Development

API Response Contract Validator

Validate a real API response JSON against the response schema declared in an OpenAPI 3.x specification

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Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/api-response-contract-validator' \
  -H 'Content-Type: application/json' \
  -d '{"openApiSpec":"openapi: 3.0.3\npaths:\n  /users/{id}:\n    get:\n      responses:\n        \"200\":\n          description: ok\n          content:\n            application/json:\n              schema:\n                type: object\n                required: [id, name]\n                properties:\n                  id: { type: integer }\n                  name: { type: string }\n                  active: { type: boolean }","responseJson":"{\"id\":\"1\",\"active\":\"yes\"}","path":"/users/42","method":"get","statusCode":"200","specFormat":"yaml","disallowAdditionalProperties":true}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/api-response-contract-validator

Parameters

Name	Type	Required	Description
openApiSpec	textarea	Yes	—
responseJson	textarea	Yes	—
path	text	Yes	—
method	select	No	—
statusCode	text	Yes	—
specFormat	select	No	—
disallowAdditionalProperties	checkbox	No	—

Response format

HTML result

JSON

{
  "result": "<div>Processed HTML content</div>",
  "error": "Error message (optional)",
  "message": "Notification message (optional)",
  "metadata": {
    "key": "value"
  }
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-api-response-contract-validator": {
      "name": "api-response-contract-validator",
      "description": "Validate a real API response JSON against the response schema declared in an OpenAPI 3.x specification",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=api-response-contract-validator",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "api-response-contract-validator",
    "arguments": {
  "openApiSpec": "openapi: 3.0.3\npaths:\n  /users/{id}:\n    get:\n      responses:\n        \"200\":\n          description: ok\n          content:\n            application/json:\n              schema:\n                type: object\n                required: [id, name]\n                properties:\n                  id: { type: integer }\n                  name: { type: string }\n                  active: { type: boolean }",
  "responseJson": "{\"id\":\"1\",\"active\":\"yes\"}",
  "path": "/users/42",
  "method": "get",
  "statusCode": "200",
  "specFormat": "yaml",
  "disallowAdditionalProperties": true
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]