> For the complete documentation index, see [llms.txt](https://docs.8select.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.8select.io/api.md).

# API

- [Changelog](https://docs.8select.io/api/changelog.md)
- [2.2.0](https://docs.8select.io/api/changelog/2.2.0.md)
- [2.1.0](https://docs.8select.io/api/changelog/2.1.0.md)
- [2.0.0](https://docs.8select.io/api/changelog/2.0.0.md)
- [1.0.1](https://docs.8select.io/api/changelog/1.0.1.md)
- [General](https://docs.8select.io/api/general.md): GraphQL-based API for all 8SELECT products
- [Introduction](https://docs.8select.io/api/general/introduction.md): At 8SELECT we are working towards providing centralized access to all of our products using GraphQL as the main API technology.
- [Authentication](https://docs.8select.io/api/general/authentication.md): All API requests must be authorized through your API ID in the HTTP request headers.
- [Pagination](https://docs.8select.io/api/general/pagination.md): Whenever two objects have a one-to-many relationship, the respective field will be paginated using cursor-based, forward pagination.
- [Exceptions](https://docs.8select.io/api/general/exceptions.md): Any errors during resolution of a GraphQL query are returned as part of the API response.
- [GraphQL Schema](https://docs.8select.io/api/general/graphql-schema.md): Full annotated GraphQL introspection schema for reference.
- [Examples](https://docs.8select.io/api/examples.md)
- [8.SIMILAR](https://docs.8select.io/api/examples/8.similar.md): Fetch similar products for a given product identifier.
- [8.SET (simplified)](https://docs.8select.io/api/examples/8.set-simplified.md): Fetch cross selling products for a given product identifier. The response is already curated into readily usable product sets.
- [8.SET](https://docs.8select.io/api/examples/8.set.md): Fetch cross selling products for a given product identifier.
- [8.SET Custom](https://docs.8select.io/api/examples/8.set-custom.md): Fetch a custom set for a given product identifier or a specific custom set by id.
- [Product Page - All Content](https://docs.8select.io/api/examples/product-page-all-content.md): Fetch all available content for a given product identifier.