OCPPClient.jl

OCPPClient.jl is a Julia WebSocket client for OCPP (Open Charge Point Protocol) charge points. It connects a charge point to a Central System Management Software (CSMS) and provides a typed Julia API for all common OCPP actions — no manual JSON required. Built on HTTP.jl and OCPPData.jl.

• OCPP 1.6 and 2.0.1 — select the protocol version with the spec keyword
• Typed request/response API — boot_notification, heartbeat, authorize, and more
• Server-call dispatch — register handlers with on! for server-initiated actions
• Event subscriptions — observe connection lifecycle with subscribe!
• Automatic reconnect — configurable reconnect interval
• Structured errors — OCPPTimeoutError, OCPPCallError, OCPPVersionError

Example Usage

julia> using OCPPClient, OCPPData

julia> cp = ChargePoint("CP001", "ws://csms.example.com/ocpp/CP001")
ChargePoint("CP001", ...)

# Register a handler for server-initiated Reset calls
julia> on!(cp, "Reset") do cp, req
           return OCPPData.V16.ResetResponse(; status = OCPPData.V16.GenericAccepted)
       end

# Connect in the background
julia> conn_task = @async connect!(cp)

julia> while cp.status != :connected; sleep(0.1); end

# Send BootNotification
julia> resp = boot_notification(cp; charge_point_vendor = "ACME", charge_point_model = "X1")
OCPPData.V16.BootNotificationResponse("2026-03-25T18:14:54.903Z", 14400, OCPPData.V16.RegistrationPending)

julia> heartbeat(cp)
OCPPData.V16.HeartbeatResponse("2026-03-25T18:14:55.070Z")

Transactions (OCPP 1.6)

julia> resp = start_transaction(cp; connector_id = 1, id_tag = "TAG002", meter_start = 0)
OCPPData.V16.StartTransactionResponse(OCPPData.V16.IdTagInfo(OCPPData.V16.AuthorizationAccepted, "2026-03-25T19:14:55.531Z", nothing), 4)

julia> stop_transaction(cp; transaction_id = resp.transaction_id, meter_stop = 1234)
OCPPData.V16.StopTransactionResponse(nothing)

OCPP 2.0.1

julia> cp = ChargePoint(
           "CP001",
           "ws://csms.example.com/ocpp/CP001";
           spec = OCPPData.V201.Spec(),
       )

julia> resp = boot_notification(
           cp;
           reason = OCPPData.V201.BootReasonPowerUp,
           charging_station = OCPPData.V201.ChargingStation(; model = "X1", vendor_name = "ACME"),
       )

julia> transaction_event(
           cp;
           event_type = OCPPData.V201.Started,
           seq_no = 0,
           transaction_info = OCPPData.V201.Transaction(; transaction_id = "txn-001"),
           trigger_reason = OCPPData.V201.Authorized,
       )

Event subscriptions

julia> subscribe!(cp) do event
           if event isa Connected
               @info "Connected" timestamp = event.timestamp
           elseif event isa Disconnected
               @info "Disconnected" reason = event.reason
           end
       end

How to Cite

If you use OCPPClient.jl in your work, please cite using the reference given in CITATION.cff.

Contributing

If you want to make contributions of any kind, please first take a look into our contributing guide directly on GitHub or the contributing page on the website.