PhoneAgent — countries with rentable SMS phone numbers for AI agents. Returns 190+ supported countries, each with the number of services offered and the cheapest price tier ($1, $2, or $5 USDC). Add ?service=<alias> (e.g. tg, wa, go, zo for OpenAI, other for any platform) to see which countries carry that service with live price and inventory pool. Companion route GET /services lists all 1,000+ service aliases; GET /services?country=<iso> lists what a single country offers. Pair with POST /rent