Frugal Tokens tool lets developers track and analyze AI coding agent costs

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A developer has released an open-source tool called Frugal Tokens that helps users monitor spending and usage patterns across AI coding agent sessions. The tool was originally built out of curiosity about session costs and the impact of cache misses on overall spend. It provides metrics such as estimated working time, overlapping sessions, per-model cost breakdowns, and session-level percentile data. Users can drill into individual sessions to inspect model calls and tool inputs and outputs, and can compare what a session would have cost under different models or caching configurations. The project, available on GitHub, runs via a single command using the Deno runtime.

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