diff --git a/Makefile b/Makefile
index 42362ef8..4960270d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: setup install install-dev install-gpu test test-contracts lint clean preflight demo
+.PHONY: setup install install-dev install-gpu test test-contracts lint clean preflight demo demo-list
 
 # ---- One-command setup ----
 
@@ -47,10 +47,10 @@ demo:
 	@echo "==> Rendering zero-key demo videos (no API keys needed)..."
 	@echo "    These use only Remotion components — animated charts, text, data viz."
 	@echo ""
-	./render-demo.sh
+	python render_demo.py
 
 demo-list:
-	@./render-demo.sh --list
+	@python render_demo.py --list
 
 lint:
 	python -m py_compile tools/base_tool.py
diff --git a/remotion-composer/public/demo-props/code-to-screen.json b/remotion-composer/public/demo-props/code-to-screen.json
new file mode 100644
index 00000000..bf8474ac
--- /dev/null
+++ b/remotion-composer/public/demo-props/code-to-screen.json
@@ -0,0 +1,93 @@
+{
+  "theme": "flat-motion-graphics",
+  "cuts": [
+    {
+      "id": "code-hook",
+      "source": "",
+      "type": "hero_title",
+      "in_seconds": 0,
+      "out_seconds": 3.5,
+      "text": "From Code to Screen",
+      "subtitle": "How a small system turns work into a polished release",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "code-tip",
+      "source": "",
+      "type": "callout",
+      "in_seconds": 3.5,
+      "out_seconds": 7.5,
+      "title": "Shipping Rule",
+      "text": "Start with one visible win, then automate the repeatable path.",
+      "callout_type": "tip",
+      "accentColor": "#22D3EE",
+      "backgroundColor": "#0F172A",
+      "color": "#F8FAFC"
+    },
+    {
+      "id": "code-compare",
+      "source": "",
+      "type": "comparison",
+      "in_seconds": 7.5,
+      "out_seconds": 13,
+      "title": "Reusable systems beat one-off edits",
+      "leftLabel": "Manual Fixes",
+      "leftValue": "9 files",
+      "rightLabel": "Shared Pattern",
+      "rightValue": "1 flow",
+      "accentColor": "#A78BFA",
+      "backgroundColor": "#0F172A",
+      "color": "#F8FAFC"
+    },
+    {
+      "id": "code-progress",
+      "source": "",
+      "type": "progress_bar",
+      "in_seconds": 13,
+      "out_seconds": 17.5,
+      "title": "Automation coverage",
+      "progress": 0.82,
+      "progressLabel": "82% of the release path is scripted",
+      "progressColor": "#34D399",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "code-kpis",
+      "source": "",
+      "type": "kpi_grid",
+      "in_seconds": 17.5,
+      "out_seconds": 24,
+      "title": "Release pulse",
+      "chartData": [
+        { "label": "PRs merged", "value": 14, "change": 18, "suffix": "" },
+        { "label": "Build minutes", "value": 11, "change": -22, "suffix": " min" },
+        { "label": "Bugs reopened", "value": 2, "change": -50, "suffix": "" }
+      ],
+      "columns": 3,
+      "chartColors": ["#22D3EE", "#34D399", "#F59E0B"],
+      "chartAnimation": "cascade",
+      "backgroundColor": "#0F172A"
+    }
+  ],
+  "overlays": [
+    {
+      "type": "section_title",
+      "in_seconds": 7.8,
+      "out_seconds": 10.6,
+      "text": "Systems",
+      "subtitle": "Design once, apply everywhere",
+      "accentColor": "#A78BFA"
+    },
+    {
+      "type": "stat_reveal",
+      "in_seconds": 13.4,
+      "out_seconds": 16.8,
+      "text": "82%",
+      "subtitle": "Automated delivery path",
+      "accentColor": "#34D399",
+      "position": "bottom-right"
+    }
+  ],
+  "captions": [],
+  "audio": {}
+}
diff --git a/remotion-composer/public/demo-props/focusflow-pitch.json b/remotion-composer/public/demo-props/focusflow-pitch.json
new file mode 100644
index 00000000..a65d687c
--- /dev/null
+++ b/remotion-composer/public/demo-props/focusflow-pitch.json
