# Status State API – Vendor Status Change History

> Status State API – Vendor Status Change History is a paid API for AI agents from status-state-api.replit.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns the historical status change events for a specific developer infrastructure vendor, showing transitions between operational/degraded/down states.

## Facts

- Endpoint: GET https://status-state-api.replit.app/api/monitors/%7Bslug%7D/changes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/status-state-api-vendor-status-change-history-326292c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_palLek6lkhz6pxK7j_rjK

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 status-state-api-vendor-status-change-history-326292c0
```

Example prompt: Can you pull up the status change history for OpenAI — I want to see all the times their status shifted from operational to degraded or down?

## When to prefer this

Use this endpoint when you need the historical timeline of status transitions for a specific developer infrastructure vendor — not just the current status. Ideal for incident retrospectives, reliability audits, or building alerting logic based on how often a vendor flips between states. Prefer this over a current-snapshot endpoint when you need the 'when did it change and from what state' answer rather than 'what is the status right now'.

## Known failure modes

- Unknown or unsupported vendor slug returns an empty array or 404
- Payment not completed via x402 protocol results in a 402 Payment Required response before data is returned
- Malformed slug parameter may return a validation error
- Vendor has no recorded changes yet, resulting in an empty changes array

## How this service works

Status State API - agent-facing status monitoring for 20 developer
infrastructure vendors. Most routes are free. Full per-vendor snapshots
and change history are paid via the x402 protocol (USDC on Base,
$0.01/call, no API key or signup required). See /.well-known/agent.json
and /.well-known/x402 for machine-readable payment discovery.

## Output

Returns a JSON array of status change events for the specified vendor slug, each containing a change ID, timestamp (createdAt), the previous status, the new status, the type of change, and an optional detail field. Useful for auditing incident frequency and duration over time.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "slug": "openai",
  "changes": [
   {
    "id": 1234,
    "detail": null,
    "createdAt": "2026-01-15T12:00:00.000Z",
    "newStatus": "degraded",
    "changeType": "status_change",
    "previousStatus": "operational"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/status-state-api-vendor-status-change-history-326292c0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from status-state-api.replit.app](https://www.zero.xyz/host/status-state-api.replit.app/llms.txt)