# Changelog State API – Vendor Change History

> Changelog State API – Vendor Change History 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).

Returns detected changelog update history (new releases, version changes, breaking signals, etc.) for a specific tracked vendor by slug.

## Facts

- Endpoint: GET https://changelog-state-api.replit.app/api/monitors/playwright/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-vendor-change-history-f05f9da6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7ig-ghzVaMmJ7lubQjTIv

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-vendor-change-history-f05f9da6
```

Example prompt: What changelog changes have been detected for the OpenAI vendor — show me the last 50 entries, filtering to only new_release events since January 1st 2025.

## When to prefer this

Use this endpoint when you need the historical change detection log for a specific vendor — not just their latest releases, but the full audit trail of detected changes including version bumps, title changes, and breaking signals. Prefer this over the 'recent releases' sibling endpoint when you need filtering by change type or time range, or when you specifically want to detect breaking signals. Best for monitoring pipelines, CI triggers, or changelog digests.

## Known failure modes

- 404 returned if a literal placeholder '{slug}' is used instead of a real vendor slug
- 404 returned if the vendor slug does not exist in the monitored vendor list
- Empty array returned if no changes match the since/type filters
- Invalid date-time format for 'since' parameter causes a validation error
- Limit out of range (>200 or <1) causes a validation error
- Payment not fulfilled (x402) blocks access to the paid response

## How this service works

Detected changelog update history for one tracked vendor.

## Output

A JSON array of changelog change records for the specified vendor, each containing the change type (e.g. new_release, version_changed, breaking_signal), detection timestamp, and relevant metadata. Results are filtered by the requested change type, time window, and limited to the specified count (default 50, max 200).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "slug"
     ],
     "properties": {
      "slug": {
       "type": "string",
       "example": "openai",
       "pattern": "^[a-z0-9][a-z0-9-]*$",
       "maxLength": 64,
       "minLength": 1,
       "description": "Vendor slug, lowercase alphanumeric with dashes. Take one from GET /api/monitors and substitute it into the path: `{slug}` is a placeholder, and requesting those literal characters returns 404. Worked example: GET /api/monitors/openai."
      }
     }
    },
    "queryParams": {
     "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",
       "default": 50,
       "maximum": 200,
       "minimum": 1,
       "description": "Maximum number of change rows to return."
      },
      "since": {
       "type": "string",
       "format": "date-time",
       "description": "Only return changes detected at or after this instant."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "enum": [
      "json"
     ],
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   },
   "description": "Detected changelog update history (paid)"
  }
 },
 "description": "Call shape for GET /api/monitors/{slug}/changes."
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/changelog-state-api-vendor-change-history-f05f9da6/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)