feat(soul): write-through to the persistence owner — memories survive restart (#117)

The soul obeys half of its own ownership rule. soul.el:571-573 says "when
ENGRAM_URL is set the HTTP Engram owns persistence — the soul must NEVER write
to the local snapshot", and it doesn't. But nothing was ever built to hand the
soul's writes TO that owner: sync is pull-only (/api/sync -> engram_load_merge),
so every node created inside the soul lived in process RAM and was shed on
restart. Measured live 2026-08-07: soul node_count=102184, engram 79197.

SCOPE CORRECTION vs the earlier internal spec: engram provisional claim 17's
"pull-then-push" is a PEER-ENGRAM to PEER-ENGRAM protocol (claims 15-18 say so
explicitly). The soul is a CALLER of the database API, not a peer. Claim 17 is
NOT authority for a soul<->engram contract and is no longer cited as such. The
design here follows from the ownership rule alone.

Mechanism: a new Accessor, persist.el, is the single boundary. Writes stage a
delta to a filesystem spool and are pushed to the owner via POST /api/load-merge
— NOT POST /api/nodes, which mints a new server-side id (breaking dedup and
edges) and drops label/tier/tags/importance/confidence (verified in a sandbox:
a tier "Canonical" probe came back "Working"). load-merge preserves the id and
every field, dedups nodes by id and edges by (from,to,relation) so retries are
no-ops, and calls persist_canonical() so THE OWNER writes its own file — the
ownership rule is honoured rather than worked around.

Spool-and-drain rather than push-per-write: measured ~0.38s per load-merge at
live scale (79k nodes/176MB), and a chat turn writes 5-7 nodes. The spool is on
disk, not in process state, because the soul serves each connection on its own
pthread and a shared buffer would lose entries to a read-modify-write race. That
also buys crash recovery: writes orphaned by kill -9 are drained on next boot.

Honesty: api_persisted (the gate all 10 MCP write handlers pass through) and
mem_store now assert AT THE OWNER instead of reading back the soul's own RAM.
With the owner down a write returns {"ok":false,"error":"write_not_persisted"}
and the delta is queued — where main returns {"ok":true} for a write that dies.

Coverage: 35 node sites + 9 edge sites routed through the boundary. Deliberately
excluded, with reasons in persist.el: 4 InternalStateEvent sites (Will's own
telemetry carve-out), the boot counter and the persona (both already have
bespoke owner-side write-backs), and soul.el's 54 genesis identity edges
(file-mode only). engram_strengthen and engram_forget are NOT propagated —
load-merge cannot update or delete, and hard-deleting at the owner would fail
verify-soul-contract.sh section B.

Also fixed here:
- routes.el GET /api/graph/edges engram_save()'d straight over the owner's
  canonical snapshot.json — a read route, in a non-owner process, clobbering the
  canonical on every call. Same defect class Will removed from the engram in el
  dc39a61. Now exports to a scratch path. With this gone the soul writes nothing
  at all in HTTP mode.
- persist.el must clear the runtime's _tl_fs_read_len hint after every fs_read.
  In vendored runtime v1.0.0-20260501 that hint becomes the NEXT response's
  Content-Length, so reading a spool file mid-request made an 86-byte reply go
  out as 497 bytes with 411 bytes of adjacent heap trailing it. Caught and fixed
  at our boundary; the runtime class was fixed upstream in el 43636ae, which is
  not the pinned runtime here.

Rung: E2E-VERIFIED, discriminating. Same harness, same engram binary:
  write-through: LEG 1 PRESENT at owner, LEG 2 SURVIVED kill -9 + restart
  main:          LEG 1 ABSENT  at owner, LEG 2 LOST
verify-soul-contract.sh: GATE PASS on both builds (27/27 routes, immutability).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

awareness.el

@@ -889,10 +889,29 @@ fn awareness_run() -> Void {
             state_set("soul.last_beat_ts", int_to_str(now_ts))
             // Persist in-process Engram (sessions, memories, conversation nodes)
             // to local snapshot so they survive restarts.
+            // FILE MODE ONLY: "soul_snapshot_path" is set exclusively in the
+            // genesis+safe_to_seed branch of soul.el, and safe_to_seed is
+            // unconditionally false when ENGRAM_URL is set. In HTTP mode the
+            // owner persists; the soul must not (soul.el:571-573).
             let snap_path: String = state_get("soul_snapshot_path")
             if !str_eq(snap_path, "") {
                 mem_save(snap_path)
             }
+            // WRITE-THROUGH RETRY (neuron#117). The HTTP-mode counterpart of the
+            // save above: hand anything still spooled to the persistence owner.
+            //
+            // This is the retry arm of the whole design. Deltas that could not be
+            // pushed — owner down, owner restarting, transient refusal — stay on
+            // disk and are re-offered here every heartbeat until they land. It is
+            // also the catch-all for writes made by the awareness loop itself,
+            // which never passes through the HTTP handler's flush point.
+            //
+            // No-op with no HTTP call when the spool is empty or ENGRAM_URL is
+            // unset, so an idle soul in file mode pays nothing for this.
+            let wt_pushed: Int = wt_drain()
+            if wt_pushed < 0 {
+                ise_post("{\"event\":\"write_through_backlog\",\"ts\":" + int_to_str(now_ts) + "}")
+            }
         }
 
         // Curiosity scan: idle-gated AND wall-clock based. Only fires when the

chat.el

@@ -1162,7 +1162,7 @@ fn hist_trim_with_bell_guard(hist: String) -> String {
             + " | evicted_at:" + ts_str
             + " | message:" + safe_content
         let preserve_tags: String = "[\"bell-history\",\"bell:" + bell_level + "\",\"evicted\",\"affective\",\"BellEvent\"]"
-        let discard: String = engram_node_full(
+        let discard: String = wt_node(
             preserve_content,
             "BellEvent",
             "bell:" + bell_level + ":preserved",
@@ -1210,7 +1210,7 @@ fn conv_history_persist(session_id: String, hist: String) -> Void {
     if !str_contains(hist, "]") { return "" }
     let tags: String = "[\"conv-history\",\"persistent\"]"
     // FIX B: one label rule, shared with the agentic path. See conv_hist_label.
-    let node_id: String = engram_node_full(
+    let node_id: String = wt_node(
         hist, "Conversation", conv_hist_label(session_id),
         el_from_float(0.7), el_from_float(0.8), el_from_float(0.9),
         "Episodic", tags
@@ -3461,7 +3461,7 @@ fn handle_dharma_room_turn(body: String) -> String {
     // engram_node(content, "episodic", ...) which wrongly put a TIER into the node_type
     // slot — that's why nodes showed node_type="episodic". Use the full, correct contract.)
     let utterance_tags: String = "[\"soul-utterance\",\"episodic\"]"
-    let discard_id: String = engram_node_full(
+    let discard_id: String = wt_node(
         clean_response, "Conversation", "soul:utterance",
         el_from_float(0.6), el_from_float(0.6), el_from_float(0.8),
         "Episodic", utterance_tags
@@ -3552,7 +3552,7 @@ fn session_summary_write(summary_text: String) -> String {
         }
     }
     let tags: String = "[\"SessionSummary\",\"session-summary\",\"previous-session\",\"consolidate\"]"
-    let node_id: String = engram_node_full(
+    let node_id: String = wt_node(
         content, "SessionSummary", "session:summary",
         el_from_float(0.85), el_from_float(0.85), el_from_float(1.0),
         "Episodic", tags
@@ -3578,7 +3578,7 @@ fn session_summary_write_dated(summary_text: String, label: String) -> String {
     let ts_str: String = int_to_str(ts)
     let content: String = "[session-summary] " + trimmed + " | ts:" + ts_str
     let tags: String = "[\"SessionSummary\",\"session-summary\",\"previous-session\",\"consolidate\"]"
-    let node_id: String = engram_node_full(
+    let node_id: String = wt_node(
         content, "SessionSummary", label,
         el_from_float(0.9), el_from_float(0.8), el_from_float(1.0),
         "Episodic", tags
@@ -3654,7 +3654,7 @@ fn auto_persist(req: String, resp: String) -> Void {
         + ",\"bell\":\"" + bell_level + "\""
         + ",\"label\":\"chat:" + ts_str + "\"}"
 
