Glossary

This glossary defines key terms used throughout ros2_medkit documentation.

A software application, typically mapping to a single ROS 2 node. Apps are hosted on Components and can participate in Functions. Available in all discovery modes.

See: Heuristic Runtime Discovery

Area

A logical or physical grouping of components, representing a vehicle subsystem or domain. Examples: powertrain, chassis, body. Areas are manifest-defined only and are never auto-generated in runtime mode.

See: Manifest-Based Discovery

Component

A hardware or virtual unit that hosts Apps. In runtime-only mode, a single host-level Component is created from HostInfoProvider. In manifest mode, components are explicitly defined.

Configuration

A ROS 2 node parameter exposed via the /configurations endpoint. Configurations can be read, modified, and reset to defaults.

See: REST API Reference

Data

Topic data from ROS 2 publishers, exposed via the /data endpoint. Data can be read (sampled) and written (published).

Discovery Mode

The method used to map ROS 2 graph entities to SOVD entities:

runtime_only: ROS 2 graph introspection (default)
hybrid: Manifest + runtime linking (recommended)
manifest_only: Only manifest-declared entities

See: Discovery Options Reference

Entity

A generic term for any SOVD object: Area, Component, App, or Function. Each entity has a unique ID, name, and set of resource collections.

Execution

An instance of an operation being called. For services, executions complete immediately. For actions, executions are asynchronous and can be polled for status or cancelled.

Fault

An error condition reported by a ROS 2 node to the fault manager. Faults have a code, severity, message, and timestamp.

See: ros2_medkit_fault_reporter

Function

A high-level capability that spans multiple Apps. Functions aggregate data and operations from their host Apps. In runtime mode, Functions are created from the first namespace segment. In manifest/hybrid mode, Functions are explicitly defined.

Gateway

The ros2_medkit_gateway node that provides the REST API. It discovers ROS 2 entities, handles HTTP requests, and manages executions.

Manifest

A YAML file that declares the system structure (areas, components, apps, functions) with stable IDs and semantic metadata.

See: Manifest Schema Reference

MCP (Model Context Protocol)

A protocol for connecting LLMs to external tools. ros2_medkit_mcp provides MCP tools that wrap the gateway REST API.

See: MCP Server for LLM Integration

Operation

A callable action or service exposed via the /operations endpoint. Operations are invoked by creating executions.

Resource Collection

A category of resources available on an entity: data, operations, configurations, or faults. Not all entities support all collections.

Runtime Linking

In hybrid mode, the process of matching manifest-declared Apps to running ROS 2 nodes based on their ros_binding configuration.

SOVD

Service-Oriented Vehicle Diagnostics — an ASAM standard for automotive diagnostics over IP networks. ros2_medkit implements a subset of SOVD adapted for ROS 2 systems.

Synthetic Component

(Removed) Previously, Components were automatically created in runtime-only mode by grouping ROS 2 nodes by namespace. This behavior has been removed. Components now come from HostInfoProvider (single host-level Component) or manifest.