Claude Code returns blank thinking blocks, but reasoning still costs you

Anthropic's Claude Code appears to be having trouble displaying summaries of its "thinking," according to several bug reports, while the underlying reasoning tokens still cost money. According to complaints, the API has been returning empty thinking blocks for Opus 4.8 and Sonnet 5 even when users explicitly request summarized thinking. Models from several sources can display their "thinking," a process that gives models additional tokens to reason through complex problems before producing a res