@@ -0,0 +1,93 @@
+{
+  "theme": "flat-motion-graphics",
+  "cuts": [
+    {
+      "id": "focusflow-hook",
+      "source": "",
+      "type": "hero_title",
+      "in_seconds": 0,
+      "out_seconds": 3.5,
+      "text": "FocusFlow",
+      "subtitle": "A calm planning app that protects deep work",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "focusflow-stat",
+      "source": "",
+      "type": "stat_card",
+      "in_seconds": 3.5,
+      "out_seconds": 7.5,
+      "stat": "3h 12m",
+      "subtitle": "Average weekly focus time recovered",
+      "accentColor": "#F59E0B",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "focusflow-bars",
+      "source": "",
+      "type": "bar_chart",
+      "in_seconds": 7.5,
+      "out_seconds": 12.5,
+      "title": "Average context switches per day",
+      "chartData": [
+        { "label": "Before", "value": 42 },
+        { "label": "After", "value": 18 }
+      ],
+      "chartColors": ["#FB7185", "#34D399"],
+      "showGrid": true,
+      "showValues": true,
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "focusflow-breakdown",
+      "source": "",
+      "type": "pie_chart",
+      "in_seconds": 12.5,
+      "out_seconds": 17.5,
+      "title": "Where reclaimed time goes",
+      "chartData": [
+        { "label": "Priority work", "value": 74 },
+        { "label": "Planning", "value": 16 },
+        { "label": "Meetings", "value": 10 }
+      ],
+      "chartColors": ["#34D399", "#22D3EE", "#A78BFA"],
+      "donut": true,
+      "centerLabel": "Priority work",
+      "centerValue": "74%",
+      "showLegend": true,
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "focusflow-close",
+      "source": "",
+      "type": "text_card",
+      "in_seconds": 17.5,
+      "out_seconds": 21.5,
+      "text": "Fewer pings. Better mornings.",
+      "subtitle": "Small product, measurable calm.",
+      "color": "#F8FAFC",
+      "backgroundColor": "#0F172A"
+    }
+  ],
+  "overlays": [
+    {
+      "type": "section_title",
+      "in_seconds": 7.7,
+      "out_seconds": 10.4,
+      "text": "Traction",
+      "subtitle": "Illustrative pilot results",
+      "accentColor": "#F59E0B"
+    },
+    {
+      "type": "stat_reveal",
+      "in_seconds": 13.2,
+      "out_seconds": 16.8,
+      "text": "74%",
+      "subtitle": "Time redirected to priority work",
+      "accentColor": "#34D399",
+      "position": "bottom-right"
+    }
+  ],
+  "captions": [],
+  "audio": {}
+}
diff --git a/remotion-composer/public/demo-props/world-in-numbers.json b/remotion-composer/public/demo-props/world-in-numbers.json
new file mode 100644
index 00000000..c2335141
--- /dev/null
+++ b/remotion-composer/public/demo-props/world-in-numbers.json
@@ -0,0 +1,95 @@
+{
+  "theme": "flat-motion-graphics",
+  "cuts": [
+    {
+      "id": "world-hook",
+      "source": "",
+      "type": "hero_title",
+      "in_seconds": 0,
+      "out_seconds": 3.5,
+      "text": "The World in Numbers",
+      "subtitle": "A zero-key showcase built from Remotion components only",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "world-population",
+      "source": "",
+      "type": "stat_card",
+      "in_seconds": 3.5,
+      "out_seconds": 7.5,
+      "stat": "8.1B",
+      "subtitle": "People sharing one connected planet",
+      "accentColor": "#22D3EE",
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "world-cities",
+      "source": "",
+      "type": "bar_chart",
+      "in_seconds": 7.5,
+      "out_seconds": 13,
+      "title": "Illustrative megacity population",
+      "chartData": [
+        { "label": "Tokyo", "value": 37 },
+        { "label": "Delhi", "value": 33 },
+        { "label": "Shanghai", "value": 29 },
+        { "label": "Sao Paulo", "value": 22 }
