{
  "openapi": "3.1.0",
  "info": {
    "title": "India GST Number GSTIN Validation API",
    "description": "Validates an Indian 15-character GSTIN and returns taxpayer name and registration details. Pre-launch design; endpoints are not live yet.",
    "version": "0.1.0",
    "x-planned-pricing": {
      "model": "free tier for evaluation, paid tiers by volume",
      "status": "planned; nothing charged before launch"
    }
  },
  "servers": [
    {
      "url": "https://openapiregistry.com/api/v1/gstin-validation",
      "description": "Pre-launch: endpoints are not live yet and answer 503."
    }
  ],
  "security": [
    {
      "ApiKeyAuth": []
    }
  ],
  "paths": {
    "/validate": {
      "get": {
        "summary": "Validate an Indian GSTIN",
        "description": "Checks a 15-character GSTIN and returns validity, taxpayer name and registration details.",
        "tags": [
          "finance"
        ],
        "operationId": "gstin-validation-validate",
        "parameters": [
          {
            "name": "gstin",
            "in": "query",
            "required": true,
            "description": "15-character Indian Goods and Services Tax Identification Number.",
            "schema": {
              "type": "string",
              "minLength": 15,
              "maxLength": 15
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Validation result.",
            "content": {
              "application/json": {
                "example": {
                  "valid": true,
                  "gstin": "27AAPFU4258B1ZV",
                  "legalName": "Example Traders Pvt Ltd",
                  "stateCode": "27",
                  "status": "ACTIVE",
                  "registrationDate": "2021-04-01"
                },
                "schema": {
                  "type": "object",
                  "properties": {
                    "valid": {
                      "type": "boolean"
                    },
                    "gstin": {
                      "type": "string"
                    },
                    "legalName": {
                      "type": "string"
                    },
                    "stateCode": {
                      "type": "string"
                    },
                    "status": {
                      "type": "string"
                    },
                    "registrationDate": {
                      "type": "string"
                    }
                  }
                }
              }
            }
          },
          "400": {
            "description": "GSTIN is malformed."
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "ApiKeyAuth": {
        "type": "apiKey",
        "in": "header",
        "name": "X-API-Key",
        "description": "Planned for launch: an API key issued on request. Free tier for evaluation, paid tiers by volume; nothing is charged before launch."
      }
    }
  }
}