Interactive TUI

perf-sentinel ships an interactive terminal UI for exploring findings, span trees and cross-trace correlations. It exposes three views as a single drill-down: Analyze (the summary dashboard), Inspect (the multi-panel browser) and Explain (one trace's full-screen span tree). Whichever entry point you use, you move between the three views without leaving the TUI.

Entry points:

• perf-sentinel analyze --tui [--input <events.json>]: opens on the Analyze view.
• perf-sentinel inspect --input <events.json>: opens on the Inspect view, reads a raw events file or a pre-computed Report JSON.
• perf-sentinel explain --tui --trace-id <id> --input <events.json>: opens on the Explain view, focused on that trace.
• perf-sentinel query --daemon <URL> inspect: live mode, opens on Inspect, reads findings and traces from a running daemon over HTTP.

In live mode (0.5.24+), the TUI also lets the operator acknowledge and revoke findings interactively from the terminal.

This TUI is the developer's trace and finding browser. For deployment monitoring there is a separate live operator TUI, perf-sentinel query monitor (since 0.8.8): five tabs cycled with Tab, Advisor (the daemon's settings-advisor hints), Energy (the effective energy/carbon mix per service and per region), Trends (live braille charts of the energy/carbon per window and of the runtime gauges as a share of their configured caps), Scrapers (live health of the energy backends from /api/energy) and Config (the read-only daemon parameters with their defaults and a one-line explanation each), auto-refreshed from the daemon every --refresh seconds (default 5). When the daemon becomes unreachable, the last good snapshot stays on screen with a stale indicator. Read-only: no acknowledgments, no API key needed.

Views and drill-down

The three views form one drill-down. Enter descends, Esc ascends:

Analyze  --Enter-->  Inspect  --Enter-->  Explain
         <---Esc---           <---Esc---

• Analyze: the scrollable summary (GreenOps waste, top offenders, quality gate), the same content as analyze stdout. Enter descends to Inspect.
• Inspect: the multi-panel browser described below. Enter drills through the panels and, from Detail, opens Explain. Esc walks back toward Analyze.
• Explain: the selected trace's annotated span tree, full screen and scrollable. Esc returns to the Inspect Detail panel.

A tab bar at the top highlights the active view. Span trees need raw spans (inspect --input <events>.json or query inspect). A pre-computed Report carries none, so Explain shows a hint instead.

Layout

The screen splits into a 2-row layout:

┌─ Traces ──┬─ Findings ────────────────┬─ Correlations ────┐
│ trace-1   │ [1] N+1 SQL CRITICAL      │ svc-a -> svc-b    │
│ trace-2   │ [2] Redundant SQL WARNING │ ...               │
│ ...       │ [3] Slow HTTP INFO        │                   │
├───────────┴───────────────────────────┴───────────────────┤
│ Detail (full-width, span tree + finding metadata)         │
└───────────────────────────────────────────────────────────┘

The active panel border highlights cyan, the rest stays gray.

Keybindings

Navigation works with arrow keys throughout. In the Inspect view the vim keys h / j / k / l also apply, and j / k scroll the Analyze and Explain views.

m toggles mouse capture (opt-in, so native terminal selection and copy-paste stay available while it is off). With it on, drag the border between two panels to redistribute their space, hovering a border highlights it with a handle glyph since a terminal application cannot change the OS mouse pointer. r resets the layout to its defaults. Panel sizes are per-session and not persisted.

Enter drills down: from Analyze to Inspect, then through the Inspect panels (Traces, Findings, Detail), then from Detail to Explain. From the Correlations panel it jumps to the Detail of the correlation's sample trace. Esc reverses each step, ascending from the top Inspect panels back to Analyze.

a and u are no-op in batch mode (inspect --input): acknowledgment requires a running daemon to persist.

Acknowledgment workflow (live mode)

When launched via query inspect, the TUI fetches findings with ?include_acked=true so already-acknowledged findings appear in the list with an italic gray [acked by <user>] indicator at the end of the line.

a: create an acknowledgment

Pressing a on a selected finding opens a modal centered on the screen with three input fields:

Plus two buttons (Submit / Cancel).

Modal navigation:

On submit, the TUI posts to /api/findings/<sig>/ack and closes the modal on 201. On error (4xx/5xx), the modal stays open with the error message at the bottom (red text).

u: revoke an acknowledgment

Pressing u on an acknowledged finding opens a confirmation modal. Submit / Enter issues a DELETE /api/findings/<sig>/ack. Cancel / Esc closes without revoking.

Expires format

Mirrors the CLI ack helper (since 0.5.22):

• Empty: no expiration, ack persists until manually revoked
• 24h, 7d, 30m: relative duration parsed by humantime
• 2026-05-11T00:00:00Z: ISO8601 absolute datetime

Invalid input shows expires: <error> in the modal footer without sending the request.

