From 62da30f3034cbe81046c333cf9390964223300f0 Mon Sep 17 00:00:00 2001
From: Good Samaritan
 <309353306+GoodSamaritan-bot-by-EG@users.noreply.github.com>
Date: Fri, 16 Oct 2026 08:54:42 +0800
Subject: [PATCH] Fix #454: Generate JSON wire schemas for Python runtime type

---
 .../ts_conversion/python_type_to_ts_nodes.py  | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/python/src/typechat/_internal/ts_conversion/python_type_to_ts_nodes.py b/python/src/typechat/_internal/ts_conversion/python_type_to_ts_nodes.py
index ae64f6b2..6175afac 100644
--- a/python/src/typechat/_internal/ts_conversion/python_type_to_ts_nodes.py
+++ b/python/src/typechat/_internal/ts_conversion/python_type_to_ts_nodes.py
@@ -2,10 +2,13 @@
 
 import collections.abc
 from collections import OrderedDict
+import datetime
+import decimal
 import inspect
 import sys
 import typing
 import typing_extensions
+import uuid
 from dataclasses import MISSING, Field, dataclass
 from types import NoneType, UnionType
 from typing_extensions import (
@@ -236,6 +239,31 @@ def convert_to_type_node(py_type: object) -> TypeNode:
         if py_type is Self:
             return ThisTypeReferenceNode
 
+        # Standard library types supported by Pydantic
+        if py_type is datetime.datetime:
+            return Annotated(
+                StringTypeReferenceNode,
+                "ISO 8601 date-time string (e.g., '2022-08-20T08:30:00.000Z')"
+            )
+        if py_type is datetime.date:
+            return Annotated(StringTypeReferenceNode, "ISO 8601 date string (e.g., '2022-08-20')")
+        if py_type is datetime.time:
+            return Annotated(StringTypeReferenceNode, "ISO 8601 time string (e.g., '08:30:00')")
+        if py_type is datetime.timedelta:
+            return Annotated(StringTypeReferenceNode, "ISO 8601 duration string (e.g., 'PT1H')")
+        if py_type is uuid.UUID:
+            return Annotated(
+                StringTypeReferenceNode,
+                "UUID string (e.g., '12345678-1234-5678-1234-567812345678')"
+            )
+        if py_type is decimal.Decimal:
+            return Annotated(StringTypeReferenceNode, "Decimal number string (e.g., '12.50')")
+        if py_type is bytes:
+            return Annotated(StringTypeReferenceNode, "Base64 encoded bytes or UTF-8 string")
+
+        if isinstance(py_type, Annotatedish):
+             return convert_to_type_node(py_type.__origin__)
+
         # TODO: consider handling bare 'tuple' (and list, etc.)
         # https://docs.python.org/3/library/typing.html#annotating-tuples
         # Using plain tuple as an annotation is equivalent to using tuple[Any, ...]: