Overview
The US ZipCode API by Smarty validates US zip codes and returns detailed geographic data such as city, state, county, and lat/lng coordinates. It is useful for checking whether a zip code is valid and enriching address data in forms or databases. A free tier is available to get started quickly.
Beginner Tip
Pass your auth credentials as query parameters auth-id and auth-token. A single lookup requires just the zipcode parameter and returns all associated cities for that zip.
Available Data
The kind of data this API exposes, based on its documentation. We could not call the endpoint to confirm the exact field names.
Example Response
Illustrative shape only — we were not able to call this endpoint (it requires credentials or exposes no public sample URL), so the fields below show the kind of data this API returns rather than a recorded response.
{
"input": "[email protected]",
"is_valid": true,
"format_valid": true,
"details": "Input passes all validation checks"
} Field Reference
input_index Index of the input record this result corresponds to, useful for batch lookups. zipcode The validated US zip code. zipcode_type Type of zip code, such as S (standard), P (PO Box), or U (unique). default_city The primary city name associated with this zip code. state_abbreviation Two-letter US state abbreviation, e.g. CA or NY. latitude Approximate latitude coordinate for the zip code area. Implementation Example
Calls a real endpoint of this API. Replace any placeholder credentials with your own key.
const url = "https://us-zipcode.api.smarty.com/lookup?zipcode=90210&auth-id=YOUR_AUTH_ID&auth-token=YOUR_AUTH_TOKEN";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
headers: {
"X-API-Key": "YOUR_API_KEY"
}
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
Common Errors & Troubleshooting
Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.
Metadata Score Breakdown
Estimated from metadata — endpoint not independently tested
Metadata estimate · endpoint not independently tested
Technical Specifications
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