Is it possible to use other old restful API or GraphQL services with Strapi service?

Hi All
Is it possible to use other old restful APIs or GraphQLs with Strapi?

For example:
https://petstore.swagger.io/ to combine into STRAPI

Target:
To use STRAPI to manage 2 old Restful API servers + 1 old GraphQL server ← Is it prossible?