OpenAPI Validation

Validate an OpenAPI 3.x specification: required fields, endpoint definitions and schema references.

Pay by wallet (x402) openapi-validate

Example

Example answer

{
  "valid": true,
  "errors": [],
  "warnings": [
    {
      "path": "/servers",
      "message": "No 'servers' defined — consumers won't know the base URL"
    }
  ],
  "error_count": 0,
  "schema_count": 0,
  "warning_count": 1,
  "endpoint_count": 0,
  "version_detected": "3.0.0"
}

Inputs

Field	Type	Required	What it is
`spec`	any	Yes	OpenAPI spec as JSON string or object

Output fields

How reliably each field appears in a successful answer.

Field	Type	Appears
`valid`	boolean	Always (present in every successful answer)
`errors`	array	Always (present in every successful answer)
`warnings`	array	Always (present in every successful answer)
`error_count`	integer	Always (present in every successful answer)
`schema_count`	integer	Always (present in every successful answer)
`warning_count`	integer	Always (present in every successful answer)
`endpoint_count`	integer	Always (present in every successful answer)
`version_detected`	string	Always (present in every successful answer)

How to call it

The same tool through each route. MCP clients reach it through Strale’s server at https://api.strale.io/mcp; the call below is what the agent sends.

# Needs an API key. max_price_cents caps what this call may cost.
curl -X POST https://api.strale.io/v1/do \
  -H "Authorization: Bearer $STRALE_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "capability_slug": "openapi-validate",
    "inputs": {
      "spec": "{\"openapi\":\"3.0.0\",\"info\":{\"title\":\"Test API\",\"version\":\"1.0\"},\"paths\":{}}"
    },
    "max_price_cents": 5
  }'

{
  "tool": "strale_execute",
  "arguments": {
    "slug": "openapi-validate",
    "inputs": {
      "spec": "{\"openapi\":\"3.0.0\",\"info\":{\"title\":\"Test API\",\"version\":\"1.0\"},\"paths\":{}}"
    },
    "max_price_cents": 5
  }
}

import { Strale } from "straleio";

const strale = new Strale({ apiKey: process.env.STRALE_API_KEY! });
const result = await strale.do({
  capability_slug: "openapi-validate",
  inputs: {
    "spec": "{\"openapi\":\"3.0.0\",\"info\":{\"title\":\"Test API\",\"version\":\"1.0\"},\"paths\":{}}"
  },
  max_price_cents: 5,
});

import os
from straleio import Strale, DoRequest

strale = Strale(api_key=os.environ["STRALE_API_KEY"])
result = strale.do(DoRequest(
    capability_slug="openapi-validate",
    inputs={
        "spec": "{\"openapi\":\"3.0.0\",\"info\":{\"title\":\"Test API\",\"version\":\"1.0\"},\"paths\":{}}",
    },
    max_price_cents=5,
))

# No account. The first request answers 402 with the price in USDC;
# an x402 client pays it from your wallet and repeats the request.
curl -i 'https://api.strale.io/x402/v2/openapi-validate?spec=%7B%22openapi%22%3A%223.0.0%22%2C%22info%22%3A%7B%22title%22%3A%22Test+API%22%2C%22version%22%3A%221.0%22%7D%2C%22paths%22%3A%7B%7D%7D'

Limitations

Custom OpenAPI extensions are not checked
Validates against OpenAPI 3.0/3.1 specification — custom extensions and vendor-specific annotations are not checked
What to do instead: For vendor extensions (x- prefixed), add your own validation rules in a post-processing step

Bundled checks that include it

API Quality Check €0.50