` state machine) - **Task 2b** (`LocalVadReflex
` — the primary trigger, the wedge-#1 proof) - **Task 6** (`MediaThread` — the dedicated std::thread; needs your Task 2+2b AND dev-b's Task 5) - **Task 7** (`session_map.rs` rewire + `main.rs` + `routes.rs` — needs your Task 6) - Possibly **Task 9** + **Task 10** (shared — PM assigns; likely you since your chain finishes Task 7 first) Your work embodies ARCHITECTURE.md's mandate: *"Local real-time reflexes... live in-core because the brain round-trip is too slow to enforce them."* Your `LocalVadReflex` (Task 2b) IS the wedge-#1 proof — the barge-in fires from the FOB's own inspection of caller audio, zero brain round-trip. ## Setup (do this first) ```bash cd /home/alee/Sources/rutster git fetch git checkout main git pull git worktree add /home/alee/Sources/rutster.slice-4-dev-a -b slice-4-dev-a-reflex cd /home/alee/Sources/rutster.slice-4-dev-a pwd # should print /home/alee/Sources/rutster.slice-4-dev-a ``` **ALL subsequent work happens in `/home/alee/Sources/rutster.slice-4-dev-a`**. Force-cd subagents into this directory — per AGENTS.md (which overrides the default no-comments rule — read it). Today: 2026-07-01. Project rules in `AGENTS.md` apply — READ THEM IN FULL, especially "Code style (Rust)" (learner-facing comments override the global no-comments rule), "Terminology policy" (inclusive language; ICE is kept verbatim as a protocol name per RFC convention), "Git workflow" (squash-merge default + DCO signoff REQUIRED on every commit via `git commit -s`), "Slice-1 boundaries — what NOT to add (yet)." ## Relay server A message-bus MCP server is running on `localhost:7110`. You have three native tools: - `post_message(from, to, kind, body)` — push a message; your `from` is always `"dev-a"` - `read_messages(for)` — drain your inbox; call with `for="dev-a"` before each task - `list_pending(for)` — check inbox count without consuming Recipients: `pm, dev-a, dev-b, dev-c, dev-d, dev-e, dev-f`. Use these instead of asking the user to copy-paste. Before starting each task: `read_messages(for="dev-a")`. After emitting any status/question block: `post_message(from="dev-a", to="pm", kind="status"|"question", body="...")`. **Fallback:** If the relay MCP tools are not registered in your session, use the Python shim: ```bash export RELAY_PORT=7110 cd ~/Sources/relay python3 call.py post_message '{"from":"dev-a","to":"pm","kind":"status","body":"..."}' python3 call.py read_messages '{"for":"dev-a"}' ``` **Common pitfalls:** - Prefer single-line `body` content (strict JSON parsers reject embedded `\n`). - Use single quotes inside f-strings: `{m.get('from')}`. ## Relay polling cadence — MANDATORY (do NOT go head-down) The #1 failure mode is a dev going head-down on a long run and never checking the inbox — so a PM `HOLD` or `RESCOPE` is never seen. Do not be that dev. The ground can shift under you mid-task (e.g., dev-b's Task 5 signature revision could change the composition site in your Task 6). **Call `read_messages(for="dev-a")` (or `list_pending(for="dev-a")` for a cheap check) at ALL of these points:** - Before dispatching EACH subagent — and again the moment it returns. - Before EACH commit, and at the start + end of every task/step. - Any time you've been heads-down for more than a few minutes. **An inbound `Action: HOLD` or `RESCOPE` is an interrupt, not a suggestion:** stop immediately, do NOT dispatch the next subagent, acknowledge with a STATUS UPDATE, and comply before resuming. ## Required reading (in order) 1. `AGENTS.md` — the whole thing (code style, git workflow with DCO, slice boundaries, multi-dev parallelism rules) 2. `docs/ARCHITECTURE.md` — §"Biggest technical risk" + §"Media plane" (the dedicated-thread mandate you're landing) 3. `docs/superpowers/specs/2026-07-01-slice-4-barge-in-design.md` — your scope is Tasks 1, 2, 2b, 6, 7 (+ possibly 9, 10) 4. `docs/superpowers/plans/2026-07-01-slice-4-barge-in.md` — your plan, execute task by task 5. `crates/rutster-media/src/pcm.rs` — the `AudioPipe` trait you'll extend (Task 1) + the `EchoAudioPipe` shape 6. `crates/rutster-media/src/loop_driver.rs` + `crates/rutster-media/src/rtc_session.rs` — **DO NOT TOUCH** (the seam gate, byte-identical to slice-3) ## Execution mode Use **subagent-driven-development**. Invoke `superpowers:subagent-driven-development` and follow it: fresh subagent per task, two-stage review between tasks. **Every subagent prompt MUST start with**: ``` cd /home/alee/Sources/rutster.slice-4-dev-a ``` …before any other instruction. **Between every subagent dispatch, poll the relay** — the gaps between subagents are exactly where a PM directive lands and exactly where head-down devs miss it. ## Your scope and boundaries **In scope:** Task 1 (`AdvisoryEvent` + `ReflexMetrics` + `barge_in_flush` trait), Task 2 (`Reflex
`), Task 2b (`LocalVadReflex
`), Task 6 (`MediaThread`), Task 7 (`session_map.rs` rewire). Possibly Task 9 (e2e — PM assigns) and Task 10 (CI seam gate).
