# MCP Scores Tools - Schema Change Gate (Analyze)

> MCP Scores Tools - Schema Change Gate (Analyze) is a paid API for AI agents from mcp-factory.bowling-anthony.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Validates customer-supplied JSON schema changes by comparing old and new schemas against provided examples, returning a structured compatibility report.

## Facts

- Endpoint: POST https://mcp-factory.bowling-anthony.workers.dev/schema-change-gate/analyze
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mcp-scores-tools-schema-change-gate-analyze-be0b0859
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_auXxnAYW1IT1dKv_sDUqO

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 mcp-scores-tools-schema-change-gate-analyze-be0b0859 -d '<json body>'
```

Example prompt: Check whether my schema change is safe — here's my old schema, my new schema, and two example payloads I want to validate against both; tell me which examples regressed and which newly pass.

## When to prefer this

Choose this endpoint when you need a structured, evidence-based compatibility report between two JSON schema versions tested against specific example data, especially in CI/CD pipelines or agent-driven schema review workflows. It is particularly useful when you want a cryptographic digest of the analysis for auditability and when you need per-call micropayment billing via x402 USDC rather than a subscription. Prefer alternatives if you need full automated fuzz testing, universal backward compatibility guarantees beyond the supplied examples, or non-JSON schema formats.

## Known failure modes

- Missing or malformed old_schema / new_schema fields returns a validation error
- No examples provided results in an empty or trivially-passing report
- Payment not provided or insufficient USDC triggers x402 payment required response
- Malformed JSON in request body returns a parse error
- Extremely large schemas or example sets may time out on the Cloudflare Worker runtime

## How this service works

Customer-input analysis tools with per-call x402 v2 USDC payments on Base. Discovery and examples are free.

## Output

A JSON object containing: an overall ok flag, a digest hash of the request, a summary object with counts of total, new_valid, old_valid, regressed, both_valid, both_invalid, newly_accepted, an array of regressed items with path and keyword details, arrays for both_invalid and newly_accepted cases, and a disclaimer clarifying the scope of validation (supplied examples only, not universal compatibility proof).

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "scope": "supplied_examples_only",
  "digest": "1a60ec41e214642ff3afd0ad82457a926e19b79218c28a95c6a3631b693e92c8",
  "summary": {
   "total": 2,
   "new_valid": 1,
   "old_valid": 2,
   "regressed": 1,
   "both_valid": 1,
   "both_invalid": 0,
   "newly_accepted": 0
  },
  "regressed": [
   {
    "index": 1,
    "reasons": [
     {
      "path": "#/enum",
      "keyword": "enum"
     }
    ]
   }
  ],
  "disclaimer": "This report reflects validation outcomes only for the examples supplied in this request. It is evidence, not proof, of compatibility: it does not cover values outside the supplied corpus and does not establish universal backward compatibility between old_schema and new_schema.",
  "both_invalid": [],
  "newly_accepted": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-scores-tools-schema-change-gate-analyze-be0b0859/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-factory.bowling-anthony.workers.dev](https://www.zero.xyz/host/mcp-factory.bowling-anthony.workers.dev/llms.txt)