Errors

On failure, code is a machine-readable error code and message is a human-readable description.

code	HTTP	Description
`OK`	200	Success
`VALIDATION_ERROR`	400	Validation failed
`TEMPLATE_VAR_MISSING`	400	Missing template variable
`INVALID_API_KEY`	401	API Key/Secret invalid or disabled
`MESSAGE_NOT_FOUND`	404	Message not found
`TEMPLATE_NOT_FOUND`	404	Template missing or not approved
`CUSTOMER_NOT_BOUND`	409	Customer not bound to LINE
`CUSTOMER_UNFOLLOWED`	409	Customer hasn't added the OA as a friend; cannot push
`IDEMPOTENCY_CONFLICT`	409	Same idempotency key but different payload
`QUOTA_EXCEEDED`	429	Monthly message quota used up
`INTERNAL_ERROR`	500	Server error

Error response example

{
  "code": "CUSTOMER_NOT_BOUND",
  "message": "Customer not bound to LINE",
  "requestId": "req_...",
  "data": null
}

CUSTOMER_NOT_BOUND / CUSTOMER_UNFOLLOWED: guide the customer to complete LINE binding / add the OA as a friend.
QUOTA_EXCEEDED: contact the platform to upgrade the plan or wait for the next billing cycle.
INVALID_API_KEY: verify the key/secret and that it isn't disabled.
Include the requestId from the response when reporting an issue.