-    let conv_node_id: String = engram_node_full(
+    let conv_node_id: String = wt_node(
         content,
         "Conversation",
         "chat:" + ts_str,
@@ -3692,7 +3692,7 @@ fn auto_persist(req: String, resp: String) -> Void {
         let bell_tags: String = "[\"safety\",\"bell\",\"bell:" + bell_level + "\",\"affective\",\"BellEvent\"]"
         let bell_ts_str: String = int_to_str(time_now())
         let bell_label: String = "bell:" + bell_level + ":" + bell_ts_str
-        let bell_node_id: String = engram_node_full(
+        let bell_node_id: String = wt_node(
             bell_content,
             "BellEvent",
             bell_label,
@@ -3751,7 +3751,7 @@ fn auto_persist(req: String, resp: String) -> Void {
         let pos_tags: String = "[\"joy\",\"positive\",\"joy:" + positive_level + "\",\"affective\",\"PositiveEvent\"]"
         let pos_ts_label: String = int_to_str(time_now())
         let pos_label: String = "joy:" + positive_level + ":" + pos_ts_label
-        let pos_node_id: String = engram_node_full(
+        let pos_node_id: String = wt_node(
             pos_content, "PositiveEvent", pos_label,
             pos_sal_a, pos_sal_b, pos_sal_c, "Episodic", pos_tags
         )

memory.el

@@ -1,9 +1,11 @@
+import "persist.el"
+
 fn tier_working() -> String { return "Working" }
 fn tier_episodic() -> String { return "Episodic" }
 fn tier_canonical() -> String { return "Canonical" }
 
 fn mem_store(content: String, label: String, tags: String) -> String {
-    let id: String = engram_node_full(
+    let id: String = wt_node(
         content,
         "Memory",
         label,
@@ -17,13 +19,23 @@ fn mem_store(content: String, label: String, tags: String) -> String {
         println("[memory] write rejected by engram (empty id): label=" + label)
         return ""
     }
-    // Read back to verify the node actually persisted — guards against silent write failures.
-    let readback: String = engram_get_node_json(id)
-    if str_eq(readback, "") || str_eq(readback, "{}") {
-        println("[memory] WRITE VERIFY FAILED: label=" + label + " id=" + id + " — node absent after write")
-        return ""
+    // wt_node has already read the node back locally and returns "" if it did
+    // not land, so the old duplicate read-back here is gone.
+    //
+    // HONESTY (neuron#117): the receipt now says WHERE the write is.
+    // The old unconditional "write verified" line asserted against the soul's
+    // own RAM — true in memory, false on disk — and printed ~115,000 times on
+    // Tim's machine while the canonical snapshot sat frozen for three days.
+    // wt_commit flushes the spool and then asks the OWNER. When it says false
+    // the node is real and recallable but not yet durable, and the log says so
+    // rather than claiming a save that did not happen. The id is still returned:
+    // the local write DID succeed, and the queued delta will be retried.
+    let durable: Bool = wt_commit(id)
+    if durable {
+        println("[memory] write persisted at owner: " + id + " label=" + label)
+    } else {
+        println("[memory] write IN MEMORY ONLY (queued for owner, not yet durable): " + id + " label=" + label)
     }
-    println("[memory] write verified: " + id + " ok")
     return id
 }
 
@@ -51,12 +63,12 @@ fn mem_strengthen(node_id: String) -> Void {
 // memory.el (imported first) so awareness.el and neuron-api.el can both call it.
 fn mem_tombstone(node_id: String) -> String {
     let tags: String = "[\"Tombstone\",\"status:deleted\"]"
-    let marker: String = engram_node_full(
+    let marker: String = wt_node(
         node_id, "Tombstone", "tombstone:" + node_id,
         el_from_float(0.01), el_from_float(0.01), el_from_float(1.0),
         "Episodic", tags)
     if !str_eq(marker, "") {
-        engram_connect(marker, node_id, el_from_float(1.0), "tombstones")
+        wt_edge(marker, node_id, el_from_float(1.0), "tombstones")
     }
     return marker
 }

neuron-api.el

@@ -195,15 +195,24 @@ fn api_compact_activated(raw: String, max_items: Int, snip: Int) -> String {
 }
 
 // api_persisted — read-back-after-write guard against hallucinated saves.
-// After a write builtin returns an id, confirm the node is actually queryable
-// via engram_get_node_json(id) (returns "" or "null" when missing). Returns
-// true only when the node is genuinely persisted.
+//
+// WIDENED FOR neuron#117. This function is the single gate every MCP write
+// handler passes through before it reports success (10 call sites), which makes
+// it the right place to close the honesty gap rather than editing ten receipts.
+//
+// It used to read back from engram_get_node_json — the SOUL'S OWN in-process
+// graph. In HTTP-engram mode that asserts the wrong thing: the soul is not the
+// persistence owner, so a node present in its RAM and absent from the owner read
+// as "persisted" and then vanished on the next restart. The guard was doing
+// exactly what its comment promised and still certifying writes that did not
+// survive. It now flushes the write-through spool and asks the OWNER.
+//
+// In file mode (no ENGRAM_URL) the soul IS the owner and wt_commit collapses to
+// the original local read-back — unchanged behaviour, which is what keeps this
+// reversible.
 fn api_persisted(id: String) -> Bool {
     if str_eq(id, "") { return false }
-    let node: String = engram_get_node_json(id)
-    // engram_get_node_json returns "{}" (empty object) when node is not found — not "" or "null".
-    // Check all three to guard against any runtime variation.
-    return !str_eq(node, "") && !str_eq(node, "null") && !str_eq(node, "{}")
+    return wt_commit(id)
 }
 
