> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/internal-developer-portal/working-with-apis.md).

# Working with APIs

- [API References](https://developer.harness.io/internal-developer-portal/working-with-apis/api-references.md)
- [API Overview](https://developer.harness.io/internal-developer-portal/working-with-apis/api-references/overview.md): Lists all the types of API and their sources available in IDP.
- [Backstage API](https://developer.harness.io/internal-developer-portal/working-with-apis/api-references/public-api.md): Lists the public API endpoints supported in IDP.