# geo.halowerk.com H3 Cell Operations

> geo.halowerk.com H3 Cell Operations is a paid API for AI agents from geo.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Creates H3 cells from coordinates, finds neighbors, or changes cell resolution using Uber's H3 hierarchical hexagonal geospatial indexing system

## Facts

- Endpoint: POST https://geo.halowerk.com/v1/h3-cell
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/geo-halowerk-com-h3-cell-operations-3af0f30b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1VNd3gkzCMh55AteTh2aR

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 geo-halowerk-com-h3-cell-operations-3af0f30b -d '<json body>'
```

Example prompt: Convert the coordinate 37.7749, -122.4194 to an H3 cell at resolution 9, then find all neighbors within k=2 rings.

## When to prefer this

Choose this endpoint when working with Uber's H3 hexagonal spatial indexing system specifically — for encoding coordinates into H3 tokens, finding k-ring neighbors, or changing cell resolution. Prefer over geohash or S2 endpoints when your downstream system expects H3 cell IDs. Prefer over custom spatial queries when you need standardized hexagonal tessellation with consistent area per resolution level.

## Known failure modes

- Invalid latitude/longitude values outside allowed ranges return validation errors
- H3 resolution out of range 0-15 causes rejection
- Cell token string malformed or unrecognized returns error
- k value exceeding maximum of 20 is rejected
- Missing required fields for the chosen operation (e.g. no lat/lon for from-coordinate) returns null or error
- Operation enum value not recognized

## How this service works

Creates or inspects H3 cells and optionally returns neighbors or changes resolution. Missing facts are returned as null and named in unavailable_fields where applicable. Derived values disclose their method; source-backed values disclose source, time window and age. 

## Output

Returns the H3 cell token for the given coordinate and resolution, or the set of neighbor cell tokens for a k-ring query, or the new cell token at the changed resolution. Missing facts are returned as null with field names listed in unavailable_fields. Derived values include their computation method.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "k": {
   "type": "integer",
   "maximum": 20,
   "minimum": 0,
   "description": ""
  },
  "lat": {
   "type": "number",
   "maximum": 90,
   "minimum": -90,
   "description": ""
  },
  "lon": {
   "type": "number",
   "maximum": 180,
   "minimum": -180,
   "description": ""
  },
  "cell": {
   "type": "string",
   "maxLength": 32,
   "minLength": 1,
   "description": ""
  },
  "operation": {
   "enum": [
    "from-coordinate",
    "neighbors",
    "change-resolution"
   ],
   "type": "string"
  },
  "resolution": {
   "type": "integer",
   "maximum": 15,
   "minimum": 0,
   "description": ""
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/geo-halowerk-com-h3-cell-operations-3af0f30b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from geo.halowerk.com](https://www.zero.xyz/host/geo.halowerk.com/llms.txt)