# docs/internals/glossary.md ยท screen/t3code-personal [View on GitCafe](https://git.cafe/screen/t3code-personal/blob/c9a0e8a119271765196dec38ef91395713da4213/docs/internals/glossary.md) Repository: [screen/t3code-personal](https://git.cafe/screen/t3code-personal) Visibility: public Requested revision: c9a0e8a119271765196dec38ef91395713da4213 Requested commit: c9a0e8a119271765196dec38ef91395713da4213 Commit: c9a0e8a119271765196dec38ef91395713da4213 Blob: 019c9d53023a855dd9eae694fdcee3c83618f811 Size: 6682 bytes [Immutable source](https://git.cafe/screen/t3code-personal/blob/c9a0e8a119271765196dec38ef91395713da4213/docs/internals/glossary.md?format=markdown) ``` # Glossary Terms whose meaning matters across T3 Code. Architecture and lifecycle constraints belong in the [overview](./overview.md), 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](../user/permission-modes.md). | | 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. | ## Composer context | Term | Meaning | | -------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | | Context record | The typed payload behind a composer chip, keyed by `contextId` in `message.context.records`. It never holds bytes. | | Context reference | One occurrence of a record in message text: `[label](t3-context://v1//)`. Several references can share one record. | | Attachment binding | The link from an image or file record to its server-owned attachment. Its attachment ID can change without changing `contextId`. | | Attachment inventory | The ordered image records shown as thumbnails above the prose, including images with no inline references. | See [composer context references](./composer-context-references.md) for the contract and lifecycle. ```