Country Facts – Filter Countries by Region, Currency, Language, Driving Side, Landlocked, or UN Membership

Use this endpoint when you need to retrieve a filtered set of countries based on one or more categorical attributes — region, currency, language, driving side, landlocked status, or UN membership. It is ideal for building country selection dropdowns, generating geographic reports, powering travel planning tools, or enriching datasets that require country segmentation. Prefer this over a full country listing endpoint when you want server-side filtering rather than downloading all countries and filtering locally.

• No filter provided — at least one query parameter is required; returns an error
• Invalid region value (e.g. misspelled continent name) — may return empty results or validation error
• Invalid ISO 4217 currency code — returns empty country list
• Invalid language code or name — returns empty results
• Limit out of range (below 1 or above 250) — may return error or default
• Network or payment failure — 402 payment required if USDC payment not processed