## Created Created by tickets.sh create. --- ## Decision # Investigation: Task state and Hook side-effect boundary ## Findings - Hook action types are already separated per hook point after Hook hardening. The next design should preserve that: flow-control actions stay event-specific rather than becoming one global `HookDecision`. - Hook inputs are still summary structs, not contexts with host-created handles. That is the missing abstraction for feature-owned behavior that needs durable host side effects. - `TaskStore` is still owned by `Pod`, and `TaskReminderState`/reminder emission is still owned by `PodInterceptor`. - The Task built-in feature module currently contributes only the four Task tools and receives `TaskStore` from Pod. This is an incomplete internal-module boundary: Task-specific state still remains on the Pod side. - `SystemItem::TaskReminder` is currently appended through `PodInterceptor::pending_history_appends()`, which is the correct durable history direction but the wrong ownership location for Task-specific logic. ## Decision Split follow-up into two steps: 1. Add Hook context host handles, especially a durable `SystemItem` append handle. Hook returns remain per-hook-point flow-control actions. No raw `Item` injection and no generic effect/event channel. 2. Move TaskStore and Task reminder logic into the Task feature module, implemented as Task-owned tools plus hooks that use the host-provided SystemItem append handle. This keeps Pod responsible for generic host surfaces and history authority, while Task owns Task-specific state and policy. --- ## Plan # Delegation intent: Hook context SystemItem append sink ## Intent Implement the first step in the Task state/reminder cleanup sequence: add event-specific Hook context support with a host-mediated durable `SystemItem` append handle, while keeping Hook return actions as per-hook-point flow-control actions. This is the prerequisite for moving TaskStore/reminder logic into the Task feature. Do not move TaskStore or Task reminders in this ticket. ## Worktree / branch - worktree: `/home/hare/Projects/yoi/.worktree/hook-context-system-item-sink` - branch: `work/hook-context-system-item-sink` ## Requirements - Evolve the public Pod Hook API so Hook handlers receive event-specific context values rather than only bare summary inputs where necessary. - Preserve the existing per-hook-point action/output types. - Do not collapse actions into one global `HookDecision`. - Add a host-created typed handle for durable model-visible `SystemItem` append. - Suggested naming: `SystemItemAppendHandle`, `SystemItemSink`, or equivalent. - Constructors/fields must stay host-private; feature/hook code can only use handles the host provides. - The handle must not expose raw `llm_worker::Item`, raw history writers, raw event senders, raw `Pod`, raw `Worker`, or `NotifyBuffer`. - The append path must use existing durable history semantics: - host-controlled pending append / commit path; - `LogEntry::SystemItem`; - `Event::SystemItem`; - model context visibility only after durable commit. - The initial approved system-item requests should be narrow. - Support what is needed for a future `TaskReminder` hook, and notification-like system items only if this falls out naturally from existing `SystemItem` machinery. - Do not introduce arbitrary `llm_worker::Item` append or generic plugin event channels. - Keep built-in internal modules distinct from external-plugin authority approval. - It is okay to add scaffolding so internal hooks can receive the handle by host policy. - Do not implement external-plugin approval or WASM imports in this ticket. - Preserve current observable behavior. - Current Task reminders should continue to be emitted by existing `PodInterceptor` logic until the follow-up ticket moves them. - Existing Hook tests and permission hook behavior must continue to pass. ## Non-goals - Moving `TaskStore` ownership into the Task feature. - Moving `TaskReminderState` or `PodInterceptor` reminder logic. - TUI UI/dialog work. - Generic event channel / arbitrary UI payloads. - External plugin loading or package approval. - Changing ToolRegistry / PreToolCall permission behavior. - Reintroducing raw `Item` injection, `ContinueWith(Vec)`, no-result tool skip, or arbitrary `ToolResult` construction. ## Suggested files - `crates/pod/src/hook.rs` - `crates/pod/src/ipc/interceptor.rs` - `crates/pod/src/pod.rs` - `crates/pod/src/controller.rs` - `crates/session-store/src/system_item.rs` or wherever `SystemItem` request/serialization is defined - existing Hook tests in `crates/pod/src/**` ## Validation Run at least: - focused Hook context / SystemItem sink tests added by this ticket - `cargo test -p pod hook --lib` - `cargo test -p pod --lib` - `cargo test -p llm-worker --lib` - `cargo check --workspace --all-targets` - `cargo fmt --check` - `./tickets.sh doctor` - `git diff --check` Run `nix build .#yoi` if feasible. ## Escalate if - Implementing the handle requires changing session/history commit semantics. - The only easy path is to expose raw `Item`, raw history writers, raw event senders, or `Pod`/`Worker` internals. - Hook action types would need to be merged into one generic return type. - Current Task reminder behavior would change before the Task ownership follow-up. ## Completion report Report: - worktree path / branch - commit hash - changed files - Hook context/action API changes - SystemItem append handle design and path to durable commit - tests added/updated - validation results - unresolved risks/follow-ups - whether ready for external review --- ## Review: approve # Review: hook-context-system-item-sink ## 1. Result: approve Approve. I found no blockers for merging `04a4a73 pod: add hook system item sink` against the stated prerequisite scope. ## 2. Summary of implementation The implementation changes the `PreLlmRequest` hook input from bare `PreRequestInfo` to `PreRequestContext`, while leaving hook return types event-specific and flow-control-only. `PreRequestContext` carries the existing request summary plus an optional `SystemItemAppendHandle`. `SystemItemAppendHandle` is host-constructed (`pub(crate) fn new`), has private storage, and exposes only `append_task_reminder(...)