# OpenAPI 3.x Document Validator

> OpenAPI 3.x Document Validator is a paid API for AI agents from modell.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Validates an OpenAPI 3.x document and reports structural errors that would prevent a machine consumer from parsing or using it correctly.

## Facts

- Endpoint: POST https://modell.halowerk.com/v1/openapi-validate
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openapi-3-x-document-validator-78c92fa2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NQ_KDA3_PjxjxcMQXm9VA

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 openapi-3-x-document-validator-78c92fa2 -d '<json body>'
```

Example prompt: Can you validate this OpenAPI 3.x spec and tell me exactly what would prevent a machine from consuming it — like missing openapi or info fields, paths with no methods, unresolved $refs, parameters without names or schemas, and request bodies without content?

## When to prefer this

Choose this endpoint when you need fast, machine-focused validation of an OpenAPI 3.x document — specifically to catch the structural errors that break API client generators, MCP converters, or other automated consumers. It is purpose-built to flag the exact issues (missing fields, broken $refs, incomplete parameters, empty request bodies) that cause downstream tooling failures, making it ideal as a pre-processing step before passing a spec to OpenAPI-to-MCP converters or schema comparison tools.

## Known failure modes

- Submitting a non-OpenAPI document (e.g. JSON Schema or Swagger 2.x) may produce unexpected or misleading errors
- Malformed JSON/YAML that cannot be parsed will fail before validation begins
- Very large specifications may exceed request size limits
- External $refs (URLs or file paths) are not resolved — only internal $refs are checked
- Partial or truncated documents may produce incomplete error reports

## How this service works

Reads an OpenAPI 3.x document and reports what would stop a machine consumer. Errors: missing openapi, info or paths; a path that declares no method; an internal $ref that resolves to nothing; a parameter without a name, location or schema; a request body without content.

## Output

A structured report listing each validation error found in the submitted OpenAPI 3.x document. Errors include: missing top-level fields (openapi, info, paths), paths declaring no HTTP method, internal $ref values that resolve to nothing, parameters missing name, location, or schema, and request bodies missing a content definition. A clean document returns no errors.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "document": {
   "type": "object",
   "description": "The OpenAPI document as JSON."
  },
  "require_examples": {
   "type": "boolean",
   "default": true,
   "description": "Report operations with no example as a warning."
  },
  "require_operation_ids": {
   "type": "boolean",
   "default": true,
   "description": "Report operations without operationId as a warning."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/openapi-3-x-document-validator-78c92fa2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from modell.halowerk.com](https://www.zero.xyz/host/modell.halowerk.com/llms.txt)