# Stack Facts: LLM Model Catalog Changes Feed

> Stack Facts: LLM Model Catalog Changes Feed is a paid API for AI agents from g5joilnmeep4ntz3nwezxt5dmu.srv.us, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-13).

Returns a diff of LLM model changes (additions, removals, modifications including pricing and capabilities) between two named snapshots of the model catalog.

## Facts

- Endpoint: GET https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/v1/models/changes?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stack-facts-llm-model-catalog-changes-feed-6f64d9ea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6owvb0p0oi5wnbdp40Kzp

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 stack-facts-llm-model-catalog-changes-feed-6f64d9ea
```

Example prompt: What changed in the LLM model catalog since snapshot models-20261009T050000Z-044bcb8b? Show me any models added, removed, or modified including pricing updates.

## When to prefer this

Choose this endpoint when you need a precise, signed diff of LLM model catalog changes between two known snapshots — particularly for automated pipelines that track model deprecations, pricing shifts, new releases, or capability updates. Prefer this over scraping provider docs or polling general model lists because it provides cryptographically signed, normalized data across multiple providers (OpenAI, Anthropic, Perplexity, etc.) with no API key required, paid per-call in USDC via x402.

## Known failure modes

- Invalid or malformed 'since' snapshot ID returns an error — must match pattern ^models-\d{8}T\d{6}Z-[0-9a-f]{8}$
- Snapshot ID references a snapshot older than the available history window — no data returned
- Payment not received or insufficient USDC balance — 402 response blocking access
- Stale data flag set to true in meta if the underlying dataset hasn't refreshed recently
- Network timeout if the upstream model data sources are unavailable

## How this service works

Check a package before install: malware, known vulnerabilities (OSV), exploited CVEs (CISA KEV) and end-of-life, plus LLM prices; signed answers, pay per call in USDC, no account or API key.

## Output

A signed JSON payload containing: the 'since' and 'to' snapshot IDs, lists of added and removed model IDs, full modified model objects (with fields like input_usd_per_mtok, output_usd_per_mtok, context_tokens, deprecation_date, tool_call, vision, reasoning, etc.), counts of changes, and a metadata block with timestamp, dataset, licence, SHA-256 hash, and cryptographic signature for integrity verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$defs": {
  "meta": {
   "type": "object",
   "required": [
    "dataset",
    "snapshot_id",
    "as_of",
    "retrieved_at",
    "source",
    "licence",
    "attribution",
    "sha256",
    "signature",
    "key_id",
    "manifest_url",
    "stale",
    "notice"
   ],
   "properties": {
    "as_of": {
     "type": "string"
    },
    "stale": {
     "type": "boolean"
    },
    "key_id": {
     "type": "string"
    },
    "notice": {
     "type": "string"
    },
    "sha256": {
     "type": "string"
    },
    "source": {
     "type": "string"
    },
    "dataset": {
     "type": "string"
    },
    "licence": {
     "type": "string"
    },
    "signature": {
     "type": "string"
    },
    "attribution": {
     "type": "string"
    },
    "snapshot_id": {
     "type": "string"
    },
    "manifest_url": {
     "type": "string"
    },
    "retrieved_at": {
     "type": "string"
    }
   }
  }
 },
 "$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": {
     "type": "string",
     "const": "GET"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "since"
     ],
     "properties": {
      "since": {
       "type": "string",
       "pattern": "^models-\\d{8}T\\d{6}Z-[0-9a-f]{8}$",
       "maxLength": 64
      }
     },
     "additionalProperties": false
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "data",
      "meta"
     ],
     "properties": {
      "data": {
       "type": "object"
      },
      "meta": {
       "$ref": "#/$defs/meta"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "to": "models-20261009T060000Z-f99d55c9",
   "added": [],
   "since": "models-20261009T050000Z-044bcb8b",
   "counts": {
    "added": 1,
    "removed": 1,
    "modified": 2
   },
   "removed": [
    "perplexity/sonar"
   ],
   "modified": [
    {
     "id": "openai/gpt-4o-mini",
     "mode": "chat",
     "name": "GPT-4o mini",
     "model": "gpt-4o-mini",
     "status": null,
     "vision": true,
     "aliases": [],
     "sources": {},
     "provider": "openai",
     "reasoning": false,
     "tool_call": true,
     "deprecated": true,
     "release_date": "2024-07-18",
     "context_tokens": 128000,
     "deprecation_date": "2026-10-01",
     "input_modalities": [
      "text"
     ],
     "knowledge_cutoff": "2023-09",
     "sources_disagree": [],
     "max_output_tokens": 16384,
     "output_modalities": [
      "text"
     ],
     "input_usd_per_mtok": 0.15,
     "output_usd_per_mtok": 0.6,
     "days_until_deprecation": -8,
     "cache_read_usd_per_mtok": 0.075,
     "cache_write_usd_per_mtok": null
    }
   ],
   "snapshots_merged": 1
  },
  "meta": {
   "as_of": "2026-10-09T06:00:00Z",
   "stale": false,
   "key_id": "sf-test-1",
   "notice": "Normalised (modified) from the …",
   "sha256": "f99d55c9aa420561de698d63d70d916…",
   "source": "https://raw.githubusercontent.c…",
   "dataset": "models",
   "licence": "MIT",
   "signature": "AvlI5FXM8fD9oncZAr9velQseOBO9X7…",
   "attribution": "Pricing data derived from LiteL…",
   "snapshot_id": "models-20261009T060000Z-f99d55c9",
   "manifest_url": "/v1/models/manifest",
   "retrieved_at": "2026-10-09T06:00:00.000Z"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stack-facts-llm-model-catalog-changes-feed-6f64d9ea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from g5joilnmeep4ntz3nwezxt5dmu.srv.us](https://www.zero.xyz/host/g5joilnmeep4ntz3nwezxt5dmu.srv.us/llms.txt)