From 556737e084ea9c945622c0518e479b195f56014b Mon Sep 17 00:00:00 2001 From: Jason Laster Date: Sun, 8 Mar 2026 20:56:44 -0700 Subject: [PATCH] Add an encyclopedia of common terms --- .docs/encyclopedia.md | 180 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 180 insertions(+) create mode 100644 .docs/encyclopedia.md diff --git a/.docs/encyclopedia.md b/.docs/encyclopedia.md new file mode 100644 index 0000000000..76df004e04 --- /dev/null +++ b/.docs/encyclopedia.md @@ -0,0 +1,180 @@ +# Encyclopedia + +This is a living glossary for T3 Code. It explains what common terms mean in this codebase. + +## Table of contents + +- [Project and workspace](#project-and-workspace) +- [Thread timeline](#thread-timeline) +- [Orchestration](#orchestration) +- [Provider runtime](#provider-runtime) +- [Checkpointing](#checkpointing) + +## Concepts + +### Project and workspace + +#### Project + +The top-level workspace record in the app. In [the orchestration contracts][1], a project has a `workspaceRoot`, a title, and one or more threads. See [workspace-layout.md][2]. + +#### Workspace root + +The root filesystem path for a project. In [the orchestration model][1], it is the base directory for branches and optional worktrees. See [workspace-layout.md][2]. + +#### Worktree + +A Git worktree used as an isolated workspace for a thread. If a thread has a `worktreePath` in [the contracts][1], it runs there instead of in the main working tree. Git operations live in [GitCore.ts][3]. + +### Thread timeline + +#### Thread + +The main durable unit of conversation and workspace history. In [the orchestration contracts][1], a thread holds messages, activities, checkpoints, and session-related state. See [projector.ts][4]. + +#### Turn + +A single user-to-assistant work cycle inside a thread. It starts with user input and ends when follow-up work like checkpointing settles. See [the contracts][1], [ProviderRuntimeIngestion.ts][5], and [CheckpointReactor.ts][6]. + +#### Activity + +A user-visible log item attached to a thread. In [the contracts][1], activities cover important non-message events like approvals, tool actions, and failures. They are projected into thread state in [projector.ts][4]. + +### Orchestration + +Orchestration is the server-side domain layer that turns runtime activity into stable app state. The main entry point is [OrchestrationEngine.ts][7], with core logic in [decider.ts][8] and [projector.ts][4]. + +#### Aggregate + +The domain object a command or event belongs to. In [the contracts][1], that is usually `project` or `thread`. See [decider.ts][8]. + +#### Command + +A typed request to change domain state. In [the contracts][1], commands are validated in [commandInvariants.ts][9] and turned into events by [decider.ts][8]. +Examples include `thread.create`, `thread.turn.start`, and `thread.checkpoint.revert`. + +#### Domain Event + +A persisted fact that something already happened. In [the contracts][1], events are the source of truth, and [projector.ts][4] shows how they are applied. +Examples include `thread.created`, `thread.message-sent`, and `thread.turn-diff-completed`. + +#### Decider + +The pure orchestration logic that turns commands plus current state into events. The core implementation is in [decider.ts][8], with preconditions in [commandInvariants.ts][9]. + +#### Projection + +A read-optimized view derived from events. See [projector.ts][4], [ProjectionPipeline.ts][11], and [ProjectionSnapshotQuery.ts][10]. + +#### Projector + +The logic that applies domain events to the read model or projection tables. See [projector.ts][4] and [ProjectionPipeline.ts][11]. + +#### Read model + +The current materialized view of orchestration state. In [the contracts][1], it holds projects, threads, messages, activities, checkpoints, and session state. See [ProjectionSnapshotQuery.ts][10] and [OrchestrationEngine.ts][7]. + +#### Reactor + +A side-effecting service that handles follow-up work after events or runtime signals. Examples include [CheckpointReactor.ts][6], [ProviderCommandReactor.ts][12], and [ProviderRuntimeIngestion.ts][5]. + +#### Receipt + +A lightweight typed runtime signal emitted when an async milestone completes. See [RuntimeReceiptBus.ts][13]. +Examples include `checkpoint.baseline.captured`, `checkpoint.diff.finalized`, and `turn.processing.quiesced`, which are emitted by flows such as [CheckpointReactor.ts][6]. + +#### Quiesced + +"Quiesced" means a turn has gone quiet and stable. In [the receipt schema][13], it means the follow-up work has settled, including work in [CheckpointReactor.ts][6]. + +### Provider runtime + +The live backend agent implementation and its event stream. The main service is [ProviderService.ts][14], the adapter contract is [ProviderAdapter.ts][15], and the overview is in [provider-architecture.md][16]. + +#### Provider + +The backend agent runtime that actually performs work. See [ProviderService.ts][14], [ProviderAdapter.ts][15], and [CodexAdapter.ts][17]. + +#### Session + +The live provider-backed runtime attached to a thread. Session shape is in [the orchestration contracts][1], and lifecycle is managed in [ProviderService.ts][14]. + +#### Runtime mode + +The safety/access mode for a thread or session. In [the contracts][1], the main values are `approval-required` and `full-access`. See [runtime-modes.md][18]. + +#### Interaction mode + +The agent interaction style for a thread. In [the contracts][1], the main values are `default` and `plan`. See [runtime-modes.md][18]. + +#### Assistant delivery mode + +Controls how assistant text reaches the thread timeline. In [the contracts][1], `streaming` updates incrementally and `buffered` delivers a completed result. See [ProviderService.ts][14]. + +#### Snapshot + +A point-in-time view of state. The word is used in multiple layers, including orchestration, provider, and checkpointing. See [ProjectionSnapshotQuery.ts][10], [ProviderAdapter.ts][15], and [CheckpointStore.ts][19]. + +### Checkpointing + +Checkpointing captures workspace state over time so the app can diff turns and restore earlier points. The main pieces are [CheckpointStore.ts][19], [CheckpointDiffQuery.ts][20], and [CheckpointReactor.ts][6]. + +#### Checkpoint + +A saved snapshot of a thread workspace at a particular turn. In practice it is a hidden Git ref in [CheckpointStore.ts][19] plus a projected summary from [ProjectionCheckpoints.ts][21]. Capture and lifecycle work happen in [CheckpointReactor.ts][6]. + +#### Checkpoint ref + +The durable identifier for a filesystem checkpoint, stored as a Git ref. It is typed in [the contracts][1], constructed in [Utils.ts][22], and used by [CheckpointStore.ts][19]. + +#### Checkpoint baseline + +The starting checkpoint for diffing a thread timeline. This flow is surfaced through [RuntimeReceiptBus.ts][13], coordinated in [CheckpointReactor.ts][6], and supported by [Utils.ts][22]. + +#### Checkpoint diff + +The patch difference between two checkpoints. Query logic lives in [CheckpointDiffQuery.ts][20], diff parsing lives in [Diffs.ts][23], and finalization is coordinated by [CheckpointReactor.ts][6]. + +#### Turn diff + +The file patch and changed-file summary for one turn. It is usually computed in [CheckpointDiffQuery.ts][20], represented in [the contracts][1], and recorded into thread state by [projector.ts][4]. + +## Practical Shortcuts + +- If you see `requested`, think "intent recorded". +- If you see `completed`, think "result applied". +- If you see `receipt`, think "async milestone signal". +- If you see `checkpoint`, think "workspace snapshot for diff/restore". +- If you see `quiesced`, think "all relevant follow-up work has gone idle". + +## Related Docs + +- [architecture.md][24] +- [provider-architecture.md][16] +- [runtime-modes.md][18] +- [workspace-layout.md][2] + +[1]: ../packages/contracts/src/orchestration.ts +[2]: ./workspace-layout.md +[3]: ../apps/server/src/git/Layers/GitCore.ts +[4]: ../apps/server/src/orchestration/projector.ts +[5]: ../apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts +[6]: ../apps/server/src/orchestration/Layers/CheckpointReactor.ts +[7]: ../apps/server/src/orchestration/Layers/OrchestrationEngine.ts +[8]: ../apps/server/src/orchestration/decider.ts +[9]: ../apps/server/src/orchestration/commandInvariants.ts +[10]: ../apps/server/src/orchestration/Layers/ProjectionSnapshotQuery.ts +[11]: ../apps/server/src/orchestration/Layers/ProjectionPipeline.ts +[12]: ../apps/server/src/orchestration/Layers/ProviderCommandReactor.ts +[13]: ../apps/server/src/orchestration/Services/RuntimeReceiptBus.ts +[14]: ../apps/server/src/provider/Layers/ProviderService.ts +[15]: ../apps/server/src/provider/Services/ProviderAdapter.ts +[16]: ./provider-architecture.md +[17]: ../apps/server/src/provider/Layers/CodexAdapter.ts +[18]: ./runtime-modes.md +[19]: ../apps/server/src/checkpointing/Services/CheckpointStore.ts +[20]: ../apps/server/src/checkpointing/Services/CheckpointDiffQuery.ts +[21]: ../apps/server/src/persistence/Services/ProjectionCheckpoints.ts +[22]: ../apps/server/src/checkpointing/Utils.ts +[23]: ../apps/server/src/checkpointing/Diffs.ts +[24]: ./architecture.md