# Live Aircraft Tracker — ADS-B Proximity Search

> Live Aircraft Tracker — ADS-B Proximity Search is a paid API for AI agents from 4yearcycle.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Returns real-time positions and flight data for aircraft within a specified radius of a geographic coordinate using ADS-B surveillance data.

## Facts

- Endpoint: GET https://4yearcycle.com/x402/flights?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/live-aircraft-tracker-ads-b-proximity-search-1aed5928
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KYgmVq5zI_xoCP2iWmTU7

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 live-aircraft-tracker-ads-b-proximity-search-1aed5928
```

Example prompt: What aircraft are currently in the air within 150 nautical miles of London Heathrow (51.477, -0.461)? Show me their callsigns, altitudes, and headings.

## When to prefer this

Choose this endpoint when you need live, real-time aircraft positions around a specific geographic point using crowd-sourced ADS-B data from adsb.lol. It is ideal for proximity-based queries (radius search) rather than tracking a specific flight by route or airline. Prefer it over airline schedule APIs when you need actual current positions rather than planned schedules, and over radar apps when you need machine-readable JSON output for programmatic use.

## Known failure modes

- Missing lat or lon parameters returns a validation error
- Radius value above 250 is silently capped at 250 nautical miles
- No aircraft in range returns count 0 with empty aircraft array
- Invalid coordinate format (outside -90/90 or -180/180 range) may return error or empty result
- Payment failure (x402) returns 402 before any aircraft data is returned

## How this service works

Interactive Bitcoin 4-year halving cycle chart on a polar disc. Live price, 200W MA, Mayer Multiple, RSI, MACD, Pi Cycle and optional paid cycle projections.

## Output

A JSON object containing a count of aircraft found (capped at 200), an array of aircraft records each with ICAO24 hex address, latitude, longitude, heading in degrees, callsign, on-ground boolean, barometric altitude in meters, and velocity in m/s, plus an attribution string crediting adsb.lol under ODbL 1.0.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "lat",
      "lon"
     ],
     "properties": {
      "lat": {
       "type": "string",
       "pattern": "^-?\\d{1,2}(\\.\\d+)?$",
       "examples": [
        "51.5",
        "40.6413"
       ],
       "description": "Latitude of the query point in decimal degrees, -90 to 90. Required."
      },
      "lon": {
       "type": "string",
       "pattern": "^-?\\d{1,3}(\\.\\d+)?$",
       "examples": [
        "-0.12",
        "-73.7781"
       ],
       "description": "Longitude of the query point in decimal degrees, -180 to 180. Required."
      },
      "radius": {
       "type": "string",
       "default": "100",
       "pattern": "^\\d{1,3}$",
       "examples": [
        "100",
        "250"
       ],
       "description": "Search radius in nautical miles around the point. Integer 1-250; values above 250 are capped. Default: 100."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "count",
      "attribution",
      "aircraft"
     ],
     "properties": {
      "count": {
       "type": "integer",
       "description": "Number of aircraft returned (capped at 200)"
      },
      "aircraft": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "icao24",
         "lat",
         "lon"
        ],
        "properties": {
         "lat": {
          "type": "number",
          "description": "Latitude, WGS84 degrees"
         },
         "lon": {
          "type": "number",
          "description": "Longitude, WGS84 degrees"
         },
         "icao24": {
          "type": "string",
          "description": "24-bit ICAO aircraft address, hex"
         },
         "heading": {
          "type": [
           "number",
           "null"
          ],
          "description": "True track over ground in degrees, 0-360"
         },
        
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 1,
  "aircraft": [
   {
    "lat": 51.280518,
    "lon": -2.687939,
    "icao24": "4022bd",
    "heading": 175.05,
    "callsign": "GPURR",
    "onGround": false,
    "altitudeM": 876,
    "velocityMs": 53.71
   }
  ],
  "attribution": "Aircraft data © adsb.lol contributors, ODbL 1.0 (https://www.adsb.lol/)"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/live-aircraft-tracker-ads-b-proximity-search-1aed5928/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 4yearcycle.com](https://www.zero.xyz/host/4yearcycle.com/llms.txt)