 // api_not_persisted — standard error for a write that did not read back.
@@ -342,7 +351,7 @@ fn handle_api_remember(body: String) -> String {
         let inner: String = str_slice(base_tags, 1, str_len(base_tags) - 1)
         "[" + inner + ",\"project:" + project + "\"]"
     }
-    let id: String = engram_node_full(content, "Memory", "memory:remembered",
+    let id: String = wt_node(content, "Memory", "memory:remembered",
         sal, sal, el_from_float(0.9),
         "Episodic", final_tags)
     if !api_persisted(id) { return api_not_persisted(id) }
@@ -369,7 +378,7 @@ fn handle_api_node_create(body: String) -> String {
             if str_eq(importance, "low") { 0.25 } else { 0.5 }
         }
     }
-    let id: String = engram_node_full(content, node_type, label,
+    let id: String = wt_node(content, node_type, label,
         sal, sal, el_from_float(0.9),
         tier, tags)
     if !api_persisted(id) { return api_not_persisted(id) }
@@ -422,11 +431,11 @@ fn handle_api_node_update(body: String) -> String {
     }
     let body_tags: String = json_get(body, "tags")
     let tags: String = if str_eq(body_tags, "") { "[\"" + node_type + "\"]" } else { body_tags }
-    let new_id: String = engram_node_full(content, node_type, label,
+    let new_id: String = wt_node(content, node_type, label,
         el_from_float(0.5), el_from_float(0.5), el_from_float(0.8),
         tier, tags)
     if !api_persisted(new_id) { return api_not_persisted(new_id) }
-    engram_connect(new_id, id, el_from_float(0.9), "supersedes")
+    wt_edge(new_id, id, el_from_float(0.9), "supersedes")
     return "{\"id\":\"" + new_id + "\",\"supersedes\":\"" + id + "\",\"ok\":true}"
 }
 
@@ -498,7 +507,7 @@ fn handle_api_capture_knowledge(body: String) -> String {
     let full: String = if str_eq(title, "") { content } else { title + ": " + content }
     let lbl: String = str_slice(title, 0, 80)
     let tags: String = "[\"Knowledge\",\"captured\"]"
-    let id: String = engram_node_full(full, "Knowledge", lbl,
+    let id: String = wt_node(full, "Knowledge", lbl,
         el_from_float(0.85), el_from_float(0.8), el_from_float(0.9),
         "Episodic", tags)
     if !api_persisted(id) { return api_not_persisted(id) }
@@ -513,12 +522,12 @@ fn handle_api_evolve_knowledge(body: String) -> String {
     if !str_eq(prior_id, "") && is_protected_node(prior_id) { return api_err_protected(prior_id) }
     let tags: String = "[\"Knowledge\",\"evolved\"]"
     // Empty label → engram_node_full derives content[:60] (LABEL FIX 2026-07-23).
-    let new_id: String = engram_node_full(content, "Knowledge", "",
+    let new_id: String = wt_node(content, "Knowledge", "",
         el_from_float(0.75), el_from_float(0.75), el_from_float(0.9),
         "Episodic", tags)
     if !api_persisted(new_id) { return api_not_persisted(new_id) }
     if !str_eq(prior_id, "") {
-        engram_connect(new_id, prior_id, el_from_float(0.9), "supersedes")
+        wt_edge(new_id, prior_id, el_from_float(0.9), "supersedes")
     }
     return "{\"id\":\"" + new_id + "\",\"supersedes\":\"" + prior_id + "\",\"ok\":true}"
 }
@@ -535,11 +544,11 @@ fn handle_api_promote_knowledge(body: String) -> String {
         "[\"Knowledge\",\"tier:canonical\",\"disposition:stable\"]"
     } else { tags_raw }
     // Empty label → engram_node_full derives content[:60] (LABEL FIX 2026-07-23).
-    let new_id: String = engram_node_full(content, "Knowledge", "",
+    let new_id: String = wt_node(content, "Knowledge", "",
         el_from_float(0.9), el_from_float(0.9), el_from_float(1.0),
         "Canonical", tags)
     if !api_persisted(new_id) { return api_not_persisted(new_id) }
-    engram_connect(new_id, prior_id, el_from_float(0.95), "supersedes")
+    wt_edge(new_id, prior_id, el_from_float(0.95), "supersedes")
     return "{\"ok\":true,\"new_id\":\"" + new_id + "\",\"supersedes\":\"" + prior_id + "\"}"
 }
 
@@ -562,7 +571,7 @@ fn handle_api_define_process(body: String) -> String {
     if str_eq(content, "") { return api_err("content is required") }
     let label: String = if str_eq(name, "") { "process:unnamed" } else { "process:" + name }
     let tags: String = "[\"Process\"]"
-    let id: String = engram_node_full(content, "Process", label,
+    let id: String = wt_node(content, "Process", label,
         el_from_float(0.8), el_from_float(0.8), el_from_float(0.9),
         "Canonical", tags)
     if !api_persisted(id) { return api_not_persisted(id) }
@@ -647,7 +656,7 @@ fn handle_api_tune_config(body: String) -> String {
     if str_eq(key, "") { return api_err("key is required") }
     let content: String = "config:" + key + "=" + value
     let tags: String = "[\"ConfigEntry\",\"config\"]"
-    let id: String = engram_node_full(content, "ConfigEntry", key,
+    let id: String = wt_node(content, "ConfigEntry", key,
         el_from_float(0.85), el_from_float(0.85), el_from_float(0.9),
         "Canonical", tags)
     if !api_persisted(id) { return api_not_persisted(id) }
@@ -694,7 +703,7 @@ fn handle_api_link_entities(body: String) -> String {
     if is_protected_node(to_id) { return api_err_protected(to_id) }
     let relation: String = json_get(body, "relation")
     let eff_relation: String = if str_eq(relation, "") { "associates" } else { relation }
-    engram_connect(from_id, to_id, el_from_float(0.5), eff_relation)
+    wt_edge(from_id, to_id, el_from_float(0.5), eff_relation)
     return "{\"ok\":true,\"from_id\":\"" + from_id + "\",\"to_id\":\"" + to_id + "\",\"relation\":\"" + eff_relation + "\"}"
 }
 
