An effort_cost_index table inside the Claude Code binary shows 'max' costs almost nothing extra on Opus 5 and more than doubles on Sonnet 5

r/ClaudeAI (70 upvotes)·medium signalXBlueskyLinkedInCopy link

A user extracted a per-model token-cost table hidden in the Claude Code binary, normalized so high = 1: opus-5 runs 0.67/0.76/1/1.60/1.70 across low through max, while sonnet-5 runs 0.47/0.74/1/2.41/5.59. That means xhigh to max is +6% on Opus 5 and +132% on Sonnet 5. The poster then ran 8 agents on Opus 5 across two real tasks and four effort levels in isolated clones, and while the magnitudes were loose, the catalog correctly predicted xhigh and max would be near-identical: 397,827 versus 397,761 output tokens.