generated: '2026-07-18'
method: searched
source: https://dddinvoices.com/documentation-e-invoicing
docs: https://dddinvoices.com/documentation-e-invoicing
summary:
  types:
  - apiKey
  api_key_in:
  - header
  oauth2_flows: []
  notes: >-
    DDD Invoices uses a custom token ("IoT") scheme carried in the HTTP
    Authorization header. There is no OAuth 2.0 / OpenID Connect surface
    documented. A per-legal-entity Connection Key is issued after sign-up and
    scopes calls to a service (EUeInvoices). Separate TEST and PROD connection
    keys are provisioned per registered legal entity.
schemes:
- name: IoTConnectionKey
  type: apiKey
  in: header
  parameter_name: Authorization
  format: 'IoT <connection-key>:EUeInvoices'
  description: >-
    Custom token authentication. The Authorization header carries the literal
    scheme keyword "IoT" followed by the legal entity's Connection Key and the
    target service name, e.g. "Authorization: IoT <connection-key>:EUeInvoices".
    HTTPS is required for all requests. TEST and PROD keys are distinct.
  sources:
  - https://dddinvoices.com/documentation-e-invoicing