USPS Web Tools retired.
Your REST API is ready.

# Validate an address
curl "https://api.revaddress.com/api/address/validate\
?street=1600+Pennsylvania+Ave&city=Washington&state=DC&zip=20500" \
  -H "X-API-Key: rv_live_a1b2c3..."

# 200 OK — 42ms
{
  "street": "1600 PENNSYLVANIA AVE NW",
  "zip": "20500-0005",
  "dpv": "Y"
}

# Install
pip install usps-v3

# Validate an address
from usps_v3 import Client

client = Client("your_api_key")
result = client.addresses.validate(
    street="1600 Pennsylvania Ave",
    city="Washington",
    state="DC",
    zip_code="20500"
)

print(result.zip)  # "20500-0005"
print(result.dpv)  # "Y" (deliverable)

// Install: npm install usps-v3
import { USPSClient } from 'usps-v3';

const client = new USPSClient("your_api_key");
const result = await client.addresses.validate({
  street: "1600 Pennsylvania Ave",
  city: "Washington",
  state: "DC",
  zipCode: "20500"
});

console.log(result.zip);  // "20500-0005"
console.log(result.dpv);  // "Y" (deliverable)