NSwag website screenshot

NSwag

NSwag is the Swagger/OpenAPI toolchain for .NET, ASP.NET Core and TypeScript, written in C# and maintained by Rico Suter under an MIT licence. It runs the contract in both directions: generating Swagger 2.0 and OpenAPI 3.0 documents from ASP.NET (Core) controllers, Web API assemblies and plain .NET types, and generating C# clients, ASP.NET Web API controllers and TypeScript clients back out of those documents. It combines what Swashbuckle and AutoRest do separately into a single toolchain, which is how it avoids the incompatibility seams between the two and gets better fidelity on inheritance, enums and reference handling via NJsonSchema. NSwag operates no hosted API of its own — it is consumed as NuGet packages, MSBuild targets, an npm-distributed CLI and NSwagStudio, a Windows GUI that authors and executes the same nswag.json configuration document the CLI runs.

NSwag publishes 1 API on the APIs.io network. Tagged areas include .NET, ASP.NET Core, C#, Code Generation, and Developer Tools.

NSwag’s developer surface includes documentation, getting-started guide, support, CLI, changelog, and 14 more developer resources.

23.5/100 emerging ▬ flat Agent 3/100 human only Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0
AccessFreemium
1 APIs
.NETASP.NET CoreC#Code GenerationDeveloper ToolsJSON-SchemaOpen-SourceOpenAPISDKSwaggerTypeScript

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0
Composite quality — 23.5/100 · emerging
Contract Quality 0.0 / 25
Developer Ergonomics 8.1 / 20
Access Clarity 3.2 / 20
Operational Transparency 4.1 / 13
Contract Governance 2.2 / 12
Discoverability 5.9 / 10
Agent readiness — 3/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Surface 0 / 5
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/nswag: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

NSwag

NSwag is an open source .NET toolchain for generating C# and TypeScript API clients and Swagger/OpenAPI specifications from ASP.NET controllers and vice versa. It ships as NuGet...

Pricing Plans 1

Published pricing tiers and plan structures.

Nswag Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Nswag Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Nswag Finops

FINOPS

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Nswag Configuration Document.Schema

2 properties

JSON SCHEMA

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Nswag Domain Security

no transport/DNS hardening detected

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Build 5

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 5

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Company 1

The organization behind the API

Source (apis.yml)

apis.yml Raw ↑
aid: nswag
name: NSwag
description: 'NSwag is the Swagger/OpenAPI toolchain for .NET, ASP.NET Core and TypeScript, written in C# and maintained by
  Rico Suter under an MIT licence. It runs the contract in both directions: generating Swagger 2.0 and OpenAPI 3.0 documents
  from ASP.NET (Core) controllers, Web API assemblies and plain .NET types, and generating C# clients, ASP.NET Web API controllers
  and TypeScript clients back out of those documents. It combines what Swashbuckle and AutoRest do separately into a single
  toolchain, which is how it avoids the incompatibility seams between the two and gets better fidelity on inheritance, enums
  and reference handling via NJsonSchema. NSwag operates no hosted API of its own — it is consumed as NuGet packages, MSBuild
  targets, an npm-distributed CLI and NSwagStudio, a Windows GUI that authors and executes the same nswag.json configuration
  document the CLI runs.'
type: Index
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/nswag.png
tags:
- .NET
- ASP.NET Core
- C#
- Code Generation
- Developer Tools
- JSON-Schema
- Open-Source
- OpenAPI
- SDK
- Swagger
- TypeScript
tags_raw:
- .NET
- ASP.NET Core
- C#
- Code Generation
- Developer Tools
- JSON Schema
- Open Source
- OpenAPI
- SDKs
- Swagger
- TypeScript
url: https://raw.githubusercontent.com/api-evangelist/nswag/refs/heads/main/apis.yml
created: '2026-03-25'
modified: '2026-08-06'
specificationVersion: '0.23'
apis:
- aid: nswag:nswag
  name: NSwag
  description: NSwag is an open source .NET toolchain for generating C# and TypeScript API clients and Swagger/OpenAPI specifications
    from ASP.NET controllers and vice versa. It ships as NuGet packages, MSBuild targets, a cross-platform CLI (nswag.exe
    / dotnet-nswag, also distributed on npm) and the NSwagStudio Windows GUI. There is no hosted NSwag service — the toolchain
    runs on the consumer's own machine or build agent.
  humanURL: https://github.com/RicoSuter/NSwag
  tags:
  - .NET
  - Code Generation
  - OpenAPI
  - SDK
  - TypeScript
  tags_raw:
  - .NET
  - Code Generation
  - OpenAPI
  - SDKs
  - TypeScript
  properties:
  - type: Documentation
    url: https://github.com/RicoSuter/NSwag/wiki
  - type: GettingStarted
    url: https://github.com/RicoSuter/NSwag/wiki/Getting-Started
  - type: GitHubRepository
    url: https://github.com/RicoSuter/NSwag
  - type: CLI
    url: cli/nswag-cli.yml
common:
- type: Releases
  url: https://github.com/RicoSuter/NSwag/releases
- type: ContributionGuide
  url: https://github.com/RicoSuter/NSwag/blob/master/CONTRIBUTING.md
- type: Website
  url: https://github.com/RicoSuter/NSwag
- type: Documentation
  url: https://github.com/RicoSuter/NSwag/wiki
- type: GettingStarted
  url: https://github.com/RicoSuter/NSwag/wiki/Getting-Started
- type: GitHubOrganization
  url: https://github.com/RicoSuter/NSwag
- type: SourceCode
  url: https://github.com/RicoSuter/NSwag
- type: Roadmap
  url: https://github.com/RicoSuter/NSwag/wiki/Roadmap
- type: Support
  url: https://github.com/RicoSuter/NSwag/issues
- type: Community
  url: https://discord.gg/BxQNy25WF6
- type: License
  url: https://github.com/RicoSuter/NSwag/blob/master/LICENSE.md
- type: Packages
  url: packages/nswag-packages.yml
- type: SDKs
  url: packages/nswag-packages.yml
- type: CLI
  url: cli/nswag-cli.yml
- type: ChangeLog
  url: changelog/nswag-changelog.yml
- type: Lifecycle
  url: lifecycle/nswag-lifecycle.yml
- type: Conformance
  url: conformance/nswag-conformance.yml
- type: DomainSecurity
  url: security/nswag-domain-security.yml
- type: LLMsTxt
  url: llms/nswag-llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-06'
  status: enriched
  artifacts_added: 9
  pass: local-v1
x-coverage:
  state: covered
  reason: ''
  detail: 'NSwag is a build-time toolchain with no hosted API, so there is no OpenAPI, AsyncAPI, MCP or agent-card surface
    to harvest — the enrichable surface is its distribution and release posture, and that was captured in full (19 first-party
    packages across NuGet/npm/Chocolatey, the CLI command surface, 12 dated releases, lifecycle, standards conformance). Two
    real gaps were recorded rather than papered over: the project publishes no SECURITY.md or security.txt, and its declared
    homepage NSwag.org no longer serves the site.'
  evidence:
  - url: https://github.com/RicoSuter/NSwag/wiki/CommandLine
    status: 200
  - url: https://nswag.org/
    status: 0
  - url: http://nswag.org/
    status: 403
  - url: https://github.com/RicoSuter/NSwag/security/policy
    status: 200
  checked: '2026-08-06'

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