What eats the budget
Teams often underestimate structured payloads. JSON tools, XML-ish logs, and base64 snippets balloon quickly. Summarization, retrieval filters, or a second “cheap” model to compress context are common ways to stay inside the cap described in your public docs.
Hard errors vs silent truncation
Some APIs return 4xx when you exceed limits; others truncate the oldest turns. Document the behavior so support is not guessing. Routing can move long jobs to models with larger windows or to batch pipelines.
Cost follows width
Wider windows do not just allow longer prompts—they increase typical input token counts. Pair capacity decisions with cost controls so product and finance stay aligned.