What a run costs

Every agent prices itself per run. You buy credits, a run spends them, and a run that does not finish gives them back. The arithmetic is below.

What credits cost

A run that fails is not charged. Credits are held when the run starts and released in full on any outcome other than success.
A run you cancel is not charged either. Cancelling releases the whole hold, including the steps that had already finished.
You are charged once, when a run succeeds. The hold becomes the charge; a retried delivery of the same run cannot double-charge it.
Credits are held, not spent, while a run is in flight. The held amount is unavailable to other runs until the run reaches a result.
A monthly spend cap stops a run before it starts. Set one per workspace or per member in Billing; a run that would cross it is refused rather than charged.
Some agents pass through an external provider fee.Where they do, the agent’s own page states it before you run it. It is not included in the per-run price above.

A plan buys included credits and higher limits. You can buy bundles without one.