neuron/docs/runbooks/2026-08-12-m-interoception-reversal.md

M-INTEROCEPTION — flags, defaults, and reversal runbook

Branch engram-tiered-storage (worktree /tmp/engram-tiered-wt), on trunk f6a0777. Six faces, each its own commit. Every behavior-changing feature is behind an env flag default OFF = byte-identical to trunk (proven per face); the read-only builtins are purely additive. NOT pushed, NOT tagged. The live :8742 daemon, ~/.neuron/engram, and launchctl were never touched — all verification ran on copies with throwaway HOME + /tmp dirs.

The server binary was rebuilt from the byte-unchanged engram/dist/engram.c plus the modified runtime and links cleanly, so these changes integrate into the real server without regenerating dist. Two HTTP routes are deferred to cutover because regenerating dist from server.el drifts ~285 lines with no source change (the prebuilt elc is a Linux x86-64 binary; a locally-built elc is a different compiler revision). The C builtins behind those routes are complete and tested via pure-C harnesses.

Flags

Flag	Default	Face	Effect when set
ENGRAM_CONSOLIDATION	0 (off)	P1	Enables the two-threshold promotion layer (ISE connection edges + permanence marking).
ENGRAM_CONSOL_CONN_MIN	0.6	P1	ISE salience needed to form connection edges.
ENGRAM_CONSOL_PERM_MIN	0.9	P1	ACT-R base-level needed to mark a node durable.
ENGRAM_CONSOL_WM_TOPK	5	P1	Max wm_top nodes a strong ISE wires to.
ENGRAM_CHRONOCEPTION	0 (off)	P2	Enables field aging (engram_age_field) + reboot catch-up.
ENGRAM_CHRONO_TC	3600 (s)	P2	Field cooling time-constant for exp(-dt/TC).
(none)	—	P0, P3, P4, P5	Additive read-only builtins / observability; no flag.

With all flags unset the runtime is byte-identical to trunk except for P4, which adds five backward-compatible fields to /api/act-stats (pure observability).

Faces, commits, and how to disable / revert

Face	Commit	Disable (no revert)	Revert
P0 embeddings builtin engram_scan_nodes_emb_json	c20cb3b	n/a (additive, unused until route wired)	git revert c20cb3b
P1 two-threshold consolidation	5f6ce5c	leave ENGRAM_CONSOLIDATION unset	git revert 5f6ce5c
P2 chronoception field aging	0af39df	leave ENGRAM_CHRONOCEPTION unset	git revert 0af39df
P3 drift-sensor primitive engram_geo_displacement	816b258	n/a (pure fn, only called if wired)	git revert 816b258
P4 afferent counters in act-stats	65ca0a3	n/a (always on; observability only)	git revert 65ca0a3
P5 dream-recall builtin engram_dreams_json	77a4bc9	n/a (additive, unused until route wired)	git revert 77a4bc9

Reverts are independent and can be applied in any order (no cross-face code dependencies; each touches distinct functions).

Data-side reversibility

• P1 connection edges carry relation="hebbian-associate", metadata {"origin":"consolidated-from-ISE"}. Remove all with one query over that marker. They are also swept automatically with their ISE at the 48h prune unless the ISE was promoted to permanence.
• P1 permanence marks a node durable via the metadata marker consolidated-from-ISE. Demote by clearing the marker; the node then becomes prunable again. No struct/schema change — the marker rides in existing metadata and survives the store round-trip.
• P2 last-tick persists to a sidecar file chrono_last_tick in the data dir. Delete it to reset catch-up; it is written only when the flag is set.

Deferred to cutover (elc-drift blocker)

• GET /api/embeddings and GET /api/graph/dump → back onto engram_scan_nodes_emb_json (P0).
• GET /api/dreams?since= → back onto engram_dreams_json (P5).

Wire by hand-patching engram/dist/engram.c surgically (mirror an existing route like route_scan_nodes), leaving all other dist lines byte-identical, and editing server.el as source of truth. Do NOT full-regenerate dist.

Known follow-up (P3, honestly flagged)

The drift sensor primitive is complete and tested, but a live self-drift reading needs a persisted SelfAnchor baseline descriptor to compare "now" against, and no persisted self node / anchored self-neighborhood exists yet. A self was NOT fabricated. Capturing a durable SelfAnchor snapshot and wiring an ENGRAM_DRIFT_SENSOR live reading is the remaining work before P3 goes live.