Scalar OpenAPI Parser


Modern OpenAPI parser written in TypeScript with support for OpenAPI 3.1, OpenAPI 3.0 and Swagger 2.0.

Goals

- [x] Written in TypeScript
- [x] Runs in Node.js and in the browser (without any polyfills or configuration)
- [x] Tested with hundreds of real world examples
- [ ] Amazing error output
- [ ] Support for OpenAPI 4.0 👀

Installation

``bash
npm add @mintlify/openapi-parser
`

Usage

$3

`ts
import { validate } from '@mintlify/openapi-parser'

const file = {
"openapi": "3.1.0",
"info": {
"title": "Hello World",
"version": "1.0.0"
},
"paths": {}
}

const { valid, errors } = await validate(file)

console.log(valid)

if (!valid) {
console.log(errors)
}
`

$3

`ts
import { dereference } from '@mintlify/openapi-parser'

const specification = {
"openapi": "3.1.0",
"info": {
"title": "Hello World",
"version": "1.0.0"
},
"paths": {}
}

const { schema, errors } = await dereference(specification)
`

$3

`ts
import { filter } from '@mintlify/openapi-parser'

const specification = {
"openapi": "3.1.0",
"info": {
"title": "Hello World",
"version": "1.0.0"
},
"paths": {}
}

const { specification } = filter(specification, (schema) => !schema?.['x-internal'])
`

$3

There’s an upgrade command to upgrade all your OpenAPI specifications to the latest OpenAPI version.

> ⚠️ The upgrade from Swagger 2.0 is still experimental and probably lacks features.

`ts
import { upgrade } from '@mintlify/openapi-parser'

const { specification } = upgrade({
swagger: '2.0',
info: {
title: 'Hello World',
version: '1.0.0',
},
paths: {},
})

console.log(specification.openapi)
// Output: 3.1.0
`

$3

`ts
import { openapi } from '@mintlify/openapi-parser'

const specification = …

// New pipeline …
const result = openapi()
// loads the specification …
.load(specification)
// upgrades to OpenAPI 3.1 …
.upgrade()
// removes all internal operations …
.filter((schema) => !schema?.['x-internal'])
// done!
.get()
`

$3

If you’re more the then/catch type of guy, that’s fine:

`ts
import { validate } from '@mintlify/openapi-parser'

const specification = …

validate(specification, {
throwOnError: true,
})
.then(result => {
// Success
})
.catch(error => {
// Failure
})
`

$3

If you just look for our types, you can install the package separately:

`bash
npm add @mintlify/openapi-types
`

And use it like this:

`ts
import type { OpenAPI } from '@mintlify/openapi-types'

const file: OpenAPI.Document = {
openapi: '3.1.0',
info: {
title: 'Hello World',
version: '1.0.0',
},
paths: {},
}
`

$3

You can reference other files, too. To do that, the parser needs to know what files are available.

`ts
import { dereference, load } from '@mintlify/openapi-parser'
import { fetchUrls } from '@mintlify/openapi-parser/plugins/fetch-urls'
import { readFiles } from '@mintlify/openapi-parser/plugins/read-files'

// Load a file and all referenced files
const { filesystem } = await load('./openapi.yaml', {
plugins: [
readFiles(),
fetchUrls({
limit: 5,
}),
],
})

// Instead of just passing a single specification, pass the whole “filesystem”
const result = await dereference(filesystem)
`

As you see, load() supports plugins. You can write your own plugin, if you’d like to fetch API defintions from another data source, for example your database. Look at the source code of the readFiles to learn how this could look like.

#### Directly load URLs

Once the fetchUrls plugin is loaded, you can also just pass an URL:

`ts
import { dereference, load } from '@mintlify/openapi-parser'
import { fetchUrls } from '@mintlify/openapi-parser/plugins/fetch-urls'

// Load a file and all referenced files
const { filesystem } = await load(
'https://cdn.jsdelivr.net/npm/@mintlify/galaxy/dist/latest.yaml',
{
plugins: [fetchUrls()],
},
)
`

#### Intercept HTTP requests

If you’re using the package in a browser environment, you may run into CORS issues when fetching from URLs. You can intercept the requests, for example to use a proxy, though:

`ts
import { dereference, load } from '@mintlify/openapi-parser'
import { fetchUrls } from '@mintlify/openapi-parser/plugins/fetch-urls'

// Load a file and all referenced files
const { filesystem } = await load(
'https://cdn.jsdelivr.net/npm/@mintlify/galaxy/dist/latest.yaml',
{
plugins: [
fetchUrls({
fetch: (url) => fetch(url.replace('BANANA.net', 'jsdelivr.net')),
}).get('https://cdn.BANANA.net/npm/@mintlify/galaxy/dist/latest.yaml'),
],
},
)
``

Community

We are API nerds. You too? Let’s chat on Discord:

Thank you!

Thanks a ton for all the help and inspiration:

- @philsturgeon to make sure we build something we won’t hate.
- We took a lot of inspiration from @seriousme and his package openapi-schema-validator early-on.
- You could consider this package the modern successor of @apidevtools/swagger-parser, we even test against it to make sure we’re getting the same results (where intended).
- We stole a lot of example specification from @mermade to test against.

License

The source code in this repository is licensed under MIT.