fix: exclude null fields from streaming chunks for Open WebUI compatibility

OpenAI's API omits null fields in streaming chunks, but Tatlock was
including them (content: null, reasoning_content: null). This caused
parsing issues in Open WebUI's streaming handler.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.0.5] - 2026-02-05
+
+### Fixed
+
+- **Streaming JSON compatibility** - Exclude null fields from streaming chunks using `exclude_none=True`; OpenAI's API omits null fields entirely, and including them (e.g., `content: null`, `reasoning_content: null`) caused parsing issues in Open WebUI
+
 ## [2.0.4] - 2026-02-05
 
 ### Fixed

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "tatlock"
-version = "2.0.4"
+version = "2.0.5"
 description = "OpenAI-compatible API with Ollama backend"
 requires-python = ">=3.12"
 dependencies = []

src/chat/router.py

@@ -31,7 +31,7 @@ async def _stream_response(
     """
     try:
         async for chunk in service.create_chat_completion_stream(request):
-            yield f"data: {chunk.model_dump_json()}\n\n"
+            yield f"data: {chunk.model_dump_json(exclude_none=True)}\n\n"
 
         yield "data: [DONE]\n\n"