Authentication

The TUI mirrors the CLI ack helper's auth resolution:

1. PERF_SENTINEL_DAEMON_API_KEY env var (priority 1)
2. --api-key-file <path> flag on query inspect (priority 2)

# env var
export PERF_SENTINEL_DAEMON_API_KEY=$(cat ~/.config/perf-sentinel/key)
perf-sentinel query --daemon http://localhost:4318 inspect

# file
perf-sentinel query --daemon http://localhost:4318 inspect \
  --api-key-file ~/.config/perf-sentinel/key

Both are equivalent. The file path supports O_NOFOLLOW symlink refusal on Unix and trims trailing newlines.

No interactive password prompt in the TUI. Raw mode and the alternate screen are incompatible with rpassword TTY input. If the daemon answers 401 without an env or file key, the modal shows "API key required: set PERF_SENTINEL_DAEMON_API_KEY or pass --api-key-file when launching query inspect." Quit, set the key, relaunch.

When the daemon has no [daemon.ack] api_key configured (default for loopback deployments), no key is needed and the modal just submits.

Caveats

Synchronous HTTP freezes the UI

run_loop is synchronous and the daemon ack write is performed via tokio::runtime::Handle::current().block_on(...) from inside the loop. The UI freezes for the duration of the request, typically 100-300 ms on localhost, longer over the network. Acceptable for a scope-minimal release. An async event loop refactor is a candidate followup if user feedback signals friction.

Findings list snapshot

The findings list is fetched once at boot. a/u refresh only the ack state via a second GET /api/findings?include_acked=true, the list of findings itself does not change in-session. To pick up newly ingested traces, quit and relaunch.

TOML acks visible, not modifiable

Findings acked in .perf-sentinel-acknowledgments.toml (CI ack) appear with the [acked by <user>] indicator and the source field set to toml. The TUI cannot promote a daemon ack to TOML or edit the TOML file. For permanent acks, edit the file via PR review per Ack workflow.

The live operator monitor

perf-sentinel query monitor (since 0.8.8) is the operator-side counterpart to the developer's Inspect browser above. It runs against a live daemon, polls it on a fixed cadence (--refresh seconds, default 5) and is read-only. Tab cycles the five tabs, j/k scroll, q quits. On the Trends tab, m toggles mouse mode to drag-resize the chart borders and r resets them, the same affordance as the Inspect browser. The data each tab surfaces (config hints, source provenance, per-region intensities) is categorical and high-cardinality, which is exactly what the bounded-label rule keeps off Prometheus /metrics.

• Advisor renders the daemon's settings-advisor hints (warning_details), color-coded by kind. A well-dimensioned daemon reports no hints; the capture below is an undersized one whose trace window is pinned near its cap.

• Energy shows the effective energy/carbon mix straight from the live green_summary: per service (effective source, measured share, energy, region) and per region (grid intensity, cold embedded vs hot real-time source).

• Trends plots the poll history as live braille charts: energy and carbon per scoring window on top, and below them the Headroom chart, each runtime gauge (active_traces, analysis_queue_depth, stored_findings) as a percentage of its configured cap with the settings advisor's 90% threshold drawn in. When the effective grid intensity is static, the two top curves track each other; they diverge when the intensity moves, either from the live Electricity Maps real-time feed or from a shifting regional mix (the capture below stages the latter). One point lands per refresh tick, up to 240 points (20 minutes at the default 5 s), and the history lives in the monitor only: restarting it starts a fresh window. The capacity fields need a 0.8.8 daemon; against an older one the Headroom panel degrades to a hint.

• Scrapers reads /api/energy for live backend health. Here cloud_energy is configured but its endpoint is unreachable, so its freshness age climbs while the unconfigured backends stay dashed.

• Config reads /api/config for the daemon's effective [daemon] settings, read-only. Each parameter shows its current value, the compiled-in default (computed locally), and a one-line explanation of what it does; values that differ from the default are flagged modified. Secrets are summarized server-side (TLS as configured/not, the ack API key as set/unset) and never shown in clear. Needs a 0.8.8+ daemon; older ones show a hint.

When the daemon becomes unreachable, the last good snapshot stays on screen with a [STALE] indicator instead of going blank.

Terminal theme

Both TUIs (this monitor and the Inspect browser) follow the terminal's own theme: they use the 16 named ANSI colors and never impose a background, so a light-themed terminal renders them on a light background and a dark one on dark. Secondary text (titles, hints, column headers) is drawn with the terminal's dim attribute rather than a fixed gray, so it stays legible on either background. There is no --theme flag: configure the colors in your terminal emulator.

See also

• Ack workflow for the relationship between TOML CI acks and daemon JSONL acks, and the full decision table.
• CLI reference for the perf-sentinel ack subcommand reference (CLI-side equivalent of a/u).
• HTML report for the browser-side ack flow via --daemon-url.
• Query API for the /api/energy endpoint the Scrapers tab reads, and the daemon's read-only HTTP surface.
• Configuration for the [daemon.ack] server-side config reference.