Worked example: support chatbot usage
A support chatbot that averages 2,500 input tokens and 800 output tokens per request, handles 200 requests per day, and runs 30 days per month would process 15 million input tokens and 4.8 million output tokens per month.
At $0.50 per 1 million input tokens and $2.00 per 1 million output tokens, that scenario is about $7.50 for input plus $9.60 for output, or roughly $17 per month before retries, tool calls, longer conversations, and background agent work.
How to use the estimate
Use the monthly result as a planning number, not a contract. Add room for retries, tests, scheduled jobs, prompt changes, longer user conversations, and background automations.
Costs, risks, and caveats
Token usage can grow quickly when agents call tools, summarize long documents, or retry failed steps. Keep API keys out of frontend code, set spending alerts where your provider supports them, and test with realistic examples before opening a workflow to users.
Recommended next steps
Estimate a low, expected, and high scenario. Then compare the API path with a local model path, especially when privacy, predictable volume, or self-hosting control matters.
Source and pricing notes
Provider prices, cache discounts, batch discounts, rate limits, and model names can change. Use the pricing page for the exact provider and model you plan to use, then rerun the estimate before turning on production traffic.
Privacy and security notes
Keep API keys on the server side, avoid sending unnecessary personal or confidential data to a model provider, and set billing alerts before agents, scheduled jobs, or background retries can run unattended.