OpenAPIExtensions

Schema names

OpenAPI allows you to define inlined schemas that do not have names.

Inline type in openapi.yml
1components:
2  schemas:
3    Movie:
4      type: object
5      properties:
6        name:
7          type: string
8        cast:
9          type: array
10          items:
11            type: object
12            properties:
13              firstName:
14                type: string
15              lastName:
16                type: string
17              age:
18                type: integer

Fern automatically generates names for all the inlined schemas. For example, in this example, Fern would generate the name CastItem for the inlined array item schema.

Auto-generated name
1export interface Movie {
2  name?: string;
3  cast?: CastItem[];
4}
5
6export interface CastItem {
7  firstName?: string;
8  lastName?: string;
9  age?: integer;
10}

If you want to override the generated name, you can use the extension x-fern-type-name.

openapi.yml
1components:
2  schemas:
3    Movie:
4      type: object
5      properties:
6        name:
7          type: string
8        cast:
9          type: array
10          items:
11            type: object
12            x-fern-type-name: Person
13            properties:
14              firstName:
15                type: string
16              lastName:
17                type: string
18              age:
19                type: integer

This would replace CastItem with Person and the generated code would read more idiomatically:

Overridden name
1export interface Movie {
2  name?: string;
3  cast?: Person[];
4}
5
6export interface Person {
7  firstName?: string;
8  lastName?: string;
9  age?: integer;
10}