openapi-typescript converts OpenAPI 3.0 and 3.1 into pure TypeScript types; openapi-fetch then infers methods, literal paths, parameters, and response unions from that schema.
oRPC supports implementation-first and contract-first APIs, offers an RPC client, and can expose the same router through OpenAPI 3.1.1 HTTP endpoints.
Speakeasy records OpenAPI, Overlays, targets, and generator versions in `.speakeasy/workflow.yaml`, enabling local or CI generation, compilation, and publishing of multi-language SDKs.
Stainless uses OpenAPI plus its configuration to generate multi-language SDKs, docs, CLIs, and MCP servers. Its value is a continuous preview, publishing, and upgrade pipeline rather than one-off codegen.
tRPC lets a client reference the server router type without a separate schema or code generation. Version 11 also has an official, alpha-stage OpenAPI 3.1 generator.
ts-rest describes methods, paths, status codes, and schemas in a shared contract, providing end-to-end server and client types without a code-generation step.
Zodios uses a central Zod endpoint definition for Axios client types, runtime validation, and aliases, with optional Express and OpenAPI packages.