# OpenCharges ## Docs - [List Billing Codes](https://docs.opencharges.com/api-reference/endpoint/v1/billing-codes/get.md): Returns all Billing COdes from the system that the user has access to - [Get single Billing Code](https://docs.opencharges.com/api-reference/endpoint/v1/billing-codes/show.md): Returns a single Billing Code from the system that the user has access to - [List NPIs](https://docs.opencharges.com/api-reference/endpoint/v1/npis/get.md): Returns all NPIs from the system that the user has access to - [Get single NPI](https://docs.opencharges.com/api-reference/endpoint/v1/npis/show.md): Returns a single NPI from the system that the user has access to - [Introduction](https://docs.opencharges.com/api-reference/introduction.md): Getting started with the OpenCharges API is simple. - [Introduction](https://docs.opencharges.com/index.md): Welcome to OpenCharges. A place for real transparency. - [Quickstart](https://docs.opencharges.com/quickstart.md): Start analyzing real negotiated rates in minutes ## OpenAPI Specs - [openapi](https://docs.opencharges.com/api-reference/openapi.json) ## Optional - [Documentation](https://docs.opencharges.com) - [Dashboard](https://app.opencharges.com) - [Website](https://www.opencharges.com) - [System Status](https://status.opencharges.com)