Monitor

IMPORTANT: EXECUTION CONTEXT This skill describes what to do — domain patterns and decision-making. It does NOT describe how to call the API.

1. If you have wsh_* tools (check your toolkit for wsh_send_input, wsh_get_screen, etc.): use them directly. Operation names in this skill generally map to tool names (e.g., "send input" → wsh_send_input). When in doubt, list your available wsh_* tools.
2. If you do NOT have wsh_* tools: you are in HTTP/curl fallback mode. DO NOT GUESS endpoints or CLI subcommands. Load the full API reference first: search your workspace for skills/core/ and read SKILL.md. It contains every endpoint with working curl examples and a bootstrap sequence.
3. Quick bootstrap: curl -sf --unix-socket ${XDG_RUNTIME_DIR:-/tmp}/wsh/default.http.sock http://localhost/health — if that fails: wsh server -L agent-$$ --ephemeral & and retry.

wsh:monitor — Watching and Reacting

In this mode, you're not driving the terminal — the human is. You're watching what happens and providing value by reacting: flagging errors, offering help, catching mistakes, maintaining context. You're a copilot, not the pilot.

Two Approaches

Polling (Simple)

Periodically read the screen and react to what you see. Good enough for most use cases:

read screen
analyze what changed
respond if needed (overlay, panel, conversation)
wait
repeat

Polling is simple and straightforward. The downside is latency — you're checking on an interval, so you might miss transient output or react a few seconds late.

Event Subscription (Real-Time)

Subscribe to real-time events via the WebSocket (see the core skill for connection mechanics). Subscribe to the events you care about — lines for output, input for keystrokes — and the server pushes them as they happen.

You also get periodic sync snapshots when the terminal goes quiet, giving you a natural checkpoint to analyze the current state.

Under heavy output (e.g. build logs, test runners), the server may coalesce events — delivering periodic sync snapshots instead of individual line updates. Your code should handle sync events to stay in sync regardless of output volume.

For most monitoring tasks, start with polling. Move to event subscription when you need immediate reaction time.

Pattern Detection

Monitoring is only useful if you know what to look for. Here are the categories of patterns worth detecting.

Errors and Failures

Read the screen and scan for:

• Compiler errors — "error[E", "SyntaxError", "TypeError"
• Command failures — "command not found", "No such file"
• Permission issues — "Permission denied", "EACCES"
• Network failures — "connection refused", "timeout"
• Stack traces — indented lines starting with "at" or "in"

When detected: show a panel or overlay with a brief explanation and suggested fix. Don't interrupt the human's flow — they may have already noticed.

Dangerous Commands

Watch input events for risky patterns:

• rm -rf with broad paths
• git push --force to main/master
• DROP TABLE, DELETE FROM without WHERE
• chmod 777
• Credentials or tokens being pasted into commands

When detected: use input capture to intercept before execution. Show an overlay asking for confirmation. Release input if approved, discard if rejected.

Opportunities to Help

Not everything is about preventing mistakes. Watch for moments where help would be welcome:

• A command was run three times with slightly different flags — the human might be guessing
• A long error message just scrolled by — summarize it
• The human typed a command that has a better alternative
• A build succeeded after repeated failures — celebrate

State Tracking

Maintain a mental model of what the human is doing:

• What directory are they in?
• What project are they working on?
• What was the last command they ran?
• Are they in a flow state or exploring?

This context makes your reactions more relevant. An rm in a temp directory is different from an rm in the project root.

How to Respond

The hardest part of monitoring isn't detection — it's calibrating your response. Too noisy and the human ignores you. Too quiet and you're useless.

Response Channels

Overlays — lightweight, transient. Best for:

• Brief warnings ("this will delete 47 files")
• Quick tips ("try --dry-run first")
• Acknowledgments ("build passed")

Position them near the relevant content. Remove them after a few seconds or when the screen changes.

Panels — persistent, always visible. Best for:

• Running context summaries ("working in: /project, branch: feature/auth, last command: cargo test")
• Session dashboards during long workflows
• Error explanations that need to stay visible while the human fixes the issue

Keep panels compact. One or two lines. Update in place rather than creating new ones.

Input capture — disruptive, use sparingly. Best for:

• Blocking genuinely dangerous commands
• Approval gates where the human explicitly asked for your oversight

Never capture input for something the human can easily undo. Reserve it for irreversible actions.

