The Hidden Invoice: Understanding AI Token Costs

Every time you call an LLM API, a small meter ticks. Most developers notice it first on a surprise bill — a prototype that felt free suddenly costs real money in production. Tokens are the unit of that meter, and understanding them is now a basic engineering literacy. What you&rsquo;re actually paying for A token is roughly four characters of English text. A prompt that says &ldquo;Summarise this…