AutopilotMonitor/docs/agent/overview.md

type, title, description, resource, tags, timestamp

type	title	description	resource	tags	timestamp
Component Overview	V2 Agent — Runtime Overview	How the V2 agent boots during Autopilot enrollment, which collectors it runs, how telemetry flows to the backend, and how it decides to stop.	/src/Agent/AutopilotMonitor.Agent.V2/Program.cs	agent runtime collectors telemetry	2026-07-11T00:00:00+02:00

V2 Agent — Runtime Overview

The agent is a .NET Framework 4.8 executable (AutopilotMonitor.Agent.exe) that runs as SYSTEM on Windows devices during Autopilot enrollment. It observes the enrollment (ESP phases, IME app installs, Hello, desktop arrival, …), streams telemetry to the backend, and decides locally — via the decision engine — when the enrollment is complete or failed. When it reaches a terminal decision it shows the optional summary dialog, uploads diagnostics, and removes itself.

Projects: src/Agent/AutopilotMonitor.Agent.V2 (exe) + AutopilotMonitor.Agent.V2.Core (library) + src/Shared/AutopilotMonitor.DecisionCore (portable decision engine).

Lifecycle

Install (bootstrap during OOBE)

AutopilotMonitor.Agent.exe --install is invoked by the Intune Platform Script (bootstrap) and never runs the monitoring runtime (src/Agent/AutopilotMonitor.Agent.V2/Program.InstallMode.cs):

1. Copy payload to %ProgramData%\AutopilotMonitor\Agent\.
2. Persist bootstrap-config.json (bootstrap token, tenant id) and await-enrollment.json.
3. Register the AutopilotMonitor-Agent scheduled task (BootTrigger, SYSTEM, ExecutionTimeLimit=PT0S, survives battery conditions).
4. Immediate runtime handoff: WMI Win32_Process.Create → schtasks /Run fallback → defer to BootTrigger on next reboot. --install exits 0 even if both immediate launches fail (fail-soft; the BootTrigger is the net).
5. Write HKLM\SOFTWARE\AutopilotMonitor\Deployed = UTC timestamp — the bootstrap re-entry lock read by the install script. Never consulted by the agent itself; intentionally preserved across cleanup.

Runtime start (each process start / boot)

Program.Main → RunAgent runs numbered phases (V1-parity exit codes 0–7):

1. Guards & bootstrap (AgentBootstrap.Run): classify previous exit (clean / exception_crash / hard_kill / reboot_kill via clean-exit.marker, crash logs, boot event 6009); ghost-restart guard (enrollment-complete.marker → cleanup + exit 0); absolute session-age emergency break; optional waits (--await-enrollment MDM cert poll, --tenant-id-wait registry wait); resolve TenantId from HKLM:\SOFTWARE\Microsoft\Enrollments; get-or-create SessionId.
2. Auth clients (mTLS with the Intune MDM device client certificate).
3. Remote config (GET /api/agent/config): live fetch → cached Config\remote-config.json → built-in defaults. Config-channel kill switch checked here, honoured only from a live fetch (cache strips all security-sensitive fields).
4. Telemetry clients, backend session registration.
5. AgentRuntimeHost.Run: builds the EnrollmentOrchestrator, starts collector hosts, decision pipeline and upload drain loop, then blocks until shutdown.

Stop triggers

• Terminal decision of the engine (Completed / Failed / WhiteGloveSealed) — the normal path.
• Max-lifetime watchdog: AgentMaxLifetimeMinutes (default 360) — hard cap per session.
• Backend kill switch (config channel at start; telemetry channel via upload responses → synthesized terminate_session action).
• Auth-failure threshold, self-update restart, Ctrl+C / ProcessExit.

Distinct from agent lifetime: CollectorIdleTimeoutMinutes (default 15) stops only the periodic collectors (Performance, AgentSelfMetrics) when nothing "real" happens; they restart on new activity.

