> For the complete documentation index, see [llms.txt](https://docs.fritesai.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fritesai.com/reference/pricing.md).

# Pricing

frites can estimate per-child spend from a config-driven, per-model rate table. Pricing is **opt-in**: there are no built-in rates. When you supply rates, frites uses them to fill in spend figures that a backend doesn't self-report.

This page documents the pricing model itself. The `pricing` config key is defined in [configuration](/reference/configuration.md).

## Authoritative vs. estimated spend

How spend is reported depends on the backend:

| Backend                     | Spend source                      | Display                                                                                      |
| --------------------------- | --------------------------------- | -------------------------------------------------------------------------------------------- |
| **claude** (`claude -p`)    | The CLI self-reports actual cost. | Authoritative: shown as `$0.0123`.                                                           |
| **codex** (ChatGPT backend) | Reports no cost.                  | Estimated from the `pricing` table when rates exist, shown with a leading tilde, `~$0.0123`. |

Without a `pricing` table, codex spend reads as `cost n/a` (and previously made codex look "free" next to claude). Supplying rates replaces those blanks with estimates. Authoritative claude figures are never overwritten by estimates: the reported cost always wins, and the estimate is only computed when the backend reported none.

## The rate table

The `pricing` config key is a map of model → rates, in **dollars per million tokens** ($/Mtok):

```json
{
  "pricing": {
    "gpt-5.5": {
      "inputPerMtok": 1.25,
      "outputPerMtok": 10.0,
      "cachedInputPerMtok": 0.125,
      "cacheWritePerMtok": 1.5625
    }
  }
}
```

| Field                | Required | Meaning                                                                                      |
| -------------------- | -------- | -------------------------------------------------------------------------------------------- |
| `inputPerMtok`       | yes      | Rate for fresh (uncached) input tokens.                                                      |
| `outputPerMtok`      | yes      | Rate for output tokens (reasoning-inclusive).                                                |
| `cachedInputPerMtok` | no       | Rate for cached/reused input (cache reads). Defaults to `inputPerMtok` when omitted.         |
| `cacheWritePerMtok`  | no       | Rate for cache-write (creation) input, claude only. Defaults to `inputPerMtok` when omitted. |

## How a rate is selected

For a given model name, frites resolves the table entry as follows:

1. **Exact match** wins. If the table has a key equal to the model name, that entry is used.
2. Otherwise a **prefix match in either direction**: a table key is used if the model name starts with the key **or** the key starts with the model name.

The bidirectional prefix rule means a coarse key like `"gpt-5.5"` covers a fully versioned model id like `"gpt-5.5-2026-…"`, and a fully versioned key still matches a bare alias. If nothing fits, no rate is found and that child's spend is left unestimated.

## How an estimate is computed

frites normalizes usage to a provider-agnostic shape before estimating:

* `inputTokens` is the **grand total** input (all categories summed).
* `cacheReadTokens` is the cached/reused portion of that total.
* `cacheCreationTokens` is the cache-write portion (claude only).
* `outputTokens` is reasoning-inclusive on both providers.

The **fresh** (newly billed) input is `inputTokens − cacheReadTokens − cacheCreationTokens` (floored at zero). The estimate is then:

```
fresh * inputPerMtok
  + cacheReads * (cachedInputPerMtok ?? inputPerMtok)
  + cacheWrites * (cacheWritePerMtok ?? inputPerMtok)
  + output * outputPerMtok
```

divided by 1,000,000. When no rates are supplied for the model, the estimate is `undefined`; estimation is strictly opt-in.

## Where estimates surface

Estimated spend appears in the same places authoritative cost does: the live per-agent progress line, the per-turn council recap, and the gateway log, always marked with a `~` so estimates are visually distinct from claude's reported figures. The same estimator (`@frites/core`) is the single source of truth used by both the gateway's answer-council path and the worktree engine path.

See [cost telemetry](/concepts/cost-telemetry.md) for how these figures are displayed during a turn, and [configuration](/reference/configuration.md) for the `pricing` key alongside the other config keys.