Glossary

Definitions of terms used throughout SystemPrompt documentation.

A

A2A (Agent-to-Agent)

An open protocol for agent-to-agent communication. Defines discovery endpoints, capabilities negotiation, and message formats for multi-agent systems.

Agent

An AI-powered service that can receive messages, use tools, and communicate with other agents. In SystemPrompt, agents are defined in YAML configuration with associated skills and OAuth scopes.

API Key

A secret token used for programmatic authentication. Passed in the Authorization header as a Bearer token.

Axum

A Rust web framework built on Tokio. SystemPrompt uses Axum for HTTP routing and middleware.

C

CLI (Command Line Interface)

The systemprompt command-line tool for managing infrastructure, agents, content, and deployments.

Client Credentials

An OAuth2 flow for service-to-service authentication where the client authenticates directly without user involvement.

Crate

A Rust package. SystemPrompt consists of 33 crates organized in a layered architecture.

D

Domain Layer

The layer containing business logic crates: users, oauth, files, analytics, content, mcp, ai, agent, templates.

E

Entry Layer

The top layer containing binary entry points: the API server and CLI.

Extension

A modular component that adds functionality to SystemPrompt. Extensions implement traits like Extension, ApiExtension, or SchemaExtension.

Extension Point

A defined location where extensions can hook into core functionality.

F

Facade Crate

The systemprompt crate that re-exports all public API from internal crates. The primary dependency for library users.

Feature Flag

A Cargo feature that enables optional functionality. Example: features = ["full"] enables all SystemPrompt features.

Frontmatter

YAML metadata at the top of Markdown files, delimited by ---. Contains title, description, slug, and other properties.

I

Infrastructure Layer

The layer providing foundational services: database, logging, config, events, security, cloud, loader.

Inventory

A Rust crate used for compile-time extension registration. Extensions use register_extension! macro.

J

Job

A background task that runs on a schedule or on-demand. Defined in services/scheduler/ or by extensions implementing JobExtension.

L

Layer

An architectural grouping of crates. SystemPrompt has five layers: Shared, Infrastructure, Domain, Application, Entry.

LLM (Large Language Model)

An AI model capable of understanding and generating text. SystemPrompt integrates with multiple LLM providers.

M

MCP (Model Context Protocol)

An open protocol for connecting AI clients to tools and resources. Defines transports, tool schemas, and resource access patterns.

MCP Server

A service that exposes tools and resources via MCP. SystemPrompt can host multiple MCP servers, each with its own endpoint and permissions.

Migration

A database schema change. SystemPrompt uses SQLx for compile-time verified migrations.

O

OAuth2

An authorization framework for secure API access. SystemPrompt implements OAuth2 for user and service authentication.

OIDC (OpenID Connect)

An identity layer on top of OAuth2. Provides user identity information via ID tokens.

P

Playbook

A documented procedure in SystemPrompt. Playbooks guide common tasks like building extensions or deploying to production.

Profile

A named configuration set containing database connection, API settings, and feature flags. Profiles enable switching between environments.

Provider

An implementation of an LLM service. SystemPrompt includes providers for Anthropic, OpenAI, and Gemini.

R

RBAC (Role-Based Access Control)

A permission system where access is granted based on user roles. SystemPrompt uses RBAC for agent and tool permissions.

Runtime

The application layer crate that orchestrates all services, extensions, and background processes.

S

Schema Extension

An extension that defines database tables. Implements SchemaExtension trait to provide SQL migrations.

Shared Layer

The bottom layer containing foundational types: models, traits, identifiers, extension, provider-contracts, client, template-provider.

Skill

A reusable capability that agents can use. Skills are defined in services/skills/ and assigned to agents.

Slug

A URL-friendly identifier derived from content titles. Example: "Getting Started" becomes getting-started.

SQLx

A Rust SQL toolkit with compile-time verification. SystemPrompt uses SQLx for all database operations.

T

Tenant

An isolated instance of SystemPrompt. Each tenant has its own database, configuration, and users.

Tokio

An async runtime for Rust. SystemPrompt uses Tokio for all asynchronous operations.

Tool

An MCP capability that performs actions. Tools have schemas defining their inputs and outputs.

Trait

A Rust interface defining behavior. Extensions implement traits like Extension, ApiExtension, etc.

W

WebAuthn

A web standard for passwordless authentication using hardware security keys or biometrics.

Well-Known Endpoint

A standardized URL path for service discovery. Example: /.well-known/agent-card.json returns the default agent's A2A card.