Fixer alternative: migrate from Fixer.io to FxFeed.io

Fixer.io alternative: migrate to FxFeed

Start with one currency pair and a date that matters to your application. Fetch that rate from both providers, compare the observation dates, and decide what differences your workflow can accept. FxFeed has different sources, response details and plan limits; changing the hostname alone is insufficient.

Map the requests

The Fixer column refers to data.fixer.io/api, documented in APILayer's official Fixer collection. The APILayer marketplace version uses a different host and authentication header. Check your integration before switching.

Task	Fixer	FxFeed v2
Authentication	access_key query parameter	X-API-Key header
Latest rates	/latest?base=EUR&symbols=USD,GBP	/latest?base=EUR&currencies=USD,GBP
Historical rates	/2024-01-02?base=EUR&symbols=USD	/historical?date=2024-01-02&base=EUR&currencies=USD
Daily time series	/timeseries with start_date, end_date, base, symbols	/timeseries with start_date, end_date, base, currencies

FxFeed accepts any supported base currency on every plan. Its free plan returns daily data; paid plans enable hourly latest rates. Both currencies must be covered on a historical date. Check FxFeed plans and currency coverage.

Before and after: a dated rate

An existing Fixer request:

curl --fail --get 'https://data.fixer.io/api/2024-01-02' \
  --data-urlencode 'access_key=YOUR_FIXER_KEY' \
  --data-urlencode 'base=EUR' \
  --data-urlencode 'symbols=USD'

The equivalent FxFeed request:

curl --fail --get 'https://api.fxfeed.io/v2/historical' \
  --header 'X-API-Key: YOUR_FXFEED_KEY' \
  --data-urlencode 'date=2024-01-02' \
  --data-urlencode 'base=EUR' \
  --data-urlencode 'currencies=USD'

Run these from your server. Each provider needs its own key. Multiply an EUR amount by rates.USD to obtain a USD amount. Keep decimal arithmetic and final rounding in your application when valuing invoices.

Update the response handling

Both dated-rate responses contain a rates object keyed by currency code, but validate the response before accessing it. FxFeed's historical date is an ISO timestamp such as 2024-01-02T00:00:00Z; the Fixer example uses a date-only string. Normalize dates explicitly in your adapter.

A successful HTTP response can still have an empty rates object for a missing date. Check for the requested currency and a positive numeric rate. Make weekend fallback a deliberate policy and retain the date actually selected. The Python guide includes a bounded fallback example; the historical converter lets you inspect the behavior interactively.

For FxFeed, handle HTTP 402 as an exhausted monthly allowance and 429 as a short-term rate limit. Use a timeout, keep keys on the server and cache successful results with a refresh policy. See the API error reference and JavaScript integration.

Check the migration before switching traffic

• Compare the base, target, observation date and returned rate for representative pairs and older dates.
• Exercise an unavailable date, an unsupported currency, a rejected key and a quota error.
• Confirm the cadence and allowance of your plan, including requests from retries and cache refreshes.
• Keep stored invoice conversions tied to the original source and rate date; switching providers should not silently rewrite old records.

Get a free FxFeed key and make the dated request above, then use the API reference for the rest of your adapter.