API Surface Model

The API surface model defines how connectors expose their functionality through lnkpt. Each connector declares one or more API surfaces, which may be internal or externally reachable depending on the connector’s design. lnkpt ensures that these surfaces are exposed consistently across deployments.

In standalone deployments, a connector may expose a single API surface, allowing lnkpt to operate as a clean, isolated endpoint host that integrates easily with existing infrastructure.

Definition of an API Surface

An API surface is the externally visible interface through which a connector provides its capabilities. API surfaces may represent:

• Retention server endpoints
• Audit log feeds
• Connections to regulated services such as .gov systems
• Any other connector‑defined interface

lnkpt does not define the behaviour of an API surface; it ensures that the surface is exposed exactly as declared by the connector.

Internal and External Surfaces

Connectors may expose two types of API surfaces:

• Internal surfaces — accessible only within the deployment environment.
• External surfaces — reachable outside the environment, such as public or regulated endpoints.

Standalone deployments often expose a single external surface, providing a clean integration point without requiring changes to existing systems.

Declared API Surfaces

Every connector must declare its API surfaces as part of its metadata. A declaration includes:

• The surface name
• The surface type (internal or external)
• The expected route or endpoint
• Any configuration required for exposure

lnkpt uses these declarations to expose the surfaces predictably, regardless of whether the deployment hosts one connector or many.

Routing and Exposure

lnkpt provides the routing layer that makes API surfaces available. This includes:

• Mapping declared surfaces to container routes
• Ensuring consistent exposure across deployments
• Maintaining isolation between connectors
• Supporting both internal and external access patterns

In standalone mode, routing is minimal and direct, allowing lnkpt to function as a clean endpoint host with no cross‑connector routing complexity.

Stability Expectations

Connectors are responsible for maintaining the stability of their API surfaces. lnkpt ensures that surfaces are exposed consistently, but the connector defines:

• Surface behaviour
• Response formats
• Versioning of the surface
• Any evidence outputs associated with the surface

lnkpt guarantees exposure, not behaviour.

Examples

The API surface model supports a wide range of connector types, including:

• Retention connectors — exposing retention server APIs for long‑term evidence storage.
• Audit connectors — exposing audit log feeds for compliance or monitoring.
• Regulated service connectors — exposing connections to .gov or other regulated endpoints.
• Enterprise connectors — exposing APIs for internal systems or data services.

These examples illustrate the flexibility of the API surface model, whether lnkpt is deployed standalone or as part of a larger connector environment.