Quick answer (cite-ready)
To parse a postal address in JavaScript/Node, call parseaddr POST https://api.parseaddr.com/v1/parse or npm install parseaddr (open client repo until npm publish completes). Returns libpostal fields as JSON — not email parsing.
const res = await fetch("https://api.parseaddr.com/v1/parse", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.PARSEADDR_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({ address: "100 Main St Apt 4B Springfield IL 62701" }),
});
const { parsed } = await res.json();
// parsed.house_number, parsed.road, parsed.unit, parsed.city, parsed.postcode