Hacker News Frontpage· rssEN18:25 · 07·12
→Claude Code sends 33k tokens before reading the prompt; OpenCode sends 7k
Systima ran Claude Code and OpenCode on the same model, same machine, and same tasks, capturing every request at the API boundary. In the simplest case Claude Code consumed roughly 33,000 tokens of system prompt, tool schemas, and injected scaffolding before the user prompt arrived; OpenCode used about 7,000. Switching to Claude Fable 5 narrowed the gap to roughly 3.3× because Claude Code sends a shorter system prompt to newer models. The cache-efficiency gap is larger: OpenCode's request prefix was byte-identical every run, so it paid to cache once and read back cheaply; Claude Code rewrote tens of thousands of cache tokens mid-session, writing up to 54× more cache tokens on the same task. In a production setup a 72 KB AGENTS.md file adds another ~20,000 tokens, five MCP servers add 5,000–7,000, pushing the first request to 75,000–85,000 tokens before the user types a word. Subagents inflate cost further: a small task that cost 121,000 tokens directly cost 513,000 when fanned out to two subagents. The one win for Claude Code: on multi-step tasks it batches tool calls into fewer requests, so the whole-task total can come out lower than OpenCode's. The post does not disclose the specific repo or MCP server names used.
#Anthropic#Claude Code#OpenCode
editor take
Systima measured API-level overhead: Claude Code burns ~33k tokens of system scaffolding before the prompt arrives, OpenCode ~7k. The cache gap is worse—Claude Code rewrites cache tokens mid-session.
HKR breakdown
hook ✓knowledge ✓resonance —