# Foundry USGS Earthquake Event Set Change Detection

> Foundry USGS Earthquake Event Set Change Detection is a paid API for AI agents from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev, paid per call via x402, $0.011/call, status unknown (last checked 2026-09-14).

Compares a set of known USGS earthquake event IDs against a fresh bounded query to identify added, retained, and absent events within a geographic window and time range.

## Facts

- Endpoint: POST https://foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/v2/official/usgs-event-set-change
- Price: $0.011/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/foundry-usgs-earthquake-event-set-change-detection-14956fb8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FTbFlH35j_fpkbz2xPC-l

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 foundry-usgs-earthquake-event-set-change-detection-14956fb8 -d '<json body>'
```

Example prompt: Check the USGS earthquake catalog for any new or changed events within 150 km of San Francisco (37.77, -122.42) between 2026-09-05T00:00:00Z and 2026-09-06T00:00:00Z with minimum magnitude 2.5, and compare against my baseline event IDs ['us7000m9g4', 'us7000m9g5'] — show me what was added, retained, or is missing.

## When to prefer this

Use this endpoint when you need to detect changes in the USGS earthquake catalog over time — specifically to identify newly catalogued events, verify that previously known events are still present, or flag events that have been revised or removed. It is the right choice when you have a prior baseline of USGS event IDs and want a structured diff against a fresh bounded query. Prefer over a plain earthquake lookup when change detection, reconciliation, or provenance-backed evidence is required.

## Known failure modes

- Invalid datetime format (must be ISO 8601 UTC with Z suffix) returns validation error
- radius_km exceeding 2000 or being zero/negative returns schema error
- limit outside 1-20 range returns validation error
- latitude/longitude out of bounds returns validation error
- baseline_event_ids array exceeding 20 items rejected
- USGS upstream unavailability may cause retrieval failure
- Empty result set returned if no earthquakes match the window — not an error

## How this service works

Pay-per-request evidence and data tools: CSV validation and reconciliation, DNS/email configuration evidence, and bounded official weather, earthquake, vehicle, company and study records. Exact USDC prices, explicit JSON contracts and source provenance. No mailbox, ownership, medical or safety guarantees.

## Output

A JSON object containing: 'added' (events now in USGS query but not in baseline), 'retained' (events present in both baseline and current query), 'unresolved_absence' (baseline IDs not explained by current query), 'not_in_current_query' (baseline IDs outside the current query window), and 'current' (the full current event set with query parameters, event list, completeness flag, evidence provenance including source URL, license, attribution, retrieval timestamp, and upstream call count). Includes limitations disclaimers about catalog revision and completeness.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "window": {
   "type": "object",
   "required": [
    "latitude",
    "longitude",
    "radius_km",
    "start_time",
    "end_time",
    "minimum_magnitude",
    "limit"
   ],
   "properties": {
    "limit": {
     "type": "integer",
     "default": 10,
     "maximum": 20,
     "minimum": 1
    },
    "end_time": {
     "type": "string",
     "format": "date-time",
     "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
    },
    "latitude": {
     "type": "number",
     "maximum": 90,
     "minimum": -90
    },
    "longitude": {
     "type": "number",
     "maximum": 180,
     "minimum": -180
    },
    "radius_km": {
     "type": "number",
     "maximum": 2000,
     "exclusiveMinimum": 0
    },
    "start_time": {
     "type": "string",
     "format": "date-time",
     "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
    },
    "minimum_magnitude": {
     "type": "number",
     "default": 0,
     "maximum": 10,
     "minimum": -2
    }
   },
   "additionalProperties": false
  },
  "baseline_event_ids": {
   "type": "array",
   "items": {
    "type": "string",
    "pattern": "^[a-zA-Z0-9]{1,100}$"
   },
   "maxItems": 20
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "route": "usgs-event-set-change",
  "result": {
   "added": [],
   "current": {
    "query": {
     "limit": 10,
     "end_time": "2026-09-06T00:00:00Z",
     "latitude": 37.77,
     "longitude": -122.42,
     "radius_km": 100,
     "start_time": "2026-09-05T00:00:00Z",
     "minimum_magnitude": 0
    },
    "events": [],
    "complete": true,
    "evidence": {
     "source": "USGS Earthquake Catalog",
     "license": "US public-domain earthquake facts; no third-party media",
     "terms_url": "https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits",
     "source_url": "https://earthquake.usgs.gov/fdsnws/event/1/query",
     "attribution": "US Geological Survey and the contributing seismic network identified in each record",
     "retrieved_at": "2026-09-06T00:00:00Z",
     "upstream_calls": 1,
     "cache_age_seconds": 0,
     "source_generated_at": null
    },
    "limitations": [
     "Reported seismic observations may be revised; no emergency warning or impact prediction.",
     "Complete means the bounded source query was not truncated at retrieval; it does not guarantee all earthquakes are catalogued.",
     "Synthetic empty result only; no live observation claimed."
    ],
    "observed_at": "2026-09-06T00:00:00Z"
   },
   "retained": [],
   "limitations": [
    "Synthetic example; absence from a query does not establish deletion."
   ],
   "observed_at": "2026-09-06T00:00:00Z",
   "unresolved_absence": [],
   "not_in_current_query": [
    "us7000m9g4"
   ]
  },
  "observed_at": "2026-09-06T00:00:00Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/foundry-usgs-earthquake-event-set-change-detection-14956fb8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev](https://www.zero.xyz/host/foundry-par007-machine-revenue-mainnet.inference-chip-index.workers.dev/llms.txt)