What is OCPI?

OCPI stands for Open Charge Point Interface. It is an open protocol for exchanging EV roaming information between charge point operators (CPOs) and e-mobility service providers (eMSPs).

A CPO operates charging infrastructure. An eMSP provides the driver’s account, app, RFID card or other service. OCPI lets a driver with one provider find and use a charger run by another, subject to commercial agreements and access rules.

The official OCPI repository, maintained by the EV Roaming Foundation, lists OCPI 2.3.0 as the latest official release. Both parties still need to agree the same version and modules.

How EV charging roaming works

A typical flow has several stages:

  1. The CPO shares locations, connectors, availability and tariffs.
  2. The eMSP shows eligible chargers and prices to its customers.
  3. The driver presents a token or sends a start command through the eMSP.
  4. The CPO backend checks the authorisation and tells the charger to start.
  5. Session updates pass from CPO to eMSP while charging continues.
  6. The CPO sends a charge detail record with the agreed energy, time and price fields.
  7. The eMSP bills the driver, and the businesses settle under their contract.

The connection may be direct or pass through a roaming hub. A hub reduces bilateral technical connections. It does not remove commercial, support or data-governance work.

What information OCPI exchanges

OCPI is split into modules. Common modules cover credentials, locations, tariffs, tokens, sessions, charge detail records and remote commands. Current session updates remain separate from the final billing and reconciliation record.

Not every implementation exposes every optional function. Test data freshness, identifiers, tariffs, time zones, currency, taxes, command responses and corrections with each partner.

OCPI versus OCPP

OCPP and OCPI are complementary:

  • OCPP connects a charging station to its CPMS or CSMS.
  • OCPI connects the business platforms of CPOs, eMSPs and roaming hubs.
  • ISO 15118 covers communication between EV and charging equipment.

A roaming start request may move from eMSP to CPO backend over OCPI. The CPO’s CPMS then sends the charger command over OCPP. That boundary helps locate a failure in the driver account, roaming link, backend or charger.

EV charging management software: how CSMS and CPMS platforms work

Hands holding black amina charger showing cable connections and connectors

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EV Charging Management Software: How CSMS and CPMS Platforms Work

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What OCPI does not guarantee

OCPI standardises data exchange. It does not guarantee that every driver can use every charger. Coverage depends on partner agreements, accepted tokens, published prices and live systems. It does not set the retail price, process card payments by itself or settle money between companies.

An eMSP price may differ from the CPO’s direct price because the customer relationship and commercial terms differ. The driver still needs clear information before charging starts.

Where amina fits

amina charging stations connect to the operator’s chosen CSMS over OCPP. The amina CSMS integration guide shows that direct charger-to-CSMS route. OCPI, where needed, sits beyond the charger between the CPMS and other roaming or service platforms.

The charger remains focused on charging, local controls and OCPP communication. Specialist platforms handle accounts, roaming, tariffs and settlement.