Vocabulary

This page defines the words used across DPG.

Network

A network is the top-level contract.

It defines:

• which domains exist
• which item types are allowed
• which instances are registered
• which actions are valid
• what request and event payloads look like

Examples:

• yellow_dot
• blue_dot

Domain

A domain is a business role inside a network.

Examples:

• student
• tutor
• seeker
• provider

A domain is not a deployment. A domain can have many instances.

Instance

An instance is a deployed backend that serves one or more network/domain bindings.

Examples:

• one API serving only yellow_dot/student
• one API serving yellow_dot/student,yellow_dot/tutor
• one API serving yellow_dot/student,blue_dot/seeker

Item

An item is a stored record under a domain.

Every item has:

• item_network
• item_domain
• item_type
• item_id
• item_state
• item_instance_url
• item_schema_url

Schema Identifier

A schema identifier is the value stored in item_type.

This should be versioned explicitly.

Good examples:

• profile_1.0
• profile_1.1
• job_posting_1.0

Item Schema

An item schema is the JSON Schema used to validate item_state.

DPG can use:

• a domain-defined inline schema from the network config
• an instance-specific custom schema URL

Action

An action is a structured interaction from one item to another.

Examples:

• connect
• apply

Requirement Schema

A requirement schema defines what a caller must send for an action interaction.

Event

An event is the structured outcome of an action.

It is validated against the event_schema defined in the action interaction.

Served Domains

SERVED_DOMAINS tells one backend which network/domain pairs it is responsible for.

Example:

SERVED_DOMAINS="yellow_dot/student,blue_dot/seeker"

Inter-Instance Fetch

An inter-instance fetch is a network-aware read across all registered instances for a given network/domain.

In DPG:

• GET /api/v1/item/fetch is instance-local
• GET /api/v1/network/item/fetch is inter-instance