📖 Glossary¶

Terms used throughout the OpenCode Masterclass. Based on the official documentation.

Core concepts¶

Term	Meaning
OpenCode	Open source AI coding agent. Runs in TUI, desktop and web.
Agent	Assistant profile with a system prompt, model, mode and permissions. Can be `primary` or `subagent`.
TUI	Full-screen terminal interface (`opencode`).
Mini	Minimal interactive interface (`opencode mini`).
Headless	Execution without an interface (`opencode run`), for scripts and CI.
Session	A conversation with the agent; keeps history and can have subagents (children).
Background service	Shared server that owns sessions, config, plugins and tool execution.

Term	Meaning
`opencode.json(c)`	Server/project configuration (model, agents, permissions…).
`cli.json`	Terminal client-only configuration (theme, keybinds…).
`AGENTS.md`	Project instructions file, loaded automatically.
Instructions	Extra files/globs (`instructions`) besides `AGENTS.md`.

Term	Meaning
Command	Reusable prompt as `/name` (`.opencode/commands/`).
Skill	On-demand instructions for a task (`.opencode/skills/`).
Tool	Built-in tool (`read`, `grep`, `edit`, `shell`, `subagent`…).
Permission	Per-agent rule with effect `allow` / `ask` / `deny`.
Policy	Binary rule (`allow`/`deny`), never asks; only restricts.
Provider	Source of models (Anthropic, OpenAI, Ollama, custom…).
Model	Identified by `provider/model` (+ variant `#high`).
Variant	Named option of a model (e.g. reasoning effort).

Term	Meaning
Plugin	Code that adds tools, hooks, transforms and RPC.
Hook	Intercepts operations (prompt, model calls, HTTP…).
Transform	Synchronous edit of a domain's state (agents, models…).
MCP	Model Context Protocol — connects the agent to external services.
Reference	Named access to directories/repos outside the project.
Attachment	File attached to a prompt.
ACP	Agent Client Protocol — editor integration.
SDK	`@opencode/sdk` — hosts OpenCode in-process.
Client	`@opencode/client` — connects to an OpenCode over the network.

Term	Meaning
Compaction	Context compaction (local or provider-native).
Snapshot	Before/after capture per step; enables `/undo`/`/redo`.
Warming	Periodic requests to keep provider caches warm.
Worktree	Isolated copy of the repo for parallel/risky work.
Console	Enterprise service: workspaces, budgets, policies, Go.
Go / Go Plus	Subscriptions ($10/$40 per month) for open source models.