video-gen

Video generation and multi-scene production via fal.ai. Two modes: light (fire-and-forget) and project (interactive pipeline with gates).

Scripts: ./scripts/generate.py, ./scripts/preview.py, ./scripts/project_init.py, ./scripts/project_state.py, ./scripts/decompose.py, ./scripts/keyframe.py, ./scripts/clip.py, ./scripts/assemble.py, ./scripts/character_sheet.py Output dir: ./output/

Setup

export FAL_KEY="your-fal-ai-key"

• Claude Code: copy this skill folder into .claude/skills/video-gen/
• Codex CLI: append this SKILL.md content to your project's root AGENTS.md

For the full installation walkthrough (prerequisites, API keys, verification, troubleshooting), see references/installation-guide.md.

Credential management

Three tiers for managing the FAL_KEY environment variable:

1. Vault skill (recommended): If you have a vault or secret-management skill, store the key there and export it before running scripts. Example: export FAL_KEY=$(vault get FAL_KEY)
2. Custom secret manager: Use your team's preferred secret manager (1Password CLI, AWS Secrets Manager, etc.)
3. Plain export: export FAL_KEY='your-fal-ai-key' in your shell profile

For project mode (keyframes + character sheets): also need image-gen peer skill.

Staying Updated

This skill ships with an UPDATES.md changelog and UPDATE-GUIDE.md for your AI agent.

After installing, tell your agent: "Check UPDATES.md in the video-gen skill for any new features or changes."

When updating, tell your agent: "Read UPDATE-GUIDE.md and apply the latest changes from UPDATES.md."

Follow UPDATE-GUIDE.md so customized local files are diffed before any overwrite.

Decision Tree

Need video?
├── Quick one-off clip? ─────────── Light Mode (generate.py)
│   Single prompt, single output, no state
│
└── Multi-scene story/production? ── Project Mode
    ├── New project? ─────────────── project_init.py → G0
    ├── Existing project? ────────── project_state.py --status
    └── Resume at gate? ──────────── Check state, pick up where left off

Quick Reference

Light Mode

# Generate with default model (ltx-2.3)
python ./scripts/generate.py \
  --prompt "A red fox running through snow" \
  --output ./output/

# Generate with specific model and settings
python ./scripts/generate.py \
  --prompt "Tokyo skyline at sunset with dramatic clouds" \
  --model kling-v3 \
  --mode t2v \
  --duration 10 \
  --resolution 1080p \
  --aspect 16:9

# Image-to-video generation
python ./scripts/generate.py \
  --prompt "The character starts walking forward" \
  --mode i2v \
  --image ./path/to/keyframe.png \
  --model veo-3

# Quick preview (uses LTX fast, cheapest)
python ./scripts/preview.py \
  --prompt "Test scene" \
  --mode t2v

Project Mode

# Initialize new project
python ./scripts/project_init.py \
  --name noir-detective \
  --scenes 5 \
  --output-dir ./projects \
  --style "cinematic, moody, film noir" \
  --tier standard \
  --logline "A detective investigates in a cyberpunk city"

# Check project status
python ./scripts/project_state.py --project ./projects/noir-detective

# Generate keyframe for scene
python ./scripts/keyframe.py \
  --project ./projects/noir-detective \
  --scene 1 \
  --style-keywords "cinematic, moody"

# Generate video clip for scene
python ./scripts/clip.py \
  --project ./projects/noir-detective \
  --scene 1 \
  --model kling-v3 \
  --duration 8

# Assemble final video
python ./scripts/assemble.py \
  --clips-dir ./projects/noir-detective/scenes \
  --output ./projects/noir-detective/output/final.mp4

Light Mode

Model Selection

What do you need?
├── Fast drafts + budget? ──────────── ltx-2.3 (fast) $0.04/s
├── Cinematic quality? ─────────────── kling-v3 $0.168/s
├── Dialogue/lip sync? ─────────────── veo-3 $0.20-0.40/s
├── Long clips (>10s)? ─────────────── sora-2 (up to 25s)
├── Budget with audio? ─────────────── wan $0.05-0.10/s
├── Anime/stylized? ────────────────── hailuo $0.045-0.08/s
└── Physics accuracy? ──────────────── cosmos $0.20/video

Script Reference: generate.py

Script Reference: preview.py

# Preview existing video file
python ./scripts/preview.py /path/to/video.mp4

# Generate and preview (uses LTX fast, $0.04/s)
python ./scripts/preview.py \
  --prompt "Quick test scene" \
  --mode t2v \
  [--image path] \
  [--output path]

Output JSON Contract

{
  "success": true,
  "file": "/abs/path/to/20260308-143052-t2v-red-fox-snow.mp4",
  "model": "ltx-2.3",
  "mode": "t2v",
  "duration_sec": 8,
  "resolution": "1080p",
  "cost_usd": 0.32,
  "seed": 42,
  "fal_request_id": "abc123"
}

Duration Constraints

Cost Quick Reference

Project Mode

Gate Pipeline (G0-G5)