oasdiff vs WSO2 API Designer

oasdiff compares OpenAPI specifications, produces changelogs, and identifies breaking changes before release. It supports OpenAPI 3.0, 3.1, and 3.2, and detects 755 distinct breaking and non-breaking API changes. The CLI is available through Homebrew, a shell installer, Docker, and pre-built Linux, macOS, and Windows binaries. Output formats include text, JSON, YAML, HTML, Markdown, and GitHub Actions annotations. Its GitHub Action compares pull-request and base-branch specifications, adding inline annotations for breaking changes. A browser diff tool compares OpenAPI or Swagger specifications without installation or sign-up. Specs and changelogs are encrypted client-side before upload, and servers retain ciphertext they cannot read. The open-source engine, CLI, and GitHub Action use the Apache 2.0 license. A free plan includes CLI diffing, changelogs, GitHub Action annotations, side-by-side review, and encrypted spec storage. Pro costs $100/month and adds approval workflow, audit trail, merge gate, and up to five reviewers across five repositories. Free review links expire after seven days; Enterprise can load specs from GitHub without uploading or storing them.

WSO2 API Designer is a Visual Studio Code extension for creating and refining OpenAPI 3.x specifications in YAML or JSON. Its design view presents API resources, operations, and reusable components, with form-based editing for operations and schemas. An API Design Skill can draft specifications from prompts with GitHub Copilot; Copilot is optional. The extension checks specifications against bundled Spectral rulesets for WSO2 AI readiness, WSO2 REST API design guidelines, and the OWASP API Security Top 10. AI-assisted analysis adds narrative feedback to rule-based findings, including issues that may affect agents and tools. Users can also point it to custom rules in a GitHub folder or an absolute local directory. Installation is available through the VS Code Marketplace, with documented compatibility for extension engine requirement ^1.100.0. WSO2 directs users to its official Discord community for discussion and help. API Designer is available in a free 30-Day Trial with limits of 5 Managed Interfaces and 10M Gateway Events. Growth costs $119 a month. Enterprise pricing is custom and not listed. WSO2 warns that security checks may need real URLs, policies, or authorization-server metadata; AI should not invent production values.