Quick Start

CostAPI is distributed via RapidAPI. Head to https://rapidapi.com/AETHAR/api/cost-of-living-price-index-api and subscribe to the Free plan — 100 requests per day, no credit card required.

RapidAPI handles billing, key issuance, and usage analytics. Upgrading or downgrading a plan takes effect immediately.

After subscribing, RapidAPI shows your personal X-RapidAPI-Key in the right-hand Code Snippets pane. This is the key you send on every request — keep it secret, never commit it to git, never embed it in client-side code.

If you're calling CostAPI directly (not through the RapidAPI gateway) — for enterprise customers with a private contract — you'll receive an Aethar-issued key with the prefix ck_ and use the header X-API-Key instead. This guide assumes the RapidAPI path; swap headers if you're on the direct path.

Compare the cost of living between Berlin and Lisbon:

curl -X GET "https://cost-of-living-price-index-api.p.rapidapi.com/v1/compare?from=Berlin&to=Lisbon" \
  -H "X-RapidAPI-Key: your_rapidapi_key" \
  -H "X-RapidAPI-Host: cost-of-living-price-index-api.p.rapidapi.com"

You should see a 200 response with an overall cost-of-living index, per-category breakdowns (rent, groceries, restaurants, transport, utilities), and the upstream source each metric was derived from (Numbeo, Expatistan, Eurostat HICP, BEA RPP, OECD, or UBS).

Browse the full endpoint reference in the left sidebar. The main tags are CPI (consumer price indices and HICP series), PPP (purchasing power parities and real-income conversions), Prices (city/country and US-metro price baskets), and Intelligence (agent-first semantic endpoints like *where should I relocate to stretch my salary?* and *rank these cities by groceries*).

For production workloads, read the Rate Limits and Errors guides to handle non-200 responses gracefully, and the Data Sources guide to understand what your data actually means.