Stainless vs Swagger Codegen

Stainless generates SDKs, documentation and MCP servers from OpenAPI specifications. Its SDK product lists TypeScript, Python, Go, Java, Kotlin, Ruby, Terraform, C# and PHP, with rich types, automatic pagination and retries included. The Docs Platform, built on Astro, keeps REST API, SDK and narrative documentation in sync with an API. Its listed features include AI-powered hybrid search, Markdown copying, AI-tool integration, and light and dark modes. Stainless also generates code-mode MCP servers so agents can work with SDKs and documentation rather than many endpoint schemas; the MCP product page names Claude Code and Cursor as clients. The Free plan costs nothing and allows up to five generators, five seats and 25 endpoints, with 100 preview builds per month and a rate limit of 25 per day. Email support is listed for Free. Users need a GitHub account for authentication and access to generated staging repositories. Exceeding Free plan terms triggers automatic enrollment in a 30-day free trial of a paid plan. Code generation cannot be hosted on-premise, although generated SDKs can be hosted in a private GitHub repository.

Swagger Codegen is an open-source tool that generates API client libraries, server stubs and documentation from OpenAPI specifications. Its template-driven engine parses OpenAPI or Swagger definitions and produces project code from schemas. Swagger states that it can generate client SDKs in over 40 languages and server boilerplate in over 20. Listed capabilities include OpenAPI import, schema-to-code generation, project scaffolding, custom templates, an interactive API reference, code samples and a command-line interface. Outputs and integrations include HTML and Confluence Wiki documentation, Apache2 configuration files and JMeter. The project is available from GitHub under the Apache-2.0 license, with a hosted option through SwaggerHub. SwaggerHub can generate code in a selected language and push it to source-control repositories. Supported client targets include C#, Dart, Go, Java, JavaScript, Kotlin, PHP, Python, R, Ruby, Scala, Swift and TypeScript variants. Server targets include ASP.NET Core, Go, Java Vert.x and JAX-RS options. The repository warns that untrusted descriptions may cause code injection.