# @suaveplan/currency-provider-ecb - Universal @suaveplan/currency provider for the European Central Bank (ECB) daily exchange-rates XML feed. Free, no API key. Implements the slim @suaveplan/currency-providers contract: typed CurrencyProviderError, injectable FetchLike from @suaveplan/types, shared httpRequest helper, mathematical conversion to any non-EUR base, AbortSignal propagation, target filtering, PARSE_ERROR / UNSUPPORTED_BASE / UNKNOWN_CURRENCY / HTTP_ERROR coverage.

Universal `@suaveplan/currency` rate provider for the European Central
Bank's daily exchange-rates XML feed. Free, no API key required. Built on the
slim `@suaveplan/currency-providers` plugin core: typed
`CurrencyProviderError` on every failure path, shared `httpRequest()` helper
for HTTP wrapping + abort-signal composition, injectable `FetchLike` from
`@suaveplan/types`, mathematical conversion to any non-EUR base, target
filtering with `UNKNOWN_CURRENCY` guarding, and `PARSE_ERROR` protection
against silently caching an empty rate map.

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## Documentation tree

- [ecb](./src/ecb/ecb.md) — `EcbProvider` is the `@suaveplan/currency` rate-source implementation for the European Central Bank's daily reference-r…
  - [ecb](./src/ecb/ecb.md) — `EcbProvider` is the `@suaveplan/currency` rate-source implementation for the European Central Bank's daily reference-r…
<!-- end:auto-docs -->

## Install

```bash
bun add @suaveplan/currency-provider-ecb @suaveplan/currency @suaveplan/currency-providers
```

## Quick start

```ts
import { CurrencyConverter } from "@suaveplan/currency";
import { EcbProvider } from "@suaveplan/currency-provider-ecb";

const converter = new CurrencyConverter({ provider: new EcbProvider() });
const rate = await converter.getRate("EUR", "USD");
```

Or via the slim core's registry, alongside other sibling provider packages:

```ts
import { CurrencyConverter } from "@suaveplan/currency";
import { CurrencyProviderRegistry } from "@suaveplan/currency-providers";
import { EcbProvider } from "@suaveplan/currency-provider-ecb";

const registry = new CurrencyProviderRegistry();
registry.register(new EcbProvider());

const converter = new CurrencyConverter({ provider: registry.get("ecb") });
```

## Features

- Free, no API key.
- ~30 fiat currencies, EUR-quoted upstream; non-EUR bases derived
  arithmetically.
- Daily refresh (~16:00 CET); weekends / holidays return the last published
  snapshot.
- `RateFetchOptions.signal` forwarded through the slim core's HTTP helper.
- Typed `CurrencyProviderError` codes: `HTTP_ERROR`, `PARSE_ERROR`,
  `UNSUPPORTED_BASE`, `UNKNOWN_CURRENCY`.
- Universal (browser / Web Worker / Node 18+ / Bun).
- Zero runtime deps beyond `@suaveplan/currency`,
  `@suaveplan/currency-providers`, `@suaveplan/types`, `tslib`.

## Modules

- [`src/ecb/ecb.md`](./src/ecb/ecb.md) — `EcbProvider` class, configuration,
  error matrix, advanced examples.