canonical: https://jentic.com/apis/currencylayer.com/currencylayer

# CurrencyLayer API

Jentic publishes the only available OpenAPI specification for CurrencyLayer API, keeping it validated and agent-ready. The CurrencyLayer API delivers real-time and historical exchange rate data for 168 world currencies. Across 6 read-only endpoints it returns live rates, historical rates, time-series data, and rate changes, converts amounts between currencies, and lists supported currencies.

## For AI agents

Fetch live and historical exchange rates, convert amounts between currencies, and read time-series and rate-change data for 168 currencies across 6 read-only endpoints. Authenticates with an API access key.

## Scope

Does not execute trades, hold balances, or process payments. Use for exchange rate data and currency conversion only.

## Capabilities

- Get live exchange rates for a set of currencies
- Get historical exchange rates for a specific date
- Convert an amount between two currencies
- Retrieve time-series exchange rates over a date range
- Get the change in rates between two dates
- List the currencies the API supports

## Use cases

### Agent-Driven Currency Conversion

An AI agent connected through Jentic can turn a natural request such as 'how much is 250 pounds in yen' into a precise figure. It calls the conversion endpoint with the amount and currency pair and returns the converted value at the current rate, so an assistant can quote prices or settle amounts without a hard-coded rate table.

Example prompt: Convert 250 GBP to JPY at the live rate and return the resulting amount

### Historical Rate Analysis

Reporting and reconciliation often need the rate that applied on a past date or across a range. The CurrencyLayer API returns historical rates for a single day and time-series data over a period, letting an agent value a transaction on its actual date or chart how a pair moved.

Example prompt: Fetch the USD to EUR rate for each day of last month and return the series

### Rate Change Monitoring

Workflows that react to currency movement need the delta, not just the latest number. The CurrencyLayer API reports the change in a currency's rate between two dates, so an agent can flag when a pair has moved beyond a threshold and trigger a downstream action.

Example prompt: Get the percentage change in the EUR to USD rate between two dates and report whether it exceeds two percent

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/live` | Get live exchange rates |
| GET | `/historical` | Get historical exchange rates for a date |
| GET | `/convert` | Convert an amount between two currencies |
| GET | `/timeframe` | Get time-series exchange rates over a date range |
| GET | `/change` | Get the change in rates between two dates |

## Key resources

- **Live** — Real-time exchange rates for supported currencies
- **Historical** — Exchange rates for a specific past date
- **Convert** — Convert an amount between two currencies
- **Timeframe** — Time-series exchange rates over a date range
- **Change** — Change in a currency's rate between two dates

## Why Jentic

- **Setup:** Wiring CurrencyLayer by hand means registering for an access key, appending it to every query, and parsing the rate responses yourself. Through Jentic you install once, import CurrencyLayer from the API Directory, store the key once, and your agent calls the rate and conversion operations directly.
- **Permission scoping:** Every operation is a read, so your agent can never modify data, and you choose which of the six operations it may call. You might allow live rates and conversion while blocking the time-series and change endpoints.
- **Credential handling:** Your CurrencyLayer access key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'convert an amount between two currencies', and Jentic returns the matching CurrencyLayer operation with its input schema so the agent calls it with the right amount and currency pair.

## Related APIs

- **ExchangeRate-API** — Live and historical exchange rates with a simple currency conversion endpoint
- **CurrencyAPI** — Real-time and historical currency exchange rates across fiat and crypto
- **FX Rates API** — Live, historical, and time-series foreign exchange rate data
- **APILayer** — Marketplace of data APIs that hosts CurrencyLayer among others

## FAQ

### Why is there no official OpenAPI spec for CurrencyLayer API?

CurrencyLayer publishes documentation but not a machine-readable OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call the API via structured tooling. It is validated against the live API and kept up to date. To run it on your own infrastructure, install Jentic One from its GitHub repo.

### What authentication does the CurrencyLayer API use?

The CurrencyLayer API authenticates with an API access key passed as the access_key query parameter, per its OpenAPI spec. Through Jentic the key is stored once by your own self-hosted instance and injected when the agent calls, so it never appears in the agent's prompt or logs.

### Is there a CurrencyLayer MCP server?

You don't need an MCP server to give your agent the CurrencyLayer API. Jentic connects it directly from the API Directory: import it, store your access key once, and your agent calls the rate and conversion operations. Operations are discovered on demand, so nothing extra loads into the agent's context.

### Can I limit what my agent is allowed to do with the CurrencyLayer API?

Yes. Every operation is a read, so the agent can never modify data, and you choose which operations it may call. You might allow live rates and conversion while blocking the time-series and change endpoints, with every call logged.

### How many currencies does the CurrencyLayer API cover?

According to its specification the API provides rates for 168 world currencies. You can list the supported currencies through the list operation and request live, historical, or time-series rates for any of them.

### What are the rate limits for the CurrencyLayer API?

The OpenAPI spec does not specify rate limits. Check the CurrencyLayer documentation at https://currencylayer.com/documentation for current plan limits before running high-volume rate lookups.

### How do I convert an amount between currencies through Jentic?

Search Jentic by intent, for example 'convert an amount between two currencies', and Jentic returns the convert operation with its input schema. Your agent supplies the amount and the currency pair and reads back the converted value. To run it on your own infrastructure, install Jentic One from its GitHub repo.