The package openapi-codegeneration can be used to generate server-side typescript code from an openapi-specification.

generated
├── index.ts
├── routes
│   ├── route_0.ts
│   ├── route_1.ts
│   ├── ...
│   └── route_n.ts
├── operations_templates
│   ├── operations_0.ts
│   ├── operations_1.ts
│   ├── ...
│   └── operations_n.ts
├── types.ts
└── validation
    ├── validation_0.ts
    ├── validation_1.ts
    ├── ...
    ├── validation_n.ts
    └── validation.mjs

The file index.ts exports the express application. The generated type declarations are available in types.ts. The folder routes contains the routers for the different endpoints of the api, each in their corresponding file. For each route there will also be a template in operations_templates containing stubs of the functions that need to be implemented for the given route. Validation functions are also generated for each route's body, parameters and responses. These can be found in the validation folder along with the file validation.mjs which contains the validation functions for all schemas contained in the openapi-specification.

src
├── generated
│   └── ...
├── index.ts
├── security.ts
├── operations
│   ├── operations_0.ts
│   ├── operations_1.ts
│   ├── ...
│   └── operations_n.ts
└── ...

In order to use the generated code the missing implementation of the functions contained in the files of the operations_templates folder must be added. For this one should create a folder operations which contains the corresponding files (e.g. copying and filling out the templates). Furthermore a file security.ts must be added which has to contain the implementation of the function checkJWT(). Finally the project should then contain an index.ts file which handles its execution.

The following dependencies are needed to work with the generated code:

"devDependencies": {
    "typescript": "^4.7.3",
    "@types/node": "^17.0.41",
    "@types/express": "^4.17.13",
    "@types/body-parser": "^1.19.2"
},
"dependencies": {
    "express": "^4.18.1",
    "body-parser": "^1.20.0"
}