# US Census Address Geocoder

> US Census Address Geocoder is a paid API for AI agents from x402-geocoder-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Geocodes a US street address to latitude/longitude coordinates plus US Census FIPS codes (state, county, tract, and block)

## Facts

- Endpoint: POST https://x402-geocoder-production.up.railway.app/geocode/address
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-geocoder-production-up-railway-app-bf418576
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0rSQd5wMp03vSOOBdpBUD

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 x402-geocoder-production-up-railway-app-bf418576 -d '<json body>'
```

Example prompt: What are the latitude, longitude, and Census FIPS codes (state, county, tract, and block) for 1600 Pennsylvania Ave NW, Washington, DC 20500?

## When to prefer this

Use this endpoint when you need both geographic coordinates (lat/lng) and US Census FIPS identifiers (state, county, tract, block) from a US street address in a single call. Ideal for workflows involving demographic analysis, census data joins, or any application requiring official Census geographic identifiers alongside coordinates. Prefer this over general-purpose geocoders when Census FIPS codes are needed.

## Known failure modes

- Address not found in Census database — returns match: false with no lat/lng, but payment is still charged
- Missing required 'street' parameter — request rejected
- Ambiguous address without city/state/zip — may return incorrect match or no match
- Non-US addresses are not supported — Census geocoder only covers US addresses
- Malformed street address string — may fail to match

## How this service works

Geocode a US street address to lat/lng plus US Census FIPS codes (state/county/tract/block). Backed by the US Census Bureau Geocoder. Query params: street (required, e.g. '1600 Pennsylvania Ave NW'), city (optional, improves accuracy), state (optional, 2-letter abbrev), zip (optional, 5-digit). Returns match: false with no lat/lng when Census can't find the address; payment is charged per call regardless of match outcome.

## Output

Returns a match status boolean; if matched, includes latitude and longitude coordinates plus US Census FIPS codes for the state, county, census tract, and census block corresponding to the input address. If no match is found, returns match: false with no coordinates.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-geocoder-production-up-railway-app-bf418576/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-geocoder-production.up.railway.app](https://www.zero.xyz/host/x402-geocoder-production.up.railway.app/llms.txt)