glossary.md

Glossary

Terms whose meaning matters across T3 Code. Architecture and lifecycle constraints belong in the overview, not in these definitions.

Workspace and conversation

Term	Meaning
Environment	One running server and the machine, credentials, workspace access, and state it owns.
Client	A web, desktop, or mobile UI connected to an environment. The desktop app can also host a server.
Project	An environment-local workspace record rooted at a directory.
Workspace root	The project's base filesystem directory on the environment.
Worktree	A separate Git checkout a thread can use instead of the project's main checkout.
Thread	The durable conversation and work history for a project. It survives provider process exits.
Turn	One user-to-agent work cycle. Provider work can finish before checkpoint and diff work settles.
Activity	A non-message timeline item, such as a tool action, approval, or failure.
T3 home	The base data directory. Runtime state normally lives under its userdata directory.

Orchestration

Term	Meaning
Command	A request to change domain state. Accepting it does not mean its side effects have finished.
Event	A persisted fact produced by a command.
Decider	The pure logic that turns a command and current state into events.
Projection / read model	A view of current state derived from persisted events.
Projector	The logic that applies events to a read model.
Reactor	A worker that performs follow-up work in response to recorded intent or runtime signals.
Command receipt	A durable record of a command's result, used to make retries idempotent.
Runtime receipt	A test-only signal that an asynchronous milestone completed.
Quiesced	The relevant follow-up workers have finished, beyond the provider turn merely ending.

Providers and checkpoints

Term	Meaning
Provider	The agent runtime T3 Code controls, such as Codex or Claude Code.
Driver	The integration for a provider kind.
Provider instance	One configured provider, with its own settings and lifecycle. Multiple instances can use the same driver.
Adapter	The boundary translating a provider's native protocol into T3 Code operations and events.
Session	The provider runtime attached to a thread. A session can be stopped and resumed without deleting the thread.
Runtime mode	The thread's permission policy. See permission modes.
Interaction mode	How the agent approaches the task, such as planning. Separate from permission policy.
Checkpoint	A saved workspace state used for diffs and restore, stored as a hidden Git ref.
Checkpoint baseline	The workspace state captured before the work being compared.
Turn diff	The workspace changes attributed to one turn.

Pull requests

Term	Meaning
Pull request link	A persisted thread association identified by host, repository, and number. Links can cross projects within an environment and carry a server-maintained snapshot.
Pull request sync	The reactor that refreshes each distinct linked review once per cadence and discovers native stack layers. Explicit refreshes and failed stack reads trigger another read.
Current pull request	The link used by single-review controls and older clients. Open work takes precedence; a completed single chain points at its top layer. Unrelated terminal links use the latest update.