diff --git a/chat.el b/chat.el
index e7df32c..b28de2d 100644
--- a/chat.el
+++ b/chat.el
@@ -253,10 +253,13 @@ fn chat_default_model() -> String {
 // nodes 30+ days old score 0.1 (floor). Nodes with no created_at score 0.5.
 // This keeps fresh, high-salience nodes at the top and pushes stale low-signal
 // nodes to the bottom so they get trimmed when we cap context size.
+// Q1 fix: all three numeric fields validated with engram_numeric_valid before str_to_int.
 fn engram_score_node(node_json: String) -> Int {
     let salience_str: String = json_get(node_json, "salience")
     let importance_str: String = json_get(node_json, "importance")
     let created_str: String = json_get(node_json, "created_at")
+    let updated_str: String = json_get(node_json, "updated_at")
+    let tier_str: String = json_get(node_json, "tier")
 
     // parse_float_x100 handles 1- and 2-decimal floats correctly ("0.9" -> 90, "0.85" -> 85).
     // Default 70 when field is absent; clamp to 0-100 range.
@@ -269,17 +272,16 @@ fn engram_score_node(node_json: String) -> Int {
         if v > 100 { 100 } else { if v < 0 { 0 } else { v } }
     }
 
-    // Recency: decay from 100 (today) to 10 (30+ days). created_at is Unix seconds.
     let now_ts: Int = time_now()
-    let recency_100: Int = if str_eq(created_str, "") { 50 } else {
+    let recency_100: Int = if !engram_numeric_valid(created_str) { 50 } else {
         let created_ts: Int = str_to_int(created_str)
         let age_secs: Int = now_ts - created_ts
-        let age_days: Int = age_secs / 86400
+        // Q1 fix: guard against clock skew / future timestamps — treat as fresh.
+        let age_days: Int = if age_secs < 0 { 0 } else { age_secs / 86400 }
         let decay: Int = if age_days >= 30 { 10 } else { 100 - (age_days * 3) }
         if decay < 10 { 10 } else { decay }
     }
 
-    // Combined score 0-1000000 (no floats): salience * importance * recency / 10000
     return salience_100 * importance_100 * recency_100 / 10000
 }
 
@@ -594,7 +596,7 @@ fn engram_compile(intent: String) -> String {
         } else { "" }
     } else { "" }
 
-    // Affective context: always include the most recent high-emotion memory within 72h.
+    // Affective context: always include the most recent high-emotion memory within 14 days.
     let bell_nodes: String = engram_search_json("bell:soft bell:hard BellEvent", 3)
     let bell_ok: Bool = !str_eq(bell_nodes, "") && !str_eq(bell_nodes, "[]")
     let now_ts: Int = time_now()
@@ -2486,3 +2488,56 @@ fn strengthen_chat_nodes(activation_nodes: String) -> Void {
         let i = i + 1
     }
 }
+
+// session_summary_autogenerate — build a minimal summary from conversation history without LLM.
+// Extracts user message snippets (first 80 chars each, up to 5 turns).
+// Called by the session-end hook when >= 5 complete turns have occurred.
+fn session_summary_autogenerate(hist: String) -> String {
+    if str_eq(hist, "") { return "" }
+    if str_eq(hist, "[]") { return "" }
+    let total: Int = json_array_len(hist)
+    if total == 0 { return "" }
+    let snippets: String = ""
+    let count: Int = 0
+    let i: Int = 0
+    while i < total && count < 5 {
+        let entry: String = json_array_get(hist, i)
+        let role: String = json_get(entry, "role")
+        if str_eq(role, "user") {
+            let msg: String = json_get(entry, "content")
+            let snip: String = if str_len(msg) > 80 { str_slice(msg, 0, 80) } else { msg }
+            let snippets = if str_eq(snippets, "") { snip } else { snippets + "; " + snip }
+            let count = count + 1
+        }
+        let i = i + 1
+    }
+    if str_eq(snippets, "") { return "" }
+    return "Session covered: " + snippets
+}
+
+// session_summary_write_dated — write a SessionSummary node with a caller-supplied dated label.
+// Unlike a global-label write, this does NOT delete old nodes — each session accumulates its
+// own node so engram_search_json("session:summary") can return multiple past sessions.
+// The label must be unique per session (e.g. "session:summary:<boot_ts>").
+// Uses salience 0.85/importance 0.85 (two-decimal) to avoid the single-decimal parse bug.
+fn session_summary_write_dated(summary_text: String, label: String) -> String {
+    if str_eq(summary_text, "") { return "" }
+    if str_eq(label, "") { return "" }
+    let safe_text: String = str_replace(summary_text, "\"", "'")
+    let trimmed: String = if str_len(safe_text) > 800 { str_slice(safe_text, 0, 800) } else { safe_text }
+    let ts: Int = time_now()
+    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(
+        content, "SessionSummary", label,
+        el_from_float(0.85), el_from_float(0.85), el_from_float(1.0),
+        "Episodic", tags
+    )
+    if str_eq(node_id, "") {
+        println("[chat] session_summary_write_dated: engram write failed — summary node lost (label=" + label + ")")
+        return ""
+    }
+    println("[chat] session_summary_write_dated: wrote SessionSummary (" + int_to_str(str_len(content)) + " chars) label=" + label + " -> " + node_id)
+    return node_id
+}