@@ -727,11 +736,11 @@ fn handle_api_evolve_memory(body: String) -> String {
         }
     }
     let tags: String = "[\"Memory\",\"evolved\"]"
-    let new_id: String = engram_node_full(content, "Memory", "memory:evolved",
+    let new_id: String = wt_node(content, "Memory", "memory:evolved",
         sal, sal, el_from_float(0.9),
         "Episodic", tags)
     if !str_eq(prior_id, "") && !str_eq(new_id, "") {
-        engram_connect(new_id, prior_id, el_from_float(0.9), "supersedes")
+        wt_edge(new_id, prior_id, el_from_float(0.9), "supersedes")
     }
     return "{\"id\":\"" + new_id + "\",\"supersedes\":\"" + prior_id + "\",\"ok\":true}"
 }
@@ -789,11 +798,11 @@ fn handle_api_cultivate(body: String) -> String {
         let content: String = json_get(body, "content")
         if str_eq(content, "") { return api_err("content is required") }
         let tags: String = "[\"Knowledge\",\"evolved\",\"cultivated\"]"
-        let new_id: String = engram_node_full(content, "Knowledge", "knowledge:cultivated",
+        let new_id: String = wt_node(content, "Knowledge", "knowledge:cultivated",
             el_from_float(0.75), el_from_float(0.75), el_from_float(0.9),
             "Episodic", tags)
         if !str_eq(prior_id, "") && !str_eq(new_id, "") {
-            engram_connect(new_id, prior_id, el_from_float(0.9), "supersedes")
+            wt_edge(new_id, prior_id, el_from_float(0.9), "supersedes")
         }
         return "{\"id\":\"" + new_id + "\",\"supersedes\":\"" + prior_id + "\",\"ok\":true,\"cultivated\":true}"
     }
@@ -809,11 +818,11 @@ fn handle_api_cultivate(body: String) -> String {
             }
         }
         let tags: String = "[\"Memory\",\"evolved\",\"cultivated\"]"
-        let new_id: String = engram_node_full(content, "Memory", "memory:cultivated",
+        let new_id: String = wt_node(content, "Memory", "memory:cultivated",
             sal, sal, el_from_float(0.9),
             "Episodic", tags)
         if !str_eq(prior_id, "") && !str_eq(new_id, "") {
-            engram_connect(new_id, prior_id, el_from_float(0.9), "supersedes")
+            wt_edge(new_id, prior_id, el_from_float(0.9), "supersedes")
         }
         return "{\"id\":\"" + new_id + "\",\"supersedes\":\"" + prior_id + "\",\"ok\":true,\"cultivated\":true}"
     }
@@ -833,7 +842,7 @@ fn handle_api_cultivate(body: String) -> String {
         if str_eq(to_id, "") { return api_err("to_id is required") }
         let relation: String = json_get(body, "relation")
         let eff_relation: String = if str_eq(relation, "") { "associates" } else { relation }
-        engram_connect(from_id, to_id, el_from_float(0.5), eff_relation)
+        wt_edge(from_id, to_id, el_from_float(0.5), eff_relation)
         return "{\"ok\":true,\"from_id\":\"" + from_id + "\",\"to_id\":\"" + to_id + "\",\"relation\":\"" + eff_relation + "\",\"cultivated\":true}"
     }
 
@@ -868,7 +877,7 @@ fn handle_api_consolidate(body: String) -> String {
     if !str_eq(summary, "") {
         let safe_summary: String = str_replace(summary, "\"", "'")
         let tags: String = "[\"SessionSummary\",\"consolidate\"]"
-        let summary_id: String = engram_node_full(
+        let summary_id: String = wt_node(
             "[session-summary] " + safe_summary,
             "SessionSummary", "session:summary",
             el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),

