# Polyform Reverse Geocoder

> Polyform Reverse Geocoder is a paid API for AI agents from polyform.polyform-org.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Converts a geographic coordinate (latitude/longitude) to US Census Bureau administrative geography: state, county, census tract, and block.

## Facts

- Endpoint: GET https://polyform.polyform-org.workers.dev/v1/geo/reverse
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polyform-reverse-geocoder-1b479525
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Vn7ndIByP7w6HqqfGUf6o

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 polyform-reverse-geocoder-1b479525
```

Example prompt: What US state, county, census tract, and block is the coordinate 40.7128° N, 74.0060° W located in? I need the full Census Bureau geographic breakdown for that point.

## When to prefer this

Use this endpoint when you need authoritative US Census Bureau geographic hierarchy (state, county, tract, block) from a coordinate — ideal for compliance, demographic analysis, voter routing, or enriching location data with FIPS codes. Prefer over commercial geocoders when Census Bureau accuracy and official administrative boundaries are required and the location is within the continental US.

## Known failure modes

- Coordinate outside the US returns no match or empty result
- Invalid or missing latitude/longitude parameters returns an error
- Coordinates in US territories or unincorporated areas may not match all geography levels
- Rate limiting or payment failure returns 402 or 429 status
- Very remote areas may have tract/block data but no named county subdivision

## How this service works

Coordinates to US state, county, tract and block geography. Source: US Census Bureau. JSON.

## Output

A JSON object containing the US Census Bureau administrative geography for the provided coordinate: state name and FIPS code, county name and FIPS code, census tract number, and census block number, all sourced from the Census Bureau's geographic data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polyform-reverse-geocoder-1b479525/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from polyform.polyform-org.workers.dev](https://www.zero.xyz/host/polyform.polyform-org.workers.dev/llms.txt)