# Architecture The codebase is split so the implementation reads through file boundaries and names, not through large explanatory docs. ## Design goals - thin pi-specific wiring - pure, testable state transitions - rendering separated from decision logic - a small stable tool contract ## Module map ### Tool surface - `src/index.ts` — extension entrypoint - `src/ask-tool.ts` — tool registration, non-interactive fallback, transcript rendering, ask payload capture - `src/answer-commands.ts` — `/answer`, `/answer:again`, and `/ask:replay` command wiring - `src/answer-extraction.ts` — configured extraction model selection, synthetic `ask_user` tool-call extraction, and tolerant text fallback - `src/ask-payload-store.ts` — branch-aware persisted ask payload lookup - `src/pending-ask.ts` — active-branch unresolved tool-call detection and recovery dismissal persistence - `src/resume-pending-ask.ts` — detached lifecycle wiring and recovered answer delivery - `src/notifications.ts` — best-effort ask notification payload rendering and channel execution - `src/remote-ask.ts` — package-prefixed local event contract, active-flow registry, and explicit remote submission validation - `src/schema.ts` — TypeBox schema - `src/types.ts` — shared types ### State - `src/state/normalize.ts` — normalize incoming questions - `src/state/answers.ts` — mutate and serialize answers - `src/state/selectors.ts` — read-only selectors - `src/state/transitions.ts` — navigation, selection, notes, input, submit, cancel - `src/state/result.ts` — convert UI state to `AskResult` - `src/state/view.ts` — view-mode helpers - `src/state.ts` — state barrel used by UI and tests ### Config - `src/config/defaults.ts` — canonical runtime defaults - `src/config/schema.ts` — persisted config schema and runtime type - `src/config/migrate.ts` — persisted-file validation boundary, including schema migration and context-aware keymap normalization/fallback - `src/config/migrations/` — ordered schema-version migration framework for persisted config shape changes - `src/config/store.ts` — non-destructive current/legacy config discovery, load, save, notice, and runtime subscription store ### UI - `src/ui/controller.ts` — connects key input, editor lifecycle, live config subscription, dirty-dismiss confirmation, and pure state transitions - `src/ui/input.ts` — raw input to commands using resolved context-aware config-backed keymaps - `src/ui/dismiss-guard.ts` — pure helpers for dirty-flow exit confirmation behavior - `src/ui/render.ts` and `src/ui/render-*.ts` — screen rendering, including config-backed footer/keymap hints - `src/ui/settings-list.ts` / `src/ui/show-settings.ts` — lightweight ask settings list rendering and launcher - `src/ui/constants.ts` and `src/ui/render-types.ts` — rendering constants/contracts ### Result formatting - `src/result-format.ts` — shared summary/result line formatting - `src/result.ts` — final result rendering - `src/text.ts` / `src/constants.ts` — shared display strings ### Tests - `tests/state.test.ts` — state transitions and serialization - `tests/input.test.ts` — editing/navigation key behavior - `tests/result.test.ts` — summaries and transcript output - `tests/render-*.test.ts` / `tests/text.test.ts` — rendering helpers ## Invariants worth preserving - submit is never blocked by unanswered questions - single-select answers serialize as arrays - when `behaviour.presentSingleAsMulti` is enabled, future single-select questions are handled with multi-select state semantics while result metadata preserves the requested `type` and adds `presentedType` - active-flow question type changes are per-question runtime overrides handled in state/controller logic; they do not mutate the stored source payload or global config - single-select free-form answers replace selected options for that question - multi-select free-form answers augment selected options instead of clearing them - preview questions keep their preview-pane behavior while also supporting the synthetic custom-answer option - deselected option notes stay in UI state - only selected option notes are emitted in the final result - editor lifecycle stays in the controller, not in the reducers - persisted ask settings are migrated to the current schema version in memory, validated, and normalized before use without rewriting the config file on load - config schema migrations preserve user-provided values and add new defaults only when fields are absent - replay payload lookup scans only the current session branch and revalidates payloads before use - interrupted-ask recovery selects only the newest unresolved `ask_user` call on the active branch, prefers its valid persisted payload, and validates original arguments as fallback - recovered forms open only for TUI `startup`, `resume`, and `fork` events; the flow stays detached from the lifecycle handler - recovered submit and cancel both persist dismissal before the same call can reopen; manual `/ask:replay` ignores that recovery marker - invalid persisted keymaps fall back to default keymaps for the current session without discarding valid behaviour, notification, or answer settings - invalid notification channels are skipped and fall back to the default bell channel if none are valid - ask settings behaviour and notification enabled changes attempt to persist immediately from the settings list; save failures revert the change and show an error; config reset is guarded by a short double-press confirmation - `presentSingleAsMulti` is applied at ask-flow creation; toggling it does not rewrite already-normalized questions in an open flow - `main.changeQuestionType` changes the active question type live (non-preview: `single <-> multi`; preview: `preview <-> multi`) and may require confirmation before destructive multi-to-single conversion - when the ask config file is missing, the first ask use attempts to write a default persisted config snapshot under `~/.pi/agent/extensions/`; if writing fails, built-in defaults are used for the session - legacy root config files are read as a fallback only when the current config file is absent; disk is left untouched - invalid config files are left untouched; defaults are loaded for the session with a notice - live config updates can affect an in-progress ask flow immediately - remote ask submissions must be explicit `answer` or `cancel` responses; pi-ask validates ids/values but never infers approve/deny semantics from labels or option values ## Documentation rule Docs should explain contracts, responsibilities, and invariants. Code and tests should explain the rest.