# Plans & credits

> What a credit is, which actions spend one, and where to watch your usage.

Source: https://docs.texttoquant.com/concepts/plans-and-credits

---

Reading and parsing are free; running a simulation costs a credit. This page is the honest
accounting of what bills, what doesn't, and how the robustness suite multiplies cost so you can
budget before you batch.

## What a credit is

A **credit is one backtest.** Your plan grants a pool of them per billing period; you can see the
pool at any time under [Account → Usage](/account/usage) or via `GET /v1/usage` (limit, used,
remaining, period end).

## What costs credits

| Action | Cost |
| --- | --- |
| Run a backtest | 1 |
| Parameter sweep | 1 per backtest in the sweep |
| Parameter grid (5×5) | 25 |
| Walk-forward, joint sweep, genetic search, strategy variants | a handful each (typically 5) |
| Run a portfolio | 1 per asset in the book |
| Portfolio sweep | values × assets (K × N) |

## What's free

- **Parsing** a query, **reading** results and history, **sharing** a run, **exporting** to CSV or
  Pine, and running **screener** scans don't spend backtest credits.
- **Monte Carlo, out-of-sample split and regime context** read the run you already paid for, no
  extra charge.
- LLM parsing and Pine compilation are gated by plan *feature*, not metered per call.

## Plans

Tiers, quotas and history/timeframe limits live on the [pricing page](/pricing). Higher tiers raise
your credit pool and history depth and unlock API access, custom Pine indicators and screener alerts.
The free tier is deliberately limited: enough to learn the product, not to run a research program.

## Rate limits

On top of your credit pool, the API is rate-limited to **120 requests/minute per IP** and
**240/minute per account**. Over a limit you get a `429`. See
[authentication](/docs/api/authentication) for the headers.

<Callout variant="danger" title="Budget before you batch">
  The robustness suite runs many real backtests, a grid is 25, a sweep is one per value. Check
  `GET /v1/usage` before a batch, and confirm the cost before a large sweep you didn't explicitly
  ask for. Retries are safe: send an `Idempotency-Key` and a replay returns the original run with
  **no second charge**.
</Callout>

Related: [robustness](/docs/reference/robustness), [authentication](/docs/api/authentication),
[pricing](/pricing).