The request asks for what to use to document a Resident Services API, which is a documentation task rather than a named product. The most fitting candidates are API documentation tools: ReadMe, which builds interactive API docs from a web editor 18, and Build with Fern, which creates interactive API docs with AI search and generates SDKs 20. Microsoft's Microsoft.OpenApi library 1 and GitHub's ASP.NET minimal-API OpenAPI skill 12 help if the API is built on .NET and needs an OpenAPI spec

A question back: What platform or stack is the Resident Services API built on (for example .NET, Node, Python), and do you need hosted interactive docs or a generated spec?

1. 1

   ReadMereadme.ioverified and signed

   Creates interactive, developer-friendly API documentation with a WYSIWYG editor and bi-directional sync with GitHub, per its page, and offers actions to get, list and create docs 18.

   WebsiteDocs

   official:API · API Endpoints+37 community tools built for it

   for agents: getDoc · getCategoryDocs · createDoc

2. 2

   Build with Fernbuildwithfern.comverified and signed

   Creates interactive API docs with AI search and generates SDKs in several languages from an API definition, per its page; its action record lists tools and agents for documentation work 20.

   WebsiteDocsPricingGet started

   for agents: tools · agents · ai

3. 3

   Microsoft.OpenApimicrosoft.comverified and signed

   A library from Microsoft for working with OpenAPI documents, which can serve as the API reference spec for the Resident Services API 1.

   WebsiteDocsPricingGet started

   official:library · Microsoft.OpenApiskill · microsoft-foundryskill · appinsights-instrumentation+136 community tools built for it

   for agents: OpenAPI · microsoft-docs · add-new-jit-ee-api

4. 4

   GitHubgithub.comverified and signed

   Hosts the API documentation repository and includes a skill that creates ASP.NET Minimal API endpoints with proper OpenAPI documentation 12.

   WebsiteDocsPricingGet started

   official:CLI · github-mcp-serverskill · add-community-extensionskill · git-commitskill · acquire-codebase-knowledge+2,468 community tools built for it

   for agents: aspnet-minimal-api-openapi · typespec-create-api-plugin · winmd-api-search