Follow

familiar.follow@2 is the Pattern that wakes the body, locks a subject, traces a path through physical space, and settles what happened. It may transition into speaking mode — mic and camera open only under separate capture authority, the Lich may speak through an admitted Avatar/Echo path — and return to following when the conversation ends.

Admission

Admission pins one exact FamiliarBody@2 revision, subject designation, path constraints, and stop conditions. A missing required body capability (camera for visual lock, GPS for outdoor navigation) refuses the mission before the body moves.

Subject designation

The body must know what to follow. The designation is explicit, attributable, and pinned at admission. "Follow whoever is nearby" is not an admissible designation.

A fallback chain is admissible: "lock BLE beacon, fall back to visual signature on AprilTag, fall back to color-blob on orange vest." Each fallback transition records a subject_lock_degraded event. When the chain is exhausted, the mission records subject_lost and executes signal-loss policy.

Subject designation never proves identity, consent, attention, or relationship. A visual lock on a face does not mean the person agreed to be followed.

Path-tracing loop

The body-local controller runs the fast safety and motion loop. Familiar owns the slower semantic mission steps, waypoint intent, observation references, and receipts:

1. Acquire — read sensor inputs, compute subject position relative to body, record lock quality
2. Plan — compute path to maintain target distance envelope, avoid known obstacles, respect terrain constraints and geofence
3. Move — issue waypoint to controller; controller handles motor actuation and local obstacle avoidance; Familiar records waypoint receipt
4. Observe — re-acquire subject, validate lock quality, record any obstacle or deviation event
5. Adjust — correct path if subject moved, lock degraded, or obstacle appeared
6. Check — evaluate stop conditions, budgets, speaking-mode triggers

acquire → plan → move → observe → adjust → check → acquire …

The local controller runs at its own pinned and measured rate; LychD promises no universal control frequency. Between semantic waypoint updates, the controller maintains or rejects the last admitted command and enforces local obstacle avoidance autonomously.

Distance, altitude, and speed envelopes

The follow envelope keeps the body near enough to observe without crowding or endangering the subject. The values below illustrate one candidate profile; they are not defaults or safety guidance, and admission must replace them with validated body- and jurisdiction-specific limits.

Envelope breaches record a deviation event. A sustained breach — subject sprinting beyond max speed, drone forced below altitude floor by terrain — may trigger a stop condition.

Obstacle avoidance

The body may encounter obstacles the subject passed but the body cannot. The avoidance mode is declared per obstacle class at admission.

The controller enforces obstacle avoidance at hardware level between waypoint updates. Familiar records the event and the controller's response; it does not micro-manage the avoidance maneuver.

Signal loss

The admitted control connection between the body's attachment and LychD may drop. On a remote Legion route this is Intercom between the Legionnaire and LychD; a local or mobile attachment names its equivalent bounded link. The body must decide what to do without a round-trip.

The signal-loss policy is pinned at mission admission and enforced autonomously by the admitted body controller. A Legionnaire carries that duty on a Legion-backed route; no Legion requirement is implied for another attachment. A late signal return after policy execution settles the mission with signal_lost; it does not silently resume as though nothing happened.

Speaking mode

The body transitions from following to conversational presence. The Lich speaks through the body's speaker; the body's camera and microphone feed the Lich's senses.

Activation

A trigger begins the speaking session. The trigger is declared at mission admission.

Active session

1. Body stabilizes — hover hold (drone), park (rover), stand (legged).
2. Disclosure indicators activate before capture — camera/microphone light and, where appropriate, an audible announcement.
3. A separately admitted camera epoch opens; Prism/Sight may return exact source-bound observations for Context or Avatar grounding.
4. A separately admitted Echo capture window opens; any transcript retains its audio source, timing, provider, language assumptions, and uncertainty.
5. An authorized Avatar voice profile may select presentation while Echo owns synthesis and speech playback chronology; the device reports the physical playback evidence.
6. Familiar records a bounded speaking-mode window referencing the exact Companion controls when present and the separately owned Prism/Echo epochs, transcript, disclosure, and delivery facts. It is an aggregate mission reference, not a second FamiliarSpeakingSession speech chronology.

Deactivation

Deactivation closes that bounded speaking-mode window, stops camera and mic streams, deactivates disclosure indicators, and returns the body to the follow loop. If the follow mission itself is complete, deactivation settles the mission.

Terminal settlement

Every follow mission ends with one attributed judgment. A partial mission names exactly what was completed and what stopped it.

Representative journey

1. Magus admits one FamiliarBody@2 — a 350 mm quadcopter with GPS, optical flow, forward RGB camera, downward rangefinder, mic, speaker. Safety envelope: max altitude 15 m, min altitude 1.5 m, geofence = property boundary, emergency stop = kill switch + autonomous low-battery land.
2. Magus designates subject: BLE beacon in pocket, visual fallback to color-blob on bright vest. Signal-loss policy: hover 10 s, then land-in-place.
3. Magus opens familiar.follow@2 mission: follow at 3 m distance, 3 m altitude, outdoor terrain, speaking mode on voice command "Hey Lich."
4. Drone lifts off, locks BLE beacon, begins path-tracing loop.
5. Drone follows Magus through garden — records waypoints, avoids tree branch (reroute event), re-acquires subject after brief visual occlusion (lock-degraded-then-reacquired event).
6. Magus stops at workbench, faces drone, says "Hey Lich, what do you think of these seedlings?"
7. The admitted voice-command event requests speaking mode. The drone stabilizes, activates its disclosure indicators, then opens bounded Prism/Sight and Echo capture windows. Their attributed observations and transcript make the seedlings and question available to the Invocation.
8. Lich responds through drone speaker: "The tomatoes are crowded — give them each a bigger pot. The basil is ready to harvest." The speaking-mode window closes with references to the exact Prism/Echo epochs, transcript, disclosure, and delivery facts.
9. Magus says "Thanks, resume follow." Speaking mode deactivates. Drone re-acquires beacon, resumes follow loop.
10. Battery reaches 25% floor. Drone records battery_low event, descends to land at current position, settles mission as partial with battery-depleted reason. Magus retrieves drone.

Return to Familiar for the full contract and boundaries.