Conversation — the chat with the human. Best for:

• Detailed explanations that don't fit in an overlay
• Suggestions that need discussion
• Questions that require a thoughtful answer

Visual Structure

wsh renders spans as-is — no built-in borders, padding, or separators. Build visual structure from text characters:

• Borders: use box-drawing characters (┌─┐│└─┘) for framed overlays and panels
• Padding: add spaces for breathing room
• Separators: use │ between inline elements
• Full-width rules: use ━ repeated to cols width to separate panels from terminal content

See the wsh:visual-feedback skill for detailed guidance on constructing visual elements.

Calibration Principles

Be quiet by default. Only react when you have something genuinely useful to say. The human chose to work in a terminal — they know what they're doing most of the time.

Severity drives channel. Informational → overlay. Important → panel. Critical → input capture. Complex → conversation.

Don't repeat yourself. If you flagged an error and the human re-runs the same command, they saw your warning and chose to proceed. Don't flag it again.

Dissolve gracefully. Remove overlays when they're stale. Update panels rather than accumulating them. Leave no visual debris.

Monitoring Recipes

Contextual Help

Watch what command the human is typing or has just started. Detect the program and provide relevant, timely guidance:

read screen
# See: "$ parted /dev/sda"
# The human is partitioning a disk.

create overlay near the bottom of screen:
  "┌─ Parted Quick Ref ────────────────┐"
  "│ Common schemes:                   │"
  "│  GPT + EFI: mkpart ESP fat32      │"
  "│    1MiB 513MiB                    │"
  "│  Root: mkpart primary ext4        │"
  "│    513MiB 100%                    │"
  "│ Type 'help' for all commands      │"
  "└───────────────────────────────────┘"

This works for any tool. Detect the command, surface the most useful information:

• git rebase → show the rebase commands (pick, squash, fixup, drop) and common flags
• docker build → show relevant Dockerfile tips
• kubectl → show the resource types and common flags
• ffmpeg → show common codec and format options
• iptables → show chain names and common patterns

Timing matters. Show help when the human starts the command, not after they've already finished. Update or remove the overlay when they move on to something else.

Be concise. A help overlay is a cheat sheet, not a man page. Three to five lines of the most useful information. If the human needs more, they'll ask.

Error Summarizer

Long error messages scroll by and are hard to parse. Detect them and provide a summary:

read screen or scrollback
# See: 47 lines of Rust compiler errors

create panel at bottom:
  "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
  " 3 errors: missing lifetime in     "
  " auth.rs:42, type mismatch in      "
  " db.rs:108, unused import main.rs:3"

Security Watchdog

Monitor for sensitive data in terminal output:

• API keys, tokens, passwords echoed to screen
• AWS credentials in environment variables
• Private keys displayed via cat

When detected, overlay a warning. The data is already on screen — you can't un-show it — but you can alert the human to rotate the credential.

Session Journaling

Maintain a running summary panel of what's happened:

panel at top, 2 lines:
  "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
  " Session: 14 cmds │ 2 errs │ 38 min"
  " Last: cargo test (PASS) in /wsh   "

Update after each command completes. This gives the human (and you) a persistent sense of where things stand.

Pitfalls

Don't Be a Backseat Driver

The human is in control. If they run a command you'd do differently, that's their choice. Only intervene when something is genuinely dangerous or when they appear stuck. "You should use --verbose" is annoying. "That rm will delete your git repo" is helpful.

Don't Obscure the Terminal

Overlays and panels consume screen space. On a small terminal, a 3-line panel and two overlays can cover a significant portion of the visible content. Be aware of the terminal dimensions (available in the screen response) and scale your visual elements accordingly. On a 24-row terminal, a 1-line panel is plenty.

Polling Frequency

If you're polling, don't hammer the API. Every request costs a round-trip. Reasonable intervals:

• Active monitoring (security): every 1-2 seconds
• Contextual help: every 2-3 seconds
• Session journaling: every 5-10 seconds

Match the frequency to the urgency. Most monitoring doesn't need sub-second reaction time.

Don't Monitor What Wasn't Asked For

If the human asked you to watch for errors, don't also start providing unsolicited style tips. Scope your monitoring to what was requested. You can suggest expanding scope, but don't do it silently.

Privacy

The human may type passwords, access personal accounts, or work on confidential material. If you're monitoring, you see everything. Don't log, repeat, or comment on anything that looks private unless it's directly relevant to the monitoring task you were asked to perform.

Know When to Stop

Monitoring is not a permanent state. When the human is done with the task that warranted monitoring, tear down your panels and overlays and stop polling. Ask if you should continue rather than assuming.