CurrencyLayer
CurrencyLayer is an APILayer product providing real-time and historical exchange rates for 168 currencies via a simple REST API with USD base on the free tier and flexible base currency on paid plans.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
HTTP-only free tier is a significant security deficiency shared with Fixer.io. API key in query parameter risks exposure in logs. HTTPS only on paid plans.
⚡ Reliability
Best When
You want a Fixer.io-equivalent API with USD as the native base currency, broad currency coverage, and access to convenience endpoints like /convert and /change without writing your own math.
Avoid When
You need ECB official rates (use Frankfurter), more than 168 currencies, or you cannot accept USD as the base on your budget tier.
Use Cases
- • Fetch live exchange rates for 168 currencies to power multi-currency pricing in a SaaS application
- • Retrieve historical rates for a specific date to support financial reporting or invoice reconciliation
- • Monitor currency fluctuations by polling the change endpoint that returns rate movement between two dates
- • Convert a specific amount between currency pairs using the convert endpoint without manual arithmetic
- • Build a timeframe analysis by querying rate data across a date range for treasury or FX risk management
Not For
- • Applications where USD base currency is not acceptable on the free tier — requires paid plan for base currency switching
- • Real-time trading requiring interbank-level precision or sub-minute updates
- • Official regulatory filings requiring a certified rate authority — CurrencyLayer sources from banks and market data providers, not a single central bank
Interface
Authentication
Access key passed as a query parameter (access_key). Free tier is HTTP-only; HTTPS requires paid plan. Same APILayer auth pattern as Fixer.io.
Pricing
Free tier is very limited — 100 requests/month and HTTP only. Similar pricing to Fixer.io as both are APILayer products.
Agent Metadata
Known Gotchas
- ⚠ Free tier is HTTP-only — never use in production as the access_key will be transmitted in plaintext
- ⚠ Base currency is locked to USD on free and Basic tiers; alternative base currencies require Professional plan
- ⚠ The /convert endpoint is only available on paid plans — free tier users must perform conversion arithmetic client-side
- ⚠ Rates are updated hourly on paid plans but only on /live endpoint calls; /historical returns the rate as of that date's last update
- ⚠ The access_key in the URL query string risks exposure in access logs and browser history — sanitize log output in production
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for CurrencyLayer.
Scores are editorial opinions as of 2026-03-06.