diff --git a/stacks/vor/.env.example b/stacks/vor/.env.example
index 3c0a1e0..3316b95 100644
--- a/stacks/vor/.env.example
+++ b/stacks/vor/.env.example
@@ -11,3 +11,17 @@ VOR_BIND=0.0.0.0
 # bind-mounted so they survive `docker compose up --force-recreate`.
 VOR_SESSIONS_DIR=/opt/docker/conf/vor/sessions
 VOR_RESPONSES_DIR=/opt/docker/conf/vor/responses
+
+# Worldtree integration — bearer token for the demo Saga instance.
+# Dev-tier Heimdall key, scoped `instantiate:saga`. Without this, the
+# /mockup/ surface falls back to an in-process MockWorldtree (canned
+# fixtures) — boot log shows `WT: in-process mock (...)` instead of
+# `WT: real Worldtree at ...`. The legacy / + /api/sessions endpoints
+# work either way. Issued by architect; rotatable.
+VOR_WORLDTREE_KEY=
+
+# Worldtree instance — defaults to the v1 demo Saga.
+VOR_WORLDTREE_BASE=http://10.250.50.152:8080
+
+# Worldtree model — v1 default.
+VOR_WORLDTREE_MODEL=qwen3.6-35-a3b-heretic
diff --git a/stacks/vor/compose.yaml b/stacks/vor/compose.yaml
index 126a8d6..c3fae09 100644
--- a/stacks/vor/compose.yaml
+++ b/stacks/vor/compose.yaml
@@ -24,6 +24,12 @@ services:
     environment:
       # Container always listens on 8765 internally; host port is the only knob.
       - PYTHONUNBUFFERED=1
+      # Worldtree integration for the /mockup/ surface. Empty key falls
+      # back to the in-process MockWorldtree (canned fixtures); a real
+      # key routes /mockup/ LLM calls at the Worldtree instance below.
+      - VOR_WORLDTREE_KEY=${VOR_WORLDTREE_KEY:-}
+      - VOR_WORLDTREE_BASE=${VOR_WORLDTREE_BASE:-http://10.250.50.152:8080}
+      - VOR_WORLDTREE_MODEL=${VOR_WORLDTREE_MODEL:-qwen3.6-35-a3b-heretic}
     healthcheck:
       test: ["CMD-SHELL", "python -c 'import urllib.request,sys; r=urllib.request.urlopen(\"http://127.0.0.1:8765/api/sessions\",timeout=3); sys.exit(0 if r.status==200 else 1)' || exit 1"]
       interval: 30s