Why do agent loops spiral in cost?

Each iteration re-sends the growing scratchpad of prior thoughts, actions, and observations as input. Without a cap, a confused agent can loop dozens of times, each iteration more expensive than the last.

What does max_iterations protect against?

It is a hard stop that bounds the worst case. Even if an agent gets stuck, it cannot exceed the cap, which lets you put a firm ceiling on the cost of any single task.

How should I choose the cap?

Set it a few iterations above your typical run so normal tasks finish, but low enough that a stuck task fails fast and cheap. This simulator shows both numbers so you can balance them.

Is my data sent anywhere?

No. The simulator runs entirely in your browser. Nothing you enter is uploaded, stored or logged.

Agent Loop Cost Simulator

Agent loop cost simulator

A ReAct-style agent runs a loop: think, act, observe, repeat. Each pass appends to a growing scratchpad that gets re-sent on the next call, so cost climbs with every iteration. A task that usually finishes in three loops can quietly run to twenty when the agent gets stuck. This simulator shows the typical cost, the worst-case cost at your max_iterations cap, and helps you set a safe ceiling.

How it works

The simulator models cost as accumulating across iterations, where each iteration’s input grows as the scratchpad lengthens. To keep it transparent it uses a per-iteration token figure that already reflects the average growing context:

typical_cost  = avg_iterations × tokens_per_iteration / 1M × price
worst_cost    = max_iterations × tokens_per_iteration / 1M × price

The gap between the two is your exposure — the amount a single runaway task can cost beyond what you expect.

Tips and notes

Always set max_iterations. An uncapped loop is an uncapped bill. Treat the cap as a non-negotiable safety control.
Fail loud, fail cheap. Configure the agent to return a clear error when it hits the cap rather than silently retrying the whole task.
Log iteration counts. If your average creeps toward the cap over time, your prompts or tools are getting harder to follow — investigate before the bill grows.