pre_filter(  # noqa: C901
     subscription: TransactionFilter, min_round: int, max_round: int
 ) -> dict[str, Any]:
     """
@@ -212,9 +212,10 @@ def indexer_pre_filter(
         args["txn_type"] = subscription["type"]
 
     if subscription.get("note_prefix"):
-        args["note_prefix"] = base64.b64encode(
-            subscription["note_prefix"].encode()
-        ).decode()
+        if isinstance(subscription["note_prefix"], bytes):
+            args["note_prefix"] = base64.b64encode(subscription["note_prefix"])
+        elif isinstance(subscription["note_prefix"], str):
+            args["note_prefix"] = subscription["note_prefix"].encode()
 
     if subscription.get("app_id") and isinstance(subscription["app_id"], int):
         args["application_id"] = int(subscription["app_id"])
@@ -294,9 +295,18 @@ def filter_transaction(t: TransactionResult) -> bool:  # noqa: C901, PLR0912
                 result = result and t["tx-type"] in subscription["type"]
 
         if subscription.get("note_prefix"):
-            result = result and t.get("note", "").startswith(
-                subscription["note_prefix"]
-            )
+            if isinstance(subscription["note_prefix"], bytes):
+                note = t.get("note", b"")
+                result = (
+                    result
+                    and len(note) >= len(subscription["note_prefix"])
+                    and note[: len(subscription["note_prefix"])]
+                    == subscription["note_prefix"]
+                )
+            else:
+                result = result and t.get("note", "").startswith(
+                    subscription["note_prefix"]
+                )
 
         if subscription.get("app_id"):
             if isinstance(subscription["app_id"], int):

src/algokit_subscriber/types/subscription.py

@@ -202,7 +202,7 @@ class TransactionFilter(TypedDict):
     receiver: NotRequired[str | list[str]]
     """Filter to transactions being received by the specified address(es)."""
 
-    note_prefix: NotRequired[str]
+    note_prefix: NotRequired[str | bytes]
     """Filter to transactions with a note having the given prefix."""
 
     app_id: NotRequired[int | list[int]]