Service Interface Types

Created: 2026-05-12 · 10 concepts

https://ontology.global.church/core#ServiceInterfaceTypeScheme

Categorical scheme classifying the wire-level interface contract of a gc:OfferedService: REST, GraphQL, SPARQL, MCP, A2A, OpenAPI-described, gRPC, Webhook, RSS/Atom, ActivityPub. Flat scheme (no hierarchy); a service has exactly one primary interface type.

Code	Label	Definition
`SIT-A2A`	Agent-to-Agent (A2A)	An Agent-to-Agent protocol endpoint enabling direct agent-to-agent invocation, task delegation, or coordination. Includes Google's A2A protocol and adjacent agent-interop specifications. Pairs naturally with MCP — MCP exposes tools to one agent, A2A lets that agent call another agent.
`SIT-AP`	ActivityPub	An ActivityPub (W3C Recommendation, https://www.w3.org/TR/activitypub/) endpoint participating in the federated social-web protocol. Relevant to community-of-practice federation between ministry organizations as fediverse adoption grows.
`SIT-GQL`	GraphQL	A GraphQL endpoint (https://spec.graphql.org/) exposing a typed schema with client-shaped queries and subscriptions. Less common in mission tech than REST; included for completeness as orgs ship developer portals.
`SIT-GRPC`	gRPC	A gRPC service (https://grpc.io/) using Protocol Buffers over HTTP/2 for typed, streaming RPC. Common in internal infrastructure; less common as a public federation interface. Carry the .proto URL in gc:hasServiceInterface.
`SIT-MCP`	Model Context Protocol (MCP)	A Model Context Protocol server (https://modelcontextprotocol.io/) exposing tools, resources, and prompts to LLM agents over JSON-RPC. The emerging federation interface for agent-to-service interoperability. Manifest URL can be carried in gc:hasServiceInterface.
`SIT-OAS`	OpenAPI-described	A REST-style service whose contract is described by an OpenAPI 3.x (Swagger) specification (https://spec.openapis.org/oas/latest.html). Use SIT-OAS in preference to SIT-REST when the OpenAPI document URL is the authoritative interface contract; pair with gc:hasServiceInterface pointing to the OAS document.
`SIT-REST`	REST / HTTP	An HTTP-based service exposing resources over verbs (GET / POST / PUT / DELETE / PATCH) with JSON or XML payloads. The dominant federation interface in the Christian-tech ecosystem today (Joshua Project, YouVersion, Bible Brain, API.Bible). See RFC 9110 (HTTP Semantics).
`SIT-RSS`	RSS / Atom Feed	An RSS 2.0 or Atom 1.0 (RFC 4287) feed exposing time-ordered items — devotional content, prayer requests, news, sermon archive entries. Lightweight, no-auth, broadly compatible with reader infrastructure.
`SIT-SPARQL`	SPARQL Endpoint	A SPARQL 1.1 query endpoint (W3C Recommendation) exposing an RDF dataset over HTTP. Supports SELECT / CONSTRUCT / ASK / DESCRIBE and (where authorized) SPARQL Update. Native to the federation use case — graph.global.church and partner KGs are the canonical examples.
`SIT-WHK`	Webhook	An inbound webhook endpoint — the offering org accepts POSTed payloads (events, notifications, signed callbacks) from registered consumers. Distinct from outbound calls: the consumer registers a URL it controls; the offerer's webhook describes the accepted payload shape.