Show per-turn stat changes under each AI message

Each AI action now carries a compact world_changes summary (derived from its
stored snapshot), rendered as small chips beneath the message: numeric stats
show a signed delta (green up / red down), flags show on/off, milestones show
a check. Gives an at-a-glance "what changed" without opening Insights.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/models.py

@@ -197,6 +197,31 @@ class Action(Base):
 
     adventure: Mapped[Adventure] = relationship(back_populates="actions")
 
+    @property
+    def world_changes(self) -> list[dict]:
+        """Compact per-turn RPG state changes (Phase 12), derived from the
+        stored snapshot, for the inline summary under an AI message. Labels are
+        path-based (no schema needed): `npc.gwen.trust` -> "gwen trust"."""
+        cs = self.context_snapshot if isinstance(self.context_snapshot, dict) else None
+        ws = cs.get("world_state") if cs else None
+        if not isinstance(ws, dict):
+            return []
+        applied = (ws.get("report") or {}).get("applied") or []
+        out: list[dict] = []
+        for entry in applied:
+            parts = str(entry.get("path", "")).split(".")
+            section, name = parts[0], parts[-1]
+            if section == "flags":
+                out.append({"kind": "flag", "label": name, "on": bool(entry.get("new"))})
+            elif section == "milestones":
+                out.append({"kind": "milestone", "label": name})
+            else:
+                label = f"{parts[1]} {parts[2]}" if section == "npc" and len(parts) == 3 else name
+                old, new = entry.get("old"), entry.get("new")
+                delta = new - old if isinstance(old, (int, float)) and isinstance(new, (int, float)) else None
+                out.append({"kind": "stat", "label": label, "delta": delta, "value": new})
+        return out
+
 
 class Script(Base):
     __tablename__ = "scripts"

backend/app/schemas.py

@@ -131,6 +131,8 @@ class ActionOut(ORMModel):
     type: str
     text: str
     reasoning: str | None = None
+    # Phase 12: compact RPG state changes for this turn (from the model property).
+    world_changes: list[dict] = []
     created_at: datetime
 
 

backend/tests/test_worldstate_integration.py

@@ -140,6 +140,20 @@ def test_turn_applies_clamped_delta_and_strips_block(client):
     assert '"player.hp": -80' in snap["raw_output"]
 
 
+def test_action_world_changes_summary(client):
+    _play(client)
+    db = SessionLocal()
+    try:
+        changes = db.get(models.Adventure, client.adv_id).actions[-1].world_changes
+    finally:
+        db.close()
+    by_label = {c["label"]: c for c in changes}
+    assert by_label["hp"]["delta"] == -30           # clamped stat, signed delta
+    assert by_label["gwen trust"]["delta"] == 15     # npc.<id>.<stat> -> "id stat"
+    assert by_label["alarm"] == {"kind": "flag", "label": "alarm", "on": True}
+    assert by_label["win"]["kind"] == "milestone"
+
+
 def test_world_state_endpoint(client):
     _play(client)
     r = client.get(f"/api/adventures/{client.adv_id}/world-state")

frontend/src/index.css

@@ -799,6 +799,28 @@ button:disabled { opacity: 0.45; cursor: default; transform: none; box-shadow: n
 .se-band-l { flex: 1; padding: 3px 6px; font-size: 0.82rem; }
 .ws-report { list-style: none; margin: 4px 0 0; padding: 0; font-size: 0.82rem; }
 .ws-report li { padding: 2px 0; color: var(--text); }
+
+/* Inline per-turn change chips under an AI message */
+.turn-changes {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 6px;
+  margin-top: 8px;
+}
+.chg {
+  font-size: 0.74rem;
+  padding: 2px 8px;
+  border-radius: 10px;
+  border: 1px solid var(--border);
+  background: var(--bg-input);
+  color: var(--text-dim);
+  font-variant-numeric: tabular-nums;
+  white-space: nowrap;
+}
+.chg-up { color: var(--player, #4caf82); border-color: color-mix(in srgb, var(--player, #4caf82) 40%, var(--border)); }
+.chg-down { color: var(--danger, #e5484d); border-color: color-mix(in srgb, var(--danger, #e5484d) 40%, var(--border)); }
+.chg-flag { color: var(--accent-bright); }
+.chg-ms { color: var(--accent-bright); border-color: color-mix(in srgb, var(--accent-bright) 40%, var(--border)); }
 .ws-report code { color: var(--accent-bright); }
 .ws-delta { color: var(--player); font-variant-numeric: tabular-nums; }
 .ws-flag { color: var(--text-dim); font-style: italic; }

frontend/src/pages/Play.jsx

@@ -622,6 +622,28 @@ function WorldStateDrawer({ advId, refreshKey }) {
   )
 }
 
+// Compact chips shown under an AI message summarizing what state changed.
+function StateChangeChips({ changes }) {
+  if (!changes?.length) return null
+  const nice = (s) => String(s).replace(/_/g, ' ')
+  return (
+    <div className="turn-changes">
+      {changes.map((c, i) => {
+        if (c.kind === 'flag') {
+          return <span key={i} className="chg chg-flag">{nice(c.label)}: {c.on ? 'on' : 'off'}</span>
+        }
+        if (c.kind === 'milestone') {
+          return <span key={i} className="chg chg-ms">✓ {nice(c.label)}</span>
+        }
+        const d = c.delta
+        const dir = typeof d === 'number' ? (d > 0 ? 'up' : d < 0 ? 'down' : 'flat') : 'flat'
+        const txt = typeof d === 'number' ? (d > 0 ? `+${d}` : `${d}`) : `→ ${c.value}`
+        return <span key={i} className={`chg chg-stat chg-${dir}`}>{nice(c.label)} {txt}</span>
+      })}
+    </div>
+  )
+}
+
 // Per-turn RPG state change, shown when inspecting a past turn's snapshot.
 function WorldStateReport({ worldState }) {
   if (!worldState) return null
@@ -1021,6 +1043,7 @@ export default function Play() {
                 className={`action ${PLAYER_TYPES.includes(action.type) ? 'player' : ''}`}>
                 <ReasoningBlock text={action.reasoning} />
                 {renderEmphasis(action.text)}
+                {action.type === 'ai' && <StateChangeChips changes={action.world_changes} />}
                 {!busy && (
                   <span className="action-tools">
                     {action.type === 'ai' && (