+      ],
+      "chartColors": ["#22D3EE", "#A78BFA", "#F59E0B", "#34D399"],
+      "showGrid": true,
+      "showValues": true,
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "world-energy",
+      "source": "",
+      "type": "pie_chart",
+      "in_seconds": 13,
+      "out_seconds": 18,
+      "title": "Illustrative energy mix",
+      "chartData": [
+        { "label": "Renewables", "value": 34 },
+        { "label": "Gas", "value": 27 },
+        { "label": "Coal", "value": 21 },
+        { "label": "Nuclear", "value": 18 }
+      ],
+      "chartColors": ["#34D399", "#22D3EE", "#F97316", "#A78BFA"],
+      "donut": true,
+      "centerLabel": "Renewables",
+      "centerValue": "34%",
+      "showLegend": true,
+      "backgroundColor": "#0F172A"
+    },
+    {
+      "id": "world-close",
+      "source": "",
+      "type": "text_card",
+      "in_seconds": 18,
+      "out_seconds": 22,
+      "text": "Big systems. Human-scale decisions.",
+      "color": "#F8FAFC",
+      "backgroundColor": "#0F172A"
+    }
+  ],
+  "overlays": [
+    {
+      "type": "section_title",
+      "in_seconds": 7.8,
+      "out_seconds": 10.8,
+      "text": "Cities",
+      "subtitle": "Dense hubs make scale visible",
+      "accentColor": "#22D3EE"
+    },
+    {
+      "type": "stat_reveal",
+      "in_seconds": 14.2,
+      "out_seconds": 17.6,
+      "text": "34%",
+      "subtitle": "Illustrative renewable share",
+      "accentColor": "#34D399",
+      "position": "bottom-right"
+    }
+  ],
+  "captions": [],
+  "audio": {}
+}
diff --git a/render-demo.sh b/render-demo.sh
index 58056ba5..b9dfffd8 100644
--- a/render-demo.sh
+++ b/render-demo.sh
@@ -1,120 +1,10 @@
 #!/usr/bin/env bash
-# render-demo.sh — Render zero-key demo videos using only Remotion components
-# No API keys, no external services, no GPU required.
-#
-# Usage:
-#   ./render-demo.sh                    # Render all demos
-#   ./render-demo.sh world-in-numbers   # Render one specific demo
-#   ./render-demo.sh --list             # List available demos
-#
-# Prerequisites: Node.js 18+, npm install in remotion-composer/
-
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-COMPOSER_DIR="$SCRIPT_DIR/remotion-composer"
-PROPS_DIR="$COMPOSER_DIR/public/demo-props"
-OUTPUT_DIR="$SCRIPT_DIR/projects/demos/renders"
 
-# Available demos
-declare -A DEMOS=(
-  ["world-in-numbers"]="The World in Numbers — 45s data visualization showcase"
-  ["code-to-screen"]="From Code to Screen — 50s developer education explainer"
-  ["focusflow-pitch"]="FocusFlow Pitch — 40s startup pitch deck video"
-)
-
-# Colors
-GREEN='\033[0;32m'
-CYAN='\033[0;36m'
-YELLOW='\033[1;33m'
-NC='\033[0m'
-
-list_demos() {
-  echo ""
-  echo -e "${CYAN}Available zero-key demos:${NC}"
-  echo ""
-  for name in "${!DEMOS[@]}"; do
-    echo -e "  ${GREEN}$name${NC}  ${DEMOS[$name]}"
-  done
-  echo ""
-  echo "Usage: ./render-demo.sh [demo-name]"
-  echo "       ./render-demo.sh          (renders all)"
-  echo ""
-}
-
-render_demo() {
-  local name="$1"
-  local props_file="$PROPS_DIR/$name.json"
-  local output_file="$OUTPUT_DIR/$name.mp4"
-
-  if [ ! -f "$props_file" ]; then
-    echo "Error: Props file not found: $props_file"
-    exit 1
-  fi
-
-  mkdir -p "$OUTPUT_DIR"
-
-  echo ""
-  echo -e "${CYAN}Rendering:${NC} ${DEMOS[$name]:-$name}"
-  echo -e "${CYAN}Props:${NC}     $props_file"
-  echo -e "${CYAN}Output:${NC}    $output_file"
-  echo ""
-
-  cd "$COMPOSER_DIR"
-  npx remotion render src/index.tsx Explainer "$output_file" \
-    --props "$props_file" \
-    --codec h264
-
-  if [ -f "$output_file" ]; then
-    local size=$(du -h "$output_file" | cut -f1)
-    echo ""
-    echo -e "${GREEN}Done!${NC} $output_file ($size)"
-  else
-    echo "Render may have failed — check output above."
