> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hasmcp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How does OpenAPI validation work?

> Ensuring submitted REST payloads match required formats precisely.

# OpenAPI Validation

HasMCP strictly utilizes OpenAPI schema standards (v3.0.x) to validate every `POST` and `PATCH` request received.

Before a physical request reaches the internal orchestration logic, the API gateway intercepts the payload and parses the JSON body against the rigid schema definition.

1. **Type Checking**: Identifies if a property expects an integer but physically receives a string, returning a `400 Bad Request`.
2. **Missing Properties**: Evaluates all `required: []` arrays in the OpenAPI doc to ensure essential properties like `name` or `type` exist.
3. **Enum Validation**: Ensures string values explicitly match the allowed permutations (e.g. Server variable types must exclusively be `"ENV"` or `"SECRET"`).

If the validation fails, HasMCP returns a detailed error payload explicitly pinpointing which structural rule was violated.