Group chats return 400 for threaded sends. Catch the error and fall back to a flat send so messages always get delivered. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Group chats return 400 for threaded sends. Catch the error and fall back to a flat send so messages always get delivered. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>