Authorize

Core CP->CSMS

Sent by the Charge Point to authorize an identifier (RFID tag, credit card, etc.) before starting a transaction.

Quick Reference

Required Fields

idTag string(20)

The identifier to be authorized (e.g., RFID tag)

Example Payload

{
  "idTag": "AABBCCDD"
}

Example Full Frame

[
  2,
  "msg-001",
  "Authorize",
  {
    "idTag": "AABBCCDD"
  }
]

Format: [MessageType, MessageId, Action, Payload]

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Overview

The Authorize message is used to validate an identifier (typically an RFID tag) with the Central System before allowing a charging session to start. This is a critical security and billing verification step.

When to Send

When a user presents an RFID tag to start charging
Before sending StartTransaction (if authorization is required)
Optionally before StopTransaction to verify the stopping user

Expected Response

The CSMS responds with an IdTagInfo object containing:

status: Accepted, Blocked, Expired, Invalid, or ConcurrentTx
expiryDate (optional): When the authorization expires
parentIdTag (optional): Group identifier for the tag

Usage Notes

Authorization can be skipped if the Charge Point has a local authorization list
The idTag must be exactly as read from the RFID reader (case-sensitive)
Some CSMSs support multiple identifier formats (RFID, credit card, app-based)

Best Practices

Local authorization cache - Cache positive authorizations to allow offline charging
Handle expiry dates - Check expiryDate in responses and cache them
User feedback - Provide immediate visual/audio feedback based on authorization status
Timeout handling - If authorization times out, decide whether to allow or deny charging

Testing Tips

Test with valid idTag to verify Accepted response
Test with unknown idTag to verify Invalid response
Test with blocked idTag to verify Blocked response
Test offline mode with cached authorizations

Common Errors

`PropertyConstraintViolation`

Cause: idTag exceeds 20 characters

Solution: Ensure idTag is max 20 characters

`TypeConstraintViolation`

Cause: Missing required field idTag

Solution: Always include idTag in the payload