Trace Format

DebugKit accepts three trace formats. All formats use the OCPP 1.6 JSON message structure.

JSON Object Format

The primary format — a structured file with metadata and events:

{
  "traceId": "trace-001",
  "metadata": {
    "stationId": "CS-SYNTHETIC-001",
    "ocppVersion": "1.6",
    "source": "csms-log"
  },
  "events": [
    {
      "timestamp": "2024-01-15T10:30:00.000Z",
      "direction": "CS_TO_CSMS",
      "message": [2, "msg-001", "BootNotification", {
        "chargePointVendor": "SyntheticVendor",
        "chargePointModel": "SM-100"
      }]
    },
    {
      "timestamp": "2024-01-15T10:30:00.500Z",
      "direction": "CSMS_TO_CS",
      "message": [3, "msg-001", {
        "currentTime": "2024-01-15T10:30:00.500Z",
        "status": "Accepted"
      }]
    }
  ]
}

JSONL Format

One event per line — useful for CSMS logs and streaming captures:

{"timestamp":"2024-01-15T10:30:00.000Z","direction":"CS_TO_CSMS","message":[2,"msg-001","BootNotification",{}]}
{"timestamp":"2024-01-15T10:30:00.500Z","direction":"CSMS_TO_CS","message":[3,"msg-001",{"status":"Accepted"}]}

Blank lines are ignored. Malformed lines produce parse warnings but don't fail.

Bare Array Format

A JSON array of raw OCPP messages — convenience for quick testing:

[
  [2, "msg-001", "BootNotification", {}],
  [3, "msg-001", {"status": "Accepted"}]
]

Direction is inferred; timestamps are null.

OCPP 1.6 JSON Message Structure

Three message types are supported:

• Call (2): [2, UniqueId, Action, Payload]
• CallResult (3): [3, UniqueId, Payload]
• CallError (4): [4, UniqueId, ErrorCode, ErrorDescription, ErrorDetails]

Timestamps

Accepted formats:

• ISO 8601 (UTC): 2024-01-15T10:30:00.000Z
• ISO 8601 (offset): 2024-01-15T12:00:00+02:00
• Unix epoch (ms): 1705312200000
• Unix epoch (s): 1705312200
• Missing/null — event timestamp is null

Limits

Direction Inference

When direction is not specified, it is inferred from the action name:

• CS_TO_CSMS — BootNotification, Authorize, StartTransaction, StopTransaction, StatusNotification, MeterValues, Heartbeat, etc.
• CSMS_TO_CS — Reset, RemoteStartTransaction, GetConfiguration, ChangeConfiguration, etc.
• UNKNOWN — unrecognized actions

For CallResult/CallError, direction is inferred from the matching Call.