# Changelog State API – Monitor Changes

> Changelog State API – Monitor Changes is a paid API for AI agents from changelog-state-api.replit.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Retrieves a filtered list of detected changes (new releases, version bumps, title edits, date shifts, breaking signals) for a specific monitored changelog identified by its slug.

## Facts

- Endpoint: GET https://changelog-state-api.replit.app/api/monitors/%7Bslug%7D/changes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/changelog-state-api-monitor-changes-33d607e7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oEyhcPdyJcxX64yRq101i

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 changelog-state-api-monitor-changes-33d607e7
```

Example prompt: Show me all the changes detected for the 'react-router' changelog monitor since January 1st, 2026 — limit it to 20 results and only include version_changed events.

## When to prefer this

Use this endpoint when you need to programmatically query historical or recent change events for a specific changelog monitor by slug, especially when you want to filter by change type or time window. Prefer this over manual changelog scraping when you need structured, evidence-backed change records with before/after values and timestamps.

## Known failure modes

- Unknown slug returns 404 with no matching monitor data
- Invalid change type enum value returns 400 validation error
- Malformed 'since' timestamp format returns 400 parse error
- No changes matching filters returns empty changes array with changeCount 0
- Payment not processed results in 402 Payment Required response
- Rate limiting or server errors return 5xx responses

## How this service works

Changelog State API — built on Replit. Update this description to reflect the app.

## Output

Returns a JSON object with the monitor's name, slug, a count of matching changes, and an array of change records each containing: unique ID, change type (new_release, version_changed, date_changed, title_changed, breaking_signal), detected timestamp, previous and new values, a summary, evidence text, and associated release metadata (URL, title, version, publishedAt).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "type": {
   "enum": [
    "new_release",
    "version_changed",
    "date_changed",
    "title_changed",
    "breaking_signal"
   ],
   "type": "string",
   "description": "Restrict to a single change type."
  },
  "limit": {
   "type": "integer",
   "description": "Maximum number of change rows to return."
  },
  "since": {
   "type": "string",
   "description": "Only return changes detected at or after this instant."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "name": "string",
 "slug": "string",
 "changes": [
  {
   "id": 1,
   "release": {
    "url": "string",
    "title": "string",
    "version": "string",
    "publishedAt": "2026-01-15T09:30:00.000Z"
   },
   "summary": "string",
   "evidence": "string",
   "newValue": "string",
   "changeType": "new_release",
   "detectedAt": "2026-01-15T09:30:00.000Z",
   "previousValue": "string"
  }
 ],
 "changeCount": 1
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/changelog-state-api-monitor-changes-33d607e7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from changelog-state-api.replit.app](https://www.zero.xyz/host/changelog-state-api.replit.app/llms.txt)