-  fi
-}
-
-# Main
-if [ "${1:-}" = "--list" ] || [ "${1:-}" = "-l" ]; then
-  list_demos
-  exit 0
+if command -v python3 >/dev/null 2>&1; then
+  exec python3 "$SCRIPT_DIR/render_demo.py" "$@"
 fi
 
-if [ "${1:-}" = "--help" ] || [ "${1:-}" = "-h" ]; then
-  echo "render-demo.sh — Render zero-key demo videos"
-  echo ""
-  echo "These demos use ONLY Remotion components (animated charts, text cards,"
-  echo "stat reveals, comparisons) — no API keys, no images, no external services."
-  echo ""
-  list_demos
-  exit 0
-fi
-
-# Check prerequisites
-if ! command -v node &> /dev/null; then
-  echo "Error: Node.js is required. Install from https://nodejs.org/"
-  exit 1
-fi
-
-if [ ! -d "$COMPOSER_DIR/node_modules" ]; then
-  echo -e "${YELLOW}Installing Remotion dependencies...${NC}"
-  cd "$COMPOSER_DIR" && npm install
-fi
-
-if [ -n "${1:-}" ]; then
-  # Render specific demo
-  if [ -z "${DEMOS[$1]+x}" ]; then
-    echo "Unknown demo: $1"
-    list_demos
-    exit 1
-  fi
-  render_demo "$1"
-else
-  # Render all demos
-  echo -e "${CYAN}Rendering all zero-key demos...${NC}"
-  for name in world-in-numbers code-to-screen focusflow-pitch; do
-    render_demo "$name"
-  done
-  echo ""
-  echo -e "${GREEN}All demos rendered!${NC} Check $OUTPUT_DIR/"
-fi
+exec python "$SCRIPT_DIR/render_demo.py" "$@"
diff --git a/render_demo.py b/render_demo.py
new file mode 100644
index 00000000..7c277784
--- /dev/null
+++ b/render_demo.py
@@ -0,0 +1,132 @@
+from __future__ import annotations
+
+import argparse
+import json
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+
+ROOT_DIR = Path(__file__).resolve().parent
+COMPOSER_DIR = ROOT_DIR / "remotion-composer"
+PROPS_DIR = COMPOSER_DIR / "public" / "demo-props"
+OUTPUT_DIR = ROOT_DIR / "projects" / "demos" / "renders"
+
+DEMO_DESCRIPTIONS = {
+    "world-in-numbers": "Global scale story with titles, stats, and charts",
+    "code-to-screen": "Developer workflow explainer with comparison and KPI cards",
+    "focusflow-pitch": "Startup-style pitch built only from Remotion components",
+}
+
+
+def discover_demos() -> dict[str, Path]:
+    if not PROPS_DIR.exists():
+        return {}
+    return {path.stem: path for path in sorted(PROPS_DIR.glob("*.json"))}
+
+
+def find_command(*names: str) -> str | None:
+    for name in names:
+        resolved = shutil.which(name)
+        if resolved:
+            return resolved
+    return None
+
+
+def ensure_demo_environment() -> str:
+    if not find_command("node", "node.exe"):
+        raise SystemExit("Error: Node.js is required. Install it from https://nodejs.org/")
+
+    npm_cmd = find_command("npm.cmd", "npm", "npm.exe")
+    if not npm_cmd:
+        raise SystemExit("Error: npm is required but was not found on PATH.")
