diff --git a/bin/gstack-telemetry-log b/bin/gstack-telemetry-log
index edcbdbab..d199dbc9 100755
--- a/bin/gstack-telemetry-log
+++ b/bin/gstack-telemetry-log
@@ -32,21 +32,30 @@ OUTCOME="unknown"
 USED_BROWSE="false"
 SESSION_ID=""
 ERROR_CLASS=""
+ERROR_MESSAGE=""
+FAILED_STEP=""
 EVENT_TYPE="skill_run"
+SOURCE=""
 
 while [ $# -gt 0 ]; do
   case "$1" in
-    --skill)       SKILL="$2"; shift 2 ;;
-    --duration)    DURATION="$2"; shift 2 ;;
-    --outcome)     OUTCOME="$2"; shift 2 ;;
-    --used-browse) USED_BROWSE="$2"; shift 2 ;;
-    --session-id)  SESSION_ID="$2"; shift 2 ;;
-    --error-class) ERROR_CLASS="$2"; shift 2 ;;
-    --event-type)  EVENT_TYPE="$2"; shift 2 ;;
+    --skill)         SKILL="$2"; shift 2 ;;
+    --duration)      DURATION="$2"; shift 2 ;;
+    --outcome)       OUTCOME="$2"; shift 2 ;;
+    --used-browse)   USED_BROWSE="$2"; shift 2 ;;
+    --session-id)    SESSION_ID="$2"; shift 2 ;;
+    --error-class)   ERROR_CLASS="$2"; shift 2 ;;
+    --error-message) ERROR_MESSAGE="$2"; shift 2 ;;
+    --failed-step)   FAILED_STEP="$2"; shift 2 ;;
+    --event-type)    EVENT_TYPE="$2"; shift 2 ;;
+    --source)        SOURCE="$2"; shift 2 ;;
     *) shift ;;
   esac
 done
 
+# Source: flag > env > default 'live'
+SOURCE="${SOURCE:-${GSTACK_TELEMETRY_SOURCE:-live}}"
+
 # ─── Read telemetry tier ─────────────────────────────────────
 TIER="$("$CONFIG_CMD" get telemetry 2>/dev/null || true)"
 TIER="${TIER:-off}"
@@ -135,6 +144,20 @@ mkdir -p "$ANALYTICS_DIR"
 ERR_FIELD="null"
 [ -n "$ERROR_CLASS" ] && ERR_FIELD="\"$ERROR_CLASS\""
 
+ERR_MSG_FIELD="null"
+[ -n "$ERROR_MESSAGE" ] && ERR_MSG_FIELD="\"$(echo "$ERROR_MESSAGE" | head -c 200 | sed 's/"/\\"/g')\""
+
+STEP_FIELD="null"
+[ -n "$FAILED_STEP" ] && STEP_FIELD="\"$(echo "$FAILED_STEP" | head -c 30)\""
+
+# Cap unreasonable durations
+if [ -n "$DURATION" ] && [ "$DURATION" -gt 86400 ] 2>/dev/null; then
+  DURATION=""  # null if > 24h
+fi
+if [ -n "$DURATION" ] && [ "$DURATION" -lt 0 ] 2>/dev/null; then
+  DURATION=""  # null if negative
+fi
+
 DUR_FIELD="null"
 [ -n "$DURATION" ] && DUR_FIELD="$DURATION"
 
@@ -144,10 +167,11 @@ INSTALL_FIELD="null"
 BROWSE_BOOL="false"
 [ "$USED_BROWSE" = "true" ] && BROWSE_BOOL="true"
 
-printf '{"v":1,"ts":"%s","event_type":"%s","skill":"%s","session_id":"%s","gstack_version":"%s","os":"%s","arch":"%s","duration_s":%s,"outcome":"%s","error_class":%s,"used_browse":%s,"sessions":%s,"installation_id":%s,"_repo_slug":"%s","_branch":"%s"}\n' \
+printf '{"v":1,"ts":"%s","event_type":"%s","skill":"%s","session_id":"%s","gstack_version":"%s","os":"%s","arch":"%s","duration_s":%s,"outcome":"%s","error_class":%s,"error_message":%s,"failed_step":%s,"used_browse":%s,"sessions":%s,"installation_id":%s,"source":"%s","_repo_slug":"%s","_branch":"%s"}\n' \
   "$TS" "$EVENT_TYPE" "$SKILL" "$SESSION_ID" "$GSTACK_VERSION" "$OS" "$ARCH" \
-  "$DUR_FIELD" "$OUTCOME" "$ERR_FIELD" "$BROWSE_BOOL" "${SESSIONS:-1}" \
-  "$INSTALL_FIELD" "$REPO_SLUG" "$BRANCH" >> "$JSONL_FILE" 2>/dev/null || true
+  "$DUR_FIELD" "$OUTCOME" "$ERR_FIELD" "$ERR_MSG_FIELD" "$STEP_FIELD" \
+  "$BROWSE_BOOL" "${SESSIONS:-1}" \
+  "$INSTALL_FIELD" "$SOURCE" "$REPO_SLUG" "$BRANCH" >> "$JSONL_FILE" 2>/dev/null || true
 
 # ─── Trigger sync if tier is not off ─────────────────────────
 SYNC_CMD="$GSTACK_DIR/bin/gstack-telemetry-sync"