{"i":14,"slug":"subagent-fan-out-cost","chart":{"id":"fan-out-startup-tax","title":"Claude Code minimal-reply input cost: three scenarios (calculation)","subtitle":"N × 6,761 median input tokens, repriced at Sonnet 5.5 rates","kind":"grouped-bar","unit":"usd","yLabel":"USD, input only","series":{"$k":["name","points"],"$r":[["Plain input, no cache surcharge",{"$k":["label","value","n"],"$r":[["10 subagents",0.1352,5],["100 subagents",1.3522,5],["500 subagents",6.761,5]]}],["First writes; all later calls read the whole prefix",{"$k":["label","value","n"],"$r":[["10 subagents",0.0392,5],["100 subagents",0.1609,5],["500 subagents",0.7018,5]]}],["Every call writes the whole prefix (1-hour price)",{"$k":["label","value","n"],"$r":[["10 subagents",0.2704,5],["100 subagents",2.7044,5],["500 subagents",13.522,5]]}]]},"note":"Calculation, not a bill. n = 5 minimal replies on Haiku 4.5, one at a time. Sonnet 5.5 prices: $2.00 input, $0.20 cache read and $4.00 1-hour write per million tokens (2026-09-21). These scenarios use assumptions, not measured bounds. These scenarios exclude output and orchestration costs. No empty-prompt control isolates the CLI prefix. The corrected Codex aggregate reports 17,051 inclusive input tokens, including 13,184 cache-read tokens. Cached input is a subset, not an additional count. We omit its input and cost projections; different models and a minimal reply do not isolate a common startup prefix.","sourceIds":["calc-fan-out","agent-routing-overhead","price-anthropic"]}}