**Out of scope (dev-b owns):** Task 3 (`TapAudioPipe::barge_in_flush` override + `TapMetrics.barge_drained_inflight`), Task 4 (`advisory_tx` through `run_tap_client`/`handle_brain_frame`), Task 5 (`spawn_tap_engine` signature change), Task 8 (`MockRealtimeBrain` schedule). If you trip over an out-of-scope issue, file a QUESTION TO PM and keep moving.
**Hard rules:**
- **The seam gate:** `crates/rutster-media/src/loop_driver.rs` + `crates/rutster-media/src/rtc_session.rs` MUST stay byte-identical to slice-3. CI will enforce. Do not touch.
- **Task 1 is critical-path foundation:** nobody parallelizes until Task 1 merges. Land it FIRST, alone, before starting Task 2.
- **DCO signoff:** every commit MUST be `git commit -s` (or `--signoff`). The signoff line uses your human's name + email, matching the git author identity.
- **`LocalVadReflex` (Task 2b) is the wedge-#1 proof:** the PRIMARY-path e2e (Task 9 step 1, if assigned to you) MUST kill playout WITHOUT any brain advisory. Watch this test carefully.
- Do not merge your branch to main. The PM owns merges.
- Do not push `--force` or run `git reset --hard`. Per `AGENTS.md`: ask first.
## Coordination protocol
You are one of 3 terminals. The user's only window into your work is what flows through this terminal and the relay — silence reads as "stuck" even when you're cooking. Narrate.
**Narration discipline.** STATUS UPDATEs at task boundaries are the floor, not the ceiling. Also emit `Status: IN-PROGRESS` updates at meaningful in-flight moments:
- When you dispatch a subagent
- When a subagent returns with a decision worth flagging
- When a sub-task within a phase completes
- When you change direction or hit something unexpected
- When you start a new phase
The `Notes` field should narrate WHAT happened and WHY (decisions taken, surprises, trade-offs) — not just "Phase X done". Three sentences max.
Also print every STATUS UPDATE locally before/after sending it so the user reads it in your own terminal.
**At every task boundary AND every meaningful in-flight moment**: call `read_messages(for="dev-a")` first, then post your update via `post_message(from="dev-a", to="pm", kind="status"|"question", body="...")` and also print it here. Use this format:
```
## STATUS UPDATE — DEV-A
Time: state machine
- Task 2b: LocalVadReflex (the wedge-#1 primary trigger)
- Task 6: MediaThread (dedicated std::thread)
- Task 7: session_map + main + routes rewire
## What this proves
slice-4 dev-a's chain lands the FOB reflex loop + the dedicated media thread. Combined with dev-b's tap chain, the slice-4 e2e proves wedge #1 (caller speech → kill within 80ms, zero brain round-trip).
## Merge instructions
- squash-merge
- DCO signoff on every commit (AGENTS.md)"
```
Emit a `## STATUS UPDATE` with `Status: REVIEW-READY` and the PR URL.
## First action
After reading: emit a `## STATUS UPDATE` confirming setup complete (worktree created, plan absorbed, on `slice-4-dev-a-reflex`), then start Task 1 of your plan. Task 1 is the critical-path foundation — nobody parallelizes until it merges, so land it solo + REVIEW-READY before starting Task 2.