- Claude Code uses significantly more tokens than OpenCode for the same tasks, with baseline overhead around 33,000 tokens vs 7,000 for a simple reply.
- Cache inefficiency is a major factor; Claude Code rewrites tens of thousands of prompt-cache tokens mid-session, leading to up to 54x more cache writes than OpenCode.
- Configuration elements like instruction files and MCP servers add substantial token overhead, with a real setup reaching 75,000–85,000 tokens before user input.
- Subagents dramatically increase token usage; a task costing 121,000 tokens directly rose to 513,000 tokens when fanned out to two subagents.