OCPI tariffs

This project provides software for doing calculations with OCPI tariffs. Specifically for the OCPI 2.2.1 and OCPI 2.1.1 version.

You can test the tariff tool online.

OCPI is a protocol owned and maintained by the EV Roaming foundation.

Goals

• Provide a reference OCPI tariff implementation

  Given a certain CDR 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.

  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 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.

Tariff structure overview

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

Interpretation

This implementation aims to follow the OCPI specification as closely as possible. However, as with any specification, details might be left open to interpretation. The following is a list of assumptions that have been made in this implementation:

• We assume that a FLAT price component can only be active once in a session. The first time a FLAT price component becomes active it will be used and subsequent active FLAT components will be ignored. Although this is not explicitly mentioned in the OCPI 2.. specs, we feel it is the correct interpretation.

• We assume that the charging periods provided as input are well-formed. Meaning, each period in the session that has a different price must be provided as a separate charging period in the CDR. No attempt will be made to subdivide or interpolate data inside a single provided period.

Contributing

We welcome community contributions to this project.

Please read our 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 or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (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.