persist.el

@@ -0,0 +1,426 @@
+// persist.el — the soul→engram WRITE-THROUGH boundary (neuron#117).
+//
+// WHY THIS FILE EXISTS
+//   soul.el:571-573 states the ownership rule: "when ENGRAM_URL is set the HTTP
+//   Engram owns persistence — the soul must NEVER write to the local snapshot
+//   (not the persistence owner)." The soul obeys the NEGATIVE half. The POSITIVE
+//   half — how a write made inside the soul actually REACHES the owner — was
+//   never built. Sync is pull-only (awareness.el `/api/sync` -> engram_load_merge),
+//   so every node the soul creates lives in its process RAM and is shed on
+//   restart. Measured live 2026-08-07: soul node_count=102184, engram
+//   node_count=79197 — ~23k nodes existing nowhere but RAM.
+//
+// SCOPE NOTE ON THE PATENT (corrects an earlier internal reading)
+//   Engram provisional claims 15-18 describe a delta-sync protocol "with peer
+//   Engram instances"; claim 17's pull-then-push sequence is PEER-ENGRAM to
+//   PEER-ENGRAM. The soul is NOT a peer Engram — it is a CALLER of the database
+//   system API (cf. claim 27, "invoked explicitly by a caller of the database
+//   system API"). So claim 17 does not specify a soul↔engram contract and is not
+//   cited as authority here. This design is derived from the ownership rule
+//   alone: the owner owns the writes, therefore the soul must HAND writes to the
+//   owner and must never write the owner's file itself.
+//
+// THE MECHANISM, AND WHY NOT `POST /api/nodes`
+//   The obvious route is the one the persona/boot-counter write-backs already
+//   use, POST /api/nodes. It is the wrong instrument here, verified against the
+//   live engram binary in a sandbox:
+//     - it mints a NEW server-side id (engram_node), so the soul's id and the
+//       owner's id diverge — the next /api/sync pull re-imports the node as a
+//       DUPLICATE, and any edge referencing the soul's id never resolves;
+//     - it accepts only {content, node_type, salience} and drops label, tier,
+//       tags, importance, confidence, metadata. A probe posted with tier
+//       "Canonical" came back tier "Working", importance 0.5.
+//   POST /api/load-merge (Will's own route, el `dc39a61`) is the right one:
+//     - engram_load_merge PRESERVES the id and every field;
+//     - it dedups nodes by id and edges by (from_id,to_id,relation), so a
+//       re-submitted delta is a NO-OP — retry safety is free, and it is the same
+//       local-wins semantics the graph already uses;
+//     - it calls persist_canonical() — THE OWNER writes its own canonical file.
+//       The soul never touches it. The ownership rule is honoured in its
+//       strongest form rather than worked around;
+//     - it returns real counts {ok, nodes_added, edges_added, node_count},
+//       so a receipt can be a MEASUREMENT instead of a fixed success shape.
+//
+// SPOOL-AND-DRAIN, AND WHY IT IS NOT JUST A DIRECT POST
+//   Measured in a sandbox against a 79k-node / 176MB graph (live scale): one
+//   load-merge costs ~0.38s, essentially all of it the owner's persist_canonical.
+//   A chat turn writes 5-7 nodes; pushing each separately would add ~2.7s per
+//   turn. So writes are STAGED and pushed in one coalesced batch.
+//   The staging buffer is the FILESYSTEM, not process state, because the soul
+//   serves each HTTP connection on its own pthread (el_runtime http_serve_async)
+//   and a shared in-process buffer would lose entries to a read-modify-write
+//   race — silently, which is the one failure mode this file exists to end.
+//   One file per write, named with uuid_v4, is race-free by construction and
+//   buys a property a memory buffer cannot: writes that could not be pushed
+//   SURVIVE A SOUL CRASH and are drained on the next boot.
+//
+// WHAT IS DELIBERATELY NOT PUSHED
+//   - InternalStateEvent / heartbeat telemetry. Will's own carve-out, stated in
+//     engram server.el 8f8ccc9: "48h-pruned, loss-tolerant, ~2/min; snapshotting
+//     28MB per heartbeat is waste."
+//   NOTE (ours, flagged for Will): we do NOT additionally exclude Working-tier
+//   nodes. That exclusion exists in `fb0bb55` to stop the boot counter leaking
+//   through the /api/sync PULL; it is about sync backflow, not durability.
+//   Applying it here would exclude mem_store — which writes tier "Working" — and
+//   mem_store is the single most important durable write path in the soul. Boot
+//   seeding reads the canonical file wholesale, so a pushed Working-tier node
+//   does survive restart. This is the one classification call this file makes
+//   that Will has not ruled on.
+//
+// WHAT THIS BOUNDARY CANNOT EXPRESS (by construction, not by omission)
+//   - engram_strengthen (salience/activation drift): load-merge SKIPS ids that
+//     already exist, so it cannot update an existing node. There is no owner-side
+//     update/upsert route. Not pushable through any current route; left as a
+//     follow-up that needs a change in the engram repo.
+//   - engram_forget (hard delete): load-merge is additive and has no delete verb.
+//     Propagating deletes would mean DELETE /api/nodes/<id>, a HARD delete at the
+//     owner — which scripts/verify-soul-contract.sh section B explicitly fails the
+//     build for ("to delete is to supersede/tombstone, never hard-remove"). Local
+//     deletes therefore stay local; the TOMBSTONE NODE and its "tombstones" edge
+//     (mem_tombstone) are pushed, and that is the sanctioned representation of a
+//     deletion in this graph.
+
+// ── Configuration ─────────────────────────────────────────────────────────────
+
+// wt_engram_url — same resolution order as ise_post: env, then the state key
+// stashed at boot. NO hardcoded localhost fallback: unlike telemetry, inventing
+// a destination for durable data would risk pushing a user's memories at whatever
+// happens to be listening on 8742. Empty means "no HTTP owner" -> file mode.
+fn wt_engram_url() -> String {
+    let env_url: String = env("ENGRAM_URL")
+    if !str_eq(env_url, "") { return env_url }
+    return state_get("soul_engram_url")
+}
+
+fn wt_api_key() -> String {
+    let env_key: String = env("ENGRAM_API_KEY")
+    if !str_eq(env_key, "") { return env_key }
+    return state_get("soul_engram_api_key")
+}
+
+// wt_enabled — true only in HTTP-engram mode. In file mode the soul IS the
+// persistence owner and every path below is a no-op, so this whole feature is
+// inert for genesis/local deployments. That is also what makes it reversible.
+fn wt_enabled() -> Bool {
+    return !str_eq(wt_engram_url(), "")
+}
+
+// wt_spool_dir — where staged deltas live. MUST be readable by the engram
+// process: /api/load-merge takes a PATH and the owner opens it itself. Both
+// processes are same-host by construction (dev-stack LaunchAgents; the GKE
+// image starts engram and soul in one container per entrypoint.sh).
+fn wt_spool_dir() -> String {
+    let raw: String = env("SOUL_OUTBOX_DIR")
+    let dir: String = if str_eq(raw, "") { env("HOME") + "/.neuron/soul-outbox" } else { raw }
+    fs_mkdir(dir)
+    return dir
+}
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+// wt_esc — minimal JSON string escape. Deliberately local rather than reusing
+// chat.el's json_safe: persist.el is imported BY memory.el, which is imported by
+// chat.el, so depending on chat.el here would be an import cycle.
+fn wt_esc(s: String) -> String {
+    let s1: String = str_replace(s, "\\", "\\\\")
+    let s2: String = str_replace(s1, "\"", "\\\"")
+    let s3: String = str_replace(s2, "\n", "\\n")
+    let s4: String = str_replace(s3, "\r", "\\r")
+    let s5: String = str_replace(s4, "\t", "\\t")
+    return s5
+}
+
+// wt_durable_class — Will's telemetry carve-out, by node_type. See header.
+fn wt_durable_class(node_type: String) -> Bool {
+    if str_eq(node_type, "InternalStateEvent") { return false }
+    return true
+}
+
+// wt_inner — strip the surrounding brackets off a JSON array so several arrays
+// can be concatenated into one. Returns "" for "[]" / "" / anything too short.
+fn wt_inner(arr: String) -> String {
+    let n: Int = str_len(arr)
+    if n < 3 { return "" }
+    if !str_starts_with(arr, "[") { return "" }
+    return str_slice(arr, 1, n - 1)
+}
+
+// wt_read — fs_read, plus a MANDATORY reset of the runtime's binary-length hint.
+//
+// THIS IS NOT OPTIONAL AND MUST NOT BE "SIMPLIFIED" BACK TO A BARE fs_read.
+// The pinned runtime (vendor/el-runtime/v1.0.0-20260501) keeps a thread-local
+// `_tl_fs_read_len` that fs_read SETS to the file's byte count (so binary files
+// can be served with a correct Content-Length) and that http_send_response
+// CONSUMES as the Content-Length of the next reply. Nothing else clears it
+// except json_get_raw. So any fs_read during request handling that is not
+// followed by a json_get_raw makes the NEXT HTTP response advertise the FILE's
+// length instead of the body's — and the runtime then sends that many bytes,
+// appending whatever adjacent heap memory follows the reply.
+//
+// Caught here, measured: a /api/neuron/memory reply that should be 86 bytes went
+// out as 497, with 411 bytes of this module's own spool paths and log strings
+// trailing the JSON. The drain reads spool files mid-request, so this boundary
+// is exactly where the landmine gets stepped on.
+//
+// Upstream el fixed the class in `43636ae` ("pair fs_read length hint with its
+// buffer"); that runtime is NOT the one vendored here, and re-pinning the
+// runtime is deliberately out of scope for this change. Clearing the hint at
+// our own boundary fixes our exposure without touching the pinned C.
+// json_get_raw is used as the reset because it is the only builtin in this
+// runtime that zeroes the hint, and it does so before any early return.
+fn wt_clear_binlen() -> Void {
+    let discard: String = json_get_raw("{}", "_wt_reset")
+}
+
+fn wt_read(path: String) -> String {
+    let data: String = fs_read(path)
+    wt_clear_binlen()
+    return data
+}
+
+// wt_sweep — best-effort removal of the zero-byte husks left by truncation.
+// The runtime exposes no unlink builtin, so a drained delta is emptied rather
+// than deleted; this reclaims the directory entries.
+//
+// `-empty` is the safety property, not an optimisation: the command is
+// STRUCTURALLY INCAPABLE of removing a delta that still has content, so it can
+// never destroy a pending write even if it runs concurrently with a stage.
+// Only the directory path is interpolated (never a filename), and it is quoted.
+// The exit code is ignored — an un-swept husk costs one directory entry.
+fn wt_sweep(dir: String) -> Void {
+    if str_eq(dir, "") { return }
+    if str_contains(dir, "'") { return }
+    exec_command("find '" + dir + "' -maxdepth 1 -name 'wt*.json' -empty -delete 2>/dev/null")
+}
+
+// ── Staging ───────────────────────────────────────────────────────────────────
+
+// wt_stage — write ONE delta file. uuid_v4 in the name makes concurrent stagers
+// collision-free without any lock. Returns true if the delta is on disk.
+fn wt_stage(nodes_json: String, edges_json: String) -> Bool {
