# Changelog State API – Change History for Foundry

> Changelog State API – Change History for Foundry 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 2026-10-17).

Returns the detected changelog update history (change events) for the Foundry vendor, filterable by change type, date, and count.

## Facts

- Endpoint: GET https://changelog-state-api.replit.app/api/monitors/foundry/changes?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/changelog-state-api-change-history-for-foundry-bbd85e51
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_guwV1JwZw558o4YTwMT3Z

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-foundry-bbd85e51
```

Example prompt: Show me the last 50 changelog change events detected for Foundry, including any breaking signals or new releases, since January 1st 2025.

## When to prefer this

Use this endpoint when you need the raw history of detected changelog mutations for the Foundry vendor specifically — particularly when you want to filter by change type (breaking signals, new releases, version bumps) or look at changes after a specific date. Prefer this over the 'recent releases' sibling endpoint when you need change-event-level granularity rather than structured release summaries.

## Known failure modes

- Invalid or unknown vendor slug returns no data or an error
- 'since' timestamp in wrong format returns a validation error
- Requesting a limit above 200 is rejected
- If Foundry has no detected changes in the requested window, an empty result set is returned
- Payment failure (x402) blocks access to results

## How this service works

Detected changelog update history for one tracked vendor.

## Output

A JSON array of detected changelog change events for the Foundry vendor, each including the change type (e.g. new_release, version_changed, date_changed, title_changed, breaking_signal), the detection timestamp, and relevant metadata about what changed in the 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 that names no vendor and never returns data. 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-foundry-bbd85e51/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)