xflags

This extension uses the country location now publicly available on X to add a country flag in the same style found on 4chan's /int/ and /pol/ boards. See the screenshot for an example of how it looks like.

It also features a VPN indicator for accounts with inaccurate location data; and a built-in console tab to track fetches, rate limiting status, etc

xflags uses X's internal API AboutAccountQuery GraphQL endpoint to retrieve user location data, then cache that for 30 days (configurable) to minimize API usage and avoid rate limiting. It uses smart caching to avoid redundant API calls, request queuing to process usernames sequentially and has a 5-minute cooldown after receiving a rate limit 429 error.

Source available at https://github.com/bitlamas/xflags.