Interfaces define how the system connects to external systems, APIs, services, and user-facing endpoints. Answer: What does the system connect to?

UID prefix: INTF- Traces up to: Features (FEAT-) Implemented by: API clients and adapters (# impl INTF-NNN) Verified by: Integration tests (# verify INTF-NNN)

• FEAT-000

  1. Feature Template UID: FEAT-000 STATUS: Template RELATIONS (Parent):

  • UC-000 Use Case Template

  RELATIONS (Child):

  • FN-000 Function Template
  • DATA-000 Data Entity Template
  • INTF-000 Interface Template

  STATEMENT:

  The system shall provide [feature description].

  Scope: - [included]

  Out of scope: - [excluded]

  Dependencies: [other features or systems required]

INTF-000

1. Interface Template UID: INTF-000 STATUS: Template RELATIONS (Parent):

• FEAT-000 Feature Template

STATEMENT:

The system shall integrate with [external system] to [purpose].

Direction: [inbound / outbound / bidirectional] Protocol: [REST / GraphQL / SMTP / webhook / file transfer] Authentication: [API key / OAuth / certificate] Data exchanged: [what flows in/out] Frequency: [real-time / batch / on-demand] Fallback behavior: [what happens when unavailable]