# Anatomy of the API Response 'usage' Object: OpenAI, Anthropic, Gemini Compared

> Source: https://sukruyusufkaya.com/en/learn/token-ekonomisi/usage-objesi-anatomi-openai-anthropic-gemini
> Updated: 2026-05-14T14:44:11.750Z
> Category: Token Ekonomisi & LLM Cost Optimization
> Module: Module 3: Cost Telemetry — Measure First, Then Optimize
**TLDR:** Every LLM API response has a 'usage' object — input_tokens, output_tokens, cached_input, reasoning_tokens, etc. These fields differ across providers. This lesson dissects each one and shows the correct parsing pattern for telemetry.