# In-Flight Monitor — Count + Activity Spark

**Date:** 2026-08-14
**Status:** Approved (design)

## Summary

Enhance the In-Flight Monitor action so its key shows the **number of
in-flight requests** for the configured model plus a **count-trend spark**:
a tiny line/area chart of that count over the last ~60s, so activity is
visible even during a single long-running request.

## Layout (72×72 SVG, rendered via `renderInflight`)

- **Top:** model short name (small, white) — existing.
- **Center:** the status. When `ready`:
  - count > 0 → the **count number**, large/bold (e.g. `3`), on the red
    `ACTIVE` background, with the existing pulse.
  - count === 0 → `IDLE` on green — existing.
  - `loading` → `LOADING`, `stopped` → `OFF`, offline → `OFFLINE`,
    unconfigured → `NO MODEL`, unknown → `…` — all unchanged.
- **Bottom strip (~14px):** the count-trend spark — a small polyline + faint
  area fill of the model's in-flight count over the last 60 samples, in the
  state color. Flat at the baseline when idle; spikes when requests come and go.

## Data Flow

- The feed side is unchanged — `InflightTracker` already exposes exact
  per-model counts.
- Each key's per-key state (in `inflight-monitor.ts`, keyed by
  `ev.action.id`) gains:
  - `history: number[]` — a 60-sample ring buffer of the live count.
  - `sampler?: ReturnType<typeof setInterval>` — a 1s interval that pushes
    `runtime.tracker.count(modelId)` into `history` and re-renders.
    Started in `onWillAppear`, cleared in `onWillDisappear`.
- Live feed events (`add`/`remove`/`snapshot`) still re-render the big
  number immediately via the existing subscription; the spark refreshes at
  1Hz.
- `renderInflight` gains an optional `history?: number[]` field. Spark
  scale: yMax = `max(max(history), 1)` so a zero line sits at the baseline.

## Files

- `src/lib/render.ts` — `renderInflight` accepts `history` and draws the
  spark; center label shows the count when active.
- `src/actions/inflight-monitor.ts` — per-key `history` ring buffer +
  1s sampler.
- `tests/render.test.ts` — new/updated assertions for count rendering and
  the spark.

## Error Handling / Edge Cases

- Spark with <2 samples renders no line (like the GPU chart).
- Sampler cleared on `onWillDisappear` (no leaks); multi-key safety
  preserved (buffer + sampler live in the per-key map entry).
- History capped at 60 samples.

## Out of Scope

- No change to the GPU Graph action, the feed, or the tracker.
- No throughput-bar variant (count trend was chosen).