---
title: 'FX auto-refresh'
description: 'Refresh exchange rates daily from the ECB feed into a DB override, read as dbRate ?? staticAnchor — display and checkout always resolve the same rate.'
canonical: 'https://cartwright.app/docs/features/fx-auto-refresh'
---

# FX auto-refresh (/docs/features/fx-auto-refresh)



`fxAutoUpdate` keeps multi-currency exchange rates current by refreshing them daily from the European Central Bank's no-key feed into a database override, instead of relying on the static rates in `brand.config.ts`. It builds on [Multi-currency](/docs/features/multi-currency).

## Why a DB override [#why-a-db-override]

The static rates in `brand.config.ts` are compile-time constants — a cron can't rewrite a `.ts` file. So `fxAutoUpdate` writes refreshed rates to `IntegrationSettings.fxRatesJson` and the rate resolver reads:

```ts
dbRate ?? staticAnchor
```

When the flag is **off** (or no rates have been fetched), resolution falls back to the static `brand.config` anchors — behaviour is byte-identical to before.

## Same rate for display and charge [#same-rate-for-display-and-charge]

The override is read through the one conversion path in `lib/money.ts` (`fxRate`/`convertMinor`), shared by storefront display, checkout, the order snapshot, and the receipt email — so there's **no drift** between the price shown and the amount charged. (The order also snapshots `Order.fxRate`, so receipts match the charge even if rates move later.)

## Enable it [#enable-it]

<Steps>
  <Step>
    Have ≥2 entries in 

    `supportedCurrencies`

     and multi-currency working.
  </Step>

  <Step>
    Turn on 

    `fxAutoUpdate`

     in 

    `/admin/features`

     (runtime).
  </Step>

  <Step>
    Set 

    `CRON_SECRET`

     — 

    `/api/cron/fx-refresh`

     runs daily and no-ops when the flag is off.
  </Step>
</Steps>

|         |                                                             |
| ------- | ----------------------------------------------------------- |
| Flag    | `fxAutoUpdate`                                              |
| Tier    | runtime (needs ≥2 currencies)                               |
| Default | **off**                                                     |
| Env     | none for rates (ECB is keyless); `CRON_SECRET` for the cron |

<Callout type="info">
  Fail-soft: if the ECB feed is unreachable the last good rates are kept; the static anchors are never dropped.
</Callout>

<Cards>
  <Card title="Multi-currency" href="/docs/features/multi-currency" />

  <Card title="Checkout (Stripe)" href="/docs/features/checkout-stripe" />
</Cards>