# microsoft/OpenAPI.NET

The OpenAPI.NET SDK contains a useful object model for OpenAPI documents in .NET along with common serializers to extract raw OpenAPI JSON and YAML documents from the model.

Repository: https://github.com/microsoft/OpenAPI.NET
Canonical: https://ross.abutalabs.com/products/openapinet
Language: C#
License: MIT
License Family: permissive
Topics: openapi, http
Last push: 2026-08-26T16:04:00+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 86, longevity 100
- inputs: {"age_days": 3338, "days_push": 7, "days_rel": 13, "gap_med": 3, "n_releases_24m": 98}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1608, forks 286 (observed 2026-08-28T04:05:10.664842+00:00)

## What it is
OpenAPI.NET is a .NET SDK providing an object model for OpenAPI documents, with readers and writers for OpenAPI JSON and YAML in V2 and V3 formats. It includes companion packages like a YAML reader and the Hidi CLI for converting OpenAPI descriptions.

## Use cases
- parse openapi json or yaml files in .net
- generate openapi documents programmatically in c#
- convert openapi between v2 and v3 formats
- serialize openapi document model to json and yaml
- build tooling that reads or writes swagger specs
- convert other api description formats into openapi

## When to choose
- you need a shared .NET object model for OpenAPI documents
- you want to read or write OpenAPI 2.x/3.x JSON and YAML in .NET
- you are building API tooling, generators, or converters on the OpenAPI spec

## When to avoid
- you need OpenAPI tooling outside the .NET ecosystem
- you want automatic OpenAPI generation from running ASP.NET code without a custom model

## Facets
- artifact type: library
- maturity: active
- function: serialization, parser, api-framework, sdk
- domain: apis, developer-tools, web-development, documentation
- platform: dotnet, cross-platform
- tags: openapi, swagger, json, yaml, api-documentation, object-model

## Member repositories
- microsoft/OpenAPI.NET (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:10.664842+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:51:34.699242+00:00, confidence not recorded.
  - readme: https://github.com/microsoft/OpenAPI.NET (fetched 2026-08-28T04:05:10.664842+00:00, sha b1314f2bc91d)
- Data as of 2026-08-30T08:39:29.467469+00:00.