+
+    npx_cmd = find_command("npx.cmd", "npx", "npx.exe")
+    if not npx_cmd:
+        raise SystemExit("Error: npx is required but was not found on PATH.")
+
+    if not (COMPOSER_DIR / "node_modules").exists():
+        print("Installing Remotion dependencies...")
+        subprocess.run([npm_cmd, "install"], cwd=COMPOSER_DIR, check=True)
+
+    return npx_cmd
+
+
+def validate_props_file(path: Path) -> None:
+    with path.open("r", encoding="utf-8") as handle:
+        payload = json.load(handle)
+
+    if not isinstance(payload.get("cuts"), list) or not payload["cuts"]:
+        raise SystemExit(f"Error: {path} must define at least one cut.")
+
+
+def render_demo(name: str, props_path: Path, npx_cmd: str) -> None:
+    validate_props_file(props_path)
+    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
+    output_path = OUTPUT_DIR / f"{name}.mp4"
+
+    print()
+    print(f"Rendering: {name}")
+    print(f"Props:     {props_path}")
+    print(f"Output:    {output_path}")
+    print()
+
+    subprocess.run(
+        [
+            npx_cmd,
+            "remotion",
+            "render",
+            "src/index.tsx",
+            "Explainer",
+            str(output_path),
+            "--props",
+            str(props_path),
+            "--codec",
+            "h264",
+        ],
+        cwd=COMPOSER_DIR,
+        check=True,
+    )
+
+    if output_path.exists():
+        size_mb = output_path.stat().st_size / (1024 * 1024)
+        print(f"Done: {output_path} ({size_mb:.1f} MB)")
+    else:
+        print("Render finished without creating the expected output file.")
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(
+        description="Render zero-key OpenMontage demo videos from checked-in Remotion props."
+    )
+    parser.add_argument("demo", nargs="?", help="Render one named demo instead of all demos.")
+    parser.add_argument("--list", action="store_true", help="List available demo fixtures and exit.")
+    args = parser.parse_args(argv)
+
+    demos = discover_demos()
+    if not demos:
+        raise SystemExit(f"Error: No demo prop files were found in {PROPS_DIR}.")
+
+    if args.list:
+        print("Available zero-key demos:")
+        for name in demos:
+            description = DEMO_DESCRIPTIONS.get(name, "Checked-in Remotion demo")
+            print(f"  {name:20} {description}")
+        return 0
+
+    if args.demo and args.demo not in demos:
+        available = ", ".join(demos)
+        raise SystemExit(f"Unknown demo '{args.demo}'. Available demos: {available}")
+
+    npx_cmd = ensure_demo_environment()
+    selected = {args.demo: demos[args.demo]} if args.demo else demos
+
+    for name, props_path in selected.items():
+        render_demo(name, props_path, npx_cmd)
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/requirements.txt b/requirements.txt
index d78bea90..026ad933 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,5 @@ pyyaml>=6.0
 pydantic>=2.0
 jsonschema>=4.20
 python-dotenv>=1.0
+Pillow>=10.0
+requests>=2.31
diff --git a/setup.py b/setup.py
index 883af726..bbbfca67 100644
--- a/setup.py
+++ b/setup.py
@@ -11,5 +11,7 @@ setup(
         "pydantic>=2.0",
         "jsonschema>=4.20",
         "python-dotenv>=1.0",
+        "Pillow>=10.0",
+        "requests>=2.31",
     ],
 )