+    let dir: String = wt_spool_dir()
+    if str_eq(dir, "") { return false }
+    let payload: String = "{\"nodes\":" + nodes_json + ",\"edges\":" + edges_json + "}"
+    let path: String = dir + "/wt-" + uuid_v4() + ".json"
+    fs_write(path, payload)
+    // Read-back-verify the stage itself. A stage that did not land is a write we
+    // would otherwise believe was queued — exactly the hallucinated-save class.
+    if str_eq(wt_read(path), "") {
+        println("[persist] wt_stage: FAILED to write spool file " + path + " — delta not queued")
+        return false
+    }
+    return true
+}
+
+// ── The write boundary ────────────────────────────────────────────────────────
+
+// wt_node — create a node locally AND queue it for the persistence owner.
+// Same signature and same return contract as engram_node_full ("" on failure),
+// so converting a call site is a rename and nothing else.
+fn wt_node(content: String, node_type: String, label: String,
+           salience: Float, importance: Float, confidence: Float,
+           tier: String, tags: String) -> String {
+    let id: String = engram_node_full(content, node_type, label,
+                                      salience, importance, confidence,
+                                      tier, tags)
+    if str_eq(id, "") { return "" }
+    // engram_get_node_json emits the SAME record shape engram_save writes (minus
+    // the embedding vector, which the owner backfills lazily), so the read-back
+    // doubles as the delta payload — no second serialization to drift.
+    let rec: String = engram_get_node_json(id)
+    if str_eq(rec, "") || str_eq(rec, "{}") {
+        println("[persist] wt_node: local write did not read back, id=" + id + " label=" + label)
+        return ""
+    }
+    if wt_enabled() && wt_durable_class(node_type) {
+        wt_stage("[" + rec + "]", "[]")
+    }
+    return id
+}
+
+// wt_edge — create an edge locally AND queue it. Mirrors engram_connect.
+//
+// The edge id is freshly generated rather than read back: the runtime exposes no
+// "id of the edge I just created" accessor, and the owner dedups edges by
+// (from_id,to_id,relation), never by id — so the id is not load-bearing. The
+// consequence, stated plainly: the soul's copy and the owner's copy of the same
+// edge carry different edge ids. Nothing in either codebase looks an edge up by
+// id (neighbors traversal scans from_id/to_id), so this is cosmetic.
+fn wt_edge(from_id: String, to_id: String, weight: Float, relation: String) -> Void {
+    engram_connect(from_id, to_id, weight, relation)
+    if !wt_enabled() { return }
+    if str_eq(from_id, "") || str_eq(to_id, "") { return }
+    let ts: Int = time_now()
+    let rec: String = "{\"id\":\"" + uuid_v4() + "\""
+        + ",\"from_id\":\"" + wt_esc(from_id) + "\""
+        + ",\"to_id\":\"" + wt_esc(to_id) + "\""
+        + ",\"relation\":\"" + wt_esc(relation) + "\""
+        + ",\"metadata\":\"{}\""
+        + ",\"weight\":" + float_to_str(weight)
+        + ",\"confidence\":1"
+        + ",\"created_at\":" + int_to_str(ts)
+        + ",\"updated_at\":" + int_to_str(ts)
+        + ",\"last_fired\":0,\"inhibitory\":0,\"layer_id\":1}"
+    wt_stage("[]", "[" + rec + "]")
+}
+
+// ── The drain ─────────────────────────────────────────────────────────────────
+
+// wt_drain — coalesce every staged delta into ONE load-merge against the owner.
+//
+// Returns: nodes_added on success (>= 0), 0 when there was nothing to do, and
+// -1 when the push FAILED. -1 is load-bearing: on failure the spool files are
+// left untouched, so nothing is lost and the next drain retries them. A caller
+// must never read a non-negative return as "my particular node is durable" —
+// use wt_durable(id) for that.
+//
+// Concurrency: several threads may drain at once. Each builds its own batch file
+// (uuid-named), and overlapping batches are harmless because load-merge dedups.
+// Files are truncated ONLY after a confirmed ok:true, so a lost race costs a
+// redundant push, never a dropped write.
+fn wt_drain() -> Int {
+    if !wt_enabled() { return 0 }
+    let dir: String = wt_spool_dir()
+    if str_eq(dir, "") { return 0 }
+
+    // el_list_len/el_list_get, NOT json_stringify(fs_list(...)): fs_list builds
+    // a native list via el_list_append, and json_stringify does not serialize
+    // that type — it renders the raw pointer value. (Verified in isolation; the
+    // same latent defect is live in studio.el's /api/tools/file/list route,
+    // which returns e.g. {"entries":4386409744}. Noted, not fixed here.)
+    let listing = fs_list(dir)
+    let count: Int = el_list_len(listing)
+    if count == 0 { return 0 }
+
+    let nodes_acc: String = ""
+    let edges_acc: String = ""
+    let drained: String = ""
+    let found: Int = 0
+    let i: Int = 0
+    // No `continue` / `break`: elc lists them as keywords but not one line of
+    // the shipped soul uses either, so they are unexercised on this build path.
+    // Guard conditions are expressed as nested ifs instead, and every rebind is
+    // at the loop-body top level where `let x = ...` is assignment (the idiom
+    // memory.el's boot-counter loop relies on) — never inside a nested block,
+    // where it would shadow instead.
+    while i < count {
+        let name: String = el_list_get(listing, i)
+        // A delta is only usable when it ends with the closing "]}" that
+        // wt_stage writes last. fs_write is not atomic, so a file being written
+        // right now can be observed half-formed; requiring the terminator means
+        // it is picked up whole on the next drain instead of merged as garbage.
+        // An empty read means "already drained and truncated" — not an error.
+        let p: String = if str_starts_with(name, "wt-") { dir + "/" + name } else { "" }
+        let raw: String = if str_eq(p, "") { "" } else { wt_read(p) }
+        let usable: Bool = !str_eq(raw, "") && str_ends_with(raw, "]}")
+        let nj: String = if usable { wt_inner(json_get_raw(raw, "nodes")) } else { "" }
+        let ej: String = if usable { wt_inner(json_get_raw(raw, "edges")) } else { "" }
+        let nodes_acc = if str_eq(nj, "") { nodes_acc } else if str_eq(nodes_acc, "") { nj } else { nodes_acc + "," + nj }
+        let edges_acc = if str_eq(ej, "") { edges_acc } else if str_eq(edges_acc, "") { ej } else { edges_acc + "," + ej }
+        let drained = if !usable { drained } else if str_eq(drained, "") { p } else { drained + "\n" + p }
+        let found = if usable { found + 1 } else { found }
+        let i = i + 1
+    }
+
+    if found == 0 { return 0 }
+
+    let combined: String = "{\"nodes\":[" + nodes_acc + "],\"edges\":[" + edges_acc + "]}"
+    let batch: String = dir + "/wtb-" + uuid_v4() + ".json"
+    fs_write(batch, combined)
+    if str_eq(wt_read(batch), "") {
+        println("[persist] wt_drain: could not write batch file " + batch + " — " + int_to_str(found) + " deltas stay queued")
+        return -1
+    }
+
+    let url: String = wt_engram_url()
+    let key: String = wt_api_key()
+    let body: String = "{\"path\":\"" + wt_esc(batch) + "\",\"_auth\":\"" + wt_esc(key) + "\"}"
+    let resp: String = http_post_json(url + "/api/load-merge", body)
+
+    // The batch file is pure scratch — the retry is rebuilt from the SPOOL, not
+    // from it. Truncate it unconditionally, before branching on the outcome, so
+    // a persistently unreachable owner cannot accumulate one husk per attempt.
+    fs_write(batch, "")
+
+    // Distinguish the two failures rather than collapsing them: "cannot reach
+    // the owner" and "the owner refused this delta" need different human
+    // responses, and a log line that says the wrong one costs a debugging hour.
+    // curl surfaces transport errors as a JSON body, so an empty response is not
+    // the only unreachable signal.
+    // (str_contains rather than a strict parse on purpose — the engram's HTTP
+    //  responses have been observed carrying trailing bytes past the JSON.)
+    let unreachable: Bool = str_eq(resp, "")
+        || str_contains(resp, "Couldn't connect")
+        || str_contains(resp, "Failed to connect")
+        || str_contains(resp, "Could not resolve")
+        || str_contains(resp, "timed out")
+    if unreachable {
+        wt_sweep(dir)
+        println("[persist] wt_drain: owner UNREACHABLE at " + url + " — " + int_to_str(found)
+            + " deltas stay queued in " + dir + " (will retry): " + resp)
+        return -1
+    }
+    if !str_contains(resp, "\"ok\":true") {
+        wt_sweep(dir)
+        println("[persist] wt_drain: owner REJECTED the delta — " + int_to_str(found)
+            + " stay queued in " + dir + ": " + resp)
+        return -1
+    }
+
+    let added: Int = json_get_int(resp, "nodes_added")
+    let added_e: Int = json_get_int(resp, "edges_added")
+
+    // Confirmed. Truncate the drained spool files so they are not re-pushed.
+    // Truncation (not deletion) because the runtime exposes no unlink builtin;
+    // an emptied file is inert to the loop above. The zero-byte husks are then
+    // swept below.
+    let paths = str_split(drained, "\n")
+    let pn: Int = el_list_len(paths)
+    let k: Int = 0
+    while k < pn {
+        let one: String = el_list_get(paths, k)
+        if !str_eq(one, "") { fs_write(one, "") }
+        let k = k + 1
+    }
+    wt_sweep(dir)
+
+    println("[persist] wt_drain: pushed " + int_to_str(found) + " deltas -> owner added "
+        + int_to_str(added) + " nodes, " + int_to_str(added_e) + " edges")
+    return added
+}
+
+// wt_durable — is this id present AT THE OWNER? The only honest answer to
+// "did my write persist" in HTTP mode.
+//
+// In file mode the soul IS the owner, so the local read-back is the owner-side
+// read-back and this collapses to the pre-existing check.
+//
+// nodes_added from wt_drain is NOT a substitute: a concurrent drain may have
+// already pushed this node, making our own added count 0 while the node is
+// perfectly durable. Presence at the owner is the fact; counts are telemetry.
+fn wt_durable(id: String) -> Bool {
+    if str_eq(id, "") { return false }
+    if !wt_enabled() {
+        let local: String = engram_get_node_json(id)
+        return !str_eq(local, "") && !str_eq(local, "null") && !str_eq(local, "{}")
+    }
+    let url: String = wt_engram_url()
+    let resp: String = http_get(url + "/api/nodes/" + id)
+    if str_eq(resp, "") { return false }
+    if str_eq(resp, "{}") { return false }
+    return str_contains(resp, "\"id\"")
+}
+
+// wt_commit — flush, then assert at the owner. The receipt callers should use.
+// Deliberately NOT a fixed success shape: it can and does return false while the
+// local write is perfectly fine in RAM, which is the true state of affairs when
+// the owner is unreachable.
+fn wt_commit(id: String) -> Bool {
+    if str_eq(id, "") { return false }
+    if !wt_enabled() {
+        let local: String = engram_get_node_json(id)
+        return !str_eq(local, "") && !str_eq(local, "null") && !str_eq(local, "{}")
+    }
+    let pushed: Int = wt_drain()
+    return wt_durable(id)
+}

