OpenAPI And RPC Workflow

Purpose

Build or diagnose contract-first server-side Swift work without mixing up three different things:

• the OpenAPI description, which is the HTTP API contract
• Swift OpenAPI Generator, which generates Swift types, client calls, and server protocol stubs from that contract
• the server transport, such as OpenAPIHummingbird or OpenAPIVapor, which registers a generated APIProtocol implementation on a real Hummingbird or Vapor app

For RPC-style services, first identify whether the user really means OpenAPI-backed HTTP operations, JSON-RPC over HTTP, gRPC, MCP-style tool calls, or a framework-specific client/server contract. Keep plain HTTP routes as the default when the service does not need a stronger protocol contract.

When To Use