nestjs-graphql-swagger-provider

Turn any Swagger/OpenAPI spec into a fully-wired NestJS GraphQL API — in one command.

This project is in active development. APIs and generated output may change without notice.

What It Does

Point it at an OpenAPI 3.0 or 3.1 spec. It generates:

<output-dir>/
  api-client.ts              # Typed REST client (via swagger-typescript-api)
  enums.ts                   # Shared enums with registerEnumType()
  pets/
    pets.module.ts
    pets.resolver.ts          # @Query for GET, @Mutation for POST/PUT/PATCH/DELETE
    pets.service.ts           # Delegates to the generated REST client
    pets.models.ts            # @ObjectType response models
    pets.dto.ts               # @InputType request DTOs

One folder per Swagger controller. Code-first GraphQL. Zero boilerplate.

Quick Start

npx nestjs-graphql-swagger-provider generate \
  --input https://api.example.com/swagger.json \
  --output ./src/generated

Options

| Flag | Description | |---|---| | --input <path-or-url> | (required) Path or URL to the OpenAPI spec | | --output <dir> | (required) Output directory for generated files | | --overwrite | Delete the output directory before generation |

Requirements

• Node.js >= 24

Generated Code Dependencies

Your NestJS project needs these additional packages:

npm install @nestjs/graphql axios

Swagger-to-GraphQL Mapping

| OpenAPI | GraphQL | |---|---| | GET endpoints | @Query() resolvers | | POST / PUT / PATCH / DELETE | @Mutation() resolvers | | Request bodies | @InputType() classes | | Path & query params | @Args() parameters | | Response schemas | @ObjectType() models | | String & integer enums | TypeScript enums + registerEnumType() | | description fields | description option on decorators | | deprecated: true | deprecationReason on decorators |

Development

npm run build        # Compile TypeScript
npm run lint         # Lint with ESLint
npm run format       # Format with Prettier
npm test             # Run tests with Vitest
npm run test:cov     # Tests with coverage

Authors

• Viktor Buzanov
• Claude Opus 4.6

License

MIT