routes.el

@@ -186,7 +186,7 @@ fn route_imprint_contextual(body: String) -> String {
         return "{\"ok\":false,\"error\":\"empty body\"}"
     }
     let tags: String = "[\"imprint\",\"contextual\"]"
-    let id: String = engram_node_full(
+    let id: String = wt_node(
         body,
         "Entity",
         "imprint:contextual",
@@ -208,7 +208,7 @@ fn route_imprint_user(body: String) -> String {
         return "{\"ok\":false,\"error\":\"empty body\"}"
     }
     let tags: String = "[\"imprint\",\"user\"]"
-    let id: String = engram_node_full(
+    let id: String = wt_node(
         body,
         "Entity",
         "imprint:user",
@@ -239,7 +239,7 @@ fn route_synthesize(body: String) -> String {
     }
     let req: String = "synthesize " + parent_a + " " + parent_b
     let tags: String = "[\"soul-inbox-pending\",\"synthesis-request\"]"
-    engram_node_full(
+    wt_node(
         req,
         "Entity",
         "synthesis-request",
@@ -395,7 +395,28 @@ fn handle_connectors(method: String, clean: String, body: String) -> String {
     return "{\"ok\":false,\"error\":\"unknown connectors route\"}"
 }
 
+// handle_request — the soul's HTTP entry point.
+//
+// NOTE ON THE NAME (neuron#117): the el runtime resolves this handler by NAME
+// via dlsym(RTLD_DEFAULT, "handle_request") — that is why the Linux build must
+// link -rdynamic. So the dispatcher body moved to route_dispatch and the name
+// `handle_request` stays put as a thin wrapper. Do not rename it back.
+//
+// The wrapper exists to give the write-through boundary a guaranteed flush
+// point. route_dispatch returns from ~60 places; a per-branch flush would be
+// forgotten on the 61st. Draining here means EVERY request that staged a write
+// pushes it before the connection closes, whatever route produced it, including
+// routes added later that know nothing about persistence.
+//
+// wt_drain is a no-op (no HTTP, no cost) when nothing is staged and when the
+// soul is not in HTTP-engram mode, so this is free on read traffic.
 fn handle_request(method: String, path: String, body: String) -> String {
+    let resp: String = route_dispatch(method, path, body)
+    let flushed: Int = wt_drain()
+    return resp
+}
+
+fn route_dispatch(method: String, path: String, body: String) -> String {
     let clean: String = strip_query(path)
 
