The Transaction JSON is provided after a successful payment. You can use this data e.g. for tracking or personalized success message.
This JSON can contain following data. Not all fields are always present!

{
  "transaction_id": "FB-T-123456",
  "status": "confirmed", // or "awaiting" if redirect payment no yet processed
  "token": "{unique transaction token}",
  "fb_source_id": 3, // always 3
  "fb_payment_form_configuration_id": 1234,
  "source_name": "general", // name of your form
  "source_promotion_code": "",
  "fb_project_id": 4921,
  "project_promotion_code": "",
  "fb_type_id": 8,
  "type_promotion_code": "",
  "amount": 12.34,
  "currency": "EUR",
  "interval": 0,
  "fb_donation_id": null,
  "by_recurring": 0,
  "fb_recurring_payment_id": null,
  "meta_info": {...}, // see General > Meta Info
  "receipt_status": "no_receipt",
  "company_name": "",
  "salutation": "Mr.",
  "title": "",
  "first_name": "Max",
  "last_name": "Mustermann",
  "birthday": null,
  "wants_newsletter": 0,
  "email": "",
  "phone": "",
  "public_name": "",
  "public_message": "",
  "address": "",
  "post_code": "",
  "city": "",
  "country": "",
  "bank_account_owner": "Max Mustermann",
  "bank_number": "123456",
  "bank_account_number": "98756000",
  "bank_iban": null,
  "bank_bic": null,
  "bank_name": null,
  "bank_country": null,
  "updated_at": "2016-08-24 22:49:05",
  "created_at": "2016-08-24 22:49:05",
  "received_at": null,
  "is_test": 0,
  "parent_url": "http://www.myorganisation.de/spenden",
  "ip": "123.456.789.0",
  "mandate_reference_id": "",
  "mandate_status": "",
  "mandate_signature_date": "",
  "mandate_last_usage_date": "",
  "mandate_transaction_type": "",
  "mandate_origin": "",
  "fb_fundraising_page_id": null,
  "fb_donation_custom_fields": [
    {
      "id": "123",
      "name": "Einsatzgebiet",
      "value": "Bayern"
    },
    //... all available donation custom fields, even if there is no value for this transaction
  ],
  "fb_person_custom_fields": [
    {
      "id": "456",
      "name": "Beruf",
      "value": "Informatiker"
    },
    //... all available person custom fields, even if there is no value for this transaction
  ]
}

Possible values: please have a look on our page for predefined values.