Health App

openapi_first.templates.health_app

OpenAPI-first FastAPI application template.

This package contains a minimal, fully working example of an OpenAPI-first FastAPI service built using the openapi_first library.

The application is assembled exclusively from: - an OpenAPI specification (openapi.yaml) - a handler namespace (routes)

No routing decorators, implicit behavior, or framework-specific convenience abstractions are used. All HTTP routes, methods, and operation bindings are defined in OpenAPI and enforced at application startup.

This package is intended to be copied as a starting point for new services via the openapi-first CLI. It is not part of the openapi_first library API surface.

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Scaffolding via CLI

Create a new OpenAPI-first health check service using the bundled template:

openapi-first health_app

Create the service in a custom directory:

openapi-first health_app my-health-service

List all available application templates:

openapi-first --list

The CLI copies template files verbatim into the target directory. No code is generated or modified beyond the copied scaffold.

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Client Usage Example

The same OpenAPI specification used by the server can be used to construct a strict, operationId-driven HTTP client.

Example client call for the get_health operation:

from openapi_first.loader import load_openapi
from openapi_first.client import OpenAPIClient

spec = load_openapi("openapi.yaml")
client = OpenAPIClient(spec)

response = client.get_health()

assert response.status_code == 200
assert response.json() == {"status": "ok"}

Client guarantees: - One callable per OpenAPI operationId - No hardcoded URLs or HTTP methods in user code - Path and request parameters must match the OpenAPI specification - Invalid or incomplete OpenAPI specs fail at client construction time