TransactionEvent

The single message that replaces StartTransaction, StopTransaction and in-session MeterValues from 1.6.

Version: OCPP 2.0.1
Direction: Charge Point → CSMS
Functional block: Transactions

This is the biggest structural change in 2.0.1. Where 1.6 had three message types with separate correlation rules, 2.0.1 has one message with an eventType of Started, Updated or Ended.

The other half of the change is that the charging station generates the `transactionId`, not the CSMS. A station no longer has to wait for a server to name a session it has already begun, which is what makes offline transaction handling dramatically simpler than it was in 1.6.

seqNo numbers the events within a transaction so the CSMS can detect gaps and order a batch that arrived out of sequence after a reconnect.

Request

Field	Type	Required	Description
`eventType`	TransactionEventEnumType	Required	`Started`, `Updated` or `Ended`.
`timestamp`	dateTime	Required	When the event occurred.
`triggerReason`	TriggerReasonEnumType	Required	What caused this event to be sent.
`seqNo`	integer	Required	Sequence number within the transaction, starting at 0.
`transactionInfo`	TransactionType	Required	Contains `transactionId` and optionally `chargingState`, `stoppedReason` and `remoteStartId`.
`offline`	boolean	Optional	True when the event was generated while disconnected. Defaults to false.
`meterValue`	MeterValue[]	Optional	Meter readings attached to this event.
`evse`	EVSEType	Optional	Which EVSE and connector. Required on the `Started` event.
`idToken`	IdTokenType	Optional	The token. Required on `Started` unless the transaction began without authorization.
`numberOfPhasesUsed`	integer	Optional	Phases actually in use.
`cableMaxCurrent`	integer	Optional	Maximum current the attached cable supports, in amperes.
`reservationId`	integer	Optional	The reservation this transaction fulfils.

json

[2, "19223201", "TransactionEvent", {
  "eventType": "Started",
  "timestamp": "2026-09-09T10:22:00Z",
  "triggerReason": "Authorized",
  "seqNo": 0,
  "transactionInfo": {
    "transactionId": "a1b2c3d4-0001",
    "chargingState": "Charging"
  },
  "evse": { "id": 1, "connectorId": 1 },
  "idToken": { "idToken": "04A1B2C3D4E580", "type": "ISO14443" },
  "meterValue": [{
    "timestamp": "2026-09-09T10:22:00Z",
    "sampledValue": [{ "value": 1204500, "measurand": "Energy.Active.Import.Register", "unitOfMeasure": { "unit": "Wh" } }]
  }]
}]

Response

Field	Type	Required	Description
`totalCost`	decimal	Optional	Running cost of the transaction, when the CSMS tracks cost.
`chargingPriority`	integer	Optional	Priority from -9 to 9, used by smart charging.
`idTokenInfo`	IdTokenInfoType	Optional	Authorization result. Returned on `Started` when an `idToken` was supplied.
`updatedPersonalMessage`	MessageContentType	Optional	A message to show the driver.

json

[3, "19223201", {
  "idTokenInfo": { "status": "Accepted" },
  "totalCost": 4.35
}]

Values

TransactionEventEnumType

Value	Meaning
`Started`	The transaction has begun. Carries `evse` and usually `idToken`.
`Updated`	An in-progress update — meter values, a state change, a periodic sample.
`Ended`	The transaction has finished. `transactionInfo.stoppedReason` says why.

ChargingStateEnumType

Value	Meaning
`Charging`	Energy is flowing.
`EVConnected`	Cable connected, not charging.
`SuspendedEV`	The vehicle paused the draw.
`SuspendedEVSE`	The station paused delivery.
`Idle`	No vehicle connected.

TriggerReasonEnumType (selected)

Value	Meaning
`Authorized`	A token was authorized.
`CablePluggedIn`	The cable was connected.
`ChargingStateChanged`	The charging state changed.
`MeterValuePeriodic`	A periodic meter sample.
`MeterValueClock`	A clock-aligned meter sample.
`EVCommunicationLost`	Communication with the vehicle was lost.
`RemoteStart`	A RequestStartTransaction.
`RemoteStop`	A RequestStopTransaction.
`StopAuthorized`	A token authorized the stop.
`EVDeparted`	The vehicle left.

Implementation notes

The station owns the transaction id. It is a string, not the integer 1.6 used, and it is generated locally. Any CSMS logic that assigned ids has nothing to do here.

`chargingState` is where the detail went. StatusNotification collapsed Charging and SuspendedEV into Occupied, so this field is now the only place that distinction exists.

Honour `offline: true`. It marks events generated during a disconnection, replayed later with their original timestamps. Treating them as live produces out-of-order sessions.

seqNo gaps mean lost events. A CSMS should detect them rather than assume the sequence is complete.