`, which queues a typed `SystemItem::TaskReminder`. `PodInterceptor::pre_llm_request` creates a per-request queue only when a log writer exists, passes the handle through the hook context, and after all pre-request hooks continue successfully drains the queue, commits each item through the existing `SystemItemCommitter` / `LogEntry::SystemItem` path, and returns the rendered history items via the internal `PreRequestAction::ContinueWith` lane. The existing Task reminder implementation remains in `PodInterceptor::pending_history_appends()` and Task ownership is not moved in this ticket. ## 3. Requirement-by-requirement assessment - **Hook return actions remain per-hook-point flow-control types:** Satisfied. `HookPromptAction`, `HookPreRequestAction`, `HookPreToolAction`, `HookPostToolAction`, and `HookTurnEndAction` remain distinct. `HookPreRequestAction` still exposes only `Continue`, `Cancel`, and `Yield`; it does not expose `ContinueWith(Vec)`. - **Public API avoids raw internals and generic effects:** Satisfied for the changed Hook surface. The new handle does not expose raw `llm_worker::Item`, history writers, event senders, `Pod`, `Worker`, `NotifyBuffer`, internal interceptor actions, no-result skip, arbitrary `ToolResult` construction, or a generic event/UI channel. Existing pre-tool denial still maps an error string to an internal synthetic result, not an arbitrary public `ToolResult`. - **`SystemItemAppendHandle` host-private construction and narrow approved surface:** Satisfied. The constructor and backing queue are crate-private/private, and public hook code can only request a task-reminder system item through `append_task_reminder`. - **Durable model-visible append path:** Satisfied within existing semantics. Hook-queued items are committed through the existing `SystemItemCommitter` path as `LogEntry::SystemItem`, which in production publishes through the segment log sink as `Event::SystemItem`; only then are corresponding model-visible history items returned to the worker through the internal interceptor action. - **Successful-continue-only injection:** Satisfied by code. `pre_llm_request` returns immediately on the first non-continue hook action before draining the local queue, so queued hook items are dropped on cancel/yield and are committed/injected only when all hooks continue. - **Task reminder behavior preserved:** Satisfied. `TaskStore`, `TaskReminderState`, `task_reminder_system_item`, `pending_history_appends`, and task-tool reset behavior remain in `PodInterceptor`; the follow-up ticket remains responsible for moving Task ownership into the Task feature. - **Existing permission/hook behavior remains conceptually valid:** Satisfied. Tool hook contexts remain bounded summaries; public pre-tool actions still provide only continue/deny/abort/pause, with no no-result skip or arbitrary tool result path. - **Tests:** Mostly satisfied. Added tests cover handle queueing of an approved task reminder, context handle absence, commit plus returned system message behavior, and no-log-writer behavior. Existing tests continue to cover public hook action restrictions and current task reminder lanes. The only test gap I noted is explicit append-then-cancel/yield no-leak coverage, but the implementation path is straightforward enough that I do not consider this a merge blocker. - **No broad refactor / no external-plugin approval implementation:** Satisfied. The diff is limited to `crates/pod/src/hook.rs`, `crates/pod/src/ipc/interceptor.rs`, and a small `PreRequestContext` type update in `crates/pod/src/pod.rs`. ## 4. Blockers None. ## 5. Non-blockers / follow-ups - Add an explicit regression test for a pre-request hook that appends through `SystemItemAppendHandle` followed by a later hook returning `Cancel` or `Yield`, asserting that no commit and no `ContinueWith` occur. The code already behaves this way, but the intended no-leak invariant is important enough to lock down. - Before any external plugin/user-script hook surface is enabled, add per-hook or per-feature authority policy for whether `PreRequestContext::system_items()` is present. This ticket intentionally avoids external-plugin approval, and current built-in/internal hook usage is acceptable. ## 6. Validation assessed or rerun Assessed: - Reviewed ticket, delegation intent, investigation note, authority-context decision, and dependent Task ownership follow-up. - Reviewed `git diff develop...HEAD`; changed files are limited to: - `crates/pod/src/hook.rs` - `crates/pod/src/ipc/interceptor.rs` - `crates/pod/src/pod.rs` - Inspected the relevant public hook API, handle construction/surface, interceptor commit path, and task reminder preservation tests. Rerun: - `cd /home/hare/Projects/yoi/.worktree/hook-context-system-item-sink && git diff --check develop...HEAD` — passed with no output. Not rerun: - I did not rerun `cargo test`, `cargo check`, or `nix build` from this external-reviewer turn because the requested validation allowance was read-only and those commands would write build artifacts. I did not find a coder validation report in the ticket thread. ## 7. Residual risk The remaining risk is in future authority granularity, not this prerequisite implementation: today the handle is present for pre-request hooks when a log writer exists, rather than being selected per installed feature/hook. That should be tightened before exposing hooks to untrusted external plugins. The existing `SystemItemCommitter` API also logs and drops commit failures rather than returning a result; this is pre-existing behavior shared by other SystemItem lanes, but it means disk-write failure handling is not made stronger by this ticket. --- ## Closed Added PreRequestContext and host-mediated SystemItemAppendHandle for pre-request hooks. Hook returns remain per-hook-point flow-control actions; the append handle has host-private construction and a narrow task-reminder request surface; queued system items commit through the existing LogEntry::SystemItem / Event::SystemItem path only on successful continue. Existing Task reminder ownership remains unchanged for the follow-up ticket. External review approved. Merge validation passed: cargo test -p pod hook --lib, cargo test -p pod --lib, cargo test -p llm-worker --lib, cargo fmt --check, cargo check --workspace --all-targets, ./tickets.sh doctor, git diff --check, nix build .#yoi, ./result/bin/yoi pod --help. ---