Termination sequence

On terminal decision (EnrollmentTerminationHandler): stop collectors → build FinalStatus → write final-status.json + launch SummaryDialog (separate WPF exe in the user session, opt-in) → 2 s late-event grace → diagnostics ZIP upload → write enrollment-complete.marker → optional reboot → self-destruct cleanup (skipped for WhiteGlove Part 1, which instead writes the whiteglove.complete marker and leaves state for Part 2).

Collector model

Collectors are wrapped in collector hosts (ICollectorHost, built by DefaultComponentFactory.CreateCollectorHosts). Each host owns collector/tracker classes plus a signal adapter that translates raw callbacks into decision signals. Main hosts (gating in parentheses; several more are opt-in via remote config):

Host	Watches
EspAndHelloHost	ESP phases, Shell-Core events, provisioning status, Hello (always)
ImeLogHost	IME log tailer (CMTrace) + IME process watcher — app installs (always)
DesktopArrivalHost	real-user desktop arrival (always)
AadJoinHost	AAD join events + hybrid login pending (always)
DeviceInfoHost	one-shot hardware/OS/network inventory (always)
StallProbeHost	idle/stall probes (config)
WindowsUpdateWatcherHost / OsBuildChangeHost	WU during OOBE, build changes (config / always)
DeliveryOptimizationHost	DO counters for bandwidth estimate (config, dormant until installs run)
OfficeInstallDetectorHost, ConsoleBypassHost, ProvisioningPackageHost, NetworkChangeHost, RealmJoinHost, GatherRuleExecutorHost, …	feature-specific (mixed gating)

Event pipeline (single rail)

Everything a collector observes flows through one path — no collector emits telemetry directly:

Collector callback
  → SignalAdapter (dual emission: decision signal + InformationalEvent)
    → SignalIngress.Post()            (bounded queue 256, back-pressure blocks producer)
      → single worker thread:
          assign ordinals → SignalLog.Append (durable)   ← source of truth
          → DecisionEngine.Reduce → apply step/effects
          → telemetry projection (best-effort)
            → TelemetrySpool → batch (≤100) → gzip → POST /api/agent/telemetry

• Wire model: EnrollmentEvent (EventType from Constants.EventTypes, monotonic Sequence = canonical order, Phase, ImmediateUpload for lifecycle-critical items), wrapped in TelemetryItem (Kind = Event / Signal / DecisionTransition, monotonic TelemetryItemId as upload cursor).
• Auth per request: client-cert mTLS + hardware headers (X-Tenant-Id, X-Device-Manufacturer/-Model/-SerialNumber, X-Bootstrap-Token pre-MDM-cert, X-Agent-Version).
• Retry: 100/400/1600 ms for transient (408/429/5xx); 413 → split batch and halve batch size; unknown 4xx → items retained (cursor holds) unless the backend flags explicit poison row keys; offline → spool keeps everything, backend dedups on re-upload; DeviceBlocked pauses the drain until UnblockAt.

Decision integration

Adapters post DecisionSignals; the engine's terminal stage fires Terminated (off the worker thread) → termination sequence above. Engine effects (timeline events like enrollment_complete, deadline scheduling, classifier runs, snapshots) are executed by the EffectRunner — the reducer itself is pure. Details: decision engine; durability and replay: logs & persistence.

On-disk layout (%ProgramData%\AutopilotMonitor\)

Path	Contents
\	bootstrap-config.json, await-enrollment.json, clean-exit.marker, session-id persistence
\Agent\	deployed binaries
\State\	decision persistence (SignalLog, Journal, Snapshot), enrollment-complete.marker, final-status.json, self-update state, .quarantine/, .part1-<ts>/
\Spool\	telemetry spool (offline queue)
\Logs\	agent trace log (agent.log), crash-*.log, ime-pattern-matches.log
\Config\	remote-config.json cache
\Agent-Update\, \Updates\	self-update staging/download

Per-file details and the recovery flow: logs & persistence.