# Changelog State API – Change History for Next.js

> Changelog State API – Change History for Next.js 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 2026-09-13).

Returns detected changelog update history for the Next.js vendor, including release events, version changes, date changes, title changes, and breaking signals.

## Facts

- Endpoint: GET https://changelog-state-api.replit.app/api/monitors/nextjs/changes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/changelog-state-api-change-history-for-next-js-8e01c548
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__Z_kp8q5bh4Udmch2g49q

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-change-history-for-next-js-8e01c548
```

Example prompt: Pull up the last 50 detected changelog changes for Next.js and filter to only breaking signals detected since the start of this month.

## When to prefer this

Use this endpoint when you need a detailed audit trail of detected changelog changes for Next.js specifically, with the ability to filter by change type or time window. Prefer this over the releases endpoint when you care about all change event types (not just structured releases), including breaking signals, title changes, and date changes. Ideal for automated monitoring pipelines that need to react to any changelog mutation.

## Known failure modes

- 404 returned if the vendor slug is unrecognized or not tracked
- Empty results if no changes match the given filters (since, type)
- Rate limiting or payment failure if the x402 payment is not completed
- Invalid date-time format for 'since' parameter causes validation error
- Limit exceeding 200 returns a validation error

## How this service works

Detected changelog update history for one tracked vendor.

## Output

A JSON array of detected changelog change events for Next.js, each including the change type (e.g. new_release, version_changed, date_changed, title_changed, breaking_signal), the timestamp when the change was detected, and relevant metadata about what changed in the vendor's changelog.

## 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-change-history-for-next-js-8e01c548/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)