dsh-sentinel

Condition-driven wakeup for DeepSeek Harness: the agent registers a watch, goes to sleep — even closes the session — and the sentinel wakes it when the condition happens. Every subscription and every fire is a user-visible session event, and the browser dock shows what is on duty.

How it works

The node half owns one server-lifetime runtime that folds a plugin-owned sidecar log ($DSH_HOME/sentinel.jsonl) into live subscriptions, probes every sensor on a shared 5s heartbeat, and delivers wakeups through the official followup channel — resuming a dormant session's agent first when needed. Subscriptions therefore survive process restarts, and conditions that become true while the server is down late-fire on the next probe.

Watching is a resident-process concern: probing and fire delivery only run while a long-running dsh process (typically dsh web) is up. Headless one-shot runs load the plugin and can create, list and cancel watches, but nothing probes after the process exits — those watches become active once a resident process starts.

One duty owner per $DSH_HOME: a lease file (sentinel.lease) makes the first process own probing and delivery; a second dsh process on the same home stays passive (tools work, writes persist to the shared sidecar) and takes over within one lease TTL of the owner dying. The owner re-reads the sidecar every heartbeat, so watches created on a passive instance are adopted automatically. Delivery is at-least-once: a fire logged but not delivered before a crash is requeued on the next boot from its delivered watermark.

The browser half is a dock card above the composer (the conversation.input.dock family) listing the session's active watches — sensor, target, live probe state, fire budget, next-probe countdown — plus recent fire history when expanded. It polls the read-only state route and renders nothing when the session has no watches.

Two surfaces make the server-global watch set visible. A sidebar branch grows under every session row that has active watches (sidebar.workspaces.sessionRow.branch, one shared poller for all rows) — collapsed it is a 👁 count, expanded it lists the session's watches and links to the dashboard. The dashboard is a standalone table of every watch across every session: session (active/dormant), sensor, target, pattern, fire budget, last probe state, next probe.

Sidebar branch	Global dashboard

Sensors

Kind	Engine	Fires on
file	path snapshot + inotify push	snapshot change (sub-second); accelerated by fs events
command	read-only shell line, probed on an interval	output/exit-code change
http	URL probed on an interval	status/body change
process	pgrep -f pattern, probed on an interval	match-set change
port	TCP connect to [host:]port, probed on an interval	reachability change (open/closed/timeout)
webhook	pure push	any POST to the returned hook URL

With pattern, probe kinds fire on the no-match→match edge of that regex and webhooks accept only matching payloads; without it, probe kinds fire on any change after the baseline.

Configuration

All deployment-tunable knobs live in the plugin's config schema (defaults in parentheses); override them on the bundle row in your profile's cordis.patch.yml:

- id: dsh-sentinel
  name: '@dsh-external/dsh-sentinel'
  config:
    heartbeatMs: 5000            # probe round interval
    probeConcurrency: 8          # in-flight probes per round
    maxSubscriptionsPerSession: 16
    maxPendingWakeups: 8         # queued wakeups per session before dropping oldest
    defaultIntervalSeconds: 30   # when a watch does not specify one (5–86400)
    defaultCooldownSeconds: 60

Invalid values fail plugin load with a schema error rather than misbehaving at runtime.

Tools

• sentinel_watch — register a watch: kind, target, optional pattern, interval (1–3600s, default 30), note (delivered verbatim with every wakeup), maxFires (default 1: one-shot), cooldown (default 60s), optional ttl.
• sentinel_list — active watches with live probe state.
• sentinel_cancel — cancel one watch by id.

Routes

• GET /plugins/dsh-sentinel/state?sessionId=… — read-only state for the dock and the sidebar branch (omit sessionId for every session).
• GET /plugins/dsh-sentinel/dashboard — the server-global watch table.
• POST /plugins/dsh-sentinel/hook?id=watch-N — webhook entry; put a curl into a CI job, git hook, or another machine's script to wake the agent.

Install

One line through the official bundle channel (build artifacts are committed, so the git-source install runs no build):

dsh plugin --profile web add "github:fuhefei/dsh-sentinel#main"

Alternatively, add the node half manually through a patch-list configuration over the shipped base:

# cordis.patch.yml
- insert:
    - id: dsh-sentinel
      name: '@dsh-external/dsh-sentinel'

The browser half ships in the same package (./client) and is injected by the Web UI's plugin loader.

Sidebar branch prerequisite

The dock and the dashboard work on a stock host. The sidebar branch needs the session-row extension holes, which the official tree does not declare yet; apply the bundled patch to your DSH source checkout and rebuild ui-workspace:

git apply /path/to/dsh-sentinel/patches/session-row-holes.patch

The patch declares sidebar.workspaces.sessionRow and sidebar.workspaces.sessionRow.branch as list holes (every registrant renders, in order) at root scope (sidebar rows render outside any session binding; the row passes its sessionId through owner props). dsh-subagent-tree ships a patch for the same hole names with different semantics (keyed/session); apply one or the other, not both.

better-sidebar integration (optional)

When dsh-better-sidebar is installed in the same profile, sentinel registers its global watch table as a sidebar tab (dsh-sentinel:watches, in the + menu) through better-sidebar's documented ctx.betterSidebar.registerTab extension surface: every watch server-wide with live probe state, fire budgets and recent fire history, fed by one shared poller. No configuration needed; without better-sidebar the registration is silently skipped and the dock / branch / dashboard keep working as before.

Develop

npm install
npm run build     # tsc -b + tsdown (lib/index.js, lib/client.js)
npm test          # vitest: domain fold/normalize, sensors, dashboard escaping, e2e wakeup flow

License

BSD 3-Clause. See LICENSE.