# OCPI tariffs
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[![docs-rs]](https://docs.rs/ocpi-tariffs "Documentation")
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[docs-rs]: https://img.shields.io/docsrs/ocpi-tariffs/latest?logo=docs.rs
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[github-activity]: https://img.shields.io/github/last-commit/tandemdrive/ocpi-tariffs
[ocpi]: https://evroaming.org/ocpi-background/
[tariffs]: https://github.com/ocpi/ocpi/blob/2.2.1/mod_tariffs.asciidoc#1-tariffs-module
This project provides software for doing calculations with [OCPI](https://evroaming.org/ocpi-background/)
[tariffs](https://github.com/ocpi/ocpi/blob/2.2.1/mod_tariffs.asciidoc#1-tariffs-module).
Specifically for the [`OCPI 2.2.1`](https://evroaming.org/app/uploads/2021/11/OCPI-2.2.1.pdf)
version.
You can test the tariff tool [online](https://tools.tandemdrive.com/).
OCPI is a protocol owned and maintained by the [EV Roaming
foundation](https://evroaming.org/).
## Goals
- Provide a reference OCPI tariff implementation
Given a certain
[CDR](https://github.com/ocpi/ocpi/blob/2.2.1/mod_cdrs.asciidoc) and
a certain tariff it's able to calculate the different (sub)totals.
The software provides as output a breakdown of how these (sub)totals were
calculated.
- Provide an extensive set of test-cases to ensure correctness.
- Collect feedback from the community
We aim to have as many parties as possible agree that this reference
implementation is a correct interpretation of the OCPI specification and
intentions. We aim for close cooperation with the [EV Roaming
Foundation](https://evroaming.org/).
We welcome community contributions to this project. We aim to make it easy for
people, familiar with OCPI, to provide new test cases.
- Provide the software as open source software so others can freely use and
test it.
Both a command line tool and a Rust library are provided.
- Expose the software functionality [online](https://tools.tandemdrive.com/)
to make it even easier for people to do calculations with the tariff
software.
- Support OCPI 3 tariffs soon after OCPI 3 is finalized.
## Non-goals
- Provide software which communicates tariffs using the OCPI protocol between
EV roaming parties.
- Produce human consumable receipts which specify the different cost components
that led to the calculated total price.
- Support OCPI version 2.1.1
The tariff structure of version 2.1.1 is (mostly?) a subset of the structure
of 2.2.1 so in practice we expect this project to also be usable on 2.1.1.
## Tariff structure overview
```mermaid
classDiagram
class Tariff {
TariffElement elements
}
class TariffElement {
PriceComponent price_components
TariffRestriction restrictions
}
class PriceComponent {
TarifDimensionType type
Number price
Number vat
int step_size
}
class TariffRestriction {
DayOfWeek day_of_week
...
}
Tariff "1" --o "1.." TariffElement
TariffElement "1" --o "1.." PriceComponent
TariffElement "1" --o "0..1" TariffRestriction
```
## Contributing
We welcome community contributions to this project.
Please read our [Contributor Terms](CONTRIBUTING.md#contributor-terms) before
you make any contributions.
Any contribution intentionally submitted for inclusion, shall comply with the
Rust standard licensing model (MIT OR Apache 2.0) and therefore be dual licensed
as described below, without any additional terms or conditions:
### License
This contribution is dual licensed under EITHER OF
- Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
at your option.
For clarity, "your" refers to TandemDrive or any other licensee/user of the contribution.