# d21 address_geocode

> d21 address_geocode is a paid API for AI agents from draconic21-x402-api.onrender.com, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-12).

Forward and reverse U.S. address geocoding powered by the U.S. Census Bureau's free Geocoder API, returning standardized coordinates and address components.

## Facts

- Endpoint: POST https://draconic21-x402-api.onrender.com/v1/address_geocode?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/d21-address-geocode-4b81a809
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZbENQbJO4cWKQPq8zm3J-

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability d21-address-geocode-4b81a809 -d '<json body>'
```

Example prompt: Can you geocode the address '1600 Pennsylvania Ave NW, Washington, DC 20500' and get me its latitude and longitude using the Census Bureau geocoder?

## When to prefer this

Choose this endpoint when you need U.S.-only geocoding at low cost ($0.008/call) without an API key, backed directly by the U.S. Census Bureau's authoritative federal dataset. Prefer it over commercial geocoders (Google Maps, HERE, Mapbox) when cost, keyless access, or U.S. government data provenance matters. Ideal for agents processing U.S. addresses in bulk or enriching records where international geocoding is not needed.

## Known failure modes

- Address not found in Census Bureau database — returns zero-count results array
- Invalid or non-U.S. address provided — Census Geocoder only covers U.S. addresses
- Malformed input — missing both address/q and lat/lon fields
- Mutually exclusive parameters provided together (address + lat/lon) — undefined behavior
- Census Bureau upstream API downtime — service unavailable error
- Non-street-level address (PO Box, rural route) may return no match

## How this service works

Address Geocode ($0.008 — below the category-leading "geocoding" comparable's $0.01): forward + reverse U.S. geocoding in one route, built entirely on the U.S. Census Bureau's free, keyless Geocoder API (a federal government service, not a resold third-party product). Accepts `q` as an alias for `address` (the leading comparable's exact param name), and every response carries an additive `count`/`items[]` block in that comparable's field-name shape. Body { address (or q) } for forward…

## Output

Returns a structured response with a count of matched results and an items array. Each item contains the matched/normalized address string, latitude, longitude, and address component fields (street, city, state, zip), shaped to be compatible with leading geocoding API response formats.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "q": {
   "type": "string",
   "description": "Alias for `address` (compatibility with the leading comparable's param name) — provide one or the other, not both."
  },
  "lat": {
   "type": "number",
   "description": "Latitude for reverse geocoding (requires lon). Mutually exclusive with address."
  },
  "lon": {
   "type": "number",
   "description": "Longitude for reverse geocoding (requires lat). Mutually exclusive with address."
  },
  "address": {
   "type": "string",
   "description": "Free-text U.S. street address for forward geocoding, e.g. '4600 Silver Hill Rd, Washington, DC 20233'. Mutually exclusive with lat/lon."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/d21-address-geocode-4b81a809/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from draconic21-x402-api.onrender.com](https://www.zero.xyz/host/draconic21-x402-api.onrender.com/llms.txt)