     // ACTIVITY STAMP (2026-07-30 self-review): every inbound HTTP request —
@@ -432,10 +453,27 @@ fn handle_request(method: String, path: String, body: String) -> String {
             return engram_scan_nodes_json(9999, 0)
         }
         if str_eq(clean, "/api/graph/edges") {
-            // TODO(reliability #8): engram_save races with awareness loop mem_save().
-            // Both now use atomic write-to-temp+rename (el_runtime.c). Serialised
-            // by engram_global_mu. Future: add engram_edges_json() builtin.
-            let snap_path: String = env("HOME") + "/.neuron/engram/snapshot.json"
+            // FIXED (neuron#117): this GET used to engram_save() straight over
+            // ~/.neuron/engram/snapshot.json — a READ route, in a process that is
+            // NOT the persistence owner, overwriting the owner's canonical file
+            // on every call. It broke soul.el:571-573 ("the soul must NEVER write
+            // to the local snapshot") and it is the same defect class Will removed
+            // from the engram itself in el `dc39a61` ("stop read routes clobbering
+            // canonical snapshot"), where route_scan_edges/route_sync were moved
+            // to scratch paths for exactly this reason. It was also the race the
+            // old TODO(reliability #8) admitted to.
+            //
+            // Export to a scratch path instead. Same response, no canonical write.
+            // The soul's own snapshot writes are otherwise already gated behind
+            // state key "soul_snapshot_path", which is set ONLY in the genesis
+            // file-mode branch (soul.el: is_genesis && safe_to_seed, and
+            // safe_to_seed is unconditionally false when ENGRAM_URL is set) — so
+            // after this change the soul writes nothing at all in HTTP mode.
+            // Future: add an engram_edges_json() builtin and drop the file round
+            // trip entirely.
+            let scratch_dir: String = env("TMPDIR")
+            let scratch_base: String = if str_eq(scratch_dir, "") { "/tmp" } else { scratch_dir }
+            let snap_path: String = scratch_base + "/soul-edges-export-" + state_get("soul_cgi_id") + ".json"
             engram_save(snap_path)
             let snap: String = fs_read(snap_path)
             let edges_raw: String = json_get_raw(snap, "edges")

safety.el

@@ -204,7 +204,7 @@ fn safety_log_bell(level: String, reason: String, input_summary: String) -> Stri
     // Emit a fallback println so the bell event leaves at least a log trace even
     // when engram is degraded. This does not replace engram persistence -- it is a
     // last-resort audit trail when the primary write cannot be confirmed.
-    let node_id: String = engram_node_full(
+    let node_id: String = wt_node(
         content,
         "BellEvent",
         "bell:" + level,

sessions.el

@@ -87,7 +87,7 @@ fn session_create(body: String) -> String {
     let folder: String = json_get(body, "folder")
     let content: String = session_make_content(id, title, ts, ts, folder)
     let tags: String = "[\"session\",\"session:meta\",\"Conversation\"]"
-    let node_id: String = engram_node_full(
+    let node_id: String = wt_node(
         content, "Conversation", "session:meta",
         el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),
         "Episodic", tags
@@ -358,7 +358,7 @@ fn session_update_patch(session_id: String, body: String) -> String {
     let created_int: Int = str_to_int(old_created)
     let new_content: String = session_make_content(session_id, eff_title, created_int, ts, eff_folder)
     let tags: String = "[\"session\",\"session:meta\",\"Conversation\"]"
-    let new_node_id: String = engram_node_full(
+    let new_node_id: String = wt_node(
         new_content, "Conversation", "session:meta",
         el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),
         "Episodic", tags
@@ -456,7 +456,7 @@ fn session_hist_save(session_id: String, hist: String) -> Void {
     // TODO(reliability #7): delete-then-insert is not atomic — concurrent saves for the
     // same session can produce orphan history nodes. State is primary truth; engram fallback.
     let tags: String = "[\"session\",\"session-history\",\"Conversation\"]"
-    let discard: String = engram_node_full(
+    let discard: String = wt_node(
         hist, "Conversation", "session:messages:" + session_id,
         el_from_float(0.6), el_from_float(0.6), el_from_float(0.9),
         "Episodic", tags
@@ -488,7 +488,7 @@ fn session_hist_save(session_id: String, hist: String) -> Void {
                 + " | ts:" + int_to_str(ts_now)
             let summary_tags: String = "[\"session-emotional-summary\",\"affective\",\"bell:" + eff_level + "\",\"BellEvent\"]"
             let summary_sal: String = if str_eq(eff_level, "hard") { el_from_float(0.95) } else { el_from_float(0.85) }
-            let sum_discard: String = engram_node_full(
+            let sum_discard: String = wt_node(
                 summary_content,
                 "BellEvent",
                 "session:emotional-summary",
@@ -529,7 +529,7 @@ fn session_hist_save(session_id: String, hist: String) -> Void {
             if !str_eq(ot_id, "") { engram_forget(ot_id) }
             let oti = oti + 1
         }
-        let discard_topic: String = engram_node_full(
+        let discard_topic: String = wt_node(
             topic_content, "Conversation", topic_label,
             el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),
             "Episodic", topic_tags
@@ -582,7 +582,7 @@ fn session_update_meta_timestamp(session_id: String) -> Void {
     let created_int: Int = str_to_int(old_created)
     let new_content: String = session_make_content(session_id, old_title, created_int, ts, old_folder)
     let tags: String = "[\"session\",\"session:meta\",\"Conversation\"]"
-    let new_id: String = engram_node_full(
+    let new_id: String = wt_node(
         new_content, "Conversation", "session:meta",
         el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),
         "Episodic", tags
@@ -629,7 +629,7 @@ fn session_auto_title(session_id: String, first_message: String) -> Void {
     let created_int: Int = str_to_int(old_created)
     let new_content: String = session_make_content(session_id, new_title, created_int, ts, old_folder)
     let tags: String = "[\"session\",\"session:meta\",\"Conversation\"]"
-    let new_id: String = engram_node_full(
+    let new_id: String = wt_node(
         new_content, "Conversation", "session:meta",
         el_from_float(0.7), el_from_float(0.7), el_from_float(0.9),
         "Episodic", tags

soul.el

@@ -657,6 +657,23 @@ if is_genesis && safe_to_seed {
     }
 }
 
+// CRASH RECOVERY (neuron#117). Deltas the previous process staged but could not
+// hand to the owner are still on disk — the spool is a filesystem queue, not a
+// memory buffer, precisely so that a soul that died mid-flight does not take its
+// unpushed writes with it. Drain them before serving, so recovered memories are
+// durable and recallable from the owner from the first request onward.
+//
+// Safe on a clean boot: an empty spool means no HTTP call at all. Safe in file
+// mode: wt_drain returns immediately when ENGRAM_URL is unset.
+let wt_recovered: Int = wt_drain()
+if wt_recovered > 0 {
+    println("[soul] write-through: recovered " + int_to_str(wt_recovered)
+        + " nodes from a previous process's spool -> persistence owner")
+}
+if wt_recovered < 0 {
+    println("[soul] write-through: spool present but the persistence owner is unreachable — queued, will retry on heartbeat")
+}
+
 println("[soul] serving on port " + int_to_str(port))
 http_serve_async(port, "handle_request")
 println("[soul] awareness loop starting")

stewardship.el

@@ -11,7 +11,7 @@ import "memory.el"
 fn steward_log_event(kind: String, detail: String) -> Void {
     let content: String = "STEWARD:" + kind + " | " + detail
     let tags: String = "[\"stewardship\",\"steward:" + kind + "\"]"
-    let discard: String = engram_node_full(
+    let discard: String = wt_node(
         content,
         "StewardshipEvent",
         "steward:" + kind,
@@ -221,7 +221,7 @@ fn steward_fingerprint_session(input: String, session_id: String) -> String {
         + " formality=" + fs_str
         + " time=" + tb_str
     let sample_tags: String = "[\"behavior\",\"BehaviorSample\",\"stewardship\"]"
-    let discard: String = engram_node_full(
+    let discard: String = wt_node(
         sample_content,
         "BehaviorSample",
         "behavior:" + session_id,